JPH0680886B2 - Manufacturing method of printed wiring board - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a printed wiring board by an additive method, which has a good chemical roughening property in the pretreatment of electroless plating and is excellent in electrolytic corrosion resistance between plated copper circuits. Regarding manufacturing method.

(Prior Art) A printed wiring board by the additive method forms a required wiring pattern on an insulating substrate with an adhesive by electroless plating. For example, a printed wiring board is plated on an insulating substrate such as a laminated plate containing a plating catalyst. After providing an adhesive layer containing a catalyst and masking the parts other than the circuit forming part with a plating resist, the surface of the adhesive layer of the circuit forming part is selectively chemically treated with an oxidizing etching solution such as chromium sulfuric acid as a pretreatment for electroless plating. Roughening,
It is obtained by immersing in an electroless copper plating solution after neutralization and washing with water to deposit copper on the circuit part.

When the plating catalyst is not mixed in the insulating substrate and the adhesive, the plating catalyst is adsorbed to at least the circuit forming portion before being immersed in the electroless copper plating solution. As the adhesive, acrylonitrile butadiene rubber, which is excellent in adhesiveness to the deposition plating, is generally used, and a thermosetting resin component such as a phenol resin or an epoxy resin is added to have heat resistance, and the adhesive coating film is also used. An inorganic filler or the like is appropriately blended to reinforce or assist chemical roughening.

As the density of printed wiring boards has increased, circuit pattern intervals have become narrower, and the occurrence of dendrites due to copper migration between patterns under an electric field has become a problem.

If the adhesive layer under the circuit is a composition containing rubber such as acrylonitrile butadiene, it may migrate easily, or it may be affected by various treatment liquids in the additive process wiring board manufacturing process. Below, dendrites frequently occur not only on the adhesive layer itself, but also on the interface with the substrate and the interface with the solder resist layer provided on the circuit. These dendrites may grow and short-circuit as a bridge, leading to defects. This frequency of occurrence is remarkable as compared with the case of the subtract method wiring board which is usually manufactured from a glass cloth base material epoxy resin copper clad laminate without using a rubber adhesive.

In the rubber adhesive, the generation of dendrites tends to be reduced by adding a large amount of a thermosetting component such as an epoxy resin or a phenol resin having a crosslinkability with the rubber to reduce the ratio of the rubber.

2-vinyl-4,6-diamino-S-for general-purpose epoxy resin
A method for producing a copper clad laminate excellent in the effect of preventing copper migration by impregnating a base material with an organic solvent solution mixed with triazine and heating and pressing the impregnated base material is disclosed in JP-A-61-8346. Proposed in the gazette.

(Problems to be Solved by the Invention) By increasing the ratio of the thermosetting resin component of the rubber-based adhesive, that is, by decreasing the ratio of rubber, the generation of dentrite tends to be reduced, but in this case, The chemical roughening property of the pretreatment of plating is remarkably lowered, and the adhesion of the deposited plating becomes insufficient.

Further, in the method of manufacturing a printed wiring board using a copper clad laminate, not only is there a limit to the simplification of the manufacturing process, but also side etching is unavoidable, and it is difficult to form a highly precise fine pattern.

The present invention is a method for manufacturing a printed wiring board by an additive method, which has a short manufacturing process, high precision, and is easy to form a fine pattern, and has a good chemical roughening property of the adhesive layer. The present invention provides a method for producing a printed wiring board having excellent electrolytic corrosion resistance.

(Means for Solving Problems) The present invention relates to acrylonitrile butadiene rubber, 2-vinyl-4,6-diamino-1,3,5 triazine and / or 2 per 100 parts by weight of a thermosetting resin component. Use an adhesive for electroless plating containing 0.1 to 20 parts by weight of vinyl-4,6-diamino-1,3,5 triazine / isocyanuric acid adduct (hereinafter referred to as "part"), preferably 0.5 to 10 parts It is a thing. If the addition amount is less than 0.1 part, the dendrite suppression effect is small,
If it exceeds 0 parts, the crosslinkability of the rubber may be deteriorated and the heat resistance may be insufficient. The acrylonitrile butadiene rubber is a copolymer of acrylonitrile and butadiene, or a copolymer of the acrylonitrile butadiene and another monomer copolymerizable therewith, such as acrylic acid. Although the acrylonitrile content is not limited, it is preferably 19% or more in commercial products. The composition ratio (% by weight) of acrylonitrile butadiene rubber and thermosetting resin components such as epoxy and phenol can be used in the range of 85/15 to 30/70, and more preferably 75/25 to 50/50. . If the acrylonitrile butadiene rubber is less than 30%, 2
Even when adding -vinyl 4,6-diamino-1,3,5 triazine or the like, chemical roughening becomes insufficient, and if it exceeds 85%, heat resistance cannot be sufficiently obtained.

As the treatment liquid used for the chemical roughening in the pretreatment of the electroless plating, an oxidizing acid such as general chromic acid-sulfuric acid or dichromic acid-sulfuric acid is used.

The adhesive is cured at 140 to 180 ° C for 30 minutes to 2 hours.

(Function) Acrylonitrile butadiene rubber is blended with a thermosetting resin component such as an epoxy resin. When the ratio of the thermosetting component is high, for example, when the content of both is 40% by weight or more, dendrite formation is reduced. Since the entire adhesive has high rigidity, the chemical roughening property is deteriorated and it becomes difficult to form a circuit by electroless plating.

Although the addition of the triazine compound of the present invention has a curing accelerating effect on the thermosetting epoxy resin, it does not have an accelerating effect on the cross-linking of the main component acrylonitrile butadiene rubber, for example, with the phenol resin, but rather has an inhibiting effect. The advantage is that selective chemical roughening is easily performed without impairing the heat resistance of the adhesive. These compatibility in the additive method printed wiring board is extremely advantageous.

Example 1 Acrylonitrile butadiene rubber (product name Nipol 1432J manufactured by Zeon Corporation) 60 parts Alkylphenol resin (product name SP-126 manufactured by Schenectady) 25 parts Novolac phenol resin (product name SP-6600 manufactured by Schenectady) 10 parts Epoxy resin (Yukaka Shell Co., Ltd. trade name Epicoat 1001FR) 15 parts Filler zirconium silicate (Shiramizu Chemical Co., Ltd. trade name Micropax 20A) 30 parts Plating catalyst (Hitachi Chemical Co., Ltd. trade name PEC-8) 8 parts 2- Vinyl-4,6 diamino-1,3,5 triazine (trade name VT manufactured by Shikoku Kasei Co., Ltd.) 5 parts was dissolved and dispersed in a mixed solvent of 1: 1 weight ratio of cellosolve acetate and methyl ethyl ketone using a kneader and 3 rolls. To prepare an adhesive solution having a solid content of 22%. This adhesive is a paper-based epoxy resin laminate (trade name, manufactured by Hitachi Chemical Co., Ltd.)
Both surfaces of LE-144) were applied by dipping so that the film thickness after drying would be 25 μm, and dried by heating at 160 ° C. for 60 minutes to obtain an insulating substrate with an adhesive.

Using a 300 mesh screen with plating resist ink on this board, a line / space 0.25 / 0.25 mm comb pattern for evaluating dendrites, 25 mm square, 1 mm wide line for measuring solder heat resistance and circuit peel strength The following test pattern was printed and cured by heating. Then dilute chromic acid mixture (55 g of CrO ₃ and 210 ml of concentrated sulfuric acid with water)
The adhesive surface of the pattern part was chemically roughened, washed with water and neutralized. Next, it is put into an electroless copper plating bath (trade name CC-41 plating solution manufactured by Hitachi Chemical Co., Ltd.) to deposit copper having a thickness of 25 μm, washed with water and dried to obtain a test pattern of an additive method printed wiring board. It was

The electrolytic corrosion resistance test is carried out at 65 ° C-90% to accelerate this.
DC100V was applied between the electrode circuits under heating and humidification of RH to continuously energize and sampled at predetermined time intervals, and the presence or absence of dendrite between the circuits was examined. Before the test, a solder resist was printed on the entire surface in advance to protect the film so that water drops would not directly adhere to the circuit surface under the test environment.

JIS C-6481 for solder heat resistance and pattern peeling strength
It was measured according to. The chemical roughening property of the adhesive layer was observed using a scanning electron microscope for the sample before plating. The results are shown in Table 1.

Example 2 Acrylonitrile butadiene rubber (trade name Nipol 1001 manufactured by Zeon Corporation) 70 parts Alkylphenol resin (trade name SP-126 manufactured by Schenectady) 20 parts Epoxy resin (trade name DEN-438 manufactured by Dow Chemical Co.) 20 parts Curing agent Boron trifluoride monoethylamine (Hashimoto Kasei Co., Ltd.) 0.5 part Filler zirconium silicate (Hakusui Chemical Co., Ltd. trade name Micropax 20A) 30 parts Plating catalyst (Hitachi Chemical Co., Ltd. trade name PEC-8) 8 parts 2 -Vinyl-4,6 diamino-1,3,5 triazine / isocyanuric acid adduct (trade name VT-OK manufactured by Shikoku Chemicals Co., Ltd.) A composition consisting of 1 part was prepared in the same manner as in Example 1 to prepare an adhesive solution. A test pattern of an additive method printed wiring board was obtained.

Example 3 Acrylonitrile butadiene rubber (product name Nipol 1032 manufactured by Zeon Corporation) 50 parts Alkylphenol resin (product name SP-126 manufactured by Schenectady) 15 parts Epoxy resin (Epicoat 1001FR manufactured by Yuka Shell Co., Ltd.) 45 parts Curing agent Imidazole (Curazole product name 2MZ manufactured by Shikoku Kasei Co., Ltd.) 0.3 part Filler, zirconium silicate (product name Micropax 20A manufactured by Shiramizu Chemical Co., Ltd.) 15 parts Filler material, calcium carbonate (Whiten SSB product name manufactured by Shiraishi Calcium Co., Ltd.) 10 parts Plating Catalyst (PEC-8) 6 parts 2-vinyl-4,6 diamino-1,3,5 triazine 1.5 parts 2-vinyl-4,6 diamino-1,3,5 triazine / isocyanuric acid adduct 0.5 parts Composition consisting of An adhesive solution was prepared in the same manner as described in Example 1 to obtain a test pattern for an additive method printed wiring board.

Reference Example In each of Examples 1, 2, and 3, a test pattern was prepared by using an adhesive containing no triazine compound.

(Advantages of the Invention) In the additive-type printed wiring board of the present invention, the occurrence of dendrites is small, the electrolytic corrosion resistance is excellent, and the chemical roughening of the adhesive layer is easily performed without impairing the heat resistance. The peeling strength of is also at a high level.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Kiyoshi Yamanoi Kiyoshi Yamakawa, Shimodate City, Ibaraki Prefecture 1500 Ogawa, Shimodate Research Laboratory, Hitachi Chemical Co., Ltd. Shimodate Research Center (72) Inventor Masao Sugano 1500 Ogawa, Shimodate, Ibaraki Prefecture Hitachi Chemical Co., Ltd. Shimodate Research Center

Claims (2)

[Claims] 1. Acrylonitrile butadiene rubber and 2-vinyl-4,6 diamino-1,3,5 triazine and / or 2 vinyl-4,6-diamino-1 with respect to 100 parts by weight of a thermosetting resin component. An adhesive containing 0.1 to 20 parts by weight of a 3,3,5 triazine / isocyanuric acid adduct is applied on an insulating substrate, cured, and then chemically roughened, and the surface of the roughened cured adhesive is electroless plated. A method for manufacturing a printed wiring board, the method including the step of forming a metal conductor circuit by means of. 2. The method for producing a printed wiring board according to claim 1, wherein the acrylonitrile butadiene rubber is 40 to 85% by weight based on the sum of the acrylonitrile butadiene rubber and the thermosetting resin component.