JP2559717B2 - Selective chemical plating method - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for selectively performing chemical plating on a predetermined part of a molded article made of a polymer compound or the same composition.

2. Description of the Related Art Plating a composition composed of the same composition reinforced with a polymer compound, fibers, and a filler has been used in the field of metal substitutes in accordance with the recent demand for weight reduction and size reduction of parts. It is also important in the field of printed wiring boards. Among these fields, it can be said that the field in which the plated portion and the non-plated portion are formed in accordance with a predetermined pattern, as in the case of a printed wiring board or the like, makes good use of the characteristics of the chemical plating method.

However, the method of providing the plated portion according to the predetermined pattern is not always satisfactory in the case of the conventional technique. For example, an attempt to use polyarylene sulfide (hereinafter abbreviated as PAS) or the same composition as a printed wiring board is disclosed in JP-A-57-96588 and JP-A-59-3991, and the like. A technique of irradiating light or laser to plate a metal on the surface irradiated with light is disclosed (Japanese Patent Laid-Open Nos. 60-110729, 61-127867, 61-127868, etc.). However, with these methods, chemical plating is performed after masking the unnecessary plating area with adhesive ink or masking ink, but the adhesive ink or masking ink, etc. does not sufficiently withstand the harsh conditions during the manufacturing process. However, there is a problem in that it is difficult to plate the through-hole portion in the positive type circuit pattern forming method in which plating is applied only to the light irradiation portion.

Therefore, it has been desired to develop a technique capable of selectively forming a precise circuit pattern by chemical plating by improving these drawbacks.

[Outline of Invention]

In summary, the present inventors previously proposed a method of selectively performing chemical plating on a molded product made of PAS or the same composition (Japanese Patent Application No. 60-285242), but as a result of further diligent research, In addition to PAS, we found the fact that even when a large number of polymers or compositions made of the same composition were used, the irradiated area was not selectively plated by irradiation with light as a pretreatment for plating during chemical plating. The present invention has been reached.

That is, the selective chemical plating method according to the present invention uses a polymer compound (PAS) containing oxygen or sulfur atoms in the molecule.
However, when chemical plating is performed on a resin molded product made of the same composition, the parts not to be plated are previously
The method is characterized in that a plating inactivating region is directly provided on the surface of the resin of the molded product by irradiating it with a wavelength of 0.1 to 600 nm, and then chemical plating is performed.

Effects According to the method of the present invention, metal plating in which conductive circuits are selectively formed by chemical plating easily by irradiating oxygen-containing or sulfur-containing polymer moldings other than PAS with light of a specific wavelength Therefore, printed wiring boards of various polymer substances can be manufactured very easily and accurately without using a masking ink or the like.

Since the subject polymer compound is generally applied to those containing an oxygen atom or a sulfur atom in the molecule, the polymer substance can be selected according to the required function.
This is one of the other utilities of the present invention.

Since the method according to the present invention is a negative pattern forming method,
It also has an advantage that plating of the through hole portion is easy.
Further, if the method of the present invention is applied to the manufacture of a printed wiring board, a desired circuit pattern can be formed on a molded product substrate molded into an arbitrary shape by injection molding, and a so-called three-dimensional printed wiring board can be manufactured. Can be performed simply and easily. Needless to say, a flexible printed wiring board can be manufactured by applying the method of the present invention to a molded product formed into a sheet or a film.

Needless to say, the production of a printed wiring board is only one example of the use of the present invention, and the method of the present invention can be effectively used when it is necessary to plate a polymer molded product. Even for polymer compounds containing oxygen or sulfur atoms in molecules other than PAS, which have different surface structures and elemental compositions, it is possible to suppress the chemical plating property by irradiating a specific wavelength, as with PAS. It was unexpected.

[Specific Description of the Invention]

Polymer molded product Polymer compound used in the present invention The polymer mainly used in the present invention is a polymer containing an oxygen atom or a sulfur atom in the molecule and other than PAS. Homopolymers and copolymers (for example, block copolymers) having a glass transition temperature of −40 ° C. or higher are preferable. For example, homopolymers and block copolymers of polysulfone, polyether sulfone, polyether imide, polyether ether ketone, polyarylene terephthalate, etc. can be used as the target polymer compound of the present invention (hereinafter, abbreviated as A polymer). ).

The polymer molded product to be subjected to chemical plating may be, in addition to the polymer A alone, a composition containing other components as subcomponents, and in many cases, it is preferable. . As such a composition, various fillers such as mica, TiO ₂ , Al ₂ O ₃ , CaCO ₃ , carbon black, talc, Ca ₂ SiO ₄ , MgCO ₃ , ZnO, CaO, etc. Examples of the resin include blends of the above resins, and blends with polyimide, polyamide, polyarylene, polyphenylene ether, polycarbonate, polyolefin, ABS, polyvinyl chloride, polymethylmethacrylate, fluororesin and the like.

When a resin is used in combination as these subcomponents, the polymer A must occupy the main part in all the resin components.

In addition, it is often recognized that the target molded article of the present invention is preferably a blend of a fibrous reinforcing agent regardless of the presence or absence of the above-mentioned subcomponents. As the fibers in this case, synthetic inorganic fibers (carbon fiber, glass fiber, silica fiber, alumina fiber, ceramic fiber, etc.), natural inorganic fiber (rock wool, etc.), synthetic organic fiber (aromatic amide fiber, phenol fiber, cellulose) Fibers) or natural organic fibers (pulp, cotton, etc.). In particular, glass fibers are preferable from the viewpoint of heat resistance, strength, economical efficiency and the like. The form of the fibers can be arbitrary,
Needless to say, the one whose surface is treated is effective.

In addition to these fillers, a small amount of coupling material, antioxidant, colorant, photosensitizer and the like can be used.

In the composition comprising these various components, the polymer A preferably accounts for 50% by volume or more of the whole. This is because if the amount is less than this range, the characteristics of polymer A cannot be fully exhibited. The volume% can be calculated from the weight of each component and the specific gravity.

The molding method for obtaining the A polymer molded product to be used in the present invention is not particularly limited, and injection molding, extrusion molding, compression molding and the like can be used. In the present invention, the term "molded product" includes pellets, granules and the like.

Addition of selective plating property The application of the selective plating method according to the present invention consists of irradiating a non-plating portion of the A polymer molding with light of a specific wavelength.

The light to be irradiated has a wavelength of 0.1 to 600 nm, preferably
Those having a wavelength of 190 to 436 nm are used, and irradiation conditions sufficient to prevent chemical plating from adhering to the molded product are selected. Also,
The irradiation time can be shortened by dispersing the photosensitizer in the polymer A or its composition. Also,
The irradiation time can be shortened by performing irradiation in an atmosphere rich in activity such as oxygen. The irradiation time depends on the distance to the light source, the intensity of the light source and the irradiation atmosphere, but is preferably 0.01 seconds or more and less than 1000 hours.
If it is less than 0.01 seconds, it is difficult to obtain the light irradiation effect, and if it is 1000 hours or more, the productivity becomes poor. Particularly preferred irradiation time is 0.01 seconds to
100 hours.

As the light source, a high pressure mercury lamp, a low pressure mercury lamp, an ultra high pressure mercury lamp, a xenon lamp, a carbon arc lamp, a fluorescent lamp, a halogen lamp and the like are suitable. In order to impart selective plating property to the A polymer molded product, a circuit or the like is masked on the molded product substrate with an aluminum foil or the like, or a negative resist is used to mask and then irradiate with light. After shining enough light,
Except for the mask, catalyzing treatment is performed by a conventional method, and chemical plating treatment is performed. The light irradiation may be performed after the catalizing treatment.

For the same purpose, the surface of the molded product is physically or chemically roughened before light irradiation, such as mechanical polishing or organic solvent (carboxylic acid amides, ethers, ketones, etc.), or an oxidizing agent. (Chromium, permanganate, sulfuric acid, etc.) or Lewis acid (AlCl ₃ , TiB, SbF ₅ , SnCl ₄ , BF ₃
If the surface is roughened by the treatment with a solution of (1), the adhesion between the metal layer formed by the chemical plating treatment and the molded product substrate can be improved. Even if such a surface-roughening treatment is performed, the effect of light irradiation is not lost if light-irradiation is performed after the surface-roughening treatment.

Chemical plating Chemical-plating processes include plastics, especially PAS,
It is essentially the same as the conventional or usable one for.

There are no restrictions on the metal used for plating, including copper, nickel,
The target is silver and other metals that can be chemically plated. Chemical copper plating is particularly useful when the present invention is applied to the production of printed wiring boards by the additive method.

The catalyzing treatment may be performed before the chemical plating operation, as described above, and it also belongs to the category of the conventional chemical plating process.

Chemical plating is a well-known technique. Specifically, for example, a water-soluble salt of a metal to be plated and a reducing agent such as formalin are included, and if necessary, a complexing agent such as sodium potassium tartrate, An aqueous solution containing an accelerator, a stabilizer, an improving agent and the like as other auxiliary components is used as a plating bath, and the object to be plated is immersed therein.

Experimental Examples The following examples specifically illustrate the present invention. These are examples, and the present invention is not limited to the following examples.

Example 1 Commercially available polyethylene terephthalate “RT580” (manufactured by Toyobo Co., Ltd.) was pressed at 280 ° C. and rapidly cooled in water at 0 ° C. to prepare an amorphous sheet having a thickness of 0.3 mm. Further, a part of this amorphous sheet was further kept at 200 ° C. for 60 minutes for crystallization to prepare a crystallized sheet.

The amorphous sheet and the crystallized sheet were covered with an aluminum mask on which a circuit pattern was drawn, and a high pressure mercury lamp UM-452 (manufactured by Ushio Inc.)
Irradiated at m for 20 hours. This high pressure mercury lamp UM made by USHIO INC.
The representative wavelength of -452 is the same as that of the 100W high-pressure mercury lamp UM-102 manufactured by the same company.

Then, the aluminum mask was removed, and chemical copper plating was performed under the following conditions.

Catalyzing: 25 ° C. × 10 minutes after washing with water Chemical copper plating: 0 ° C. × 20 minutes after washing with water Drying The composition of the treatment liquid used was as follows.

Catalyzing liquid (0.020g PdCl ₂ ＋ 0.2g SnCl ₂ ＋ 12N HCl 10ml) Total 10
0ml chemical plating solution _{(1.56g CuSO 4 · 5H 2 O} + 1.0g NaOH + 5.0g NaKC 4 H 4 O 6 · 4H 2 O + 37% formalin 1.0 ml / aqueous solution) the total amount 1
00 ml The obtained results are shown in Table 1. Selective chemical plating has been performed in which only the non-irradiated portion is plated regardless of the amorphous sheet or the crystallized sheet.

Example 2 The sample used in Example 1 was subjected to chemical plating by the same method as in Example 1 except that the sample was etched with chromic acid before being irradiated with light or etched with chromic acid after being irradiated with light. The composition of chromic acid used was 0.2 g Na ₂ Cr ₂ O ₇
2H ₂ O + 100 ml 95% H ₂ SO ₄ , etching conditions are 0 ° C ×
It was set to 5 seconds.

As a result, the one that was subjected to the etching treatment before the light irradiation had a property that the light irradiation portion was not plated, but the one that was subjected to the etching treatment after the light irradiation caused plating to occur in the light irradiation portion.

Example 3 A commercially available polyhexamethylene terephthalate [“Duranex 3300” (manufactured by Polyplastics Co.) containing 30% by weight of glass fiber] was injection molded at a resin temperature of 260 ° C., a mold temperature of 60 ° C. and an injection pressure of 800 kg / cm ^2. An injection-molded plate having a thickness of 3 mm × 10 cm × 12 cm was prepared. The obtained injection-molded plate was washed with acetone, etched with chromic acid, irradiated with light in the same manner as in Example 1, and subjected to chemical copper plating.

The light-irradiated portion was not plated, and only the non-light-irradiated portion was plated to form a circuit-like pattern.

As described above, selective chemical plating can be performed even in the case of a molded product containing glass fiber.

Example 4 It could be confirmed by the same method that the following chemical compounds can be subjected to selective chemical plating similar to that in Example 1.

Polysulfone P1700 Nissan Chemical Polyethersulfone 200P Mitsui Toatsu Polyetherterketone 45G Mitsui Toatsu Polyetherimide 1000 Engineering Plastic Polyethylene terephthalate “Lumirror” Toray Then, it was rapidly cooled in water at 0 ° C. to prepare an amorphous sheet having a thickness of 0.3 mm. Similarly, press the amorphous sheet of polymer compound to 280 ℃ () and 380 ℃ respectively.
(), 280 ° C () and 310 ° C (). Also, this quenched amorphous sheet was heated at 280 ° C./20 minutes and at 200 ° C./20 minutes to crystallize, and a crystallized sheet of was prepared. As in Example 1, the surfaces of the amorphous sheet and the crystallized sheet were covered with a negative aluminum mask having a circuit-shaped pattern, and the distance to the light source was increased by a high-pressure mercury lamp (USHIO UM-102 type). Irradiation was carried out at 20 cm for 10 hours. The typical wavelength of the Ushio electrode high pressure mercury lamp UM-102 used in the experiment was 302.2n.
m, 313.2nm, 334.1nm, 365.0nm, 404.7nm, 435.8nm, 54
It was 6.1 nm, 577.0 nm, etc.

Then, chemical plating was performed in the same manner as in Example 1 except for the aluminum mask.

In all of the polymer compound molded articles, plating was performed only on the portions not irradiated with ultraviolet light, regardless of the amorphous sheet or the crystallized sheet.

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Claims (1)

(57) [Claims] 1. When chemical plating is applied to a polymer compound containing an oxygen or sulfur atom in the molecule (excluding polyarylene sulfide) or a resin molded product made of the same composition, 0.1 is preliminarily applied to a portion not requiring plating. A selective chemical plating method, which comprises irradiating light having a wavelength of ˜600 nm to directly provide a plating inactivating region on the surface of the resin of the molded product, and then performing chemical plating.