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 .
Examiner’s note
The examiner notes that applicant has distinguished between ‘surface’ waviness (recited in the claim) and ‘waviness’ of the fiber substrate. The examiner notes that based on these two features, the ‘surface’ waviness is the exterior surface of the prepreg, while the waviness of the fiber substrate is that of the cloth or fibers themselves which my undulate or be larger than that of the surface waviness (see specification (paragraph 0011).
Claim Objections
Claims 1 and 10 are objected to because of the following informalities: Line 5 of claim 1 and line 6 of claim 10 recite “the thermosetting resin is overlaid…” It appears that this phrase should be corrected to recite “the thermosetting resin composition for proper antecedent basis since both claim use the phrase “thermosetting resin composition.” In addition, this change would be consistent with paragraph 0019 of the instant specification which states that “…the thickness of the resin composition overlaid on the fiber substrate on each of both surfaces of the prepreg may be referred to as a resin thickness.”
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
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.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
Claim(s) 1 – 3, 5 – 9 and 13 – 17 is/are rejected under 35 U.S.C. 103 as being unpatentable over Watari, et al. (US 2020/0010632 A1) in view of Hayashi, et al. (US 8,446,734 B2).
With respect to claim 1 and 14 – 17, Watari, et al. teach a prepreg comprising a fiber substrate (figure 1 or 2; paragraph 0021), impregnated with a thermosetting resin composition (paragraph 0021 and 0027; the examiner notes that Watari, et al. teach the use of an epoxy resin impregnating the fibers; epoxy resins are thermosetting resin(s) and also the same as used by applicant {see specification, paragraph 0024}), the prepreg having in the fiber substrate an impregnated region and a non-impregnated region (see figure 1 and 2; paragraph 0046); the prepreg having a waviness in the fiber (figure 1 and 2), but a surface waviness which is ‘flat.’
In addition, Watari teaches wherein a portion of the thermosetting resin is overlaid on opposing surfaces of the fiber substrate, each portion of the thermosetting resin overlaid on respective opposing surfaces of the fiber substrate having a resin thickness defined as the minimum distance from an outermost surface of the thermosetting to the opposing surface of the fiber substrate (see figure 2 below).
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Watari, et al. however, does not specifically state that the difference of the resin thicknesses of the resin overlaid on the fiber substrate on respective opposing surfaces of the fiber substrate is 0 – 10 um (i.e, the resin thicknesses on either side can be the same), or wherein the difference in thickness is/are the ranges as recited in claims 14 – 17. In addition, Watari, et al., however is silent with respect to the thickness of the fiber substrate and the surface waviness being 5 micron or less.
With respect to the resin thicknesses, examiner notes that the claim recites the difference in thickness is defined as the distance from an outer surface of the resin to the opposing surface of the fiber substrate. Because the claim does not recite where on the outer surface the thickness is measured from, and because the surface of the fiber varies and undulates, the examiner contends that a point may be chosen on the surface to a point on the fiber mat or surface (on either side of the prepreg), such that the resin thicknesses are the same and thus, would render obvious the difference of 0 – 10 um or ranges less than that. The claim does not preclude having variations in the surface(s).
With respect to the substrate thickness, Hayashi, et al., similarly teach a prepreg with a fiber substrate impregnated by an epoxy resin (column 3, lines 15 – 20 and 45 – 50). The fiber substrate thickness can vary (see Table 5), anywhere from 85 microns (pre-pressing) to 50 microns (post-pressing). Such thicknesses are typical values for the fiber substrate which can be used in circuit board manufacture (column 1, lines 10 – 20).
Thus, it would have been obvious to one of ordinary skill in the art to use the thicknesses per Hayashi, et al. prior to the effective filing date of the claimed invention for the purposes of having a fiber thickness suitable in circuit board manufacture.
With respect to the surface waviness, Hayashi, et al. does not specifically teach the 5 micron or less parameter; however, Hayashi, et al. teach that waviness is apparent due to the weave of the fiber substrate. Furthermore, because of the undulation, a springy effect may occur which results from a larger undulation of the fiber (column 9, lines 60 – 65). It is important to keep the undulation(s) as small as possible in order to avoid the ‘springy’ effect which can pose the problem of resin peeling off at the interface between the fiber stacks (column 10, lines 1 – 10). Thus, per Hayashi, et al. it is important to keep the undulation value (S/L) greater than 1 time but smaller than 1.20 times. It is apparent from this ratio and from the teachings in Hayashi, et al. that smaller undulations are critical.
Therefore, it would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to keep the surface waviness less than 5 micron for the purpose of avoiding the ‘springy’ effect thereby inhibiting any peeling of the resin from the interface with the fiber stack and furthermore, ensuring solid contact with any further layer (i.e, metal foil) bonded thereon to manufacturing a circuit board, for example. (Hayashi, et al. not only appreciates small undulations with respect to the fiber, but also to the prepreg itself – per Hayashi, et al. ‘flatness’ is key to ensuring contact between interface(s)).
With respect to claim 2, Watari, et al. teach that the degree of impregnation is 25 – 98% (paragraph 0021 – 0022).
The examiner notes that Watari, et al. do not teach the specific method recited in claim 2; however, the examiner contends that the method by which the impregnation ratio is calculated flows from the product itself. In other words, Watari, et al. teach a prepreg comprised of the 1) same layers, 2) same composition (epoxy resin, reinforced fibers, carbon fiber as exemplary materials and 3) made by equivalent methods as that disclosed by applicant (vacuum molding the prepreg; it is noted, however, that applicant also states in the specification that the method of making is not particularly limited and may include conventional methods) and thus, the impregnation ratio is expected to flow from the prior art prepreg.
With respect to claim 3, Watari, et al. teach that the degree of impregnation is 35 – 90% (paragraph 0021 – 0022).
With respect to claim 5, Hayashi, et al. teach that fiber substrate thickness can vary (see Table 5), anywhere from 85 microns (pre-pressing) to 50 microns (post-pressing). Such thicknesses are typical values for the fiber substrate which can be used in circuit board manufacture (column 1, lines 10 – 20). This range is within the recited range of 70 – 120 micron.
With respect to claim 6, Watari, et al. teach a laminate comprising one or more plies of the prepreg according to claim 1 (see paragraph 0093).
With respect to claim 7, Hayashi, et al. teach that the prepreg may be part of a metal-clad laminate comprising a metal foil and one or more plies of the prepreg (column 1, lines 20 – 25).
With respect to claim 8, Hayashi, et al. teach that the prepreg may be part of a laminate used in a printed wiring board (column 1, lines 35 – 45; column 13, lines 15 – 25).
With respect to claim 9, Hayashi, et al. teach that the prepreg may be used in a wiring board and a semiconductor device (column 1, lines 35 – 45; column 4, lines 30 – 35).
With respect to claim 13, Hayashi, et al. teach that the prepreg may be used in a metal-clad laminate further placed in a printed wiring board (column 1, lines 20 – 25; column 4, lines 30 – 35).
Claims 10 – 12 and 18 – 20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Watari, et al. (US 2020/0010632 A1) in view of Hayashi, et al. (US 8,446,734 B2).
With respect to claim 10 and 18 – 20, Watari, et al. teach a method of producing a prepreg having a fiber waviness but a ‘flat’ surface waviness (figure 1 and 2); comprising impregnating a fiber substrate having a thickness with a film of a thermosetting resin through lamination (paragraph 0046), the method of producing a prepreg including providing in the fiber substrate an impregnated region and a non-impregnated region with the thermosetting resin composition (figure 1 and 2; paragraph 0047 – 0049), wherein a portion of the thermosetting resin is overlaid on each opposing surface of the fiber substrate, each portion of the thermosetting resin overlaid on respective surfaces of the fiber substrate having a resin thickness defined as the minimum distance from an outermost surface of the thermosetting resin to the opposing surface of the fiber substrate (see annotated figure below).
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Watari, et al. however, does not specifically state that the difference of the resin thicknesses of the resin overlaid on the fiber substrate on respective opposing surfaces of the fiber substrate is 0 – 10 um (i.e, the resin thicknesses on either side can be the same) or the ranges as recited in claims 18 – 20. In addition, Watari, et al., is also silent with respect to the thickness of the fiber substrate and the surface waviness being 5 micron or less.
With respect to the resin thicknesses, examiner notes that the claim recites the difference in thickness is defined as the distance from an outer surface of the resin to the opposing surface of the fiber substrate. Because the claim does not recite where on the outer surface the thickness is measured from, and because the surface of the fiber varies and undulates, the examiner contends that a point may be chosen on the surface to a point on the fiber mat or surface (on either side of the prepreg), such that the resin thicknesses are the same and thus, would render obvious the difference of 0 – 10 um or ranges less than that. The claim does not preclude having variations in the surface(s).
With respect to the fiber thickness, Hayashi, et al., similarly teach a prepreg with a fiber substrate impregnated by an epoxy resin (column 3, lines 15 – 20 and 45 – 50). The fiber substrate thickness can vary (see Table 5), anywhere from 85 microns (pre-pressing) to 50 microns (post-pressing). Such thicknesses are typical values for the fiber substrate which can be used in circuit board manufacture (column 1, lines 10 – 20).
Thus, it would have been obvious to one of ordinary skill in the art to use the thicknesses per Hayashi, et al. prior to the effective filing date of the claimed invention for the purposes of having a fiber thickness suitable in circuit board manufacture.
With respect to the surface waviness, Hayashi, et al. does not specifically teach the 5 micron or less parameter; however, Hayashi, et al. teach that waviness is apparent due to the weave of the fiber substrate. Furthermore, because of the undulation, a springy effect may occur which results from a larger undulation of the fiber (column 9, lines 60 – 65). It is important to keep the undulation(s) as small as possible in order to avoid the ‘springy’ effect which can pose the problem of resin peeling off at the interface between the fiber stacks (column 10, lines 1 – 10) and furthermore, ensuring solid contact with any further layer (i.e, metal foil) bonded thereon to manufacturing a circuit board, for example.
Thus, per Hayashi, et al. it is important to keep the undulation value (S/L) greater than 1 time but smaller than 1.20 times. It is apparent from this ratio and from the teachings in Hayashi, et al. that smaller undulations are critical.
Therefore, it would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to keep the waviness less than 5 micron for the purpose of avoiding the ‘springy’ effect thereby inhibiting any peeling of the resin from the interface with the fiber stack and furthermore, ensuring solid contact with any further layer (i.e, metal foil) bonded thereon to manufacturing a circuit board, for example. Hayashi, et al. not only appreciates small undulations with respect to the fiber, but also to the prepreg itself – per Hayashi, et al. ‘flatness’ is key to ensuring contact between interface(s)
With respect to claim 11, Watari, et al. teach that the degree of impregnation is 25 – 98% (paragraph 0021 – 0022).
The examiner notes that Watari, et al. do not teach the specific method recited in claim 11; however, the examiner contends that the method by which the impregnation ratio is calculated flows from the product itself. In other words, Watari, et al. teach a prepreg comprised of the 1) same layers, 2) same composition (epoxy resin, reinforced fibers, carbon fiber as exemplary materials and 3) made by equivalent methods as that disclosed by applicant (vacuum molding the prepreg; it is noted, however, that applicant also states in the specification that the method of making is not particularly limited and may include conventional methods) and thus, the impregnation ratio is expected to flow from the prior art prepreg.
With respect to claim 12, Hayashi, et al. teach a method of producing a metal-clad laminate comprising disposing metal foils on both surfaces of one ply of a prepreg or on both surfaces of the prepreg laminate including one or more plies of the prepreg and then press-molding (see Hayashi, et al. column 1, lines 20 – 25).
Claim(s) 4 is/are rejected under 35 U.S.C. 103 as being unpatentable over Watari, et al. in view of Hayashi, et al. as applied to claim 1 above, and further in view of Suh (US 2010/0236820 A1).
Watari, et al. and Hayashi, et al. teach the limitations recited above; however, are both silent with respect to any surface roughness of the prepreg.
In analogous art of prepregs used in a metal clad laminate for a printed wiring board (see abstract), Suh teaches a surface roughness of 0.1 – 5 micron (paragraph 0026). This range of surface roughness is important to promote bond strength between the prepreg and the metal thin film to which it is bonded (paragraph 0051). If the roughness is less than this range, the bond strength is insufficient (paragraph 0051). Alternatively, if the roughness is greater than this range, voids may form between the metal thin film and the prepreg (paragraph 0051).
Thus, it would be obvious to one of ordinary skill in the art to include the surface roughness of Suh in the prepreg of Watari, et al. as modified by Hayashi, et al. before the effective filing date of the claimed invention for the purpose of ensuring bond strength between the prepreg and the metal thin film used to make the printed wiring board per the teachings of Suh.
Claim(s) 1 – 3, 5 – 9 and 13 – 17 is/are rejected under 35 U.S.C. 103 as being unpatentable over Hayashi, et al. (US 8,446,734 B2) in view of Hughes, et al. (US 2014/0309336 A1).
With respect to claim 1 and 13 – 17, Hayashi, et al. teach a prepreg comprising a fiber substrate having a thickness of 40 micron or more (figure 1; column 4, lines 15 – 20; see Table 5, note that Hayashi, et al. teach prepreg thickness ranging from 85 – 99 micron [pre-pressing] and 50 – 73 micron [post-pressing] which overlaps and encompasses the recited range of 40 micron or more), impregnating with a thermosetting resin (column 3, lines 45 – 50 [note that Hayashi, et al. teach the use of an epoxy resin which is a thermosetting resin, examiner notes that applicant similarly uses epoxy resins]; column 4, lines 15 – 20) wherein the fiber substrate has a fiber waviness (figure 1) but a ‘flat’ surface to the prepreg.
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In addition, the reference teaches wherein a portion of the thermosetting resin is overlaid on each opposing surface of the fiber substrate, each portion of the thermosetting resin overlaid on respective surfaces of the fiber substrate having a resin thickness defined as the minimum distance from an outermost surface of the thermosetting resin to the opposing surface of the fiber substrate (see annotated figure above – resin which impregnates the fiber mat has portions which overlay both the top and bottom of the mat itself). However, Hayashi, et al. does not specifically teach that the difference of the resin thicknesses of the resin overlaid on the fiber substrate on respective opposing surfaces of the fiber substrate is 0 – 10 um (i.e, the resin thicknesses on either side can be the same). In addition, Hayashi, et al., is also silent with respect to the thickness of the fiber substrate and the surface waviness being 5 micron or less.
With respect to the resin thicknesses, examiner notes that the claim recites the difference in thickness is defined as the distance from an outer surface of the resin to the opposing surface of the fiber substrate. Because the claim does not recite where on the outer surface the thickness is measured from, and because the surface of the fiber varies and undulates, the examiner contends that a point may be chosen on the surface to a point on the fiber mat or surface (on either side of the prepreg), such that the resin thicknesses are the same and thus, would render obvious the difference of 0 – 10 um or ranges less than that. The claim does not preclude having variations in the surface(s).
With respect to the surface waviness, Hayashi, et al. does not specifically teach the 5 micron or less parameter; however, Hayashi, et al. teach that waviness is apparent due to the weave of the fiber substrate. Furthermore, because of the undulation, a springy effect may occur which results from a larger undulation of the fiber (column 9, lines 60 – 65). It is important to keep the undulation(s) as small as possible in order to avoid the ‘springy’ effect which can pose the problem of resin peeling off at the interface between the fiber stacks (column 10, lines 1 – 10) and furthermore, ensuring solid contact with any further layer (i.e, metal foil) bonded thereon to manufacturing a circuit board, for example.
Thus, per Hayashi, et al. it is important to keep the undulation value (S/L) greater than 1 time but smaller than 1.20 times. It is apparent from this ratio and from the teachings in Hayashi, et al. that smaller undulations are critical.
Therefore, it would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to keep the waviness less than 5 micron for the purpose of avoiding the ‘springy’ effect thereby inhibiting any peeling of the resin from the interface with the fiber stack and furthermore, ensuring solid contact with any further layer (i.e, metal foil) bonded thereon to manufacturing a circuit board, for example. Hayashi, et al. not only appreciates small undulations with respect to the fiber, but also to the prepreg itself – per Hayashi, et al. ‘flatness’ is key to ensuring contact between interface(s)
In addition, Hayashi, et al. fails to teach the fiber substrate with impregnated and non-impregnated regions.
Hughes, et al. teach a prepreg with a fiber substrate impregnated with a thermosetting resin (figure 1). In addition, Hughes, et al. teach regions within the prepreg which are unimpregnated (item 6 – figure 1). In conventional prepregs wherein the fiber is fully infused with the resin, consolidation may be challenging as trapped gases are difficult to remove (paragraph 0004). The unimpregnated region acts as an air path during molding to release any volatiles (paragraph 0032 and paragraph 0043).
Thus, it would have been obvious to one of ordinary skill in the art to have non-impregnated regions in the prepreg of Hayashi, et al. as taught by Hughes, et al. prior to the effective filing date of the claimed invention for the purpose of allowing an air flow path to remove trapped gases per Hughes, et al.
With respect to claims 2 – 3, Hughes, et al. may not specifically teach the method as recited to obtain the ratio of the impregnated region (it is noted that Hughes, et al. do teach an impregnation ratio of 10 – 70% which overlaps or is encompassed within the recited range (See Hughes, et al. paragraph 0077).
The examiner contends however, that the method by which the impregnation ratio is calculated flows from the product itself. In other words, Hayashi, et al. teach a prepreg comprised of the 1) same layers, 2) same composition (epoxy resin, reinforced fibers, carbon fiber as exemplary materials and 3) made by equivalent methods as that disclosed by applicant (vacuum molding the prepreg and/or press molding to form the prepreg; it is noted, however, that applicant also states in the specification that the method of making is not particularly limited and may include conventional methods) and thus, the impregnation ratio is expected to flow from the prior art prepreg.
Thus, the examiner contends that the prepreg of Hayashi, et al. modified with the non-impregnated regions as taught by Hughes, et al. would be expected to have the impregnation ratio as claimed because of the equivalent materials, composition and method of making (in addition to the equivalent technology area).
With respect to claim 5, the fiber substrate of Hayashi, et al. has a thickness ranging from 85 – 99 micron [pre-pressing] and 50 – 73 micron [post-pressing] which overlaps and encompasses the recited range of 70- 120 micron).
With respect to claim 6, Hayashi, et al. teach a laminate comprises one or more plies of the prepreg (column 4, lines 5 – 30).
With respect to claim 7, Hayashi, et al. teach a metal-clad laminate comprising a metal foil and one or more plies of the prepreg (column 1, lines 20 – 25).
With respect to claim 8, Hayashi, et al. teach that the prepreg may be part of a laminate used in a printed wiring board (column 1, lines 35 – 45; column 13, lines 15 – 25).
With respect to claim 9, Hayashi, et al. teach that the prepreg may be used in a wiring board and a semiconductor device (column 1, lines 35 – 45; column 4, lines 30 – 35).
With respect to claim 13, Hayashi, et al. teach that the prepreg may be used in a metal-clad laminate further placed in a printed wiring board (column 1, lines 20 – 25; column 4, lines 30 – 35).
Claims 10 – 12 and 18 – 20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Hayashi, et al. (US 8,446,734 B2) in view of Hughes, et al. (US 2014/0309336 A1).
With respect to claim 10 and 18 – 20, Hayashi, et al. teach a method of producing a prepreg comprising a fiber substrate having a thickness of 40 micron or more (figure 1; column 4, lines 15 – 20; see Table 5, note that Hayashi, et al. teach prepreg thickness ranging from 85 – 99 micron [pre-pressing] and 50 – 73 micron [post-pressing] which overlaps and encompasses the recited range of 40 micron or more), impregnating with a thermosetting resin (column 3, lines 45 – 50 [note that Hayashi, et al. teach the use of an epoxy resin which is a thermosetting resin, examiner notes that applicant similarly uses epoxy resins]; column 4, lines 15 – 20) through lamination (column 1, lines 35 – 40) wherein the fiber substrate has a fiber waviness (figure 1) but a ‘flat’ prepreg surface.
In addition, the reference teaches wherein a portion of the thermosetting resin is overlaid on each opposing surface of the fiber substrate, each portion of the thermosetting resin overlaid on respective surfaces of the fiber substrate having a resin thickness defined as the minimum distance from an outermost surface of the thermosetting resin to the opposing surface of the fiber substrate (see annotated figure above – resin which impregnates the fiber mat has portions which overlay both the top and bottom of the mat itself). However, Hayashi, et al. does not specifically teach that the difference of the resin thicknesses of the resin overlaid on the fiber substrate on respective opposing surfaces of the fiber substrate is 0 – 10 um (i.e, the resin thicknesses on either side can be the same). In addition, Hayashi, et al., is also silent with respect to the thickness of the fiber substrate and the surface waviness being 5 micron or less.
With respect to the resin thicknesses, examiner notes that the claim recites the difference in thickness is defined as the distance from an outer surface of the resin to the opposing surface of the fiber substrate. Because the claim does not recite where on the outer surface the thickness is measured from, and because the surface of the fiber varies and undulates, the examiner contends that a point may be chosen on the surface to a point on the fiber mat or surface (on either side of the prepreg), such that the resin thicknesses are the same and thus, would render obvious the difference of 0 – 10 um. The claim does not preclude having variations in the surface(s).
With respect to the surface waviness, while Hayashi, et al. does not specifically teach the 5 micron or less parameter; Hayashi, et al. teach that waviness is apparent due to the weave of the fiber substrate. Furthermore, because of the undulation, a springy effect may occur which results from a larger undulation of the fiber (column 9, lines 60 – 65). It is important to keep the undulation(s) as small as possible in order to avoid the ‘springy’ effect which can pose the problem of resin peeling off at the interface between the fiber stacks (column 10, lines 1 – 10) and furthermore, ensuring solid contact with any further layer (i.e, metal foil) bonded thereon to manufacturing a circuit board, for example.
Thus, per Hayashi, et al. it is important to keep the undulation value (S/L) greater than 1 time but smaller than 1.20 times. It is apparent from this ratio and from the teachings in Hayashi, et al. that smaller undulations are critical.
Therefore, it would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to keep the waviness less than 5 micron for the purpose of avoiding the ‘springy’ effect thereby inhibiting any peeling of the resin from the interface with the fiber stack and furthermore, ensuring solid contact with any further layer (i.e, metal foil) bonded thereon to manufacturing a circuit board, for example. Hayashi, et al. not only appreciates small undulations with respect to the fiber, but also to the prepreg itself – per Hayashi, et al. ‘flatness’ is key to ensuring contact between interface(s)
In addition, Hayashi, et al. fails to teach the fiber substrate with impregnated and non-impregnated regions.
Hughes, et al. teach a prepreg with a fiber substrate impregnated with a thermosetting resin (figure 1). In addition, Hughes, et al. teach regions within the prepreg which are unimpregnated (item 6 – figure 1). In conventional prepregs wherein the fiber is fully infused with the resin, consolidation may be challenging as trapped gases are difficult to remove (paragraph 0004). The unimpregnated region acts as an air path during molding to release any volatiles (paragraph 0032 and paragraph 0043).
Thus, it would have been obvious to one of ordinary skill in the art to have non-impregnated regions in the prepreg of Hayashi, et al. as taught by Hughes, et al. prior to the effective filing date of the claimed invention for the purpose of allowing an air flow path to remove trapped gases per Hughes, et al.
With respect to claim 11, Hughes, et al. may not specifically teach the method as recited to obtain the ratio of the impregnated region (it is noted that Hughes, et al. do teach an impregnation ratio of 10 – 70% which overlaps or is encompassed within the recited range (See Hughes, et al. paragraph 0077).
The examiner contends however, that the method by which the impregnation ratio is calculated flows from the product itself. In other words, Hayashi, et al. teach a prepreg comprised of the 1) same layers, 2) same composition (epoxy resin, reinforced fibers, carbon fiber as exemplary materials and 3) made by equivalent methods as that disclosed by applicant (vacuum molding the prepreg and/or press molding to form the prepreg; it is noted, however, that applicant also states in the specification that the method of making is not particularly limited and may include conventional methods) and thus, the impregnation ratio is expected to flow from the prior art prepreg.
Thus, the examiner contends that the prepreg of Hayashi, et al. modified with the non-impregnated regions as taught by Hughes, et al. would be expected to have the impregnation ratio as claimed because of the equivalent materials, composition and method of making (in addition to the equivalent technology area).
With respect to claim 12, Hayashi, et al. a method of producing a metal-clad laminate comprising disposing metal foils on both surfaces of one ply of a prepreg or on both surfaces of the prepreg laminate including one or more plies of the prepreg and then press-molding (see Hayashi, et al. column 1, lines 20 – 25).
Claim(s) 4 is/are rejected under 35 U.S.C. 103 as being unpatentable over Hayashi, et al. in view of Hughes, et al. as applied to claim 1 above, and further in view of Suh (US 2010/0236820 A1).
Hayashi, et al. and Hughes, et al. teach the limitations recited above; however, are both silent with respect to any surface roughness of the prepreg.
In analogous art of prepregs used in a metal clad laminate for a printed wiring board (see abstract), Suh teaches a surface roughness of 0.1 – 5 micron (paragraph 0026). This range of surface roughness is important to promote bond strength between the prepreg and the metal thin film to which it is bonded (paragraph 0051). If the roughness is less than this range, the bond strength is insufficient (paragraph 0051). Alternatively, if the roughness is greater than this range, voids may form between the metal thin film and the prepreg (paragraph 0051).
Thus, it would be obvious to one of ordinary skill in the art to include the surface roughness of Suh in the prepreg of Hayashi, et al. as modified by Hughes, et al. before the effective filing date of the claimed invention for the purpose of ensuring bond strength between the prepreg and the metal thin film used to make the printed wiring board per the teachings of Suh.
Response to Arguments
Applicant's arguments filed November 17, 2025 have been fully considered but they are not persuasive.
Applicant’s primary argument is that the reference(s) of Watari, et al. and Hayashi, et al. fail to teach or render obvious the newly-introduced limitations reciting the 1) resin thickness overlaid on the fiber substrate and wherein 2) a difference between the resin thicknesses of the resin overlaid on the fiber substrate on respective surfaces of the fiber substrate is 0 – 10um.
In addition, with respect to the surface waviness, applicant asserts that Hayashi, et al. while discussing the undulation(s) of the fiber or substrate, fail to teach or render obvious the undulation of the surface of the impregnated resin – i.e, the surface waviness of the prepreg itself.
To applicant’s first point regarding the difference in the resin thicknesses, examiner respectfully disagrees. With respect to Watari, et al., applicant argues that the figure included from the reference and the accompanying discussion note that there is a large variation in the resin thicknesses on respective opposing surfaces of the fiber substrate and thus, the reference cannot anticipate or render obvious the difference in resin thicknesses as recited. However, examiner contends that any variation in the resin thicknesses is not precluded from the claim. The claim recites a portion of the thermosetting resin is overlaid on each opposing surface of the fiber substrate – Watari has a ‘portion’ as recited which is the outer or exterior surface of the resin (identified in annotated figure 2), each ‘portion’ overlays the fiber substrate or mat and the resin thickness can be taken as the distance from the resin exterior surface to any point on the surface of the fiber substrate. The claim also does NOT preclude any surface of the fiber mat to be embedded or impregnated within the resin and the claim does not preclude any variation in either the resin surface or the fiber surface. Thus, the examiner contends that any distance from the outer resin surface to the fiber surface may be drawn and those distances at both the top and bottom of the prepreg may be measured such that the resin thicknesses are the same and thus, the difference in resin thickness as recited in the claims is/are rendered obvious.
The examiner would also like to point out that regarding the resin thicknesses and the difference thereof between the resin overlays, the instant specification teaches methods, materials and structures which are equivalent to that in the prior art of Watari, et al. and Hayashi, et al. Paragraph 0043 states:
A method of impregnating the fiber substrate with the resin film through lamination will be then described.
The resin film with the release film is disposed on at least one surface of the fiber substrate in such a manner that the resin film is brought into contact with the fiber substrate. Thereafter, the resin film with the release film thus disposed and the fiber substrate are heated and pressurized, and thereby the fiber substrate is impregnated with the resin film. At this time, the non-impregnated region with the thermosetting resin composition is provided in the fiber substrate. The prepreg of the present embodiment with the release film is thus obtained in this manner.
The heating and pressurizing herein is preferably performed through lamination. Examples of the method of the lamination include roll lamination (a) and a lamination method under reduced pressure (b), such as a vacuum lamination method.
The method above is equivalent to that described in the prior art and thus, the examiner further contends that the difference in resin thickness of the portions overlaying the fiber substrate would be obvious and expected. While the rejection notes that the distance from the exterior surface of the resin to the fiber surface may be chosen at any given point and may be the same on both sides of the fiber substrate, the examiner notes that the resin thickness is also a function of the composition, structure, processing of the prepreg and parameters during processing. Both Watari, et al. and Hayashi, et al. teach the same compositions for the resin and fiber substrate; Hayashi teaches the overlapping thickness and both teach the same processing method and temperature(s) for heating and thus, any adjustment to the method can produce resin thicknesses on either side of the fiber substrate such that the thicknesses are the same and thus, the difference in thicknesses of opposing surfaces would be 0.
Turning to applicant’s specification and discussion regarding the resin thickness and differences thereof, paragraph 19 states:
In observing the cross section of the prepreg with a metallograph as shown in Fig. 3, the resin thickness is the minimum distance from the outermost surface of the resin to the glass cloth on each of both surfaces of the prepreg in the observation image. In Fig. 3, the thermosetting resin composition with which the fiber substrate is impregnated is not shown for convenience.
Based on the above excerpt, the examiner also notes that while the resin layer (in figure 3) looks to sit above the fiber substrate, such that it is easy to delineate where the resin stops and the substrate begins, per the above paragraph, the figure is misleading as some resin will be located within the fiber substrate and thus, the distance from the exterior surface of the resin to the fiber substrate would be consistent with what is shown in the prior art. In other words, the minimum distance may be drawn from the exterior resin surface to any point on the fiber substrate even if that part of the substrate has an undulation or is embedded within the resin.
Regarding the reference of Hayashi, applicant’s arguments regarding the surface waviness are not persuasive. As noted in the rejection, per Hayashi, undulation(s) should be kept small to avoid peel off. Hayashi, et al. continues to state that “flat” or a “straight” state (see column 10, lines 1 – 10) is critical to prevent peel off and thus deformation. While Hayashi, et al. discusses the flat or straight state with respect to the fibers, the examiner contends that this teaching is equally applied to the surface of the prepreg which may be laminated to a foil or plastic film. Based on the overall teachings in Hayashi, et al., the examiner contends that one of ordinary skill in the art would conclude that any surface waviness should be kept minimal or suppressed because the flat state ensures proper adhesion, no deformation and resists peel off.
References of interest
Wadahara, et al. (US 2013/0122241 A1) and Tanaka, et al. (US 2011/0083890 A1) are cited of interest.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to MARIA VERONICA EWALD whose telephone number is (571)272-8519. The examiner can normally be reached Mon-Fri ~9am-5:30pm EST.
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/MARIA V EWALD/Supervisory Patent Examiner, Art Unit 1783