JPH0239115B2 - TASOHAISENBANNOSEIZOHOHO - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for manufacturing a multilayer wiring board. Conventional technology A conventional multilayer wiring board is made by laminating an inner wiring board with wiring patterns on both sides and a copper-clad laminate with prepreg interposed therebetween, then drilling holes and chemically plating and electroplating the entire surface. After that, an etching process is performed to remove unnecessary copper foil and form an outer layer circuit. In addition, multilayer wiring boards produced using the Addi-Dave method use an insulating plate whose surface is coated with an adhesive containing a plating catalyst, a plating resist layer is formed on this insulating plate, and the inner layer wiring is immersed in an electroless copper plating solution. After making a board, roughening the copper surface of this inner layer circuit, and sequentially forming an insulating layer and an adhesive layer, holes are drilled for through holes, and a plating resist layer for the outer layer is formed. Multilayer wiring boards are manufactured by forming outer layer circuits and through holes by copper plating. Problems to be Solved by the Invention In the process of manufacturing multilayer wiring boards, the copper surface is The surface is roughened using chemicals. After this treatment, an insulating resin with a viscosity of 200 to 500 ps is printed and coated on the copper surface, but the insulating resin is not filled in all the uneven parts of the copper surface, and there are some cavities that become microvoids. If the holes formed and where these cavities remain become through-holes in the subsequent drilling process, the interface between the roughened surface of the inner layer copper and the insulating resin will be etched in the electroless plating process. There was a problem in that the coating liquid penetrated, impairing adhesion and reducing the heat resistance of the product. Means for Solving the Problems The present invention roughens the surface of the inner layer copper of the inner layer circuit board, then performs primer treatment, sequentially forms an insulating resin layer and an adhesive layer, makes holes, and then forms a plating resist layer. In this method, a plating catalyst is added to the primer and insulating resin in the step of forming an outer layer circuit and through-holes by electroless plating. EXAMPLE The method for manufacturing a multilayer wiring board according to the present invention will be described with reference to the drawings. A plating resist layer 3 is formed on both sides of a glass epoxy resin insulating board 1 coated with a catalyst-containing adhesive 2. Thereafter, electroless plating is performed to manufacture the inner layer wiring board 10 on which the inner layer circuit 4 is formed. The surface of the inner layer circuit 4 of this inner layer wiring board 10 is treated with a roughening liquid to form uneven portions 5, and then the surface of the inner layer circuit 4 of the inner layer wiring board 10 is treated with a roughening liquid at a rate of 10 cm/min using a primer treatment liquid having the composition shown in Table 1 or Table 2.
Immerse the substrate at a speed of After dipping, drying is performed at 160° C. for 30 minutes to form a primer layer 11. In addition,
A plating catalyst is added to this primer treatment solution.

【table】

【table】

[Table] After this, a mixture of 100 parts of the resin for the insulating layer and 3 to 15 parts of a plating catalyst such as diluted palladium is printed to form the insulating layer 13, and then an adhesive layer 15 is formed. A multilayer wiring board 30 provided with an outer layer circuit 20 and through holes 22 is manufactured by electrolytic plating. The cross section of the through hole 22 of this multilayer wiring board 30 was observed with an electron microscope to confirm that there was no penetration of the plating liquid between the layers, and the evaluation results shown in Table 3 were obtained.

[Table] Note that when the thickness of the insulating layer 13 is thin, the plating precipitation inside the through hole is good, but when the thickness is thick, the shape of the plating becomes irregular, so in this case, seeder treatment should be performed inside the hole. This makes the surface of the through-hole copper smooth. Effects of the Invention The present invention roughens the copper surface of the inner layer circuit, and then performs a primer treatment that has excellent affinity with the epoxy insulating layer, and in particular, performs a primer treatment with an epoxy novolac type to improve the adhesion between the layers. By adding a plating catalyst to the primer treatment solution and the insulating layer, it is now possible to obtain a thick and uniform plating layer within the through-holes, resulting in high-quality multilayer wiring boards. I got it.

[Brief explanation of drawings]

FIG. 1 is a sectional view of the present invention, and FIG. 2 is a sectional view of an inner layer wiring board. In the drawings, 4: inner layer copper foil, 5: uneven portion, 1
0: Inner layer circuit board, 11: Primer layer, 13: Insulating layer, 15: Adhesive layer, 18: Plating resist,
20: outer layer circuit, 22: through hole, 30: multilayer wiring board.

Claims (1)

[Claims] 1. The inner layer copper surface of the inner layer circuit board is roughened, a primer layer is formed thereon, an insulating resin layer and an adhesive layer are sequentially laminated, and a hole drilling process is performed. , after forming the outer plating resist layer,
A method for manufacturing a multilayer wiring board, comprising adding a plating catalyst to the primer liquid and insulating resin when forming through holes and outer layer circuits by electroless plating. 2. The method of manufacturing a multilayer wiring board according to claim 1, wherein after the hole drilling process, a seeder treatment is performed in the hole.