DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 04/27/2026 has been entered.
Response to Amendment
The Amendment filed on 03/24/2026 has been entered. Claims 1-20 remain pending in the application.
Claim Objections
Claim 1 is objected to because of the following informalities: “the entirety of the first sidewall of the of the third die” should read “the entirety of the first sidewall of the . Appropriate correction is required.
Claim Rejections - 35 USC § 112(a)
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112:
The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention.
Claim 1 is rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention.
Claim 1 recites the limitation “wherein the underfill material is in physical contact with an entirety of the first sidewall of the second die, and an entirety of the second sidewall of the second die, and wherein the underfill material is in physical contact with an entirety of the first sidewall of the first die, and an entirety of the first sidewall of the third die”. In paragraph [0040], rows 3-4, the specification discloses “the underfill material 100 extends up along sidewall of the dies 68A and the dies 68B”, but does not specify that the underfill material is in physical contact with an entirety of the sidewalls. Fig.5, and other similar figures, where the underfill material is presented in physical contact with the sidewalls of dies 68A and 68B, shows only a cross section of the device. Furthermore, no other parts of the specification teach the above limitation.
For the purpose of examination, the limitation of claim 1 will be interpreted as wherein, in a cross-sectional view, the underfill material is in physical contact with an entirety of the first sidewall of the second die, and an entirety of the second sidewall of the second die, and wherein the underfill material is in physical contact with an entirety of the first sidewall of the first die, and an entirety of the first sidewall of the third die”.
Claims 2-7 are also rejected as being dependent on claim 1.
Claim Rejections - 35 USC § 112(b)
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 1 and 14 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claim 1 recites the limitation “wherein the underfill material is in physical contact with an entirety of the first sidewall of the second die, and an entirety of the second sidewall of the second die, and wherein the underfill material is in physical contact with an entirety of the first sidewall of the first die, and an entirety of the first sidewall of the third die”. In paragraph [0040], rows 3-4, the specification discloses “the underfill material 100 extends up along sidewall of the dies 68A and the dies 68B”, but does not specify that the underfill material is in physical contact with an entirety of the sidewalls. In Fig.5, and other similar figures, where the underfill material is showed in physical contact with the sidewalls of dies 68A and 68B, only shows a cross section of the device. Therefore, the limitation cited above only applies when the device is viewed in a cross section.
For the purpose of examination, the limitation of claim 1 will be interpreted as wherein, in a cross-sectional view, the underfill material is in physical contact with an entirety of the first sidewall of the second die, and an entirety of the second sidewall of the second die, and wherein the underfill material is in physical contact with an entirety of the first sidewall of the first die, and an entirety of the first sidewall of the third die”.
Claims 2-7 are also rejected as being dependent on claim 1.
Claim 14 recites the limitation “attaching a heat dissipation structure to the package component and the substrate using an adhesive material, wherein after attaching the heat dissipation structure to the package component, the package component is also coupled to the heat dissipation structure using a thermal interface material, wherein the thermal interface material is in physical contact with the underfill material and the encapsulant, wherein the heat dissipation structure comprises: a top portion overlapping the package component and the substrate, the top portion being above the package component; and a bottom portion surrounding the package component”.
Claim 14 can be interpreted as: the package component is coupled to the heat dissipation structure using a thermal interface material after attaching the entire heat dissipation structure, comprised of both the top and bottom portion, to the package component and the substrate. This cannot be realized since, once the top portion of the heat dissipation structure is attached, the thermal interface material can no longer be inserted between the package component and the top portion.
In paragraphs [0078] and [0079], the specification describe attaching only the bottom portion of the heat dissipation structure (not the entire heat dissipation structure) in a first step and attaching the top portion and the thermal interface material in a later step.
Therefore for the purpose of examination, claim 14 will be interpreted as: “attaching a portion of a heat dissipation structure to the package component and the substrate using an adhesive material, wherein after attaching the portion of the heat dissipation structure to the package component, the package component is also coupled to the heat dissipation structure using a thermal interface material, wherein the thermal interface material is in physical contact with the underfill material and the encapsulant, wherein the heat dissipation structure comprises: a top portion overlapping the package component and the substrate”.
Claims 15-20 are also rejected as being dependent on claim 14.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claims 1 and 2 are rejected under 35 U.S.C. 103 as being unpatentable over Yu et al., (United States Patent Application Publication Number, US 2020/0402877 A1) hereinafter referenced as Yu_877, in view of Wang et al., (Patent Application Publication Number, US 2021/0098330 A1) hereinafter referenced as Wang_330, in view of Zohni et al. (United States Patent Number US 10,840,192 B1), hereinafter references as Zohni and in view of Shih-Chao Chiu et al., (United States Patent Application Publication Number, US 2022/0130734 A1), hereinafter referenced as Chiu.
Regarding claim 1, Yu_877 teaches a device comprising: a package substrate (Fig.17, element #300); an interposer having a first side bonded to the package substrate (Fig.17, element #96 has bottom side bonded to the substrate, element #300); a first die (Fig.17, element #88 located on the left side of the figure), a second die (Fig.17, element #68), and a third die (Fig.17, element #88 located of the right side of the figure), bonded to a second side of the interposer, the second side being opposite the first side (Fig.17, dies #88 and #68 are bonded to the top side of element #96), wherein the second die is a logic die, and the first die and the third die are memory dies (paragraph [0019], row 1 and paragraph [0042], rows 4-5), wherein the second die is disposed between the first die and the third die (Fig.17, die #68 is disposed between dies #88); an underfill material disposed in a first gap between the first die and the second die, and in a second gap between the third die and the second die, between the first die and the interposer, between the second die and the interposer, and between the third die and the interposer (Fig.17, element #100), wherein a first sidewall of the second die is facing a first sidewall of the first die (Fig.17, left sidewall of element #68 is facing the right sidewall of die #88 located on the left side of the figure), a second sidewall of the second die is facing a first sidewall of the third die (Fig.17, right sidewall of element #68 is facing the left sidewall of die #88 located on the right side of the figure), wherein, in a cross-sectional view, the underfill material is in physical contact with an entirety of the first sidewall of the second die, and an entirety of the second sidewall of the second die, and wherein the underfill material is in physical contact with an entirety of the first sidewall of the first die, and an entirety of the first sidewall of the third die (Fig.17, element #100 is in contact with the entirety of the sidewalls); an encapsulant disposed over the interposer, wherein the encapsulant encapsulates the first die, the second die, the third die, and the underfill material (Fig.17, element #112), wherein a material of the encapsulant is different from the underfill material,
(the underfill material can be a polymer, paragraph [0037], row 9-11, the encapsulant can be an epoxy, paragraph [0044], rows 2-3) wherein a second sidewall of the first die is in physical contact with the encapsulant and the underfill material, the second sidewall of the first die being on an opposite side of the first die as the first sidewall of the first die(Fig.17, left sidewall of element #88 located on the left side of the figure), and wherein a second sidewall of the third die is in physical contact with the encapsulant and the underfill material, the second sidewall of the third die being on an opposite side of the third die as the first sidewall of the third die (Fig.17, right sidewall of element #88 located on the right side of the figure).
Yu_877 does not teach a ring on the package substrate, wherein the ring surrounds the first die, the second die, and the interposer; and a heat spreader over and coupled to top surfaces of the ring, and top surfaces of the first die, the second die, the encapsulant, and the underfill material, and wherein a bottommost surface of the ring is above a topmost surface of the package substrate. Wang_330 teaches a ring on the package substrate wherein the ring surrounds the first die, the second die, and the interposer (Fig.6A, element #164 and top view in Fig.6B); and a heat spreader over and coupled to top surfaces of the ring, and top surfaces of the first die, the second die, the encapsulant, and the underfill material (Fig.6A, element #162), and wherein a bottommost surface of the ring is above a topmost surface of the package substrate (Fig.6A, bottom surface of element #164 is above the top surface of element #120). It would have been obvious to one ordinary skilled in the art, before the effective filing date of the claimed invention to incorporate the teachings of Wang_330 and disclose a ring on the package substrate, wherein the ring surrounds the first die, the second die, and the interposer; and a heat spreader over and coupled to top surfaces of the ring, and top surfaces of the first die, the second die, the encapsulant, and the underfill material, wherein a bottommost surface of the ring is above a topmost surface of the package substrate. As disclosed by Wang_330, the structure formed by the ring and the heat spreader improve the heat dissipation of the semiconductor package (paragraph [0002], rows 8-12). Connecting the ring to and above the substrate provides mechanical stability to the entire device.
The combination of Yu_877 and Wang_330 does not teach wherein a first coefficient of thermal expansion of a first material of the ring and a second coefficient of thermal expansion of a second material of the heat spreader are different. Zohni teaches the ring may be made of ceramic, metal or other materials (Fig 1, element #154, columns 4, rows 14 and 17-22) and the top portion can be made of “thermally conductive material such as copper, nickel plate copper or aluminum or other suitable materials” (Fig.1, element #150, column 3, rows 47-51). A person of ordinary skilled in the art, will recognize that different materials have different coefficients of thermal expansion. Therefore, Zohni teaches a first coefficient of thermal expansion of a first material of the ring (Fig.1, element #154) and a second coefficient of thermal expansion of a second material of the heat spreader (Fig.1, element #150) are different. It would have been obvious to one ordinary skilled in the art, before the effective filing date of the claimed invention to incorporate the teachings of Zohni and disclose wherein a first coefficient of thermal expansion of a first material of the ring and a second coefficient of thermal expansion of a second material of the heat spreader are different. This allows the material of the ring to be optimized for mechanical stability (acts as a stiffener) and the material of the heat spreader to be optimized for heat dissipation.
The combination of Yu_877, Wang_330 and Zohni does not teach wherein in a cross-sectional view a combined structure of the heat spreader and the ring have a H-shaped profile. Chiu teaches a cross-sectional view of a combined structure of the heat spreader and the ring have a H-shaped profile (Fig.10, ring element #310 and heat spreader, element #320 have a H-shaped profile). Therefore, it would have been obvious to one ordinary skilled in the art, before the effective filing date of the claimed invention, to incorporate the teachings of Chiu and disclose an H-shaped configuration of the heat dissipation structure, as taught by Chiu. This configuration serves as a package stiffener to alleviate package warpage during device operation.
Zohni further teaches wherein an outer sidewall of the ring (Fig.1, left outer sidewall, element #152) and an outer sidewall of the heat spreader (Fig.1, left sidewall of element #150) are offset from and overhang an outer sidewall of the package substrate (Fig.1, are offset and overhang left sidewall #160 of the substrate, element #122). It would have been obvious to one ordinary skilled in the art, before the effective filing date of the claimed invention to incorporate the teachings of Zohni and disclose an outer sidewall of the ring and an outer sidewall of the heat spreader are offset from and overhang an outer sidewall of the package substrate. This provides more area of bonding between the ring and the substrate which increases mechanical stability and an increase of the size of the heat spreader, thus providing a larger area for heat dissipation.
Regarding claim 2, the combination of Yu_877, Wang_330 and Zohni and Chiu teaches the device of claim 1 as set forth in the obviousness rejection. Wang_330 further teaches the device of claim 1, wherein the heat spreader is coupled to the top surfaces of the first die, the second die, the third die, the encapsulant, and the underfill material with a thermal interface material (Fig.6A, element #162 is coupled to the top surface of dies #106, encapsulant #107 and #underfill #140, with a thermal interface material, element #110). It would have been obvious to one ordinary skilled in the art, before the effective filing date of the claimed invention, to incorporate the teachings of Wang_330 and disclose the heat spreader is coupled to the top surfaces of the first die, the second die, the third die, the encapsulant, and the underfill material with a thermal interface material. The thermal interface material increases heat transfer from the dies to the heat spreader, and, coupling it to the entire area formed by the top surfaces of the dies, the underfill and the encapsulant top makes the coupling more reliable, and prevents the formation of air pockets or bubbles that may impede the heat dissipation away from the dies.
The combination of Yu_877 and Wang_330 does not teach wherein the heat spreader is coupled to the ring with an adhesive material. Zohni teaches wherein the heat spreader (Fig.1, element #150) is coupled to the ring (Fig.1, element #154) with an adhesive material (column 3, rows 57-58). It would have been obvious to one ordinary skilled in the art, before the effective filing date of the claimed invention, to incorporate the teachings of Zohni and disclose wherein the heat spreader is coupled to the ring with an adhesive material. As disclosed by Zohni, coupling the heat spreader to the ring with an adhesive increases the rigidity of the device (column 3, row 55-57).
Yu_877 further teaches wherein the underfill material in the first gap has a first height, the underfill material in the second gap has a second height, and the encapsulant has a third height at a point at which the encapsulant has the largest thickness, wherein the third height of the encapsulant is equal to the first height and the second height (Fig.17, height of the underfill, element #100, in the two gaps is equal to the height of left sidewall of the encapsulant, element #112).
Claim 3 is rejected under 35 U.S.C. 103 as being unpatentable over Yu_877, in view of Wang_330, Zohni, Chiu and in view of Ho et al., (Unites States Patent Number, US 10,163,754 B2), hereinafter referenced as Ho.
Regarding claim 3, the combination of Yu_877, Wang_330 and Zohni and Chiu teaches the method of claim 1 as set forth in the obviousness rejection. Wang_330 teaches wherein in the heat spreader comprises: a central portion overlapping the first die (Fig.6A, the central portion of heat spreader #160 is the portion on top of the dies #106); and edge portions that surround the central portion when seen in a top-down view (Fig.6A, portions of element #160 that overlap the ring #164 and surround the central portion), wherein a thickness of the central portion is equal to a thickness of the edge portions. Zohni also teaches the heat spreader comprises: a central portion overlapping the first die (Fig.1, central portion of heat spreader #150 is the portion on top of dies #114); and edge portions that surround the central portion when seen in a top-down view (Fig.1, portions of element #150 that overlap the ring #154 and surround the central portion), wherein a thickness of the central portion is equal to a thickness of the edge portions.
The combination of Yu_877, Wang_330, Zohni, and Chiu does not teach a thickness of the central portion is smaller than a thickness of the edge portions. Ho teaches a thickness of the central portion (Fig.5B, region of heat spreader element #24B overlapping die element #12 from top-down view) is smaller than a thickness of the edge portions (Fig.5B, regions of heat spreader element #24B that are located on top of adhesive element #21). Therefore, it would have been obvious to one ordinary skilled in the art, before the effective filing date of the claimed invention, to incorporated the teachings of Ho and disclose a thickness of the central portion is smaller than a thickness of the edge portions. A thinner heat spreading structure on top of the semiconductor chip results in enhanced heat dissipation, while thicker edge regions help preserve the package mechanical integrity.
Claims 4 to 7 are rejected under 35 USC § 103 as being unpatentable over Yu_877, in view of Wang_330, Zohni, Chiu and in view Chung-Cheng Wang (United States Patent Application Publication Number, US 2008/0122067 A1), hereinafter referenced as Wang_067.
Regarding claim 4, the combination of Yu_877, Wang_330 and Zohni and Chiu teaches the device of claim 1 as set forth in the obviousness rejection and the combination of Yu_877, Wang_330, Zohni, Chiu, and Ho teaches the device of claim 3 as set forth in the obviousness rejection. The combination of Yu_877, Wang_330, Zohni, Chiu, and Ho does not teach a topmost surface of the central portion is lower than topmost surfaces of the edge portions. Wang_067 teaches a topmost surface of the central portion (Fig.2, heat spreader #10 has a central portion #12 with a topmost surface, element #121) is lower than topmost surfaces of the edge portions (Fig.2, heat spreader #10 has an edge portion #11 with a topmost surface, element #111, which is higher than the topmost surface of central portion #121). Therefore, it would have been obvious to one ordinary skilled in the art, before the effective filing date of the claimed invention, to incorporated the teachings of Wang_067 and disclose a heat spreader with the features taught by Wang_067. Considering the heat spreader disclosed by Wang_067 and Zohni, making the topmost surface of the central portion lower than that of the edges allows for a lighter weight and more cost-effective heat spreader while maintaining the physical integrity of the package. Furthermore, considering the heat spreader disclosed by Wang_067 (Fig.2 element #10), making the topmost surface of the central portion lower than that of the edges, allows the central portion of the head spreader to be as closer to the electronic components contained in the package, while maintaining the heat spreader thickness and its mechanical properties, which provides enhanced heat dissipation.
Regarding claim 5, the combination of Yu_877, Wang_330 and Zohni and Chiu teaches the device of claim 1 as set forth in the obviousness rejection and the combination of Yu_877, Wang_330, Zohni, Chiu, and Ho teaches the device of claim 3 as set forth in the obviousness rejection, and the combination of Yu_877, Wang_330, Zohni, Chiu, Ho and Wang_067 teaches the device of claim 4 as set forth in the obviousness rejection. The combination of Yu_877, Wang_330, Zohni, Chiu, Ho and Wang_067 doesn’t teach a difference in height between the topmost surfaces of the edge portions and the topmost surface of the central portion is greater than the thickness of the central portion. According to Wang_067, the central portion of the head spreader being closer to the electronic components contained in the package provides enhanced heat dissipation (paragraph [0028], rows 38-49), while the edge portions of the head spreader being higher than that of the central portion allows for more space inside the package to accommodate other electronic components contained by the package and the connecting wires of these elements (Fig.2). Furthermore, the thickness of the different portions of the heat spreader affects the mechanical integrity of the package and the effectiveness of the heat dissipation. Therefore, it would have been obvious to one of ordinary skilled in the art, before the effective filling date of the claimed invention, to optimize the difference in height between the topmost surfaces of the edge portions and the topmost surface of the central portion relative to the thickness of the central portion through routine experimentation (MPEP 2144.05). The height values of the central and edge portions are a result effective variable because it is important to ensure effective heat dissipation and the mechanical integrity of the package, while maintaining a small package footprint.
Regarding claim 6, the combination of Yu_877, Wang_330 and Zohni and Chiu teaches the device of claim 1 as set forth in the obviousness rejection, and the combination of Yu_877, Wang_330, Zohni, Chiu, and Ho teaches the device of claim 3 as set forth in the obviousness rejection, and the combination of Yu_877, Wang_330, Zohni, Chiu, Ho and Wang_067 teaches the device of claim 4 as set forth in the obviousness rejection. The combination of Yu_877, Wang_330, Zohni, Chiu, Ho and Wang_067 does not teach a difference in height between the topmost surfaces of the edge portions and the topmost surface of the central portion is less than the thickness of the central portion. According to Wang_067, the central portion of the head spreader, being as close as possible to the electronic components contained in the package, provides enhanced heat dissipation (paragraph [0028], rows 38-49), while the edge portions of the head spreader being higher than that of the central portion allows for more space inside the package to accommodate the electronic components contained by the package and the connecting wires of these elements (Fig.2). Furthermore, the thickness of the different portions of the heat spreader affects the mechanical integrity of the package and the effectiveness of the heat dissipation. Therefore, it would have been obvious to one of ordinary skilled in the art, before the effective filling date of the claimed invention, to optimize the difference in height between the topmost surfaces of the edge portions and the topmost surface of the central portion relative to the thickness of the central portion through routine experimentation (MPEP 2144.05). The height values of the central and edge portions are a result effective variable and, as above, it is obvious to optimize them, because it is important to ensure effective heat dissipation and the mechanical integrity of the package, while maintaining a small package footprint.
Regarding claim 7, the combination of Yu_877, Wang_330 and Zohni and Chiu teaches the device of claim 1 as set forth in the obviousness rejection, and the combination of Yu_877, Wang_330, Zohni, Chiu, and Ho teaches the device of claim 3 as set forth in the obviousness rejection, and the combination of Yu_877, Wang_330, Zohni, Chiu, Ho and Wang_067 teaches the device of claim 4 as set forth in the obviousness rejection. Zohni further teaches wherein a width of each edge portion (Fig.1, horizontal width of the portions of heat spreader #150 that overlap the ring #154) is larger than a difference between an outer radius and an inner radius of the ring (Fig.1, horizontal width of each edge portion is larger than the horizontal width of the bottom portion of the ring located between surface #160 and outer wall #152). Therefore, it would have been obvious to one ordinary skilled in the art, before the effective filing date of the claimed invention, to incorporated the teachings of Zohni an disclose wherein a width of each edge portion is larger than a difference between an outer radius and an inner radius of the ring. As shown by Zohni in Fig.1, having the difference between an outer radius and an inner radius of the ring smaller than the width of the rest of the ring allows attaching the ring on two sides of the substrate, thus increasing the reliability of the connection, and having the edge portion aligned with the outer sidewall of the ring (same width of the ring top side of the ring) creates a smooth outer surface without extra corners that can chip away.
Claims 8 to 13 are rejected under 35 USC § 103 as being unpatentable over Chen_Hua Yu et al., (United States Patent Number, US 10,163,852 B2), hereinafter referenced as Yu_852, in view of Il Shim et al., (Unites States Patent Application Publication Number, US 2004/0075987 A1), hereinafter referenced as Shim, in view of Chen_Hua Yu et al., (United States Patent Number, US 9,583,415 B2), hereinafter referenced as Yu_415 and in view of Ando et al., (United States Patent Number, US 6,111,322 A), hereinafter referenced as Ando.
Regarding claim 8, Yu_852 teaches a device comprising: a package component comprising: an interposer (Fig.20, structure formed by RDL layers, elements #62, #48, voltage regulators #100, conductive posts #30 and vias #136 conducts signals and controls power between the attached electronic devices, #66, and therefore acts as an interposer); and a first die connected to the interposer (Fig.20, element #66B, column 6, rows 49-50); a substrate connected to the interposer (Fig.20, element #76, column 7, row 62), wherein the interposer is disposed between the first die and the substrate; a heat dissipation structure over and coupled to the package component and the substrate (Fig.20, element #78, column 8, row 4), the heat dissipation structure having a first height (Fig.20, vertical distance between the topmost surface of element #78 and the top surface of the substrate, element #76), wherein the heat dissipation structure comprises: a central portion overlapping and adhered to the package component (Fig.20, top horizontal part of element #78); and first edge portions on opposite sides of the package component (Fig.20, bottommost horizontal portions of element #78, located to the left and right side of the figure), wherein the first edge portions are adhered to the substrate (Fig.20, column 8, rows 9-10).
Yu_852 does not teach wherein each of the first edge portions comprises a first recess having a first depth, wherein the first depth is less than the first height, wherein a first angle between a bottom surface of the first recess and a first sidewall of the first recess is an obtuse angle, wherein a second angle between the bottom surface of the first recess and a second sidewall of the first recess is an obtuse angle, wherein a height of the first sidewall is equal to a height of the second sidewall, and wherein the bottom surface of the first recess is disposed below a bottom surface of the first die, and below a top surface of the interposer. Shim teaches first edge portions on opposite sides of the package component (Fig.26, elements #2504 are on opposite sides of element #108 which occupies area, element #302 in Fig.25), wherein the first edge portions are adhered to the substrate (Fig.26, elements #2504 are adhered to substrate, element #110) wherein each of the first edge portions comprises a first recess having a first depth (Fig.26, elements #2504 have a recess), wherein the first depth (Fig.26, vertical distance between the topmost surface of element #2504 and the top surface of the recess) is less than the first height (Fig.26, vertical distance between the topmost surface of element #302 and bottommost surface of element #2504), wherein a first angle between a bottom surface of the first recess and a first sidewall of the first recess is an obtuse angle, wherein a second angle between the bottom surface of the first recess and a second sidewall of the first recess is an obtuse angle (Fig.26, bottom surface of the recess forms obtuse angles with the sidewalls), wherein a height of the first sidewall is equal to a height of the second sidewall (Fig.26, the recesses have sidewalls of the same height), and wherein the bottom surface of the first recess is disposed below a bottom surface of the first die (Fig.30, bottom surface is below the bottom surface of the first die). Yu teaches bottom surface of the edges (Fig.20, bottom surface of the bottommost horizontal portions of element #78 are equivalent to bottom surface of the recesses of Shim) are disposed below a bottom surface of the first die and below a top surface of the interposer (Fig.20, bottom surface of the bottom left and right horizontal sides of the heat dissipation structure are below the top surface of the interposer).Therefore, it would have been obvious to one ordinary skilled in the art, before the effective filing date of the claimed invention, to incorporated the teachings of Shim and disclose wherein each of the first edge portions has the claimed structure. The recessed edge portions increase the surface area of the heat dissipation structure and therefore, result in enhanced heat dissipation, while preserving the package mechanical integrity and reducing the amount of material needed for the heat dissipation structure.
The combination of Yu_852 and Shim does not teach wherein a first one of the first edge portions has an outermost sidewall that has a height that is substantially equal to the first height, wherein a topmost surface of the first one of the first edge portions is level with a top surface of the central portion, and wherein the topmost surface of the first one of the first edge portions is disposed between the second sidewall of the first one of the first edge portions and the outermost sidewall of the first one of the first edge portions. Yu_415 teaches wherein a first one of the first edge portions (Fig.15, the edge portion is the left portion of the heat dissipation structure, element #24 that comprises the 2 left pins, element #46) has an outermost sidewall that has a height that is substantially equal to the first height (Fig.15, the height of the leftmost sidewall of element #24 is equal to the vertical distance between the top surface of the central portion and the substrate), wherein a topmost surface of the first one of the first edge portions is level with a top surface of the central portion (Fig.15, topmost surface of the leftmost pin #46 is level with the top surface of the central portion, central portion is the portion without the pins), and wherein the topmost surface of the first one of the first edge portions is disposed between the second sidewall of the first one of the first edge portions and the outermost sidewall of the first one of the first edge portions (Fig.15, the topmost surface of the leftmost pin, element #46, is disposed between the second sidewall, which is the right sidewall of the leftmost pin and the outermost sidewall which is the left sidewall of the leftmost pin), wherein the first one of the first edge portions comprises a first portion of the first one of the first edge portions (Fig.15, leftmost pin #46) and a second portion of the first one of the first edge portions (Fig.15, second from the left pin #46), wherein the first recess of the first one of the first edge portions is disposed between the first portion of the first one of the first edge portions and the second portion of the first one of the first edge portions (Fig.15, the first recess is between the leftmost pins #46). Therefore, it would have been obvious to one ordinary skilled in the art, before the effective filing date of the claimed invention, to incorporated the teachings of Yu_415 and disclose wherein a first one of the first edge portions has an outermost sidewall that has a height that is substantially equal to the first height, wherein a topmost surface of the first one of the first edge portions is level with a top surface of the central portion, and wherein the topmost surface of the first one of the first edge portions is disposed between the second sidewall of the first one of the first edge portions and the outermost sidewall of the first one of the first edge portions. Having the outermost sidewall with the same height as the height of the central region of the heat spreader, and the topmost surface of the edge portion leveled with the top surface of the central portion, maximizes the heat dissipation area without increasing the size of the package.
The first and the second portions of the first one of the first edge portions of Yu_415, as defined above, are pins #46 which have vertical sidewalls. Therefore, the width of the pins is constant in a vertical direction from a top surface of the substrate to the topmost surface of the first one of the first edge portions. Ando teaches first and second portions of the first edge potion which are pins having a trapezoidal shape. Therefore, the width of the pins decreases in a vertical direction from a top surface of the substrate to the topmost surface of the first one of the first edge portions (Fig.6). Therefore, Ando teaches wherein a horizontal width of the first portion of the first one of the first edge portions decreases in a vertical direction from a top surface of the substrate to the topmost surface of the first one of the first edge portions, and wherein a horizontal width of the second portion of the first one of the first edge portions decreases in a vertical direction from the top surface of the substrate to the topmost surface of the first one of the first edge portions. Thus, both Yu_415 and Ando disclose portions of different shapes that are used for cooling. Therefore, the shape of the portions is a matter of choice, which a person of ordinary skill in the art would have found obvious absent persuasive evidence that the particular shape of the claimed portions has a significant role.
Regarding claim 9, the combination of Yu_852, Shim, Yu_415 and Ando teaches the method of claim 8 as set forth in the obviousness rejection. The combination of Yu_852, Shim, Yu_415 and Ando does not teach a ratio of the first depth to the first height is larger than 0.1 and smaller than 0.99. Those ordinary skilled in the art, will recognize that the height of the heat spreader is determined by the size, the number and/or the arrangement of the package components contained inside the package, while the edge regions provide mechanical integrity to the package. Therefore, it would have been obvious to one of ordinary skilled in the art, before the effective filling date of the claimed invention, to optimize the ratio through routine experimentation (MPEP 2144.05). The ratio is a result effective variable because it is important to ensure the mechanical integrity of the package, while maintaining a small package footprint.
Regarding claim 10, the combination of Yu_852, Shim, Yu_415 and Ando teaches the method of claim 8 as set forth in the obviousness rejection. Shim further teaches wherein a width of the first recess (Fig.26, element #2504) decreases in a vertical direction towards a top surface of the substrate (Fig.26, a width, measured as the horizontal distance between the recess sidewalls, decreases in a vertical direction towards the top surface of the substrate).
Regarding claim 11, the combination of Yu_852, Shim and Yu_415 teaches the method of claim 8 as set forth in the obviousness rejection. Yu_852 further teaches wherein a thickness of the central portion is smaller than the first depth. (Fig.20, vertical thickness of the top horizontal part of element #78 is smaller than the first depth, which is the vertical distance between the top surface of the top horizontal portion and the top surface of the bottom horizontal portion of the heat dissipation structure).
Regarding claim 12, the combination of Yu_852, Shim, Yu_415 and Ando teaches the method of claim 8 as set forth in the obviousness rejection. Shim further teaches, wherein each first recess is positioned centrally in a corresponding first edge portion (Fig.26, each recess is position centrally in each region, element #2504).
Regarding claim 13, the combination of Yu_852, Shim, Yu_415 and Ando teaches the method of claim 8 as set forth in the obviousness rejection. The applicant did not specify the details of alignment of an outer sidewall of the heat dissipation structure and an outer sidewall of the substrate. For the purpose of examination, alignment will be considered resulting in an outer sidewall of the heat dissipation structure and an outer sidewall of the substrate as being on the same vertical line, when viewed in cross section. Yu_852 teaches wherein an outer sidewall of the heat dissipation structure is aligned with an outer sidewall of the substrate (Fig.20, outer sidewalls of the bottom horizontal portions are on the same vertical line with the outer sidewalls of the substrate, element #76).
Claims 14-17, 19 and 20 are rejected under 35 USC § 103 as being unpatentable over Zohni in view of Wang_330, Yu_877, Ho and in view of Pu Wang et al., (United States Patent Application Number, US 2021/0098332 A1), hereinafter referenced as Wang_332.
Regarding claim 14, Zohni teaches a method comprising: attaching a package component(Fig.1 element #114, column 2, rows 66-67 and column 3, row 1-2 ) to a substrate (Fig.1, element #122, column 2, rows 62-63), wherein the package component comprises: a first die and a second die bonded to an interposer (Fig.1, elements #114); an underfill material disposed in a first gap between the first die and the second die, between the first die and the interposer, and between the second die and the interposer (Fig.1, element #142).
Zohni does not teach an encapsulant disposed over the interposer, wherein the encapsulant encapsulates the first die, the second die, and the underfill material, wherein a material of the encapsulant is different from the underfill material, wherein the underfill material in the first gap has a first height, and the encapsulant has a second height at a point at which the encapsulant has the largest thickness, wherein the second height of the encapsulant is equal to the first height of the underfill material. Wang_330 teaches an encapsulant disposed over the interposer (Fig.6A, encapsulant, element #107 disposed over the interposer, element #IP), wherein the encapsulant encapsulates the first die (Fig.6A, first die is element #106 located to the left side of the figure), the second die (Fig.6A, second die is element #106 located to the center of the figure), and the underfill material (Fig.6A, element #140), wherein the underfill material in the first gap has a first height, and the encapsulant has a second height at a point at which the encapsulant has the largest thickness, wherein the second height of the encapsulant is equal to the first height of the underfill material (Fig.6A, the height of the underfill material in the first gap has the same value as the height of the left side of the encapsulant portion located at the left side of leftmost element #106). Therefore, it would have been obvious to one of ordinary skilled in the art, before the effective filling date of the claimed invention to incorporate the teaching of Wang_330 and disclose an encapsulant disposed over the interposer, wherein the encapsulant encapsulates the first die, the second die, and the underfill material, wherein a material of the encapsulant is different from the underfill material, wherein the underfill material in the first gap has a first height, and the encapsulant has a second height at a point at which the encapsulant has the largest thickness, wherein the second height of the encapsulant is equal to the first height of the underfill material. As disclosed by Wang_330, the encapsulant material is chosen to optimize for thermal expansion coefficient (paragraph [0045]), which can reduce thermal stress in the device. Furthermore, having the height of the underfill material in the first gap equal to the height of the encapsulant provides a planar surface which maximizes the contact area with the heat spreader, thus increasing heat dissipation.
The combination of Zohni and Wang_330 does not teach wherein a material of the encapsulant is different from the underfill material. Yu_877 teaches wherein a material of the encapsulant is different from the underfill material (Fig. 17, the underfill material, element #100, can be a polymer, paragraph [0037], row 9-11, and the encapsulant, element #112 can be an epoxy, paragraph [0044], rows 2-3). Therefore, it would have been obvious to one of ordinary skilled in the art, before the effective filling date of the claimed invention to incorporate the teaching of Yu_877 and disclose wherein a material of the encapsulant is different from the underfill material. The encapsulant material can be chosen to optimize for thermal expansion coefficient in order to reduce thermal stress in the device (paragraph [0038], rows 10-13), and therefore, it might be different from the underfill material which needs to protect the electrical connections between the dies and the interposer.
Zohni further teaches attaching a portion of a heat dissipation structure to the package component and the substrate (Fig.12, formed by elements #1200, #154 and #150) using an adhesive material (column 9, rows 30-34 and 42-45), wherein after attaching a portion of the heat dissipation structure to the package component (Fig.14, step 1410), the package component is also coupled to the heat dissipation structure using a thermal interface material (the top portion of the heat dissipation structure, element #150, is attached after the bottom portion is attached in step 1410, column 10, rows 53-54, thermal interface material, element #140 couple the package component to the heat dissipation structure).
Zohni does not teach wherein the thermal interface material is in physical contact with the underfill material and the encapsulant. Wang_330 teaches wherein the thermal interface material is in physical contact with the underfill material and the encapsulant (Fig.6A, element #110 is in physical contact with elements #107 and #140). Therefore, it would have been obvious to one of ordinary skilled in the art, before the effective filling date of the claimed invention, to incorporate the teaching of Wang_330 and disclose wherein the thermal interface material is in physical contact with the underfill material and the encapsulant. This increases the contact area between the heat spreader and the rest of the device, which makes the coupling more reliable, and prevents the formation of air pockets or bubbles that may impede the heat dissipation away from the dies.
Zohni further teaches wherein the heat dissipation structure comprises: a top portion overlapping the package component and the substrate (Fig.1, element #150, column 3, rows 47-51), the top portion being above the package component (Fig.1, element #150 is on top of package component element #114); and a bottom portion surrounding the package component, the bottom portion being disposed between the top portion and the substrate (Fig.12, formed by elements #1200 and the portion of element #154 located above the substrate, element #122, in the vertical direction).
Zohni teaches the top portion comprises an edge portion and a central portion having the same, uniform thickness (Fig.1, central portion is the portion of element #150 overlapping element #112 form top down view, and the edge portion is the portion of element #150, to the left and right sides of the central portion).
The combination of Zohni, Wang_330, and Yu_877 does not teach wherein the top portion comprises an edge portion with a first thickness and a central portion having a uniform second thickness that is smaller than the first thickness. Ho teaches the top portion comprises a edge portion (Fig.5B, portion of element #24B to the left and right side of the central portion, which is the portion of element #24B overlapping element #17 from top down view) with a first thickness (Fig.5B, the thickness of element #24B on top of element #22) and a central portion (Fig.5B, portion of element #24B overlapping element #17 from top down view) with a second thickness (Fig.5B, thickness of the portion of element #24B overlapping element #17 from top down view) that is smaller than the first thickness (Fig.5B, central portion has a smaller thickness than edge portion), the edge portion surrounding the central portion and overlapping the bottom portion (Fig.5B, edge portions surround the central portion of element #24B and sit on top of bottom portion, element #22). Therefore, it would have been obvious to one ordinary skilled in the art, before the effective filing date of the claimed invention, to incorporated the teachings of Ho and disclose a heat dissipation element with an edge portion with a first thickness and a central portion having a uniform second thickness that is smaller than the first thickness. A thinner heat spreading structure on top of the semiconductor chip results in enhanced heat dissipation, while thicker edge regions preserve the package mechanical integrity.
Zohni further teaches wherein a width of the central portion is greater than a width of the package component (Fig.1, the horizontal width of the central portion, as defined above, is larger than the horizontal width of both elements #144), the edge portion surrounding the central portion and overlapping the bottom portion (Fig.1, edge portion, as defined above, surrounds the central portion and overlaps element #1200).
The combination of Zohni, Wang_330, Yu_877 and Ho does not teach wherein a bottom surface of the edge portion and a bottom surface of the central portion are at a same level, wherein a top surface of the edge portion is above a top surface of the central portion. Wang_332 teaches wherein a bottom surface (Fig.5, bottom surface of element #600) of the edge portion (Fig.5, portion formed by element #610 and the portion of element #600 between the right sidewall of element #610 and the leftmost sidewall of element #600, together with the portion formed by element #620 and the portion of element #600 between the left sidewall of element #620 and the rightmost sidewall of element #600) and a bottom surface of the central portion (Fig.5, central portion is the portion of element #600 between elements #610 and #620) are at a same level (Fig.5, bottom surface of element #600), wherein a top surface of the edge portion is above a top surface of the central portion (Fig.5, top surface of elements #610 and #620, which belong to the edge portion are above the top surface of the central portion). Therefore, it would have been obvious to one ordinary skilled in the art, before the effective filing date of the claimed invention, to incorporate the teachings of Wang_332 and disclose wherein a bottom surface of the edge portion and a bottom surface of the central portion are at a same level, wherein a top surface of the edge portion is above a top surface of the central portion. A heat dissipation structure having the central and edge portions with a common flat horizontal surface can be easily manufacture, without the need for extra etching or machining steps, while in the same time, a thinner heat spreading structure on top of the semiconductor chip results in enhanced heat dissipation, while thicker edge regions help preserve the package mechanical integrity.
Zohni further teaches wherein an outer sidewall of the top portion (Fig.12, left sidewall of element #150) and an outer sidewall of the bottom portion (Fig.12, outer wall, element #1204) are offset from and overhang an outer sidewall of the substrate (Fig.12, are offset from the left sidewall #160 of the substrate), wherein a bottommost surface of the bottom portion is above a topmost surface of the substrate (Fig.12, element #1210 is above element #102), wherein after attaching the heat dissipation structure to the package component and the substrate, a first portion of the adhesive material is disposed between the substrate and a first portion of the bottom portion of the heat dissipation structure (an adhesive is disposed between the substrate, element #122, and the first portion, where the first portion is the portion of the mounting surface, element #1208, overlapping element#122 in the vertical direction, column 9, rows 30-34 and 42-45), and a second portion of the adhesive material is disposed on a bottom surface of a second portion of the bottom portion of the heat dissipation structure (an adhesive is disposed between the substrate, element #122, and a bottom surface second portion, where the second portion is the portion of the mounting surface, element #1208, to the left side of the first portion as defined above, column 9, rows 30-34 and 42-45), wherein the second portion of the bottom portion of the heat dissipation structure and the second portion of the adhesive material overhang and extend laterally beyond the outer sidewall of the substrate (Fig.12, as defined above the second portions overhang and extend laterally beyond the outer sidewall #160).
Regarding claim 15, the combination of Zohni, Wang_330, Yu_877, Ho, and Wang_332 teaches the method of claim 14 as set forth in the obviousness rejection. Zohni further teaches the method of claim 14, wherein the bottom portion of the heat dissipation structure comprises a ring (element #154 is a ring column 4, row 14).
Regarding claim 16, the combination of Zohni, Wang_330, Yu_877, Ho, and Wang_332 teaches the method of claims 14 and 15 as set forth in the obviousness rejection. Furthermore, Zohni teaches the bottom portion of the heat dissipation structure may be made of ceramic, metal or other materials (element #1200, may be made of the same material as element #154, column 9, rows 28-29, which is made of ceramic or metal, column 4, row 17-22) and the top portion can be made of “thermally conductive material such as copper, nickel plate copper or aluminum or other suitable materials” (column 3, rows 47-51). Those ordinary skilled in the art recognize that different materials have different coefficients of thermal expansion. Therefore, Zohni teaches a first coefficient of thermal expansion of a first material of the top portion (Fig.1, element #150) of the heat dissipation structure is different from a second coefficient of thermal expansion of a second material of the bottom portion (Fig.1, element #1200) of the heat dissipation structure.
Regarding claim 17, the combination of Zohni, Wang_330, Yu_877, Ho, and Wang_332 teaches the method of claims 14 and 15 as set forth in the obviousness rejection. The applicant did not specify the details of alignment of the outer sidewall of the edge portion and the outer sidewall of the ring. For the purpose of examination, alignment will be considered resulting in the outer wall of the edge portion of the top portion and the outer wall of the bottom portion as being on the same vertical line, when viewed in cross section. Zohni teaches a width of the edge portion (Fig.1, central portion is part of element #150 overlapping element #112, and the edge portion is portion of element #150, to the left and right side of the central portion; width is the horizontal width of the left side edge portion) is greater than a difference between an outer radius and an inner radius of the ring (Fig.12, the difference between an outer radius and an inner radius is the horizontal distance between elements #1202 and #1212 and is smaller than the width of the edge portion), and wherein an outer sidewall of the edge portion is aligned with an outer sidewall of the ring (Fig.12, the outer wall of the edge portion of the top portion element #150, and the outer wall of the bottom portion #1200 are on the same vertical line).
Regarding claim 19 the combination of Zohni, Wang_330, Yu_877, Ho and Wang_332 teaches the method of claims 14 and 15 as set forth in the obviousness rejection. Zohni further teaches wherein a width of the top portion (Fig.1, width of element #150 measured from left to right, column 3 rows 47-51), is larger than a width of the substrate (Fig.1, width of element #150 is larger than a width of element #122, when measured from left to right).
Regarding claim 20, the combination of Zohni, Wang_330, Yu_877, Ho, and Wang_332 teaches the method of claim 14 as set forth in the obviousness rejection. Furthermore, Zohni teaches the bottom portion of the heat dissipation structure may be made of copper or aluminum (element #1200, may be made of the same material as element #154, column 9, rows 28-29, which can be made of copper, column 4, row 20) and the top portion can be made of “thermally conductive material such as copper, nickel plate copper or aluminum” (element #150, column 3, rows 47-51). Therefore, Zohni teaches that the top portion of the heat dissipation structure and the bottom portion of the heat dissipation structure comprise the same continuous material.
Claim 18 is rejected under 35 USC § 103 as being unpatentable over Zohni in view of Wanf_330, Yu_877, Ho, Wang_332 and in view of Charles W.C. Lin et al. (United States Patent Number, US 9,570,372 B1), hereinafter referenced as Lin.
Regarding claim 18, the combination of Zohni, Wang_330, Yu_877, Ho, and Wang teaches the method of claims 14 and 15 as set forth in the obviousness rejection. Zohni teaches the heat spreader comprises: a central portion and edge portions that surround the central portion when seen in a top-down view (Fig.1, central portion is part of element #150 overlapping element #112, and the edge portion is the portion of element #150, to the left and right side of the central portion) that have the same thickness.
The combination of Zohni, Wang_330, Yu_877, Ho, and Wang_332 does not teach wherein a thickness of the edge portion is in a range from 1.5mm to 3.5mm. Lin teaches a heat spreader (Fig.13, element #21) with edge portions (Fig.13, portions on the left and right side of cavities #211) with a thickness in the range 0.1mm to 10mm (column 8, rows 19-26). Therefore, the claimed range from 1.5mm to 3.5mm lies inside the range disclose by prior art and a prima facie case of obviousness exists (MPEP 2144.05). Therefore, it would have been obvious to one ordinary skilled in the art, before the effective filing date of the claimed invention, to incorporate the teachings of Lin and disclose the claimed range for the heat spreader edges. Thin edges are not mechanically strong, while thicker edges increase the size of the package.
Response to Arguments
Applicant’s arguments filed on 03/24/2026 have been fully considered but they
are not persuasive. Applicant’s arguments with respect to claims have been considered but are moot because the new ground of rejection does not rely on any reference as applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
Conclusion
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/CRISTIAN A TIVARUS/Examiner, Art Unit 2899 /DALE E PAGE/Supervisory Patent Examiner, Art Unit 2899
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