JPH10308566A - Manufacturing method of electric circuit board - Google Patents

Abstract

(57) [Problem] To provide an electric circuit board having rigidity, heat resistance, solder resistance, and coefficient of thermal expansion required for an electric circuit board and having excellent plating adhesion at a portion corresponding to a circuit. SOLUTION: This molded article is composed of (a) one predetermined mold formed of an easily-plateable resin and (b) one predetermined mold formed of a hard-to-plate resin. The above (a) and (b) are combined to form an electric circuit pattern on the surface of the molded body, and are integrally formed by injection molding. In a method for producing an electric circuit board produced by performing electrolytic plating, a composition comprising an easily-platable resin, comprising syndiotactic polystyrene, inorganic fibers, and a butadiene-based polymer compound or an inorganic filler treated with palladium chloride. The above production method.

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 an electric circuit board for patterning a conductive circuit directly on the surface of a molded article. More specifically, the present invention relates to a method for manufacturing an electric circuit board capable of precisely forming a fine line portion of a circuit on the surface of a molded body and having excellent plating adhesion at a portion corresponding to a circuit on the surface of the molded body.

[0002]

2. Description of the Related Art Circuits on an electric circuit board are required to be capable of forming a precise pattern and have a smooth surface. That is, the plating of the circuit portion needs to have a smooth finish and a strong plating adhesion strength. Conventionally, it has been considered difficult to use a crystalline thermoplastic resin which is hardly attacked by an acid or an alkali solvent in a circuit portion to be plated, because a plating adhesion promoting treatment is difficult. For example, JP-A-63
No. -50482 discloses that a crystalline thermoplastic resin is substantially unaffected by an adhesion promoting treatment, remains hydrophobic and resistant to adhesive plating, and is unsuitable as a material corresponding to a circuit portion. is there. However, it is described that the amorphous thermoplastic resin is hydrophilic as a result of the adhesion promoting treatment and has a high affinity for electroless plating, and is therefore suitable as a material corresponding to a circuit portion. Therefore, even if the crystalline thermoplastic resin is subjected to electroless plating, there are problems such as insufficient adhesive strength and surface smoothness, and high cost. In addition, PPS (polyphenylene sulfide)
Is considered to be useful as a material corresponding to a circuit part because of its relatively low material price and excellent heat resistance and dimensional stability, but has not been put to practical use because plating adhesion processing is difficult. For example, Japanese Unexamined Patent Publication No. 1-136394 discloses PPS as one of the easily-plateable thermoplastic resin materials, but does not provide any specific explanation because of the difficulty in plating adhesion treatment. Japanese Patent Application Laid-Open No. 1-184983 discloses a liquid crystalline polyester resin as an easily-platable resin. However, since a molding orientation peculiar to liquid crystal occurs, there are problems such as large warpage, brittleness, and high price as electric circuit components. Have a point.

[0003]

The crystalline thermoplastic resin is suitable for producing a fine molded product because of its excellent melt fluidity. For this reason, it is considered to be a material suitable for manufacturing a fine pattern required for an electric circuit board. However, plating adhesion processing is difficult, and it has not been put to practical use. SUMMARY OF THE INVENTION An object of the present invention is to provide an electric circuit board having rigidity, heat resistance, solder resistance, and coefficient of thermal expansion required for an electric circuit board and having excellent plating adhesion at a portion corresponding to a circuit.

[0004]

Means for Solving the Problems The present inventors have made intensive studies to achieve the above object, and as a result, have found that a syndiotactic polystyrene composition can achieve the above object, thereby completing the present invention. Reached. That is, the present invention
A molded article comprising one predetermined mold (a) formed of an easily-platable resin and one predetermined mold (b) formed of a hard-to-plate resin, )
And (b) are combined so as to form an electric circuit pattern on the surface of the molded body, and are integrally injection-molded. Then, a portion corresponding to the electric circuit pattern on the molded body surface is subjected to electroless plating. In the method for producing an electric circuit board to be produced, the above-mentioned method is provided, wherein the easily-platable resin is a composition comprising syndiotactic polystyrene, inorganic fibers, and a butadiene-based polymer compound treated with palladium chloride. Further, the present invention provides the above method for producing an electric circuit board, wherein the easily-platable resin is a composition comprising syndiotactic polystyrene, inorganic fibers, and an inorganic filler treated with palladium chloride. I do.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a substrate according to the present invention will be described with reference to the accompanying drawings. FIG. 1 is a plan view of an electric circuit board according to the present invention, and FIG. 2 is a sectional view taken along line AA ′ of FIG. In FIG. 1, a circuit portion 2 of an electric circuit board 1 is a surface-exposed portion of one predetermined mold (a) made of an easily plating resin material. The remaining non-circuit portion 3 is a surface exposed portion of one predetermined mold (b) made of a difficult-to-plate resin material. An electric circuit is formed in the circuit section 2 by plating.

[0006] The substrate of the present invention is manufactured by a two-color molding method in which injection-molded resin material and hard-to-plate resin material are integrally molded. The details are as follows. (1) One predetermined mold (a) made of an easily-platable resin material corresponding to a circuit setting portion is prepared, and this is set in a cavity of a mold having a cavity in which the whole substrate is formed. This is a method in which a space portion is filled with a difficult-to-plate resin material and injection-molded by integrally combining a circuit-forming portion and a non-circuit portion so as to form an electric circuit pattern on a substrate surface. . When the flow of the hard-to-plate resin material is likely to be hindered during injection molding of the mold (b) of the non-circuit portion, it is preferable to provide the hole 4 in the mold (a). Alternatively, only a fine portion corresponding to the circuit portion may be formed. However, as shown in FIG. 2, a portion 5 of the mold (a) which forms a circuit which emerges on the surface of the substrate is made fine, and a connecting portion is formed inside the substrate. The circuit forming portions 5 may be connected by 6. (2) Contrary to (1), the non-circuit portion is formed of a difficult-to-plate resin material, and then placed in another mold for forming a circuit portion, and the space is filled with the easily-plateable resin material. Is a method of injection molding.

When the surface of the substrate formed by the above method is plated, only the circuit forming portion is plated, so that a desired circuit can be formed on the substrate. In the present invention, in order to strengthen the adhesion of plating, a circuit portion to be plated can be subjected to an etching treatment at an appropriate stage. The etching treatment may be performed at the stage of the molded article alone corresponding to the circuit formed of the easily-plated resin, or at the stage of the molded article in which the circuit equivalent part and the non-circuit equivalent part are integrated. When a butadiene-based polymer compound treated with palladium chloride is used as a chemical used for the etching treatment, potassium bichromate or an aqueous sulfuric acid solution of chromic anhydride may be used. When an inorganic filler treated with palladium chloride is used, an appropriate chemical is selected and used depending on the type of the filler. For example, the following chemicals can be mentioned. Potassium dichromate or sulfuric acid aqueous solution of inorganic chromic acid. Aqueous solution of stannic chloride and hydrochloric acid, aqueous hydrochloric acid solution, etc. An aqueous solution containing an α-halogenated aliphatic carboxylic acid having 2 to 5 carbon atoms (first component) and a mineral acid (second component). The first component is a carboxylic acid represented by the following formulas (1) and (2). During _{C n H 2n + 1 CH 2} -m X m COOH (1) CX 3 COOH (2) [ the above equation, X is indicates F, Cl or Br, m is 1-2
And n represents an integer of 0 to 3] Compounds represented by the above formulas (1) and (2) are specifically exemplified as follows. Monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, monochloropropionic acid, dichlorobutyric acid, monochlorovaleric acid, dichlorovaleric acid, and substituted fluorine or bromine thereof. Examples of the mineral acid of the second component include hydrochloric acid and sulfuric acid. As the first component or the second component, one kind or a mixture of two or more kinds can be used. An aqueous solution mainly containing an alkali metal hydroxide or an alkaline earth metal hydroxide. Examples of the alkali metal include lithium, sodium and potassium, and examples of the alkaline earth metal include strontium and barium.

[0008] In order to make the syndiotactic polystyrene easy to be plated and to use it as a material of the mold (a) of the present invention, it is necessary to carry out the following treatment. One is to mix and mix inorganic fibers and palladium chloride-treated butadiene-based polymer compound with syndiotactic polystyrene. The other is to mix and mix syndiotactic polystyrene with inorganic fibers and an inorganic filler treated with palladium chloride. The composition obtained as described above has mechanical properties such as tensile strength and bending strength,
Excellent heat resistance and excellent adhesion to plating. In addition, a composition in which inorganic fibers are blended and mixed with syndiotactic polystyrene, that is, a composition having almost the same composition except that an easily plating resin composition and a butadiene polymer compound treated with palladium chloride or an inorganic filler are not blended. By using the composition as a hard-to-plate resin, the easily-plated resin can better adhere to the hard-to-plate resin and prevent the occurrence of defects such as a gap between the two due to a temperature change and a gap.

The syndiotactic polystyrene used in the present invention is a crystalline polystyrene in which benzene rings synthesized using a metallocene catalyst are arranged regularly and alternately. The syndiotactic polystyrene may contain a rubber component to such an extent that crystallinity is not impaired.
A particularly preferred syndiotactic polystyrene is "Zarek" (trade name) manufactured by Idemitsu Petrochemical Co., Ltd.

[0010] The inorganic fibers used in the present invention are not particularly limited as long as the strength and rigidity of the resin can be improved. For example, widely used glass fibers may be used. The compounding amount of the inorganic fibers is 5 to 80 parts by weight, preferably 1 to 100 parts by weight of the resin composition.
0 to 60 parts by weight. Below the lower limit, the reinforcing effect is small, and it is difficult to obtain the expected mechanical strength and rigidity. If the upper limit is exceeded, the formability deteriorates, the surface appearance of the plating layer is impaired, and the adhesion strength of the plating layer also decreases.

The butadiene-based polymer compound treated with palladium chloride used in the present invention is a mixture of a butadiene-based polymer compound and palladium chloride as a chemical plating catalyst. Examples of the butadiene-based polymer compound include a butadiene polymer, a copolymer of butadiene and styrene, a copolymer of butadiene and an acrylic monomer, and a terpolymer of butadiene / styrene / acrylic monomer. Palladium chloride is used in an amount of 0.001-2.
0 parts by weight, preferably in the range of 0.01 to 1.0 parts by weight. If the amount of palladium chloride is less than the above lower limit, the plating adhesive strength is lost. Since the butadiene-based polymer compound is easily attacked by the etching chemical, by performing the etching treatment, the adhesive strength with plating can be further improved. The compounding amount of the butadiene-based polymer compound treated with palladium chloride is 1 to 100 parts by weight, preferably 3 to 50 parts by weight, per 100 parts by weight of the resin composition. If the amount is less than the above lower limit, the surface of the substrate is not sufficiently roughened by etching, so that the adhesion strength of the plating layer is reduced, and it is difficult to obtain a substrate having good surface smoothness, and the appearance of the plating layer is impaired.

The inorganic filler treated with palladium chloride used in the present invention is a mixture of inorganic filler and palladium chloride. As inorganic fillers, magnesium silicate, calcium silicate, aluminum silicate, kaolin, talc, clay, diatomaceous earth, silicate compounds such as wollastonite, magnesium phosphate, calcium phosphate, barium phosphate, zinc phosphate, Examples thereof include phosphate compounds such as magnesium pyrophosphate and calcium pyrophosphate, and carbonate compounds such as calcium carbonate and magnesium carbonate. As the inorganic filler, generally available ones can be used, but those having a particle size of 20 μm or less, preferably 5 μm or less are preferably used. If the particle size is larger than the above upper limit, the surface of the substrate is excessively roughened, the plating adhesion strength is reduced, and the appearance of the plated surface is impaired.
Palladium chloride is used in an amount of 0.1 to 100 parts by weight of the inorganic filler.
001 to 2 parts by weight, preferably 0.01 to 1.0 part by weight, are added and mixed. If the amount of palladium chloride is less than the above lower limit, the plating adhesion strength is impaired. Since the inorganic filler is easily attacked by the etching chemical, the plating adhesion strength can be further improved by performing the etching treatment. The amount of the inorganic filler treated with palladium chloride is 5 to 100 parts by weight, preferably 10 to 90 parts by weight, per 100 parts by weight of the resin composition. If it is less than the above lower limit, the roughening of the substrate surface due to etching becomes insufficient, the adhesion strength of the plating layer is reduced, the surface smoothness is deteriorated, and the appearance of the plating layer is impaired.

As the hard-to-plate resin composition, a crystalline thermoplastic resin composition having a molding shrinkage and a thermal expansion coefficient similar to those of the easily-plateable resin composition is suitable. For example, a composition comprising the same syndiotactic polystyrene, inorganic fibers and butadiene-based polymer compound or inorganic filler as the easily-plateable resin composition is suitable. Further, syndiotactic polystyrene, PPS resin, polyamide resin, polyester resin, polypropylene resin, etc. alone or in a mixture, or inorganic fibers,
An inorganic filler may be blended so as to have a molding shrinkage and the like substantially similar to those of the easily-plateable resin composition.

In each of the easily-plateable resin composition and the hard-to-plate resin composition, various commonly used additives such as a stabilizer and a melt flow improver can be added. For example, a resin composition having improved moldability due to addition of an additive, a resin composition having improved flame retardancy, and the like. The mixing of the various components described above can be carried out by various methods, but a preferred method is a method of melt-kneading using an ordinary vented extruder.

[0015]

According to the production method of the present invention, sufficient strength as a substrate can be maintained without impairing the heat resistance, high strength and melt fluidity of syndiotactic polystyrene,
An electric circuit board having solder heat resistance of 250 ° C. to 280 ° C. for 10 seconds is provided. According to the present invention, there is provided a method for producing an electric circuit board with improved plating adhesion of syndiotactic polystyrene. Syndiotactic polystyrene has the coefficient of linear expansion closest to metals among plastics and has excellent heat resistance, so metal peeling due to the difference in thermal expansion between the metal and the resin in the plated part is unlikely to occur,
This has the advantage that the adhesion of the plated portion can be kept high. Furthermore, the syndiotactic polystyrene composition used in the production method of the present invention has good fluidity and can be precisely molded to a fine line portion, so that it is suitable for providing an electric circuit board having a fine pattern. The electric circuit board provided by the present invention has extremely small dielectric constant and dielectric loss tangent and is stable, and thus is extremely useful as an antenna component which is a promising application of the electric circuit board.

[0016]

The present invention will be described in more detail with reference to the following examples. Example 1 62 parts by weight of syndiotactic polystyrene, 28 parts by weight of glass fiber, and 5 parts by weight of a butadiene polymer compound (MBS resin 67E manufactured by Techno Polymer Co., Ltd.) mixed with 0.25% by weight of palladium chloride were mixed. After mixing using a single-screw extruder, cylinder temperature 2
The mixture was melt-kneaded at 60 to 290 ° C and extruded into a strand. Then, after washing with water and cooling, it was cut into pellets and dried to obtain a syndiotactic polystyrene composition. A test piece was formed using the pellet. With respect to this test piece, a physical property test and a plating property when metal plating was performed were examined. The metal plating was obtained by performing the following etching treatment and then performing chemical plating of copper according to a standard method.

Etching Treatment Annealing 150 ° C., 30 minutes Degreasing Anyex PC-1: 15 g / l 50 ° C., 5 minutes Anyex PC-2: 10 ml / l Etching CrO ₃ : 400 g / l 70 ° C., 5 minutes H ₂ SO ₄ : 400 g / l Neutralized and reduced H ₂ SO ₄ : 10 ml / l room temperature, 2 minutes H ₂ O ₂ Note: “ENIREX PC-1” and “PC-2” are manufactured by Ebara Uzilite Co., Ltd.

(1) Physical property test Tensile strength (ASTMD639) 900 to 1,000 kgf / cm ² Flexural strength (ASTMD790) 1,400 to 1,700 kgf / cm ² Flexural modulus (ASTMD790) 50,000 to 70,000 kgf / cm ² Thermal deformation temperature (1.80 (ASTMD648) 235 ° C Linear expansion coefficient (ASTMD696) 2.5 × 10 ^-5 / ° C Specific gravity (ASTMD792) 1.25 Mold shrinkage (ASTMD150) 0.3 to 0.6% Dielectric constant (1MHz) (ASTMD150) 2.8 Dielectric loss (1MHz) ( (ASTMD150) <0.001 (2) Plating performance Adhesion strength 1.0kg / cm Plating surface appearance Good Solder resistance No blistering (250 ° C, 10 seconds)

Example 2 After mixing 60 parts by weight of syndiotactic polystyrene, 15 parts by weight of glass fiber and 20 parts by weight of calcium pyrophosphate to which 0.07% by weight of palladium chloride had been added and mixed, a single screw type extruder was used. And melt-kneaded at a cylinder temperature of 260 to 290 ° C. and extruded into a strand. Then, after washing with water and cooling, it was cut into pellets and dried to obtain a syndiotactic polystyrene composition. A test piece was formed using the pellet. With respect to this test piece, a physical property test and a plating property when metal plating was performed were examined. The metal plating was obtained by performing the following etching treatment and then performing chemical plating of copper according to a standard method.

Etching Treatment Annealing 150 ° C., 30 minutes Degreasing Anyex PC-1: 15 g / l 50 ° C., 5 minutes Anyex PC-2: 10 ml / l Etching KOH aqueous solution: 40-60% by weight, 70-80 ° C., 20- 40 minutes Neutralization-reduced HCl aqueous solution: 5% by weight, room temperature, 2 minutes

(1) Physical property test Tensile strength (ASTMD639) 900 to 1,000 kgf / cm ² Flexural strength (ASTMD790) 1,400 to 1,700 kgf / cm ² Flexural modulus (ASTMD790) 50,000 to 70,000 kgf / cm ² Thermal deformation temperature (1.80 MPa) (ASTMD648) 220 ° C Linear expansion coefficient (ASTMD696) 2.5 × 10 ^-5 / ° C Specific gravity (ASTMD792) 1.35 Mold shrinkage (ASTMD150) 0.3 to 0.6% Dielectric constant (1MHz) (ASTMD150) 2.8 Dielectric loss (1MHz) ( (ASTMD150) <0.001 (2) Plating performance Adhesion strength 1.0kg / cm Plating surface appearance Good Solder resistance No blistering (250 ° C, 10 seconds)

Example 3 After syndiotactic polystyrene (60 parts by weight) and glass fiber (25 parts by weight) were mixed by a mixer, the mixture was melted and kneaded at a cylinder temperature of 260 to 290 ° C. using a single screw type extruder to form a strand. Extruded. Then, after washing with water and cooling, it was cut into pellets and dried to obtain a syndiotactic polystyrene composition. A test piece was formed using the pellet. A physical property test was performed on this test piece.

(1) Physical property test Tensile strength (ASTMD639) 900-1,100 kgf / cm ² Flexural strength (ASTMD790) 1,400-1,800 kgf / cm ² Flexural modulus (ASTMD790) 50,000-70,000 kgf / cm ² Thermal deformation temperature (1.80 (ASTMD648) 230 ° C Linear expansion coefficient (ASTMD696) 2.5 × 10 ^-5 / ° C Specific gravity (ASTMD792) 1.25 Mold shrinkage (ASTMD150) 0.3 to 0.4% Dielectric constant (1MHz) (ASTMD150) 2.8 Dielectric loss (1MHz) ( (ASTMD150) <0.001

Example 4 An electric circuit board is prepared using the syndiotactic polystyrene compositions obtained in Examples 1 and 3. Using the composition of Example 3 as the hard-to-plate resin and the composition of Example 1 as the easily-plateable resin, substrates for electric circuits shown in FIGS. 1 and 2 were produced by two-color injection molding. This was subjected to copper chemical plating in the same manner as in Example 1 to obtain an electric circuit board having an electric circuit pattern. For this electric circuit board, 150 ° C x 10 minutes and -20 ° C
A repeated cooling test was performed for 10 minutes. No peeling disconnection was observed in the plated portion.

Comparative Example 1 In Example 2, syndiotactic polystyrene 6
A polyamide 66 resin composition was obtained in the same manner as in Example 2, except that 60 parts by weight of the polyamide 66 resin was used instead of 0 parts by weight. A test piece was formed from the obtained pellets, and a physical property test and a plating property test were performed in the same manner as in Example 2. (1) Physical property test Tensile strength (ASTMD639) 1,400 to 1,700 kgf / cm ² Flexural strength (ASTMD790) 1,900 to 2,300 kgf / cm ² Flexural modulus (ASTMD790) 60,000 to 90,000 kgf / cm ² Thermal deformation temperature (1.80 MPa) ( (ASTMD648) 240 to 250 ° C Linear expansion coefficient (ASTMD696) 2.3 to 2.5 × 10 ^-5 / ° C Specific gravity (ASTMD792) 1.3 Mold shrinkage (ASTMD150) 0.2 to 1.0% Dielectric constant (1MHz) (ASTMD150) 3.3 Dielectric loss (1MHz ) (ASTMD150) <0.015 (2) Plating performance Adhesion strength 1.0kg / cm Plating surface appearance Good Solder test Blistering (250 ° C, 10 seconds)

[Brief description of the drawings]

FIG. 1 is a plan view of an electric circuit board.

FIG. 2 is a sectional view taken along line A-A ′ of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electric circuit board 2 Circuit part 3 Non-circuit part 4 Hole 5 Circuit formation part which emerges on the board surface 6 Connection part

──────────────────────────────────────────────────の Continued on front page (51) Int.Cl. ⁶ Identification code FI C08L 47/00 C08L 47/00 C23C 18/31 C23C 18/31 A H05K 3/00 H05K 3/00 W 3/18 3/18 E 3/38 3/38 A (72) Inventor Teruki Hyogaya 2-6-1 Miwa, Mita-shi, Hyogo Ryodenkasei Co., Ltd.

Claims (5)

[Claims] 1. A molded article comprising (a) one predetermined mold formed of an easily plating resin and (b) one predetermined mold formed of a difficult plating resin. Then, the above (a) and (b) are combined so as to form an electric circuit pattern on the surface of the molded body, and are integrally injection-molded. Thereafter, a portion corresponding to the electric circuit pattern on the surface of the molded body is formed. In the method for producing an electric circuit board produced by performing electroless plating, the easily-platable resin is a composition comprising a syndiotactic polystyrene, an inorganic fiber, and a butadiene-based polymer compound treated with palladium chloride. Manufacturing method. 2. The method for producing an electric circuit board according to claim 1, wherein the easily-platable resin is a composition comprising syndiotactic polystyrene, inorganic fibers, and an inorganic filler treated with palladium chloride. Manufacturing method. 3. The method according to claim 1, wherein the hard-to-plate resin is a composition comprising syndiotactic polystyrene and inorganic fibers. 4. The method according to claim 1, wherein the hard-to-plate resin is a crystalline thermoplastic resin composition having a molding shrinkage and a thermal expansion coefficient similar to those of the easily-plateable resin. 5. A part corresponding to a pattern of an electric circuit on a surface of a molded body is subjected to an etching treatment.
Or the production method according to 2.