JPH05105778A - Laminated board manufacturing method - Google Patents

Abstract

(57) [Abstract] [Purpose] As a laminated board suitable for SMD-compatible printed wiring boards, it has low elasticity required to secure solder connection reliability of SMD, and also has heat resistance and moisture insulation. Secure. [Structure] As a glass woven cloth prepreg to be arranged in the surface layer, an elastomer having functional groups reactive at both ends with a thermosetting resin impregnated in the glass cloth (for example,
A compound pretreated with a combination system of Chemical Formula 2) and a modified silicone oil having a functional group reactive with the thermosetting resin is used. Use ratio is solid weight ratio, elastomer /
Modified silicone oil = 20/80 to 90/10 and the amount of adhesion to the glass woven fabric is 30% by weight or less. [Chemical 1] [Chemical 2]

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to surface mount parts (hereinafter,
The present invention relates to 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 increase in density, integration, and miniaturization of electronic and electrical equipment, components mounted on a printed wiring board to be incorporated therein are also changed from insertion discrete components to surface mount SMDs. Is moving to. As for 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. Therefore, when the cooling / heating cycle is repeated, the stress resulting from 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 board, which is the substrate material of the printed wiring board, is reduced in the plane direction so that the stress caused by the difference in the coefficient of thermal expansion between the SMD and the board is absorbed by the board of low elasticity, and the solder connection portion has a large stress. 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 heat-molding the base material. For example, a flexibility-imparting agent is simply added to the matrix resin. A technique for reducing elasticity by adding or reacting the added flexibility-imparting agent with a matrix resin or a curing agent has been studied. In addition, when an inorganic filler is contained, atomization and spheroidization of the inorganic filler have been studied.

[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 as a substrate of a printed wiring board, that is, heat resistance is required. Also, there is a problem in that the moisture-proof insulation characteristic is deteriorated. 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, to secure heat resistance and moisture-proof insulation together with low elasticity required for ensuring solder connection reliability. That is.

[0004]

In order to solve the above-mentioned problems, the first production method according to the present invention is such that a sheet-like base material made of glass fiber is impregnated with a thermosetting resin, and the sheet-like base material is laminated. In the production of a laminated plate to be heat-pressed by heating, at least the sheet-like base material arranged on the surface layer is subjected to the following pretreatment. That is, a sheet-shaped substrate is pretreated with a combined system of an elastomer having functional groups that react with the thermosetting resin at both ends and a modified silicone oil having functional groups that react with the thermosetting resin. However, it is characterized in that the ratio of both used is a solid weight ratio of elastomer / modified silicone oil = 20/80 to 90/10 and the amount of adhesion to the sheet-shaped substrate is 30% by weight or less. To do. In the second manufacturing method according to the present invention, a sheet-shaped base material made of glass fiber is impregnated with a thermosetting resin, and is laminated on at least a surface layer in the manufacture of a laminated plate in which the thermosetting resin is superposed and heat-pressed. The thermosetting resin with which the above-mentioned sheet-shaped base material is impregnated has the following composition. That is, an elastomer having functional groups that react with the thermosetting resin at both ends and a modified silicone oil having functional groups that react with the thermosetting resin are in a solid weight ratio of elastomer / modified silicone oil = 20 / 80-90
/ 10 is added in an amount of 50 parts or less relative to 100 parts of the solid weight of the thermosetting resin.

[0005]

In the method according to the present invention, an elastomer having functional groups capable of reacting with a thermosetting resin at both ends and a modified silicone oil having a functional group capable of reacting with a thermosetting resin are used together to form a printed wiring board. It is intended to secure the solder connection reliability as an SMD-compatible substrate by achieving low elasticity without deteriorating necessary characteristics. That is, the elastomer and the modified silicone oil crosslink with the thermosetting resin to reduce the elastic modulus of the entire laminate. by the way,
When the above elastomer is used alone by mixing it with a thermosetting resin, the elastomer has a highly polar skeleton such as acrylonitrile, so that the moisture-proof insulation and heat resistance of the laminate are deteriorated. Therefore, by using the modified silicone oil in combination, it is possible to suppress the deterioration of the moisture resistance and the heat resistance. However, the use ratio of the elastomer and the modified silicone oil is elastomer / modified silicone oil = 20/80 to 90/10 in terms of solid weight ratio. When the proportion of the elastomer is small and the proportion of the modified silicone oil is large, the adhesiveness of the metal foil integrally attached to the surface during molding of the laminated plate is deteriorated. When the proportion of the elastomer is large and the proportion of the modified silicone oil is small, the moisture resistance and heat resistance are deteriorated.

Furthermore, the presence of the low-elasticity elastomer at the interface between the thermosetting resin and the sheet-shaped substrate or in the thermosetting resin absorbs the internal stress of the laminated plate caused by the curing shrinkage of the thermosetting resin. ,ease. Due to such an action, it has an effect of suppressing the warp and twist of the laminated plate which have been conventionally caused by the internal stress.

[0007]

EXAMPLE The sheet-like substrate made of glass fiber used in the present invention is a glass woven cloth, a glass non-woven cloth, a glass-paper mixed paper non-woven cloth 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, processability improvement, and cost reduction.
O ₃ .3H ₂ O, talc, MgO, SiO ₂ etc.) may be blended. The laminated sheet produced by the method according to the present invention may be either an ANSI grade composite type in which the sheet-shaped substrate is a combination of a glass woven fabric and a glass nonwoven fabric, a type of a glass woven fabric alone, or a type of a glass nonwoven fabric alone. But it's okay. It also includes a laminated board for a multilayer printed wiring board.

The elastomer used in the method according to the present invention is carboxylated polybutadiene acrylonitrile (Chemical formula 1) at both ends, aminated polybutadiene acrylonitrile (Chemical formula 2) at both ends, or an epoxidized polymer at both ends of the elastomer.

[0009]

[Chemical 1]

[0010]

[Chemical 2]

The modified silicone oil used in the method according to the present invention may have a functional group at any position of side chain type, both terminal type, one terminal type, and both side chain both terminal type. Is an amino group, epoxy group, hydroxyl group, etc.
Any material that reacts with the thermosetting resin may be used.

Examples 1-5, Comparative Examples 1-3, Conventional Example 1-
2 Bisphenol A type epoxy resin (Epoxy oil shell epoxy Ep to 100 parts by weight of both ends carboxylated polybutadiene acrylonitrile (Ube Industries CTBN))
-828) 40 parts by weight, a curing accelerator 2-ethyl-4-
0.5 parts by weight of methyl imidazole (2E4MZ) and 30 parts by weight of toluene as a diluting solvent were mixed, and the mixture was heated to 100 ° C.
Reaction was carried out under the condition of 2 hours to prepare epoxidized polybutadiene acrylonitrile (elastomer) at both ends. Next, the elastomer and a modified silicone oil having an amino group as a functional group (X-22-16 manufactured by Shin-Etsu Chemical Co., Ltd.)
1) and were dissolved in methyl ethyl ketone to prepare a varnish (A) having the blending amount shown in Table 1.

To a glass fiber woven cloth having a basis weight of 205 g / m ² ,
The above varnish (A) was impregnated and dried to obtain prepregs (A) having the respective resin adhesion amounts shown in Table 1. 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. Next, a bisphenol A type epoxy resin varnish (C) mixed with an inorganic filler (resin / filler = 100/50) is impregnated into a glass nonwoven fabric having a basis weight of 50 g / m ² and dried to adhere the resin containing the filler. Quantity 84
A weight% of prepreg (C) was obtained. 6 plies of prepreg (C) are placed, 1 ply of prepreg (B) is placed on each side of the prepreg, and 18 μm thick copper foil is placed on both sides of the prepreg (C). A composite type copper clad laminate was obtained.

Table 2 shows the characteristics of each of the laminated plates. In Table 2, the solder crack occurrence rate (horizontal direction) of Example 4 is higher than those of the other Examples.
The solder crack generation rate is lower than that of the conventional laminated plate in which the glass woven fabric is pretreated with the varnish containing 0.1% by weight of the elastomer alone (the total amount of the elastomer and the modified silicone oil in Example 4), and the heat resistance is high. It was confirmed that the sex was improved. Since the solder crack generation rate is low in the vertical direction, the longitudinal direction of SMD mounting is aligned with the vertical direction of the substrate having a low solder crack generation rate.

[0015]

[Table 1]

[0016]

[Table 2]

(Note) (1) JIS method (2) PCT Conditions: 121 ° C, 2 atm, 6 hr (3) Sample: Normal state Solder temperature: 300 ° C (4) Solder crack occurrence rate (n = 100) # 3125 Chip: -30 ° C and 120 ° C repeated 1000
Cycle (5) Sample Size, Number of Samples: 340 × 255 mm, 12 Work Treatment Steps: Whole Surface Etching + 150 ° C. Heating for 30 minutes Examples 6-10, Comparative Examples 4-6, Conventional Examples 3-4 Elastomers in the above Examples The modified silicone oil and the modified silicone oil were blended in the bisphenol A type epoxy resin in the blending amounts shown in Table 3 to prepare a varnish (D). Basis weight 205g /
A glass woven fabric of m ² was impregnated with the 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, and one ply of prepreg (D) is placed on each side of the ply, and a thickness of 18μ on each side.
1 m copper foil is placed and the thickness is 1.
A 6 mm composite type copper-clad laminate was obtained.

Table 4 shows the characteristics of each of the laminates. In Table 4, the solder crack occurrence rate of Example 9 is higher than that of the other Examples, but 0.1% by weight of the elastomer alone (elastomer and modified silicone oil in Example 9) was used. It was confirmed that the occurrence rate of solder cracks was lower and the heat resistance and the like were improved as compared with the laminated plate in the prior art using a prepreg obtained by impregnating and drying a glass woven fabric with the compounded varnish.

[0019]

[Table 3]

[0020]

[Table 4]

[0021]

As described above, according to the method of the present invention, as a laminated board used for a substrate of an SMD-compatible printed wiring board, a low temperature centering on a surface direction necessary for securing solder connection reliability of SMD is obtained. In addition to elasticity, heat resistance and moisture insulation resistance 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 before. Further, the warp of the laminated plate could be made small.

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Claims (2)

[Claims] 1. In the production of a laminated plate in which a sheet-shaped base material made of glass fiber is impregnated with a thermosetting resin, and the heat-pressed resin is superposed on the sheet-shaped base material, the sheet is placed at least on the surface layer.
A method for producing a laminated plate, which comprises subjecting a substrate-like base material to a pretreatment in the following step (a). (A) Pretreatment is performed by using an elastomer having functional groups that react with the thermosetting resin at both ends and a modified silicone oil that has a functional group that reacts with the thermosetting resin in combination, and the use ratio of both is fixed. The mold weight ratio is elastomer / modified silicone oil = 20/80 to 90/10, and the amount of adhesion to the sheet-shaped substrate is 30% by weight or less. 2. In the production of a laminated plate in which a sheet-like base material made of glass fiber is impregnated with a thermosetting resin, and the heat-curable resin is superposed on the sheet-like base material, at least the sheet-like base material to be arranged on the surface layer is A method for manufacturing a laminated board, which comprises impregnating a thermosetting resin having the following composition (b). (B) An elastomer having functional groups that react with the thermosetting resin at both ends, and a modified silicone oil having functional groups that react with the thermosetting resin in a solid weight ratio,
Elastomer / modified silicone oil = 20 / 80-9
0/10 is added in an amount of 50 parts or less based on 100 parts of the solid weight of the thermosetting resin.