JPS62131593A - Formation of resin molded electric circuit - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for forming an electric circuit on a resin molded product or a resin molded substrate.

Conventional Technology When forming an electric circuit on a resin molded product or a resin molded substrate having insulation properties, normally, as shown in FIG. Alternatively, the conductive path 2 is formed by electrolytic plating. When forming a current circuit and passing a large current using the conventional method described above, when forming the conductive path 2 using a copper-clad laminate, the stub T of the copper-clad laminate must be
is limited to 18 μm, 135 μm, and 170 μm, so the “11W” of the conductive path 2 must be increased, which has the disadvantage that the entire board inevitably becomes larger.Also, in the case of electrolytic plating, in order to increase the thickness T, However, there are disadvantages in that the processing time becomes longer, the manufacturing cost becomes higher, and the thickness becomes larger and the size becomes larger.

In addition, when a large current and a small current are applied together, each of the above-mentioned methods has disadvantages such as the processing time being tUt and time consuming.

Purpose of the Invention The present invention has been made in view of the above-mentioned drawbacks.
It is possible to form a large current circuit in a simple manner and in a short period of time without increasing the size of the circuit as in the case of the above-mentioned copper-clad laminate, and without increasing the thickness of the conductive path as in the case of the above-mentioned electrolytic plating. Moreover, it is possible to easily form it even when a large current and a small current are mixed.

Structure of the Invention The present invention has been made to achieve the above-mentioned object.When molding a resin-molded substrate, a groove is provided on the surface of the resin-molded substrate, and the inside of the groove is coated with electroless plating, electrolytic plating, or A feature is that a conductive path is formed by the combination thereof. Furthermore, the present invention provides ribs in the above d4 to increase the circuit cross-sectional area when a large current is flowing, and when a mixture of large current and small current is flowing, it is proportional to each current value. The present invention is characterized in that the cross-sectional shape of the circuit of the groove is changed by changing the cross-sectional shape of the groove.

Hereinafter, the present invention will be explained with reference to FIGS. 1 to 3. When molding a resin molded product or resin molded substrate 3 to serve as an insulator by injection molding or compression molding, the required amount is removed from its surface. A medium W concave groove 4 is integrally molded. After the resin molding, a conductive metal such as copper or nickel is adhered to the inside of the groove 4 (left and right side surfaces 4a, 4b and bottom surface 4c) by electroless plating or a combination of electrolytic plating. Conductor track 5 with uniform thickness on the surface of thin film 4
is formed.

When the conductor path 5 is formed by the above method, it has the same width W as the conductor path 2 shown in FIG.
Since the conductor path 5 is formed, a larger circuit cross-sectional area can be secured and a larger current can flow.

In addition, when a large current is to flow, as shown in FIG. bottom surface 4°C, left and right sides 4°a, 4°b, and left and right sides 6a of rib 6
, 6b and the top surface 6C, conductor paths 5' are formed by plating, similar to the two legs.

As described above, if the rib 6 is provided within the groove 4° and the conductor path 5' is formed inside the FfI #4 and on the surface of the rib 6, the W in the same circuit as in FIGS. A large circuit cross-sectional area can be secured, allowing a larger current to flow. It goes without saying that a plurality of the ribs 6 are provided depending on the amount of current.

Figure 3 shows the case where a large current and a small current are passed together, and the width Wl of the groove 4゛ and the width W of 4''° are changed so that the circuit cross-sectional area is proportional to each current value. , mold these 17
A conductor path 5° is formed by plating on the inside of the 44", 4°°. In this case, a large current circuit and a small current circuit can be formed by simply setting the width of the plurality of molded grooves appropriately. A mixed circuit board can be easily formed.

According to the number-of-ships electric circuit formation method, when resin molding an insulating plate,
Since the concave groove is integrally molded and a conductor path is formed by plating on the entire inner surface of the groove, including the bottom and left and right sides, a large current can flow in the same circuit as in the conventional case. Therefore, the size of the entire circuit board can be reduced when a large current flows. In addition, when forming the large current circuit by electroless plating, electrolytic plating, or a combination thereof, there is no need to adjust the thickness of the conductor.
Processing time can be shortened and manufacturing costs can be reduced. Furthermore, for circuit boards with a mixture of large current circuits and small current circuits, it is only necessary to form grooves with different cross-sections according to each current value, and in the case of very large current circuits, there is a rib inside the groove. This has the advantage that a circuit corresponding to the current value can be formed extremely easily.

[Brief explanation of drawings]

1, 2, and 3 are cross-sectional views of a circuit board formed by the method of the present invention, and FIG. 4 is a cross-sectional view of a circuit board formed by a conventional method.

Claims (3)

[Claims] (1) When molding a resin molded product or resin molded substrate, grooves are formed on the surface of the molded product, and a conductive path is formed inside the groove by electroless plating, electrolytic plating, or a combination thereof. Electric circuit formation method. (2) In the method for forming an electric circuit according to claim (1), an electric circuit of a resin molded product is characterized in that a rib is provided in the groove to increase the cross-sectional area of the circuit in order to flow a large current. Circuit formation method. (3) In the electric circuit forming method described in claim (1), in order to flow a mixture of large current and small current, the circuit cross-sectional shape of the groove may be changed in proportion to each current value. Characteristic electrical circuit formation method for resin molded products.