JPH0745914A - Plastic molded article having pattern-shaped metal layer - Google Patents

Abstract

PURPOSE:To obtain a plastic molded article which can mount a lead insertion type electronic component and has a pattern-shaped metal layer which can be brought into contact with and connected to the inside of a device. CONSTITUTION:In a molded article wherein through holes 4 for insertion of lead pins 3 of an electronic component are provided in a plastic molded body 2 and pattern-shaped metal layers 5 are formed on the surface of the molded body 2 and on the inner walls of the through holes 4, one side of an opening of each through hole 4 is formed wider than the other side or the central part thereof.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molded article, and more particularly, it has a patterned metal layer and through holes, and has a patterned metal layer for mounting electronic parts by inserting lead pins into the through holes and soldering. The present invention relates to a plastic molded product.

[0002]

2. Description of the Related Art A plastic molded article having a patterned metal layer used as an electric circuit on its surface or the like is advantageous in terms of weight saving, space saving, and reduction in the number of parts,
It can be manufactured efficiently by injection molding of plastic. When mounting electronic parts, there are a method of inserting a lead pin and a surface mounting method. In the former case, as shown in FIG. 4 (A), a through hole 21 for inserting a lead pin of an electronic component is provided at a predetermined position of the molded body 20, and a metal layer 22 is formed on the inner wall and the periphery thereof by plating or the like. Formed, Figure 4
As shown in (B), the lead pin 23 is inserted into the through hole 21 from one side of the through hole 21, and the solder 24 is supplied from the other side for soldering (there may be soldering from the same side in some cases). Thereby, electronic components can be mounted. At this time, the tip of the lead pin 23 projects from the opening (the surface of the molded body 20) of the through hole 21.

[0003]

By the way, the molded product after mounting the electronic parts often comes into contact with the device when it is incorporated into the device. At this time, the tip of the lead pin projects from the surface of the molded product. , And the device cannot be contacted and connected. In particular, in a device having a membrane switch on one side, the molded product and the membrane film are not contact-connected, but when the molded product is incorporated in the vicinity of the membrane film, the protruding lead pin may damage the membrane film.

Further, as shown in FIG.
It is proposed to shorten the lead pin 23 or lengthen the through hole 21 so that the solder does not protrude, but in this case, the solder 24 does not sufficiently enter the through hole 21 and soldering cannot be performed. , Electronic parts could not be mounted.

If all the electronic parts can be of the surface mount type, there will be no such problem, but depending on the part, the lead insertion type must be used, which is a big problem.

An object of the present invention is to solve the above-mentioned problems of the prior art and to provide a plastic molded product having a patterned metal layer capable of mounting a lead insertion type electronic component and being contact-connectable in the apparatus.

[0007]

In order to achieve the above object, a plastic molded article having a patterned metal layer of the present invention has a through hole for inserting a lead pin of a lead type electronic component in the plastic molded body. In a molded product in which a patterned metal layer is formed on the surface of the molded body and on the inner wall of the through hole, one of the openings of the through hole is formed wider than the other or the central part (claim 1). ). It is preferable that the metal layer is formed inside a surface of the molded body opposite to the lead insertion side (claim 2).

Further, in a molded product in which a through hole for inserting a lead pin of a lead-type electronic component is provided in a plastic molded product and a patterned metal layer is formed on the surface of the molded product and the inner wall of the through hole, A plurality of protrusions, which are longer than the tips of the lead pins protruding from the opening of the through hole when the electronic component is mounted, are provided on the surface of the molded body opposite to the lead insertion side (claim 3). It is preferable that one of the openings of the through hole is formed wider than the other or the central portion (claim 4).

[0009]

By forming one of the openings of the through-hole wider than the other or the center, even if the lead-pin is inserted into the through-hole so that the tip of the lead-pin does not protrude from the surface of the molded product,
By supplying the solder from the widely formed opening, the solder sufficiently enters the through hole and the soldering can be performed, so that the lead type electronic component can be mounted without the lead pin protruding (claim 1). . Solder adheres to the metal layer when performing the soldering.Therefore, if the metal layer is formed inside the surface on the side opposite to the lead insertion side of the molded body, the solder will also contact the lead insertion side of the molded body. It does not project from the opposite surface (claim 2).

Further, by providing a plurality of convex portions on the surface of the molded body on the side opposite to the lead insertion side, even if the tip of the lead pin projects from the through hole when an electronic component is mounted, the tip of the convex portion is the tip. Since it is inside the surface, the surface and the device can be contact-connected (claim 3).
By forming one of the openings of the through-hole wider than the other or the central part, the solder is easily supplied into the through-hole by supplying the solder from the widely-formed opening. The reliability is improved and the mounting of electronic parts is facilitated (claim 4).

[0011]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a view showing a first embodiment of a molded product according to the present invention, in which (A) is a cross-sectional view showing the shape of a through hole formed in the molded product, and (B) is mounting an electronic component. It is sectional drawing which shows the state after.

In FIG. 1, reference numeral 1 denotes a molded product, which is a through hole 4 for inserting a lead pin 3 of a lead type electronic component (not shown) into a plastic molded body 2.
And a patterned metal layer 5 is formed on the surface of the molded body 2 and the inner wall of the through hole 4.

The through hole 4 is formed in a circular cross section whose diameter gradually increases from the central portion to the side opposite to the lead insertion side. The metal layer 5 on the inner wall of the through-hole 4 is formed up to almost the center of the inclined portion whose diameter is gradually increased. That is, the metal layer 5 is formed inside the surface of the molded body 2 opposite to the lead insertion side.

The plastic molded body 2 is molded from a thermoplastic resin. As the thermoplastic resin, all general plastic resins can be used, but thermoplastic resins called engineering plastics excellent in rigidity, dimensional stability, electrical characteristics, thermal characteristics, chemical resistance, etc., such as polycarbonate and polyamide. , Polysulfone, polyetherimide, polyethersulfone, polyphenylene sulfide, liquid crystal polymer (trade name: Novacurate, Vectra, etc.), and thermosetting resin such as phenol resin, epoxy resin, diallyl phthalate resin are suitable.

Since it is necessary to form a metal layer 5 of copper or the like on the surface of the molded body 2 as a conductor, it is preferable to use a material that can be easily bonded to a metal, especially a material that can be electroless plated. Further, since the metal layer 5 and the electric parts are connected by soldering, it is particularly preferable to use a synthetic resin having high heat resistance, such as polyether sulfone, polyaryl sulfone, polyphenylene sulfide, polyether imide, and liquid crystal polymer.

A filler such as glass fiber, potassium titanate fiber or calcium carbonate may be mixed in these resins.

The molded body 2 may be molded of insulating ceramics such as steatite (natural talc is the main raw material), alumina, beryllia, boron nitride, mica ceramic, or a mixture of these and glass.

The metal layer 5 can be formed by various methods such as electroless plating, paste application, metal foil attachment, and vapor deposition. Since solder adheres to that portion, the metal layer 5 is provided on the side opposite to the lead insertion side. Is preferably formed inside the surface of the molded body 2 (the opening of the through hole 4), and in the illustrated example, is formed up to almost the center of the inclined portion of the through hole 4. When the metal layer 5 is formed on the surface by plating, among the various resins described above, an amorphous or low molecular weight solvent,
A material that is easily roughened by chemicals or a material into which an electroless plating catalyst such as a noble metal such as palladium, gold, silver, etc. is mixed is used as the material of the molded body.

The molding can be performed by injection molding or press molding. By forming a pin having a shape and size corresponding to the through hole 4 in the mold during molding, the through hole 4
Can be formed during molding. Also, after molding,
The through hole 4 having a specific shape and size may be formed with a tool such as a drill.

The through hole 4 usually has a circular cross section as shown in the drawing, but may have a cross sectional shape other than that, for example, a square or a hexagon. The size of the through hole 4 is
At least the size that allows the lead pin 3 to be inserted, and the size that the gap with the lead pin 3 is filled with an appropriate amount of solder 6 is required. If the through hole 4 is circular, its diameter is usually selected in the range of 0.5 to 1.5 mm.

In the illustrated example, the lead pin 3 of the electronic component is inserted into the through hole 4 of the molded body 2 from the upper (other) opening in the illustrated example, and then soldered and molded as shown in FIG. 1 (B). Electronic components are mounted on the product 1.

The electronic component is the body of the electronic component (not shown).
In addition, a lead type electronic component in which a lead pin 3 as an electrical connecting portion is extended is adopted.

Insertion of the electronic component into the through hole 4 of the lead pin 3 may be carried out by an automatic machine at a possible portion, and the rest may be carried out manually or entirely. At the time of insertion, the tip of the lead pin 3 does not protrude from the surface 2a of the molded body 2 when the electronic component is mounted on the molded body 2. For example, as shown in FIG. It should be located approximately in the center of the ramp. Further, the length of the lead pin 3 of the electronic component may be formed such that the tip does not protrude from the surface 2a of the molded product 2 when the electronic component is mounted on the molded product 2.

Soldering may be carried out using any of solder dipping, flow soldering, and hand soldering.

The soldering of the lead pins 3 in the through holes 4 may be performed by solder dipping or flow soldering using an automatic machine for possible portions, and other operations may be individually performed by hand, or all of them may be performed by hand. It may be done manually.

For soldering in the through-hole 4, the solder 6 is supplied from a widely formed opening (opening on the side opposite to the lead insertion side (lower side in the illustrated example)). As a result, even if the tip of the lead pin is inside the surface of the molded body 2 (the opening of the through hole 4), the opening is wide, so that the solder 6 can sufficiently enter the through hole 4, so that the soldering is performed. Will be possible. At the time of this soldering, the solder 6 adheres to the metal layer 5. However, since the metal layer 5 is formed inside the surface 2a on the opposite side to the lead insertion side of the molded body 2, the solder 6 is formed. It does not protrude from the surface.

In this way, the lead pin 3 is inserted into the through hole 4 having one opening wider than the other or the central portion so that the tip of the lead pin 3 does not protrude from the surface 2a of the molded body 2, and the wide opening is formed. By soldering from
Since the solder 6 sufficiently enters the through hole 4, the lead type electronic component can be mounted on the molded body 2 without the lead pin 3 protruding.

In the first embodiment, the case where the diameter of the through hole is gradually increased from the central portion to the opening on the side opposite to the lead insertion side has been described. The through holes may be formed by any method as long as they are widely formed. For example, as shown in FIG. 3, the through holes may be formed so that the diameter gradually increases from one opening to the other opening. Further, the diameter may be gradually increased from the central portion to both openings.

2A and 2B are views showing a second embodiment of the molded product according to the present invention, in which FIG. 2A is a sectional view showing the shape of a through hole formed in the molded product, and FIG. It is sectional drawing which shows the state after.

In the second embodiment, as shown in the drawing, the through hole 8 is formed on the surface of the molded body 7 opposite to the lead insertion side.
This is an example in which a plurality of protrusions 9 are provided in the vicinity of the opening.

The convex portion 9 may be formed at the time of molding the molded body 7, may be formed by making unevenness with a tool or the like after molding, or may be formed by attaching a projection. That is, the tip of the lead pin 3 is formed inside the tip surface of the convex portion when the electronic component is mounted. The metal layer 10 is
In the first embodiment, it is formed inside the surface of the molded body 2 on the side opposite to the lead insertion side, but in the second embodiment, the convex portion 9 is formed.
It may be formed around the opening of the through hole 8 as long as it is inside the tip surface 9a.

With this structure, the molded article 1
When the lead-type electronic component is mounted on No. 1, even if the tip of the lead pin 3 projects from the opening of the through hole 8, the tip is inside the tip surface 9a of the convex portion 9 and substantially the molded body 7 is formed. Since it is inside the surface of the device, it becomes possible to make a contact connection between the surface and the device.

3A and 3B are views showing a third embodiment of the molded product according to the present invention, in which FIG. 3A is a sectional view showing the shape of a through hole formed in the molded product, and FIG. It is sectional drawing which shows the state after.

The third embodiment is an embodiment in which the second embodiment and the first embodiment are combined, and one of the openings of the through hole of the second embodiment is the other or the central portion. This is an example in which it is formed wider. As shown in FIG. 3, for example, the through-hole is formed in a circular cross-section whose diameter is gradually increased from the opening on the lead insertion side toward the opening on the opposite side, and the through hole is formed on the side opposite to the lead insertion side of the molded body 12. Surface of the through hole 13
A plurality of protrusions 9 are provided in the vicinity of the opening.

Even with this structure, even when the lead type electronic component is mounted on the molded product 14 as in the second embodiment, even if the tip of the lead pin 3 projects from the opening of the through hole 13, the tip of the lead pin 3 may be projected. Is inside the tip surface 9a of the convex portion 9 and substantially inside the surface of the molded body 12, so that the surface and the device can be contact-connected.

Further, when the solder 6 is supplied to the through hole 13, the solder 6 is easily supplied into the through hole 13 by supplying the solder 6 from the widely formed opening, so that the solder 6 is not soldered. The reliability is improved and the mounting of electronic components is facilitated.

Therefore, as described in the first to third embodiments, one of the openings of the through hole 4 is formed wider than the other or the central part, or the lead insertion side of the molded bodies 7 and 12 is formed. By providing a plurality of convex portions 9 longer than the tips of the lead pins 3 protruding from the openings of the through holes 8 and 13 when the electronic component is mounted on the surface on the opposite side, the plastic molded product 1 having the patterned metal layer according to the present invention 1 , 11 and 14 have a three-dimensional structure, the tip of the lead pin 3 does not protrude from the surface of the molded body 2, 7 or 12 even if a lead insertion type electronic component is mounted, and there is no obstacle to any device. Contact connection is possible.

The present invention can be applied not only to a molded product having a three-dimensional structure but also to a flat molded product such as a printed circuit board.

[0040]

In summary, the present invention has the following excellent effects.

1) According to the structure of claim 1, even if the lead pin is inserted into the through hole so that the tip of the lead pin of the electronic component does not protrude from the surface of the molded product, soldering is possible, and the lead type electronic component is mounted. A molded product can be obtained in which the lead pin does not protrude.

2) According to the structure of claim 2, a molded product can be obtained in which neither the lead pin nor the solder protrudes from the surface of the molded body on the side opposite to the lead insertion side.

3) According to the structure of claim 3, even when the tip of the lead pin projects from the through hole when the electronic component is mounted, since the tip of the lead pin is inside the tip surface of the convex portion, it can contact the device without any obstacle. A molded product that can be connected is obtained.

4) According to the structure of claim 4, a molded product which can be mounted with lead-insertion type electronic components and can be contact-connected to the inside of the apparatus, has improved reliability of soldering and is easy to mount electronic components can get.

[Brief description of drawings]

1A and 1B are views showing a first embodiment of a molded product according to the present invention, in which FIG. 1A is a cross-sectional view showing the shape of a through hole formed in the molded product, and FIG. It is sectional drawing which shows a state.

2A and 2B are views showing a second embodiment of a molded product according to the present invention, in which FIG. 2A is a sectional view showing a shape of a through hole formed in the molded product, and FIG. It is sectional drawing which shows a state.

3A and 3B are views showing a third embodiment of a molded product according to the present invention, in which FIG. 3A is a sectional view showing the shape of a through hole formed in the molded product, and FIG. It is sectional drawing which shows a state.

4A and 4B are views showing an example of a conventional molded product, in which FIG. 4A is a sectional view showing the shape of a through hole formed in the molded product, and FIG. 4B is a sectional view showing a state after mounting an electronic component. is there.

FIG. 5 is a cross-sectional view showing an example proposed to prevent a lead pin from protruding when mounting an electronic component in a through hole.

[Explanation of symbols]

 2 molded body 3 lead pin 4 through hole 5 metal layer

 ─────────────────────────────────────────────────── --- Continuation of the front page (72) Inventor Ryo Sato 5-1-1 Hidaka-cho, Hitachi, Ibaraki Hitachi Power Systems Laboratory, Hitachi Cable (72) Inventor Hideki Asano 5 Hidaka-cho, Hitachi, Ibaraki 1-1-1 Hitachi Cable Co., Ltd. Power Systems Research Center

Claims (4)

[Claims] 1. A molded article in which a through hole for inserting a lead pin of a lead-type electronic component is provided in a plastic molded article, and a patterned metal layer is formed on the surface of the molded article and the inner wall of the through hole. A plastic molded product having a patterned metal layer, characterized in that one of the openings of the through hole is formed wider than the other or the central part. 2. The plastic molded product having a patterned metal layer according to claim 1, wherein the metal layer is formed inside a surface of the molded body opposite to the lead insertion side. 3. A molded article in which a through hole for inserting a lead pin of a lead-type electronic component is provided in a plastic molded article, and a patterned metal layer is formed on a surface of the molded article and an inner wall of the through hole, A plastic having a patterned metal layer, characterized in that a plurality of protrusions longer than the tips of the lead pins protruding from the opening of the through hole at the time of mounting an electronic component are provided on the surface of the molded body opposite to the lead insertion side. Molding. 4. The plastic molded product having a patterned metal layer according to claim 3, wherein one of the openings of the through hole is formed wider than the other or the central portion.