JP2935329B2 - Manufacturing method of metal foil clad laminate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
The present invention relates to a method for manufacturing a laminated board suitable as a material for a printed wiring board on which a SMD is mounted.

[0002]

2. Description of the Related Art In recent years, with the increase in density, integration, and miniaturization of electronic and electric equipment, the components mounted on a printed wiring board have been changed from insertion type discrete components to surface mount type SMDs. Is shifting to. Things to be aware of as an SMD compatible printed wiring board
There is a problem of the reliability of the solder connection between the SMD and the printed wiring. That is, the thermal expansion coefficient in the plane direction of the laminate, which is the substrate of the printed wiring, is considerably larger than the thermal expansion coefficient of the SMD (the thermal expansion coefficient of the SMD = 4 to 6 ppm, the thermal expansion coefficient of the substrate = 15 to 25 ppm). Therefore, when the cooling / heating cycle is repeated, the stress due to the difference in the coefficient of thermal expansion acts on the solder connection portion each time, and the solder connection portion is easily cracked. Therefore, by reducing the elasticity in the plane direction of the laminated board, which is the substrate material of the printed wiring board, the stress caused by the difference in the thermal expansion coefficient between the SMD and the board is reduced by the low-elasticity board, so that the solder connection portion has a large elasticity. It is considered that the stress does not work. The laminate is manufactured by impregnating a sheet-like base material with a thermosetting resin as a matrix resin, laminating the sheet-like materials together with a metal foil, and then press-molding the same together with a metal foil. A technology for lowering the elastic modulus by simply adding or reacting the added flexibility imparting agent with a matrix resin or a curing agent has been studied. In the case where an inorganic filler is contained, atomization and spheroidization of the inorganic filler have been studied.

[0003]

However, in the above-mentioned conventional low elasticity technology, although the elastic modulus of the laminated board can be reduced, other characteristics required as a substrate of a printed wiring board, that is, heat resistance, In addition, there is a problem that the peel strength of the metal foil is reduced. The problem to be solved by the present invention is to provide a laminated board suitable for a substrate of an SMD-compatible printed wiring board, as well as a low elasticity required for securing the reliability of solder connection, as well as heat resistance, insulation and metal foil drawing. It is to secure the peeling strength.

[0004]

In order to solve the above-mentioned problems, a first production method according to the present invention comprises impregnating a sheet-like base material made of glass fiber with a thermosetting resin, and stacking the same to form a metal. In the laminate to be heated and pressed together with the foil, in the production of a laminate in which the sheet-like substrate of the surface layer is made of a glass woven fabric, before impregnation of the thermosetting resin, a glass woven fabric to be arranged at least on the surface layer, A preliminary treatment is performed with a varnish of the composition containing the following (A) to (D). (A) Acrylonitrile butadiene rubber (B) Alkylphenol resin (C) Epoxy resin (D) Inorganic filler Here, the usage ratio of (A) and (B) is a solid weight ratio,
(A) / (B) = 75/25 to 90/10. The usage ratio of the total amount of (C) and ((A) + (B)) is a solid weight ratio, and (C) / ((A) + (B)) = 60/4.
0 to 80/20. Furthermore, ((A) + (B) +
The use ratio of (D) is 10 to 40 parts by weight with respect to 100 parts of the total solid weight of (C)). In the pretreatment, the amount of resin adhered to the sheet-like base material (including an inorganic filler, the same applies hereinafter) is set to 30% by weight or less. The amount of resin adhered to the sheet-like substrate in the pretreatment is preferably 10 to 30% by weight.

A second production method according to the present invention is a laminate prepared by impregnating a thermosetting resin into a sheet-like base material made of glass fiber, laminating the thermosetting resin together with a metal foil and press-molding the same together with a metal foil. In the production of a laminate in which the sheet-like substrate is made of a glass woven fabric, the following (A), (B) and (D) are blended with at least the thermosetting resin impregnated in the glass woven fabric disposed on the surface layer. (A) Acrylonitrile butadiene rubber (B) Alkylphenol resin (D) Inorganic filler Here, the usage ratio of (A) and (B) is a solid weight ratio,
(A) / (B) = 75/25 to 90/10. Further, with respect to the solid weight of 100 parts of the thermosetting resin,
The usage ratio of the total amount of ((A) + (B)) is set to 40 parts by weight or less. And (the thermosetting resin + (A) +
The use ratio of (D) is 10 to 40 parts by weight with respect to 100 parts 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 elasticity can be reduced without deteriorating the characteristics required for the printed wiring board by using (A), (B), (C) and (D) together. Therefore, the solder connection reliability is ensured as an SMD compatible substrate. By the way, (A) alone (C)
When used in combination, the heat resistance and flame retardancy of the laminate are reduced, and the compatibility at the time of compounding the resin is lacking. But,
The compatibility of (A) and (C) is improved by the combined use of (B), and the heat resistance of the laminate is improved by adding (D).
Ensures flame retardancy. The ratio of the amounts used in (A), (B), (C) and (D) is limited for the following reason.
First, when the proportion of (A) is large and the proportion of (B) is small, the compatibility at the time of compounding the resin is inferior, and the moisture-resistant insulation properties of the laminate are reduced. If the proportion of (A) is small and the proportion of (B) is large, the elastic modulus of the laminate becomes 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-resistant insulation properties, heat resistance, and adhesiveness of the metal foil of the laminate decrease. Many (C) ((A) +
If the total amount of (B)) is small, the elastic modulus of the laminate becomes high, and the object of the present invention cannot be achieved. Further, when the amount of (D) is small, the flame resistance of the laminate decreases. If the resin adhesion amount exceeds 30% by weight in the pre-impregnation, the moisture-resistant insulation properties, heat resistance and adhesive strength of the metal foil of the laminate decrease. In the second production method according to the present invention, the ratio of the amounts of (A), (B) and (D) used is limited to the thermosetting resin for the same reason as described above.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Sheet-like substrates made of glass fibers used in the present invention include glass woven fabric, glass non-woven fabric, glass-paper mixed non-woven fabric and the like. 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, quality improvement, improvement of workability, the purpose of cost reduction, the inorganic filler _{(Al 2 O 3, Al 2} O 3 · H 2 O, Al 2
O ₃ .3H ₂ O, talc, MgO, SiO _2, etc.). The laminate manufactured by the method according to the present invention may be a composite type in which the sheet-like substrate is made of a combination of a glass woven fabric and a glass nonwoven fabric, or a type in which the glass woven fabric is used alone. It also includes a laminate 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 a 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 novolak type epoxy resin, or a cresol novolak type epoxy resin, but is not particularly limited. The alkylphenol resin used in the method according to the present invention, as an alkyl group,
Those having a methyl group, an ethyl group, a propyl group, and an isopropyl group are desirable, but are not particularly limited, and 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 Carboxylated acrylonitrile butadiene rubber at both ends ("CTBN" manufactured by Ube Industries, Ltd.), alkylphenol resin (alkyl group: An isopropyl group, "Permanol 100" manufactured by Mitsui Toatsu Chemicals, a bisphenol A type epoxy resin ("Ep-828" manufactured by Yuka Shell Epoxy), and aluminum hydroxide as an inorganic filler, as shown in Tables 1 and 2 The varnish (A) for pre-impregnation was prepared by dissolving the above solution in the dilution solvent methyl ethyl ketone and adding dicyandiamide as a curing agent. The above varnish (A) is unit weight 20
5 g / m ² glass fiber woven fabric was pre-impregnated and dried to obtain prepregs (A) having the respective resin adhesion amounts shown in Tables 1 and 2. Further, the prepreg (A) was impregnated and dried with a separately prepared bisphenol A epoxy resin varnish (B) 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 The ₂ O) bisphenol A type epoxy resin varnish obtained by blending the (solid weight of resin / filler = 100/50), the unit weight 50 g / m ² was impregnated dried glass nonwoven fabric, a resin adhesion amount 84 wt% of A prepreg (C) was obtained. 6 layers of prepreg (C), prepreg (B) on both sides
Were placed one by one, 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-press lamination.

Conventional Example 1 Substantially Example 1 except that pre-impregnation of varnish (A) was not performed.
In the same manner as in the above, a composite type copper-clad laminate having a thickness of 1.6 mm was obtained.

[0010]

[Table 1]

[0011]

[Table 2]

Tables 3 and 4 show the characteristics of each of the above laminates. Comparison of Examples 1, 4, and 9 in which only the resin adhesion amount was changed shows that the resin adhesion amount is more preferably 10% by weight or more. In Tables 3 and 4, each characteristic was measured as follows. Copper foil peel strength: JIS method Insulation resistance: Measured after pressure cooker treatment (121 ° C., 2 atm, 6 hr) Solder heat resistance: Measured time until blistering occurs when a normal sample is immersed in a 300 ° C. solder bath : -30 ° C with # 3125 chip mounted on the surface
Rate after 1000 cycles of repeated heating and cooling at 120 ° C. (n = 100) Tracking resistance: CTI value by IEC method

[0013]

[Table 3]

[0014]

[Table 4]

Examples 10 to 18, Comparative Examples 8 to 14 The varnish (A) in Examples 1 to 9 and Comparative Examples 1 to 7 was replaced with aluminum hydroxide by using quartz powder instead of aluminum hydroxide. A varnish (C) for pre-impregnation having the compounding amount shown in No. 6 was prepared. The varnish (C) was used for pre-impregnation, and a 1.6 mm-thick composite-type copper-clad laminate was obtained in the same manner as in the above examples.

[0016]

[Table 5]

[0017]

[Table 6]

Examples 10 to 18 and Comparative Examples 8 to 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 and Comparative Examples 15 to 19 Bisphenol A type epoxy resin was added to both ends carboxylated acrylonitrile butadiene rubber ("C" manufactured by Ube Industries, Ltd.)
TBN ”), an alkylphenol resin (alkyl group: isopropyl group,“ Permanol 10 ”manufactured by Mitsui Toatsu Chemicals, Inc.
0 ") and aluminum hydroxide as an inorganic filler in the amounts shown in Tables 9 and 10 to prepare a varnish (D). In the table, the total of the carboxylated acrylonitrile butadiene rubber at both ends and the alkylphenol resin (A +
The blending amount of B) is the weight based on 100 parts by weight of the solidified bisphenol A type epoxy resin. In the table, the amount of aluminum hydroxide (D) is the weight based on the total solid weight of 100 parts of the bisphenol A type epoxy, the carboxylated acrylonitrile butadiene rubber at both ends and the alkylphenol resin. Unit weight 205 g / m ²
The varnish (D) was impregnated and dried on the glass woven fabric of Example 1 to obtain a prepreg (D) having a resin adhesion amount of 40% by weight. Six layers of prepreg (C) are stacked, one ply of prepreg (D) is arranged on each side, and a thickness of 18 μm is further formed on both sides.
1.6m thick by heat and pressure lamination molding
Thus, a composite type copper-clad laminate of m was obtained.

[0022]

[Table 9]

[0023]

[Table 10]

Tables 11 and 12 show the characteristics of the laminates of Examples 19 to 25, Comparative Examples 15 to 19, and Conventional Example 1. The measuring method of each characteristic is as described in Table 3.
From the comparison of Examples 19, 22, and 25 in which the amount of (A + B) was changed with respect to the bisphenol A type epoxy resin,
It is understood 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 The varnish (D) in Examples 19 to 25 and Comparative Examples 15 to 19 was replaced with aluminum hydroxide by quartz powder instead of aluminum hydroxide. A varnish (E) having the blending amount shown in 14 was prepared. In the table, the compounding amount of the total (A + B) of the carboxylated acrylonitrile butadiene rubber at both ends and the alkylphenol resin is the weight with respect to the solid weight of 100 parts of the bisphenol A type epoxy resin. Also,
In the table, the blending amount of the quartz powder (D) is the total solid weight of bisphenol A type epoxy, acrylonitrile butadiene rubber with carboxylated at both terminals and alkylphenol resin of 1
The weight is based on 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 according to the present invention, the laminated board used for the substrate of the SMD-compatible printed wiring board is centered on the plane direction necessary for securing the solder connection reliability of the SMD. In addition to lowering the elasticity, it was possible to secure heat resistance, moisture-resistant insulation, and metal foil peeling strength. By securing the moisture-resistant insulation, it is 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 before.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) B32B 1/00-35/00 H05K 1/03

Claims (4)

(57) [Claims] 1. A laminated board in which a thermosetting resin is impregnated into a sheet-like base material made of glass fiber, which is laminated and heated and pressed together with a metal foil, wherein the sheet-like base material of the surface layer is made of glass woven fabric. Before the impregnation of the thermosetting resin, the glass woven fabric to be disposed at least on the surface layer is made of (A) an acrylonitrile butadiene rubber, (B) an alkylphenol resin, (C) an epoxy resin, and (D) an inorganic resin. The composition is preliminarily treated with a varnish of a composition containing a filler, and the use ratio of the above (A) and (B) is expressed by a solid weight ratio of (A)
/ (B) = 75/25 to 90/10, and the use ratio of the total amount of the above (C) and ((A) + (B)) is expressed as (C) / ((A) + (B)) = 60/4
0 to 80/20, and the use ratio of (D) is 10 to 40 with respect to 100 parts of the total solid weight of ((A) + (B) + (C)).
A method for producing a metal foil-clad laminate, wherein the amount is in terms of parts by weight and the amount of resin adhered to a sheet-like substrate (including an inorganic filler) in the pretreatment is 30% by weight or less. 2. The method for producing a metal-foil-clad laminate according to claim 1, wherein the amount of resin adhered to the sheet-like substrate (including an inorganic filler) in the pretreatment is 10 to 30% by weight. . 3. A laminated sheet in which a thermosetting resin is impregnated into a sheet-like base material made of glass fiber, which is laminated and heated and pressed together with a metal foil, wherein the sheet-like base material of the surface layer is made of glass woven fabric. In the production of a laminated board, (A) acrylonitrile butadiene rubber, (B) an alkylphenol resin, and (D) an inorganic filler are blended with at least the thermosetting resin impregnated in the glass woven fabric disposed on the surface layer. The use ratio of (A) and (B) is expressed as solid weight ratio, (A)
/ (B) = 75/25 to 90/10, and based on 100 parts of the solid weight of the thermosetting resin, ((A)
+ (B)) is not more than 40 parts by weight, and (D) is used with respect to 100 parts of the total solid weight 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 thermosetting resin having a solid weight of 100 parts,
The method for producing a metal foil-clad laminate according to claim 3, wherein the usage ratio of the total amount of ((A) + (B)) is 20 to 40 parts by weight.