United States Patent [t9J
`Azuma et al.
`
`111111111111111111111111111111111111111111111111111111111111111111111111111
`US005286330A
`[tt] Patent Number:
`[45] Date of Patent:
`
`5,286,330
`Feb. 15, 1994
`
`[75]
`
`[54] METHOD OF PRODUCING COPPER-CLAD
`LAMINATED BOARD
`Inventors: Keiji Azuma; Kimikazu Katoh, both
`of Tokyo; Ryoichi Oguro, Imaichi,
`all of Japan
`[73] Assignees: Sumitomo Bakelite Company Limited;
`Circuit Foil Japan Co., Ltd., both of
`Tokyo, Japan
`[21] Appl. No.: 877,833
`[22] Filed:
`May 1, 1992
`[30)
`Foreign Application Priority Data
`May 13, 1991 [JP]
`Japan .................................. 3·201525
`[51)
`Int. CI.s ................................................ B65C 9/25
`[52] u.s. Cl. ······································ 156/323; 29/829;
`100/211; 100/295; 156/153; 156/307.4;
`174/259
`[58] Field of Search ..................... 156/323, 153, 307.4;
`29/829; 100/211, 295; 174/259
`References Cited
`U.S. PATENT DOCUMENTS
`3,677,876 7/1972 Oliver ................................. 156/323
`
`[56)
`
`FOREIGN PATENT DOCUMENTS
`50-60772 5/1975 Japan .
`
`62-214939 9/1987 Japan .
`62-274795 11/1987 Japan .
`Primary Examiner-John J. Gallagher
`Attorney, Agent, or Firm-Frishauf, Holtz, Goodman &
`Woodward
`[57]
`ABSTRACI'
`A method for preparing a copper-clad laminated board
`for a printed circuit board which comprises: (a) prepar(cid:173)
`ing a prepreg by permeating a thermosetting resin into
`a fabric and then drying the resulting material to a half(cid:173)
`hardened state, (b) laminating a both-side roughened
`copper foil on both sides or one side of the prep reg or a
`plurality of prepregs bonded together, (c) placing the
`resulting laminate from step (b) between both press
`plates of a press machine, (d) placing a polyamide film
`having a melting point equal to or higher than 170° C.
`between the exposed side of the both-side roughened
`copper foil of the laminate and a press plate, (e) pressing
`the laminate with the press plates of the press machine
`at a temperature of 170° C. or higher, a pressure of 10
`kgf!cm2 or higher for a time of 60 minutes or longer, (f)
`separating the laminate from the press machine and (g)
`peeling the polyamide film from the laminate to obtain
`the copper-clad laminated board. The copper-clad lami(cid:173)
`nated board can be used for a printed circuit board.
`
`13 Claims, No Drawings
`
`1 of 4
`
`FITBIT EXHIBIT 1009
`
`

`
`1
`
`5,286,330
`
`METHOD OF PRODUCING COPPER-CLAD
`LAMINATED BOARD
`
`2
`a CCLB for a printed circuit board comprises a step to
`press-mold the CCLB with a polyamide-type film hav(cid:173)
`ing a melting point equal to or higher than a lamination
`temperature placed between the BSRCF and the press
`BACKGROUND OF THE INVENTION
`5 plates. Generally the lamination temperature is 170" C.
`or higher.
`The present invention relates to a method of produc-
`Polyamide-type films to be used in this invention
`ing a copper-clad laminated board for a printed circuit
`include nylon 6 expressed by a chemical formula of
`board, which uses a mold releasing film, such as a polya-
`(-NH(CH2)sCO-),.or nylon 66 expressed by a chemi-
`mide-type ftlm.
`Methods of producing a copper-clad laminated board 10 cal formula of (-NH(CH2)6NHCO(CH2)4CO-)n,
`which can be formed into a film industrially. The polya-
`(hereinafter abbreviated as "CCLB") for a multi-lay-
`ered printed circuit board (hereinafter abbreviated as
`mide-type film has only to have a melting point equal to
`"MLPCB") include press molding of a both-side rough-
`or higher than a lamination temperature, and preferably
`ened copper foil (hereinafter abbreviated as "BSRCF")
`has a thickness of 10 to 100 JLm for easier handling,
`placed on a single prepreg therewith, and press molding 15 although not particularly limited thereto.
`of BSRCFs placed on both sides of a lamination of
`The measurement of the melting point of the polyam-
`multiple prepregs therewith. The roughening of a cop-
`ide is conducted by ASTMD 2117-64.
`per foil is performed to improve the bonding between
`The press molding of CCLB is usually carried out
`the copper foil and the prepreg.
`under conditions of a heating temperature of 170" C. or
`However, a BSRCF has a shortcoming that when it is 20 higher, a pressure of 10 kgf/cm2 or higher and a time of
`pressed with a prepreg, the fine ~gge?ne~s on the
`60 minutes or longer. Accordingly, the melting point of
`ro_ughened surface ?f ~he copper fall, wh1ch IS pressed
`a polyamide-type film is preferably 170" C. or higher in
`w1th a press plate, IS hke~y to be crushed.
`order to prevent adhesion of a portion of the film to the
`To prevent the crushmg of the ruggedness on the
`rugged portion on the surface of the BSRCF or to the
`surface ?fthe B~RCF, a metal ~lm such as a cop~er foil 25 press plate.
`or alummum fall, or a conventiOnally used orgamc film
`Even when the conventional type films other than a
`polyamide-type film have a melting point of 170" c. or
`such as polypr~pylene, polyethylene terephthalate,
`polyethylene,. tnphenylpentene or TEJ?RA (trade
`higher, a portion of the films sticks on the ruggedness of
`.
`.
`name of a resm film made by Du Pont) IS placed be-
`1 t
`f
`t
`d BSRCF t th
`f
`30 the BSRCF or 1s fused on the press plate, poss1bly for
`e lme 0 press
`weled~ a press P a e an a
`a
`the following reason. These films are inferior to a polya-
`til
`f
`. 1
`mo mg.
`. d
`.
`.
`Hereupon, prepregs were acquired by permeating a
`m1. e-type 1 m m c eavage, Impact resistance, racture
`thermosetting resin, such as phenolic resin, an epoxy
`resistance.
`.
`. .
`.
`.
`.
`A prepreg to be used 1~ th1s 1~vent10n IS acqu1red ~y
`resin, a polyimide resin, an epoxy modified polyimide
`resin or a cyanate ester resin, in a fabric or nonwoven 35 per:meatmg a the~osettm~ r~sm, s~ch as a phenoh_c
`resm, an ~P?XY re~m, a poly1m1de resm, an. ep?XY mod_J-
`fabric of a glass fiber, an aramid fiber, a polyester fiber,
`a carbon fiber or paper and drying the resultant struc-
`tied poly1m1de resm or a cyanate ester resm, m a fabnc
`or nonwoven fabric of a glass fiber, an aramid fiber, a
`ture.
`'
`'
`However when a metal foil is used when there is a
`polyester fiber, a carbon fiber, or paper, and drying the
`resin powd~r or the like remaining o~ the press plate, 40 resultant structure in a half hardened state.
`DETAILED DESCRIPTION OF THE
`the metal foil stick on the press plate at that remaining
`portion and remains as foreign matter on the press plate,
`PREFERRED EMBODIMENTS
`producing so-called stamping marks. Besides, when the
`Embodiments of the present invention will be more
`aforementioned plastic film is used, it does not have the
`desirable property of separation from the press plate. 45 specifically described below.
`Also, even when the plastic film is peeled off from the
`EXAMPLE 1
`BSRCF, printing of that film surface on the surface of
`With four glass epoxy prepregs EI-6765 (products of
`the BSRCF would be seen on the electron microscopic
`Sumitomo Bakelite, 180 JLm in thickness and a resin
`level due to cleavage fracture of the film used. This
`content of 45%) placed between BSRCFS, STD foils
`printing will have a bad effect upon the subsequent 50
`(products of Circuit Foil Japan), 70 JLm in thickness, the
`process of the molded CCLB.
`upper and lower copper foils were sandwiched by
`nylon 6 films (melting point of 220" C. and thickness of
`20 JLm) as a polyamide-type film, and the top and bot(cid:173)
`tom portions of the resultant structure were held with
`press plates and were press-molded at a heated tempera(cid:173)
`ture of 170" C. for 180 minutes. After the press molding,
`the product was separated from the press plates, and the
`peeling characteristic of the film from the copper foil
`and the easiness of separation of the film from the press
`plate were evaluated.
`
`SUMMARY OF THE INVENTION
`It is therefore an object of the present invention to
`provide a method of producing a copper-clad laminated 55
`board for a printed circuit board, which can maintain
`the ruggedness on the roughened surface of a BSRCF,
`which is opposite to the surface contacting with a pre(cid:173)
`preg, keeps the roughened surfaces from being stained,
`and is easily separable from a press plane.
`According to the present invention, in a step of yield(cid:173)
`ing a CCLB for a printed circuit board by laminating a
`BSRCF on both sides or one side of a single prepreg or
`bonded plural prepregs, said prepreg acquired by per(cid:173)
`meating a thermosetting resin in a fabric or nonwoven 65
`fabric and drying the resultant structure to a hard-hard(cid:173)
`ened state, and placing the resultant structure between
`press plates of a press machine; a method of producing
`
`60
`
`EXAMPLE2
`Example 2 was produced in the same manner as Ex(cid:173)
`ample 1 except for the use of nylon 66 film (melting
`point of 230• C. and thickness of 25 JLm) as a polyamide(cid:173)
`based film, and the same evaluation as made for Exam(cid:173)
`ple 1 was also conducted.
`
`2 of 4
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`

`
`5,286,330
`
`3
`COMPARATIVE EXAMPLE 1
`Comparative Example 1 was produced in the same
`manner as Example 1 except that nothing was placed
`between the copper foil and the press plate, and the 5
`same evaluation as made for Example 1 was also con(cid:173)
`ducted.
`
`COMPARATIVE EXAMPLE 2
`Comparative Example 2 was produced in the same 10
`manner as Example 1 except that the film of Example 1
`was changed to an aluminum foil 100 JLm in thickness,
`and the same evaluation as made for Example 1 was also
`conducted.
`
`15
`
`COMPARATIVE EXAMPLE 3
`Comparative Example 3 was produced in the same
`manner as Example 1 except for the replacement of the
`film of Example 1 with polyethylene terephthalate film
`(melting point of 250• C. and thickness of 37 JLm) , and 20
`the same evaluation as made for Example 1 was also
`conducted.
`
`COMPARATIVE EXAMPLE 4
`Comparative Example 4 was produced in the same 25
`manner as Example 1 except for the replacement of the
`film of Example 1 with triphenylpentene (melting point
`of 210" C. and thickness of 30 JLm), and the same evalua(cid:173)
`tion as made for Example 1 was also conducted.
`The results of the evaluation on Examples 1 and 2 and 30
`Comparative Examples 1 to 4 are shown in Table 1
`below.
`
`4
`
`What is claimed is:
`1. A method for preparing a copper-clad laminated
`board for a printed circuit board which comprises:
`(a) preparing a prepreg by permeating a thermoset(cid:173)
`ting resin into a fabric and then drying the resulting
`material to a half-hardened state,
`(b) laminating a both-side roughened copper foil on
`both sides or one side of the prepreg or plurality of
`prepegs bonded together, whereby a side of the
`roughened copper foil is exposed,
`(c) placing the result laminate from step (b) between
`both press plates of a press machine,
`(d) placing a polyamide film having a melting point
`equal to or higher than 170• C. between the ex(cid:173)
`posed side of the both-side roughened copper foil
`of the laminate and a press plate,
`(e) pressing the laminate with the press plates of the
`press machine at a temperature of 170' C. or
`higher, a pressure of 10 kgf/cm2 or higher for a
`time of 60 minutes or longer,
`(f) separating the laminate from the press machine
`and
`(g) peeling the polyamide film from the laminate to
`obtain the copper-clad laminated board.
`2. The method according to claim 1, wherein the
`fabric is a nonwoven fabric.
`3. The method according to claim 1, wherein the
`polyamide-type film is selected from the group consist(cid:173)
`ing of a nylon 6 film and a nylon 66 film.
`4. The method according to claim 1, wherein the
`polyamide-type film has a thickness of 10 to 100 JLm.
`5. The method according to claim 3, wherein the
`
`Material
`for Pro-
`tection
`Film
`
`TABLE 1
`Peeling
`Property
`to Cop-
`per Foil
`
`Remainder
`on Copper
`Foil
`
`Shape of
`Ruggedness
`on Copper
`Foil
`
`No change
`No change
`Crush
`occurred
`No change
`
`Separation
`Property
`to Press
`Plate
`
`X
`
`X
`
`None
`None
`None
`
`Present
`
`X
`
`Present
`
`No change
`
`X
`
`Present
`
`No change
`
`X
`
`Nylon 6
`Example I
`Nylon 66
`Example 2
`Comparative None
`Example 1
`Comparative Aluminum
`Example 2
`foil
`Comparative Poly-
`Example 3
`ethylene
`tereph-
`thalate
`Comparative Triphenyl·
`Example 4
`pentene
`
`Evaluated on'
`I. Peelina property to copper foiL
`'' No film ldherina to copper foil
`x, Film ldhered to copper foil
`2. Remainder on COJ>peT foil'
`Oboerved with an electron microscope (X 2000)
`3. Shape of rvaednas 011 copper foil'
`Oboerved with an electron microscope (X 2000)
`4. Seperation property to press plate'
`,, No film or foil remainina on press plate
`x, Film or foil romaiDed on p,.... plate
`
`The production method of the present invention to
`provide a method of producing a copper-clad laminated
`board for a printed circuit board, which can prevent the 60
`film from being stuck on the BSRCF or prepreg, can
`maintain the ruggedness on that roughened surface of
`the BSRCF, which is opposite to the surface contacting
`with the prepreg, and can facilitate production of a
`CCLBs with both sides roughened for a printed circuit 65
`board, which has an excellent separation property with
`respect of the press plate. This method is therefore
`suitable for mass production of BSRCFs at a low cost.
`
`fabric is a nonwoven fabric.
`6. The method according to claim 4, wherein the
`fabric is a nonwoven fabric.
`7. The method according to claim 3, wherein the
`polyamide film has a thickness of 10 to 100 JLID.
`8. The method according to claim 7, wherein the
`fabric is a non-woven fabric.
`9. The method according to claim 7, wherein the
`thermosetting resin is selected from the group consist(cid:173)
`ing of a phenolic resin, an epoxy resin, a polyimide resin
`and a cyanate ester resin.
`
`3 of 4
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`

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`5,286,330
`
`5
`10. The method according to claim 7, wherein the
`thermosetting resin is an epoxy modified polyimide
`resin.
`11. The method according to claim 9, wherein the
`fabric is a fabric of a glass fiber, an aramid fiber, a poly- 5
`ester fiber, a carbon fiber or paper.
`12. The method according to claim 1, wherein the
`thermosetting resin is an epoxy resin, the polyamide-
`
`6
`type film is made from nylon 6, the temperature is 170°
`C. and the time is 180 minutes.
`13. The method according to claim 1, wherein the
`thermosetting resin is an epoxy resin, the polyamide(cid:173)
`type film is nylon 66, the temperature is 170° C. and the
`time is 180 minutes.
`* * * * *
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`4 of 4