JPH0728107B2 - Electric circuit board - Google Patents

Description

The present invention relates to the shape and structure of an electric circuit board that is used in such a manner that a movable member such as a sliding member contacts or may contact an electric circuit. The present invention provides a circuit board in which the circuit portion is not damaged by the movable member.

[Conventional technology and problems]

Conventionally, various polymer materials have been used for substrates such as printed wiring boards, power transformer boards, and substrates for thyristor modules. Phenolic resin laminated plates and glass are used from the viewpoints of time-dependent deformation prevention, heat deformation prevention, rigidity, etc. −
A thermosetting resin has been used as a resin such as an epoxy laminated plate. However, since these use a thermosetting resin as a material, their shape is limited to a flat plate. Therefore, in the case of an electric circuit board that is used such that a movable member such as a sliding member contacts or may contact an electric circuit incorporated in an electric device, since the electric circuit is formed by plating, the circuit surface is a substrate. It rises from the surface.

Therefore, the movable portion slides on the circuit surface, which inevitably damages the plated circuit portion due to friction and impairs the circuit function such as conductivity. In order to avoid this, a new process is required to form a three-dimensional structure with a space between the movable member and the substrate, and for this reason, the electric equipment is inevitably large.

In order to solve the problems of the prior art, the present inventor has made earnest studies and, as a result, has provided an electric circuit portion of a portion where the movable member slides on the circuit surface at a position lower than the substrate surface, and the movable member has the electric circuit portion. It is only necessary to avoid contact between the electric circuit part and the easy-to-plate thermoplastic resin material and the difficult-to-plate thermoplastic resin material by double molding, so that the electric circuit part in the part which is easily brought into contact with the movable member is formed on the substrate. They have found that they can be provided at a position lower than the surface, and arrived at the present invention.

[Means for solving problems]

That is, the present invention comprises (a) one predetermined mold made of an easily-platable thermoplastic resin material, and (b) one predetermined mold made of a hard-to-plate thermoplastic resin material. (A) and (b) are combined on the surface of the molded product so that (a) forms an electric circuit pattern, and the part (a) of the surface of the integrally injection-molded substrate is plated. The present invention provides an electric circuit board characterized in that the electric circuit part of a portion in contact with other equipment is provided at a position lower than the surface of the board.

The example of the present invention shown in FIGS. 1 to 4 will be described.

A plan view of the electric circuit board is shown in FIG. 1. In FIG. 1, the circuit portion 2 of the electric circuit board 1 is (a) a predetermined mold made of an easily-platable thermoplastic resin material. This is the exposed surface of the. The remaining non-circuit portion 3 is a surface-exposed portion of one predetermined mold made of (B) a non-plating thermoplastic material. An electric circuit (not shown in FIG. 1) is formed on the circuit portion by plating. The cross section of the portion of the substrate on which the movable member 4 such as a switch slides is shown in FIGS. In that case, the electric circuit 5 at the portion in contact with the movable member 4 is provided below the surface of the substrate in the concave portion 6.

By doing so, the movable member 4 and the electric circuit 5 do not come into contact with each other, and even if the movable member 4 moves, there is no damage due to friction of the electric circuit 5 and there is no disconnection at the electric circuit 5. .

The substrate of the present invention is made by a so-called two-color injection molding method in which an easily-platable thermoplastic resin material and a hard-to-plate thermoplastic resin material are integrally injection-molded. As a specific embodiment in this case, (1) corresponding to a portion where a circuit needs to be set, (a) one predetermined mold made of an easily-platable thermoplastic resin material is first made, and then this is formed. Set it in the cavity of the mold that has the cavity that forms the whole board, fill the space with (b) difficult-to-plate thermoplastic resin material, and mold
On the surface of the substrate, (a) is a method of integrally combining a circuit forming portion and a non-circuit portion so as to form an electric circuit pattern and performing injection molding. When it is difficult to mold only the fine portion corresponding to the circuit portion, the portion 7 forming the circuit on the substrate surface of (a) needs to be fine as shown in FIG. It is advisable to connect them so that they are connected internally to form the base portion 8.

(2) Contrary to (1), the non-circuit part (b) referred to in (1) is first molded with a hard-to-plate thermoplastic resin material, and then placed in another mold for circuit part molding, This is a method of injection molding so as to fill the space with a plateable thermoplastic resin material. This method is not suitable for forming fine circuits.

The substrate thus formed is plated on only the circuit forming portion (a) by plating the surface thereof, so that a desired circuit can be formed and provided on the substrate.

The easily-platable thermoplastic resin material used in the present invention is not particularly limited as long as it is a thermoplastic resin capable of adhering a metal by plating and having a surface state having an adhesiveness to a certain degree or more. This may be appropriately selected depending on the usage conditions of the substrate. Further, as the hardly-plating thermoplastic resin material, any thermoplastic resin having a surface state in which metal adhesion due to plating does not substantially occur with respect to the plating method, conditions, etc. to be applied can be used. . But,
As an electrical wiring board, it is necessary to meet the requirements for soldering, durability, mechanical properties, etc. from the intended use, and it is heat resistant, has high mechanical strength, good dimensional stability, and a thermal expansion coefficient of metal. A material that is similar and does not easily peel the plated metal is desirable.

From this viewpoint, as the plastic suitable for the present invention, thermotropic liquid crystalline polyester (hereinafter, abbreviated as liquid crystalline polyester) which exhibits anisotropy when melted, polysulfone, polyethersulfone, polyetherimide, polyphenylene sulfide, polyether Examples thereof include ether ketone.

In particular, liquid crystalline polyester is a thermoplastic resin that has excellent physical properties such as rigidity, heat distortion resistance, and dimensional stability because it is possible to form fine wire circuits due to its good moldability.
It is the most suitable material for the substrate of the present invention.

Specifically, the liquid crystalline polyester is a melt-processable polyester having a property that polymer molecular chains have a regular parallel arrangement in a molten state.
The state in which the molecules are arranged in this way is often referred to as a liquid crystal state or a nematic phase of a liquid crystalline substance. The liquid crystal state, that is, the presence of the anisotropic molten phase can be confirmed by the presence or absence of optical anisotropy using a DC polarizer.

The polymer exhibiting the anisotropic melt phase used in the present invention is preferably an aromatic polyester and an aromatic polyesteramide, and a polyester partially containing the aromatic polyester and the aromatic polyesteramide in the same molecular chain is also a preferable example. . Specific examples of the compounds as the constituents and specific examples of the polyester forming the anisotropic molten phase which is preferable for use in the present invention are described in JP-A-61-69866.

Particularly preferred are aromatic polyesters and aromatic polyester amides having as a constituent at least one compound selected from the group consisting of aromatic hydroxycarboxylic acids, aromatic hydroxyamines and aromatic diamines.

More specifically, 1) Polyester consisting only of aromatic hydroxycarboxylic acid 2) a) Aromatic hydroxycarboxylic acid and b) One or more kinds of aromatic dicarboxylic acid and alicyclic dicarboxylic acid and c) Aroma Group diol, alicyclic diol, polyester composed of one or more kinds of aliphatic diol 3) a) aromatic hydroxycarboxylic acid, aromatic hydroxyamine, aromatic diamine and b) aromatic dicarboxylic acid, alicyclic Polyesteramide consisting of one or more of group dicarboxylic acids 4) a) Aromatic hydroxycarboxylic acids, aromatic hydroxyamines, aromatic diamines and b) One of aromatic dicarboxylic acids, alicyclic dicarboxylic acids or A polyesteramide comprising two or more kinds and c) one or more kinds of an aromatic diol, an alicyclic diol, and an aliphatic diol is mentioned. You can

Specific examples include those having the following structures.

These liquid crystalline polyesters may be polymer blends with other thermoplastic resins as long as the intended performance of the present invention is not impaired. Further, these thermoplastic resins can be used as a mixture of two or more kinds. In addition, various additives and reinforcing agents can be added to these resins, if necessary, in order to improve various properties such as mechanical / electrical / chemical properties and flame retardancy. .

The above-mentioned plastics suitable as the substrate material of the present invention, particularly the liquid crystalline polyester, are difficult to plate as they are without adding any inorganic compound, and thus are suitable as the material of the hardly plating resin of the present invention. On the other hand, the periodic table group II element and its oxide, sulfate, phosphate, silicate,
Carbonates and aluminum, silicon, tin, antimony,
By adding one or more inorganic fillers selected from the group consisting of bismuth elements and their oxides, and palladium chloride, the plating property can be improved. That is, even if these plastics are the same, they can be selectively used depending on the presence or absence of the above-mentioned inorganic filler as the easy plating property and the difficult plating property, and can be used in combination with the substrate structure of the present invention.

Examples of the inorganic filler for imparting such plateability include oxides of magnesium oxide, calcium oxide, barium oxide, zinc oxide and the like, magnesium phosphate, calcium phosphate, barium phosphate, zinc phosphate, magnesium pyrophosphate, pyrophosphate. Calcium, sulfates such as barium sulfate, magnesium silicate, calcium silicate, aluminum silicate, kaolin, talc, clay, diatomaceous earth, wollastonite and other silicates, magnesium carbonate, calcium carbonate, barium carbonate, zinc carbonate. it can.

Although such an easily-platable thermoplastic material has a slight decrease in tensile strength and the like, it has little heat resistance, and can be sufficiently used as the easily-platable thermoplastic resin material of the present invention for that purpose.

The purpose of use of the electric circuit board of the present invention is not particularly limited, and may be used, for example, in a case where other equipment, for example, a jig is in contact with or may be in contact with the electric circuit on the board during assembly work. Not to mention getting it.

〔The invention's effect〕

Since the electric equipment using the electric circuit board of the present invention has a slight gap only in the contact surface with the sliding parts, there is no damage due to the movement of the sliding parts, and it can be easily molded and downsized. In addition, there is an advantage that the thickness of the electric device can be reduced.

[Brief description of drawings]

FIG. 1 is a plan view of an electric circuit board of the present invention, and FIG.
FIG. 2 is a schematic sectional view taken along the line II-II of FIG. 3, FIG. 3 is a schematic sectional view taken along the line III-III of FIG. 1, and FIG. 4 is a schematic sectional view for explaining the electric circuit board of the present invention. DESCRIPTION OF SYMBOLS 1 ... Electrical circuit board 2 ... Circuit part 3 ... Non-circuit part 4 ... Movable member 5 ... Electrical circuit 6 ... Dent part 7 ... Circuit formation part which appears on the board surface 8 ... Basic part

Claims (1)

[Claims] 1. A method comprising: (a) one predetermined mold made of an easily-platable thermoplastic resin material; and (b) one predetermined mold made of a hard-to-plate thermoplastic resin material. (A) and (b) are combined on the surface of the molded product so that (a) forms an electric circuit pattern, and the part (a) of the surface of the integrally injection-molded substrate is plated. The electric circuit board, wherein the electric circuit portion of a portion in contact with other equipment is provided at a position lower than the surface of the board.