JPH0732541A - Manufacturing method of metal foil clad laminate - Google Patents

Abstract

(57) [Abstract] [Purpose] As a laminated board suitable for SMD-compatible printed wiring boards, the elasticity in the surface direction is reduced to improve the solder connection reliability of SMDs, but at the same time, the insulation and heat resistance are improved. Provided is a laminate having a metal foil peeling strength secured. [Structure] A glass woven fabric constituting the surface layer of the laminated plate,
Pretreatment is performed with a varnish containing (A) acrylonitrile butadiene rubber, (B) alkylphenol resin, (C) epoxy resin, and (D) aluminum hydroxide. The compounding ratio is a solid weight ratio, (A) / (B) = 75/25 to 90
/ 10, (C) / ((A) + (B)) = 60/40 to 8
0/20, solid weight of ((A) + (B) + (C)) 10
(D) is 10 to 40 parts by weight with respect to 0. The amount of resin adhered to the glass woven fabric is 30% by weight or less by the pretreatment.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to surface mount parts (hereinafter,
A method for manufacturing a laminated board suitable as a material for a printed wiring board on which "SMD" is mounted.

[0002]

2. Description of the Related Art With the recent trend toward higher density, higher integration and smaller size of electronic and electrical equipment, components mounted on a printed wiring board to be incorporated therein are also changed from insertion type discrete components to surface mount type SMDs. Is moving to. As for the SMD compatible printed wiring board,
There is a problem of reliability of the solder connection portion between the SMD and the printed wiring. That is, the coefficient of thermal expansion in the plane direction of the laminated board which is the substrate of the printed wiring is considerably larger than the coefficient of thermal expansion of SMD (the coefficient of thermal expansion of SMD = 4 to 6 ppm, the coefficient of thermal expansion of the substrate = 15 to 25 ppm). Therefore, when the cooling / heating cycle is repeated, the stress caused by the difference in the coefficient of thermal expansion acts on the solder connection portion each time, and the solder connection portion is likely to be cracked. Therefore, the elasticity of the laminated plate, which is the substrate material of the printed wiring board, is reduced in the plane direction, and the stress due to the difference in the thermal expansion coefficient between the SMD and the substrate is relaxed by the low-elasticity substrate, and the solder connection part has a large It is considered to prevent the stress from working. The laminated plate is manufactured by impregnating a sheet-shaped base material with a thermosetting resin that is a matrix resin, and stacking and stacking the heat-pressurized resin and heat-pressing it together with a metal foil. Techniques for lowering the elastic modulus have been studied by simply adding or by reacting the added flexibility-imparting agent with a matrix resin or a curing agent. In addition, when an inorganic filler is contained, it has been studied to make the inorganic filler finer and spherical.

[0003]

However, although the elastic modulus of the laminated board can be lowered by the above-mentioned conventional technique for lowering elasticity, another characteristic required for the substrate of the printed wiring board, that is, heat resistance is required. Also, there is a problem that the peeling strength of the metal foil is reduced. The problem to be solved by the present invention is, as a laminated board suitable for a substrate of an SMD-compatible printed wiring board, a low elasticity required for ensuring solder connection reliability, as well as heat resistance, insulation and metal foil drawing. It is to secure peeling strength.

[0004]

In order to solve the above-mentioned problems, the first manufacturing method according to the present invention is to impregnate a sheet-like base material made of glass fiber with a thermosetting resin, and stack the same on top of the metal to form a metal. A laminated sheet to be heat-press molded together with a foil, in the production of a laminated sheet in which the sheet-shaped base material of the surface layer is made of glass woven fabric, before impregnation of the thermosetting resin, a glass woven fabric to be arranged in at least the surface layer, Pretreatment with a varnish of the composition containing (A) to (D) below. (A) Acrylonitrile butadiene rubber (B) Alkylphenol resin (C) Epoxy resin (D) Inorganic filler Here, the use ratio of (A) and (B) is a solid weight ratio,
(A) / (B) = 75/25 to 90/10. Further, the use ratio of the total amount of (C) and ((A) + (B)) is a solid weight ratio, (C) / ((A) + (B)) = 60/4
0 to 80/20. Furthermore, ((A) + (B) +
The use ratio of (D) is set to 10 to 40 parts by weight based on 100 parts of the total solid weight of (C)). The amount of resin adhered to the sheet-shaped base material (including the inorganic filler; the same applies hereinafter) in the pretreatment is set to 30% by weight or less. The amount of resin adhered to the sheet-shaped substrate in the pretreatment is preferably 10 to 30% by weight.

The second manufacturing method according to the present invention is a laminated plate in which a sheet-like base material made of glass fibers is impregnated with a thermosetting resin, and the thermosetting resin is laminated and heat-pressed together with a metal foil. In the production of a laminated plate in which the sheet-shaped base material is made of glass woven cloth, the following (A), (B) and (D) are blended with at least the thermosetting resin impregnated in the glass woven cloth arranged in the surface layer. (A) Acrylonitrile butadiene rubber (B) Alkylphenol resin (D) Inorganic filler Here, the use ratio of (A) and (B) is a solid type weight ratio,
(A) / (B) = 75/25 to 90/10. Further, with respect to the solid weight of 100 parts of the thermosetting resin,
The use ratio of the total amount of ((A) + (B)) is 40 parts by weight or less. Then, (the thermosetting resin + (A) +
The use ratio of (D) is 10 to 40 parts by weight based on 100 parts by weight of the total solid weight of (B)). The use ratio of the total amount of ((A) + (B)) to the solid weight of 100 parts of the thermosetting resin is preferably 20 to 40 parts by weight.

[0006]

In the first production method according to the present invention, in the pre-impregnation, the combined use of (A), (B), (C) and (D) makes it possible to reduce the elasticity without deteriorating the characteristics required as a printed wiring board. In order to ensure the solder connection reliability as an SMD-compatible substrate. By the way, (A) alone (C)
When used in combination with, the heat resistance and flame retardancy of the laminated plate are lowered, and the compatibility at the time of compounding the resin is lacking. But,
The combined use of (B) improves the compatibility between (A) and (C), and the addition of (D) improves the heat resistance of the laminate.
The flame resistance is secured. The reason for limiting the ratio of the amounts of (A), (B), (C), and (D) used is as follows.
First, if the proportion of (A) is high and the proportion of (B) is low, the compatibility at the time of resin blending will be poor, and the moisture-proof insulating property of the laminate will be poor. When the ratio of (A) is low and the ratio of (B) is high, the elastic modulus of the laminated plate is high, and the object of the present invention cannot be achieved. Next, when the amount of (C) is small and the total amount of ((A) + (B)) is large, the moisture-proof insulating property of the laminate, the heat resistance, and the adhesiveness of the metal foil are deteriorated. Many (C) ((A) +
When the total amount of (B)) is small, the elastic modulus of the laminated plate becomes high and the object of the present invention cannot be achieved. Furthermore, when the amount of (D) added is small, the flame resistance of the laminated plate is reduced. If the resin adhesion amount exceeds 30% by weight in the pre-impregnation, the moisture-proof insulating property of the laminate, the heat resistance and the adhesive strength of the metal foil deteriorate. In the second manufacturing method according to the present invention, the ratio of the amounts of (A), (B) and (D) used with respect to the thermosetting resin is limited for the same reason as above.

[0007]

EXAMPLE The sheet-like substrate made of glass fiber used in the present invention is a glass woven fabric, a glass nonwoven fabric, a glass-paper mixed nonwoven fabric, or the like. Further, as the thermosetting resin, an epoxy resin, a phenol resin, a urea resin, a polyimide, a polyester or the like can be appropriately used. These thermosetting resins include inorganic fillers (Al ₂ O ₃ , Al ₂ O ₃ · H ₂ O, Al ₂ O ₃ ) for the purpose of quality improvement, workability improvement, cost reduction, etc.
O ₃ · 3H ₂ O, talc, MgO, may be blended SiO _2, etc.). The laminated sheet produced by the method according to the present invention may be a laminated sheet of a composite type in which the sheet-shaped substrate is a combination of a glass woven fabric and a glass nonwoven fabric, or a type of a glass woven fabric alone. It also includes a laminated board for a multilayer printed wiring board. The acrylonitrile butadiene rubber used in the method according to the present invention is preferably of a type having a carboxyl group or a glycidyl group at the terminal, but is not particularly limited. The epoxy resin used in the method according to the present invention is preferably a bisphenol A type epoxy resin, a phenol novolac type epoxy resin, or a cresol novolac type epoxy resin, but is not particularly limited. The alkylphenol resin used in the method according to the present invention has, as an alkyl group,
Those having a methyl group, an ethyl group, a propyl group, or an isopropyl group are preferable, but not particularly limited thereto, and they can be used as a mixture with a phenol resin.

(Explanation of Examples Corresponding to Claims 1 to 2) Examples 1 to 9 and Comparative Examples 1 to 7 Carboxyl Acrylonitrile Butadiene Rubber with Both Terminals (“CTBN” manufactured by Ube Industries), alkylphenol resin (alkyl group: Isopropyl group, "Permanol 100" manufactured by Mitsui Toatsu Chemicals, bisphenol A type epoxy resin ("Ep-828" manufactured by Yuka Shell Epoxy), and aluminum hydroxide as an inorganic filler are shown in Tables 1 and 2. A varnish (A) for pre-impregnation was prepared by dissolving it in a diluting solvent methyl ethyl ketone in an amount and adding dicyandiamide as a curing agent. Unit weight of the above varnish (A) is 20
A glass fiber woven cloth of 5 g / m ² was pre-impregnated and dried to obtain a prepreg (A) having each resin adhesion amount shown in Table 1 and Table 2. Further, the separately prepared bisphenol A type epoxy resin varnish (B) was impregnated into the prepreg (A) and dried to obtain a prepreg (B) having a total resin adhesion amount of 40% by weight. In addition, an inorganic filler (Al ₂ O ₃ or Al ₂ O ₃・ 3
H ₂ O) -blended bisphenol A type epoxy resin varnish (resin / filler = 100/50 by solid weight) is impregnated into a glass nonwoven fabric having a unit weight of 50 g / m ² and dried to obtain a resin adhesion amount of 84% by weight. A prepreg (C) was obtained. 6 plies of prepreg (C) are piled up and prepreg (B) is placed on both sides.
Was placed 1 ply on each side, and a copper foil having a thickness of 18 μm was placed on both sides, and a 1.6 mm thick composite type copper-clad laminate was obtained by heat and pressure lamination molding.

Conventional Example 1 Substantial example 1 except that the varnish (A) was not pre-impregnated.
A 1.6 mm thick composite type copper-clad laminate was obtained in the same manner as in.

[0010]

[Table 1]

[0011]

[Table 2]

Tables 3 and 4 show the characteristics of each of the above laminated plates. From the comparison of Examples 1, 4, and 9 in which only the resin adhesion amount is changed, it is understood that the resin adhesion amount is more preferably 10% by weight or more. In Tables 3 and 4, each property was measured as follows. Copper foil peel strength: JIS method Insulation resistance: Measured after pressure cooker treatment (121 ° C, 2 atm, 6 hr) Soldering heat resistance: Measure the time until blistering occurs by dipping a normal sample in a solder bath at 300 ° C Solder crack : Surface mount # 3125 chip at -30 ℃
Rate of cracking after 1000 cycles of cold heat and 120 ° C (n = 100) Tracking resistance: CTI value by IEC method

[0013]

[Table 3]

[0014]

[Table 4]

Examples 10 to 18 and Comparative Examples 8 to 14 Quartz powder was used in place of aluminum hydroxide as the inorganic filler of the varnish (A) in Examples 1 to 9 and Comparative Examples 1 to 7 shown in Tables 5 and 5. A varnish (C) for pre-impregnation having the compounding amount shown in 6 was prepared. Using the varnish (C) for pre-impregnation, a composite type copper-clad laminate having a thickness of 1.6 mm was obtained in the same manner as in the above-mentioned examples.

[0016]

[Table 5]

[0017]

[Table 6]

Examples 10-18, Comparative Examples 8-14,
Tables 7 and 8 show the characteristics of each laminate of Conventional Example 1. The measuring method of each characteristic is as described in Table 3.

[0019]

[Table 7]

[0020]

[Table 8]

(Explanation of Examples Corresponding to Claims 3 to 4) Examples 19 to 25, Comparative Examples 15 to 19 Bisphenol A type epoxy resin is used, and both ends carboxylated acrylonitrile butadiene rubber (“C manufactured by Ube Industries”
TBN "), alkylphenol resin (alkyl group: isopropyl group," Permanol 10 "manufactured by Mitsui Toatsu Chemicals, Inc.
0 ") and aluminum hydroxide as an inorganic filler in the compounding amounts shown in Tables 9 and 10 to prepare a varnish (D). In the table, the total of both ends carboxylated acrylonitrile butadiene rubber and alkylphenol resin (A +
The blending amount of B) is the weight based on 100 parts by weight of the bisphenol A type epoxy resin in solid form. Further, in the table, the blending amount of aluminum hydroxide (D) is the weight based on 100 parts by weight of the total solid weight of the bisphenol A type epoxy, the carboxyl acrylonitrile butadiene rubber having carboxyl groups at both ends and the alkylphenol resin. Unit weight 205g / m ²
The above woven cloth was impregnated with the above varnish (D) and dried to obtain a prepreg (D) having a resin adhesion amount of 40% by weight. Six plies of prepreg (C) are stacked, one ply of prepreg (D) is placed on each side of the ply, and the thickness is 18 μm on each side.
Place the copper foil and heat and pressure laminate molding to a thickness of 1.6m
A composite type copper clad laminate of m was obtained.

[0022]

[Table 9]

[0023]

[Table 10]

The characteristics of the laminates of Examples 19 to 25, Comparative Examples 15 to 19 and Conventional Example 1 are shown in Tables 11 and 12. The measuring method of each characteristic is as described in Table 3.
From the comparison of Examples 19, 22 and 25 in which the compounding amount of (A + B) with respect to the bisphenol A type epoxy resin was changed,
It can be seen that the blending amount of (A + B) is more preferably 20 parts by weight or more.

[0025]

[Table 11]

[0026]

[Table 12]

Examples 26 to 32, Comparative Examples 20 to 24 Table 13 and Table 13 show quartz powder instead of aluminum hydroxide as the inorganic filler of the varnish (D) in Examples 19 to 25 and Comparative Examples 15 to 19 described above. A varnish (E) having a compounding amount shown in 14 was prepared. In the table, the total amount (A + B) of both-terminal-carboxylated acrylonitrile-butadiene rubber and the alkylphenol resin is the weight based on 100 parts by weight of the bisphenol A type epoxy resin in solid form. Also,
In the table, the blending amount of the quartz powder (D) is the total solid weight of the bisphenol A type epoxy, the carboxyl acrylonitrile butadiene rubber at both ends and the alkylphenol resin, which is 1
It is the weight with respect to 00 parts. Using the varnish (E), a composite type copper-clad laminate having a thickness of 1.6 mm was obtained in the same manner as in the above examples.

[0028]

[Table 13]

[0029]

[Table 14]

Tables 15 and 16 show the characteristics of the laminates of Examples 26 to 32, Comparative Examples 20 to 24, and Conventional Example 1. The measuring method of each characteristic is as described in Table 3.

[0031]

[Table 15]

[0032]

[Table 16]

[0033]

As described above, according to the method of the present invention, as a laminated board used for the substrate of the SMD compatible printed wiring board, the plane direction necessary for ensuring the solder connection reliability of the SMD is centered. In addition to the low elasticity, heat resistance, moisture insulation resistance, and metal foil peeling strength could be secured. By ensuring the moisture-proof insulation, it becomes possible to provide through-holes with a narrow pitch, and it is possible to manufacture a SMD compatible printed wiring board with a higher density than in the past.

Claims (4)

[Claims] 1. A laminated plate comprising a glass fiber sheet-like base material impregnated with a thermosetting resin, which is laminated with a metal foil under heat and pressure, wherein the surface layer sheet-like base material is made of a glass woven cloth. In the production of the laminated sheet, the glass woven cloth to be arranged on at least the surface layer is impregnated with the thermosetting resin, (A) acrylonitrile butadiene rubber, (B) alkylphenol resin, (C) epoxy resin, (D) inorganic Pretreatment with a varnish of a composition containing a filler, and the use ratio of (A) and (B) in solid weight ratio is (A)
/ (B) = 75/25 to 90/10, and the use ratio of the total amount of (C) and ((A) + (B)) is (C) / ((A) + (B)) = 60/4
0 to 80/20, and the proportion of (D) used is 10 to 40 with respect to 100 parts by weight of the total solid amount of ((A) + (B) + (C)).
A method for producing a metal foil-clad laminate, characterized in that the amount of the resin adhered to the sheet-shaped substrate (including the inorganic filler) in the pretreatment is 30% by weight or less in addition to the amount by weight. 2. The method for producing a metal foil-clad laminate according to claim 1, wherein the amount of resin adhered to the sheet-shaped substrate (including the inorganic filler) in the pretreatment is 10 to 30% by weight. . 3. A laminated plate in which a sheet-like base material made of glass fiber is impregnated with a thermosetting resin, and is laminated with a metal foil by heating and pressing, and the sheet-like base material of the surface layer is made of glass woven cloth. In the production of a laminated sheet consisting of: (A) acrylonitrile butadiene rubber, (B) an alkylphenol resin, and (D) an inorganic filler are blended with the thermosetting resin impregnated in at least the glass woven fabric arranged in the surface layer, The use ratio of (A) and (B) in solid weight ratio is (A)
/ (B) = 75/25 to 90/10, and with respect to 100 parts by solid weight of the thermosetting resin, ((A)
+ (B)) is used in an amount of 40 parts by weight or less, and (D) is used for 100 parts by weight of the total amount of (the thermosetting resin + (A) + (B)). A method for producing a metal foil-clad laminate, wherein the ratio is 10 to 40 parts by weight. 4. A solid weight of 100 parts of thermosetting resin,
The method for producing a metal foil-clad laminate according to claim 3, wherein the use ratio of the total amount of ((A) + (B)) is 20 to 40 parts by weight.