JP2001102721A - Manufacturing method of composite molded item - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method by which a composite molded item, such as the injection circuit board, injection molded circuit parts, etc., having a small size can be manufactured with high dimensional accuracy by markedly improving the productivity. SOLUTION: In a method for manufacturing a composite molded item, the item is manufactured in such a way that, after a molded aggregate composed of a plurality of single base molded bodies which become the skeletons of the composite molded item is formed by injection molding resin, cutting grooves for hand breaking are formed along dividing lines and plated metallic wiring patterns are selectively formed on the surface of the aggregate. Then finally the aggregate is divided into the single base molded bodies, by breaking the aggregate by hand along the cutting grooves.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing a composite molded article. More specifically, the present invention relates to a method for manufacturing a composite molded article such as an injection molded circuit board (generally abbreviated as MCB), an injection molded circuit component (generally abbreviated as MID), or the like.

[0002]

2. Description of the Related Art In recent years, composite molded articles such as injection molded circuit boards and injection molded circuit parts have been widely used as circuit members for reducing the size and weight of electric equipment.

[0003] In these composite molded articles, first, a base injection-molded article is molded using a plastics material (hereinafter, referred to as an easily-platable plastics material) that can easily perform electroless plating, and then the molded article is formed. An electric circuit pattern made of an electroless plating layer is formed on the surface.

Accordingly, composite molded articles such as these injection molded circuit boards and injection molded circuit parts can be used not only for flat circuits and flat wirings such as conventional printed wiring boards, but also for three-dimensional circuits and three-dimensional wirings. is there. (For example, see JP-A-63-
No. 50482, Japanese Unexamined Patent Publication No. 1-297989, etc.)
Now, composite molded articles such as these injection molded circuit boards and injection molded circuit components are manufactured by the following two methods.

(1) Double molding method The outline of the double molding method is as follows.

First, a base injection-molded article is formed using an easily-plateable plastics material.

[0007] This molding is called primary molding. The base injection molded body obtained by the primary molding is also called a primary molded body.

Next, a plastics material that is difficult to electrolessly plating (hereinafter, referred to as a non-platable plastics material) is secondarily formed on the outer surface of the unnecessary part of the primary molded body.

[0009] This molding is called secondary molding. The molded body obtained by the secondary molding is called a secondary molded body.

[0010] Next, the portion of the secondary molded body to which metal plating is applied, that is, the exposed portion of the easily-plated plastics of the secondary molded body is subjected to surface treatment, and then subjected to electroless plating, followed by post-treatment. In this way, a conductive wiring pattern composed of an electroless metal plating layer is formed to obtain a composite molded product.

(2) Single molding method The outline of the single molding method is as follows.

First, a base injection-molded article is formed using an easily-plateable plastics material.

Next, after subjecting the surface of the base injection molded body to a surface treatment, electroless plating is performed.

Next, the electroless plating layer provided on the surface of the base injection-molded article is exposed, developed, and etched so that a predetermined wiring pattern can be formed. A composite molded article is formed by forming a pattern.

[0015]

The most problematic point when manufacturing by the double molding method or the single molding method is various problems caused by the fact that the dimensions of the composite molded article to be manufactured are too small.

For example, there are the following disadvantages.

Injection Moldability When molding a base injection molded body using an easily plating plastics material, the size of the base injection molded body to be injection molded is small, and therefore, the injection moldability is poor.

Electroless Metal Plating Property When performing electroless plating on the surface of the base injection molded article,
Since the size is too small, it is difficult to fix the plating jig to the plating jig, and it takes time to set the electroless plating apparatus. In addition, useless materials are used for the spool and the runner.

Further, a large discard pattern is required as compared with the main body. Further, when barrel plating is required, the plating operation is technically difficult and there is a problem that the cost is increased.

As a result, the productivity of electroless plating is low.

[0021] Cutting workability of the composite molded article When the obtained composite molded article is subjected to a cutting step, a cutting treatment liquid used in the cutting step, for example, water is formed on a conductive wiring formed on the surface of the composite molded article. Contaminating the pattern. Therefore, when a cutting step is performed on the obtained composite molded article, it is necessary to add a washing step for removing the cutting treatment liquid.

The present invention has been made in view of such a point, and an object of the present invention is to solve the above-mentioned disadvantages of the prior art and to provide a composite of a small-sized injection molded circuit board or injection molded circuit component. It is an object of the present invention to provide a method of manufacturing a composite molded product capable of producing a molded product with high dimensional accuracy and with remarkably enhanced productivity.

[0023]

SUMMARY OF THE INVENTION The gist of the present invention resides in that, after injection molding of a molded assembly obtained by integrating a plurality of base molding single bodies to be a skeleton using a resin, the molded assembly is molded. The groove is cut along the dividing line along the dividing line, and thereafter, a metal-plated wiring pattern is selectively formed on the surface of the molded assembly. Finally, the molded assembly is cut into the cut groove. A method for manufacturing a composite molded product, wherein the composite molded product is divided into a plurality of composite molded products by hand folding along the same.

In the present invention, the molded assembly is obtained by injection-molding a primary molded assembly obtained by integrating a plurality of primary molded units to be a skeleton using a hard-to-plate resin, and then forming an outer periphery of the primary molded assembly. It is preferable to mold the main portion of the surface by a double molding method in which an easy-plating resin is cast and formed, or by a single molding method using an easy-plating resin or a hard-to-plate resin.

In the present invention, the groove for the hand-cut groove is preferably one selected from dicing groove, carbon dioxide laser groove, cutter groove, and press punching groove.

[0026]

Next, an embodiment of the method for producing a composite molded product according to the present invention will be described.

In the present invention, the number of the molded base is determined by the size and shape of the molded base, the processability of the metal plating pattern, and the like. In general, the number of base molded units constituting a composite molded product is several to several hundreds.

In the present invention, the resin molding of the molded assembly may be performed by combining a hard-to-plate resin and an easily-plateable resin, by combining only the easily-plateable resin, or by using only the easily-plateable resin. Or molding with only a difficult-to-plate resin.

In the present invention, the easily-platable resin may be any resin capable of electroless metal plating, and examples thereof include ABS resin, polycarbonate resin, polyetherimide resin, polyphenylene sulfide resin, and easily-plateable liquid crystal resin. These are simple or electroless metal plating catalysts,
For example, a material containing palladium, tin, gold, silver, or the like may be used, or a material added with a ferrer, for example, glass fiber, potassium titanate fiber, or calcium carbonate may be used.

Here, when an easily plating resin containing no electroless metal plating catalyst is used, an electroless metal plating catalyst is additionally added before performing the electroless metal plating. There are a catalyst accelerator method and a sensitizing acti-ending method for adding the electroless metal plating catalyst additionally. In the catalyst accelerator method, first, an electroless metal plating catalyst such as palladium, tin or the like is deposited by immersing in an electroless metal plating catalyst solution such as palladium or tin and then activating with an acid.

In the present invention, the resin which is difficult to be plated may be any resin which is difficult to perform electroless metal plating. It is not a resin in which electroless metal plating is difficult or impossible in any case. In other words, the hard-to-plate resin may be any resin that is less likely to be electrolessly metal-plated than the easily-plated resin. Therefore, the easily-platable resin may be an easily-plateable resin. These include thermosetting resins such as epoxy resins.

In the present invention, the wiring pattern may be a conductive metal layer. Here, examples of the conductive metal layer include a metal plating layer, vapor deposition, sputtering, and a conductive paint film.

The metal plating layer may be formed by electroless metal plating, electrolytic metal plating, or a combination thereof.

In order to form a metal plating layer on the formed assembly, the formed assembly is subjected to a roughening treatment in advance.

Examples of the roughening solution include a chromic acid / sulfuric acid solution, an aqueous potassium hydroxide solution, and a hydrofluoric acid / sulfuric acid solution.

The types of metal plating include copper plating, nickel plating, and gold plating.

When the one-time molding method is employed, the surface of the molded assembly is roughened, a conductive layer is formed, a resist agent is applied, and then exposure, development, etching, and the like are performed.

[0038]

EXAMPLES Next, examples of the method for producing a composite molded product according to the present invention will be described.

(Example 1) The method for producing a composite molded product according to Example 1 of the present invention is a so-called twice molding method.

Injection Molding of Primary Molded Assembly First, a primary molded aggregate was integrally formed by integrating 16 primary molded units to be used as a skeleton using polyphenylene sulfide as a hard-to-plate resin.

FIG. 1 is a perspective view of the primary molded assembly thus obtained.

In FIG. 1, reference numeral 10 denotes a primary molded unit, and reference numeral 11 denotes a primary molded assembly.

That is, the primary molded aggregate 2 is the primary molded unit 1
Are integrated with each other.

Next, the castable form of the secondary molded aggregate Next, the primary plating aggregate 2 obtained in this manner is coated with a palladium catalyst as an easily plating resin in a plating essential portion of the outer peripheral surface thereof. A secondary molded assembly was formed by casting a liquid crystal polymer.

That is, an easy-plating liquid crystal polymer mixed with a palladium catalyst as an easy-plating resin is poured into the main portion of the outer peripheral surface of each of the secondary molding units constituting the secondary molding assembly. It is shaped. In other words, the castable easy-to-plate liquid crystal polymer is exposed at the plating portion on the outer peripheral surface of each of the secondary molded units constituting the secondary molded assembly.

Next, the secondary molded aggregate obtained above is mounted on a die sink device, and the secondary molded unit constituting the secondary molded aggregate is 4
Five hand-cut grooves were cut so that they could be broken by hand.

The grooving conditions are as follows: a dicing blade having a width of 0.2 mm, a rotation speed of 10,000 rpm, a feed speed of 1 cm / sec, and a margin of 0.5 mm.

FIG. 2 is a perspective view showing the secondary molded assembly obtained by cutting the thus-obtained hand-cut groove.

In FIG. 2, reference numeral 20 denotes a secondary molding alone, reference numeral 21 denotes a secondary molded assembly, reference numeral 22 denotes a hand-cut groove of the first embodiment,
Is the margin of Example 1.

Here, the hand-cut groove 22 of the first embodiment is used.
Is 0.2 mm, which is almost the same width as the width of the dicing blade.

Next, roughening treatment of the secondary molded body having the groove formed by cutting the hand-cut groove is carried out. The exposed portion of the easy-to-plate liquid crystal polymer which was formed by casting was roughened.

The roughening solution is an aqueous solution of potassium hydroxide having a concentration of 11 mol / l.

The conditions for the roughening treatment are as follows: the temperature of the aqueous potassium hydroxide solution is 70 ° C., and the time is 30 minutes.

Next, the mixture was neutralized with dilute hydrochloric acid.

Next, the electroless metal plating operation of the roughened secondary formed aggregate is performed. Next, the rough cut secondary groove is grooved, and the rough portion of the outer peripheral surface of the roughened secondary formed aggregate is roughened. Electroless metal plating was performed on the chemically treated surface.

In this electroless metal plating, first, electroless copper plating was applied as a base plating to a thickness of 20 μm.

Next, electroless nickel plating was performed to a thickness of 5 μm on the electroless copper plating layer of the base plating.

Next, electroless gold plating was performed on the electroless nickel plating layer to a thickness of 0.3 μm.

Next, a hand-formed work of the electroformed metal-plated secondary molded body is performed. Next, the hand-cut cut groove is grooved and roughened as described above. Was taken and manually folded along the hand-cutting groove and the like to obtain 16 composite molded products.

FIG. 3 is a perspective view of the composite molded product of Example 1 thus obtained.

In FIG. 3, reference numeral 30 denotes a composite molded product of Example 1, 31 denotes a primary-molded hard-to-plate resin portion, 32
Is an easily-plated resin-molded portion formed by secondary molding, 33 is a wiring pattern made of electroless metal plating, and 34 is a cut surface of the hand-folded portion of the first embodiment.

As described above, according to the method for manufacturing a composite molded product of Embodiment 1 of the present invention, 16 composite molded products 30 can be produced with high dimensional accuracy and 16 times higher productivity. Was.

Example 2 The method for producing a composite molded product according to Example 2 of the present invention is a so-called single molding method.

Injection Molding of Base Molded Assembly First, a base molded aggregate in which 16 base molded single bodies to be a skeleton are integrally formed by using an epoxy resin that is difficult to plate and does not contain a catalyst is injection molded. did. Next, the base molded assembly obtained above is mounted on a die sink device so that four base molded units constituting the base molded assembly can be broken by hand. Then, five hand-cut grooves were cut.

The grooving conditions are a dicing blade having a width of 0.2 mm, a rotation speed of 10,000 rpm, a feed speed of 1 cm / sec, and a margin of 0.5 mm.

FIG. 4 is a perspective view showing the base molding assembly obtained by cutting the thus-obtained cut-off groove.

In FIG. 4, reference numeral 40 denotes a base molded unit;
Is a base molded assembly, 42 is a hand-cut groove of Example 2,
Reference numeral 43 denotes a margin of the second embodiment.

Here, the groove width of the bend groove 42 in the second embodiment is 0.2 mm, which is almost the same as the width of the dicing blade.

[0069] Next, a catalyst was applied to the base molded assembly obtained by cutting the hand-cut grooves, and a catalyst was applied to the outer peripheral surface of the base molded assembly obtained by cutting the hand-cut grooves obtained above.

Next, electroless copper plating was performed on the catalyst surface of the base molded assembly obtained by grooving the hand-cut groove obtained above on the catalyst surface of the base molded assembly. The thickness was set to 5 μm.

Application of Resist Agent on Electroless Copper Plating of Base Molded Assembly Next, the electroless copper plating layer of the base molded aggregate obtained by grooving the cut groove obtained above and plating with electroless copper Was coated with a resist agent.

Formation of Predetermined Wiring Pattern on Resist Agent of Base Molded Assembly Next, the above-mentioned cut-off groove is grooved and electroless copper-plated, and further, on the electroless copper plating layer On the resist agent of the base molding aggregate coated with the resist agent,
Exposure was performed so that a predetermined wiring pattern was formed. Next, the resist agent in the non-pattern portion was removed by development, and then the underlying copper plating layer in the non-pattern portion was removed using a ferric chloride-based etchant.

Next, electrolytic copper plating was performed to a thickness of 10 μm on the thus formed pattern made of electroless copper plating.

Next, electrolytic nickel plating was performed on the electrolytic copper plating layer to a thickness of 5 μm.

Next, electrolytic gold plating was performed on the thus formed electroless nickel layer so as to have a thickness of 0.3 μm.

[0076] Next, the hand-formed work of the electroformed metal-plated base molding assembly is cut off as described above, and the electroformed metal-plated base molding assembly is obtained. By hand-folding along the hand-cut groove and the like, 16 composite molded articles were obtained by a single molding method.

FIG. 5 is a perspective view of a composite molded product obtained by the single molding method obtained in this manner.

In FIG. 5, 50 is a composite molded product of the second embodiment, 53 is a wiring pattern made of metal plating, and 54 is a second embodiment.
This is the cut surface of the hand.

As described above, according to the method for manufacturing a composite molded product of Example 2 of the present invention, 16 composite molded products 50 could be produced with high dimensional accuracy and 16 times higher productivity. .

[0080]

According to the method for producing a composite molded product of the present invention, a composite molded product such as an injection molded circuit board or an injection molded circuit component can be produced with high dimensional accuracy and markedly enhanced productivity. Which is industrially useful.

[Brief description of the drawings]

FIG. 1 is a perspective view of a primary molded assembly obtained by a method for producing a composite molded product according to Example 1 of the present invention.

FIG. 2 is a perspective view showing a secondary molded assembly obtained by cutting a bent groove obtained by the method of manufacturing a composite molded product according to Example 1 of the present invention.

FIG. 3 is a perspective view of a composite molded product obtained by the method for producing a composite molded product of Example 1 of the present invention.

FIG. 4 is a perspective view showing a base molded assembly obtained by cutting a bent groove obtained by the method of manufacturing a composite molded product according to the second embodiment of the present invention.

FIG. 5 is a perspective view of a composite molded product obtained by the method for producing a composite molded product according to the second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Primary molded unit 11 Primary molded unit 20 Secondary molded unit 21 Secondary molded unit 22 Hand-cutting groove of Example 1 23 Cutting margin of Example 1 30 Composite molded product of Example 1 31 Primary molded difficult plating Resin molded part 32 Secondary molded easy-plated resin molded part 33 Wiring pattern made of electroless metal plating 34 Hand-cut cut surface of Example 1 40 Base molded unit 41 Base molded aggregate 42 Hand-cut groove of Example 2 43 Cut-off margin of Example 2 50 Composite molded article of Example 2 53 Metal-plated wiring pattern 54 Hand-cut cut surface of Example 2

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B29L 31:34 B29L 31:34 (72) Inventor Yuji Yoshida 5-1-1 Hidakacho, Hitachi City, Ibaraki Prefecture No. Hitachi Cable, Ltd. Hidaka Factory (72) Inventor Shinichi Takaba 5-1-1 Hidakacho, Hitachi City, Ibaraki Prefecture Hitachi Cable Co., Ltd. Hidaka Factory (72) Inventor Minoru Usui Hitachi City, Ibaraki Prefecture 5-1-1 Takamachi Hitachi Cable, Ltd. Hidaka Factory F-term (reference) 4F213 AA49 AG03 AH36 WA02 WA05 WA14 WA53 WA55 WA63 WA73 WA92 WB01 4K022 AA13 AA42 BA03 BA08 BA14 BA35 CA08 DA01 EA03 5E343 AA01 AA12 BB15 BB21BB66 DD59 GG11

Claims (4)

[Claims] After injection molding a molded assembly obtained by integrating a plurality of base molding single bodies to be a skeleton using a resin, the molded assembly is cut along hand-cut grooves along the dividing lines. Thereafter, a wiring pattern made of metal plating is selectively formed on the surface of the molded assembly, and finally, the molded assembly is manually folded along the cut-off groove to form a plurality of composite molded products. A method for producing a composite molded product, which comprises dividing. 2. The injection molding of a primary molded assembly obtained by integrally integrating a plurality of primary molded units forming a skeleton by using a hard-to-plate resin, and then forming an outer peripheral surface of the primary molded aggregate. The method for producing a composite molded product according to claim 1, wherein the molding is performed by a double molding method in which an easily-platable resin is cast and formed on a main portion of the plating. 3. The method for producing a composite molded article according to claim 1, wherein the molded assembly is molded by a one-time molding method using an easily plating resin or a hardly plating resin. 4. The grooving of the hand-cutting grooving groove is one selected from dicing grooving, carbon dioxide laser grooving, cutter grooving, and press punching grooving. A method for producing the composite molded article according to the above.