JPH02122589A - Circuit substrate - Google Patents

Abstract

PURPOSE:To obtain a circuit substrate which improves workability and makes this substrate compact and highly dense; besides, permits a large electric current to flow by connecting directly circuit patterns which are formed at both faces of an insulating substrate consisting of a thermoplastic resin at a part of a through hole that is formed in the substrate. CONSTITUTION:A through hole 12 is made at a part where the circuit patterns of an insulating substrate 11 consisting of a thermoplastic resin, for example, polycarbonate are formed and connected each other. Respective circuit patterns 13a and 13b are formed at the surface and rear of the insulating substrate 11 and at a substrate part in which the through hole 12 is located, the circuit pattern 13a is pushed down in a great way to the lower side of the substrate by the through hole 12. Then, coming directly into contact with the circuit pattern 13b at the rear of the substrate, the circuit pattern 13a is connected electrically to the circuit pattern 13b.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a circuit board, and particularly to a high current circuit board with a through-hole function.

(Prior Art) As is well known, substrates with metal foil pasted on both sides and metal core substrates are known as hybrid IC substrates for large current circuits. FIG. 1 shows an example of a circuit board using a double-sided copper-clad laminate. 1 in the figure is a copper foil pattern (circuit pattern) 2a on both sides.

2b is an insulating substrate made of glass epoxy resin or phenol resin. A through hole 3 is provided at a predetermined position of the insulating substrate 1, and a through hole 5 is formed by forming, for example, a Cu paste layer 4 through a plating process to connect the circuit patterns 2a and 2b in the through hole 3. ing.

However, in the conventional circuit board, after opening the through hole 3 in the insulating substrate 1, a Cu paste layer 4 is formed by plating process to connect the circuit patterns 2a and 2b formed on both sides of the substrate 1. are doing. However, in the plating process, it is necessary to perform base polishing by puff polishing or barrel polishing, and various work steps are required, such as cleaning treatment to remove trace amounts of oil and fat remaining on the base material such as insulating substrates. This results in decreased workability. In addition, in conventional circuit boards, the paste layer 4 must be formed thick in order to allow a large current to flow through the paste layer 4, but in this case, it takes a long time to form the paste layer 4, so The number of through holes 5 is increased to allow a large current to flow. Therefore, there is a drawback that the circuit board becomes larger.

The present invention was made in view of the above circumstances, and facilitates through-hole functionality by directly connecting circuit patterns formed on both sides of an insulating substrate made of thermoplastic resin through through-holes provided in the substrate. It is an object of the present invention to provide a circuit board that can be obtained with high efficiency, has improved workability, can be made smaller and more dense, and can also flow a large current.

[Structure of the Invention] (Means for Solving the Problems) The present invention provides an insulating substrate made of thermoplastic resin, circuit patterns provided on both surfaces of the insulating substrate, and circuits on both surfaces of the insulating substrate. a through-hole provided in a part of the board to which the patterns are to be connected, and the circuit patterns on both sides of the board are directly connected to each other at the through-hole part by crimping from at least one of the upper and lower sides of the insulating board. This circuit board is characterized by:

Examples of the thermoplastic resin according to the present invention include vinyl resins such as polyethylene, polystyrene, polycarbonate, and polyvinyl chloride; chain polymer celluloids such as polyamide;
Examples include natural polymer derivatives such as cellulose acetate and chlorinated rubber.

In the present invention, the circuit pattern on both sides of the insulating substrate may be electrically connected in the through hole 1 in a patterned state, or metal plates may be formed on both sides of the insulating substrate 2.
Both metal plates may be electrically connected within the through hole and then patterned to form a circuit pattern.

(Function) According to the present invention, the circuit patterns on both sides of the substrate are electrically connected by pressing at least one of the circuit patterns located above or below the through hole.

Alternatively, a circuit pattern connected within the through holes can also be obtained by forming metal plates on both sides of an insulating substrate, electrically connecting both metal plates within the through holes, and then patterning.

According to the present invention, circuit patterns formed on both sides of an insulating substrate can be easily and directly electrically connected using simple means such as pressing or spot welding without forming through holes as in the conventional method. A circuit board is obtained.

Of course, the circuit pattern in the through-hole can have a through-hole function as in the prior art. Therefore, it is possible to have a smaller size and higher density than before, and also allows a large current to flow.

(Example) An embodiment of the present invention will be described below with reference to FIG.

11 in the figure is an insulating substrate made of thermoplastic resin, for example polycarbonate. A through hole 12 is provided in a portion of this insulating substrate 11 where a circuit pattern to be described later is to be formed and connected.
is opened. A circuit pattern 13a is provided on the front and back surfaces of the insulating substrate 11, respectively.

+3b is formed. Among these circuit patterns, in the board portion where the through hole 12 is located, the circuit pattern 1
3a is pushed largely toward the lower side of the board through the through hole 12, and is in direct contact with and electrically connected to the circuit pattern 13b on the back of the board. Here, circuit pattern 1 on both sides of the board
When connecting 3a and 13b at the through hole 12,
This is done by spot welding while pressing the circuit pattern Ha from one side of the through hole 12. Note that after forming the circuit pattern 13a in this way, pressing and spot welding may be performed, but it is also possible to form metal plates on both sides of the board, press and spot weld, and then pattern the circuit patterns 13a and 13b. may be formed.

According to the circuit board according to the above embodiment, the circuit pattern 1 is formed on both sides of the insulating substrate 11 made of thermoplastic resin.
3a and 13b, and these circuit patterns 13a
, 13b are directly electrically connected to each other through the through holes 12 provided at appropriate positions in the insulating substrate 11, so that the insulating substrate 11 The circuit patterns 13a and 13b formed on both sides of the container can be electrically connected to the container using simple means such as pressing or spot welding. Therefore, within the through hole 12, the circuit pattern 13a,
By directly connecting 13b, work efficiency is significantly improved compared to the conventional method, and large current can be passed without using a large number of through holes as in the conventional method, and the device can be made smaller and more dense. .

Note that the circuit board according to the present invention is not limited to the one shown in FIG. 1, but may have the structure shown in FIG. 2, for example. This circuit board has circuit patterns 13a on both sides of an insulating board 11.
, 13b are formed by compressing the through hole 12 from above and below.

[Effects of the Invention] As detailed below, according to the present invention, the circuit patterns formed on both sides of an insulating substrate made of thermoplastic resin are directly connected through the through holes provided in the substrate. By doing so, it is possible to easily obtain a through-hole function, improve workability, and provide a circuit board that can be made smaller and more dense, and can also flow a large current.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a circuit board according to an embodiment of the present invention, FIG. 2 is a cross-sectional view of a circuit board according to another embodiment of the present invention, and FIG. 3 is an explanatory diagram of a conventional circuit board. . 11... Insulating substrate made of thermoplastic resin, 12...
-Through holes, 13a, 13b...Circuit pattern.

Claims (1)

[Claims] An insulating substrate made of thermoplastic resin, circuit patterns provided on both sides of the insulating substrate, and a through hole provided in a portion of the substrate to which the circuit patterns on both sides of the insulating substrate are to be connected, A circuit board characterized in that the circuit patterns on both sides of the board are directly connected to each other at the through hole portion by pressure bonding from at least one of above and below the insulating board.