JP2008258266A - Terminal connection structure to metal base substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a connection structure such as a power supply output terminal or the like to a metal base substrate. <P>SOLUTION: The terminal connection structure includes the metal base substrate provided with a through-hole and formed by joining a conductive pattern part on a metal base via an insulating substrate and a threaded terminal member arranged in the side of the conductive pattern part of the metal base substrate in opposition to the through-hole. The terminal member and the metal base substrate are mechanically connected with an insulating screw via the through-hole and the terminal member and the conductive pattern part are electrically connected through a soldering process. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a terminal connection structure for fixing a terminal member such as a power supply terminal to a metal base substrate, for example.

  Recently, metal base boards have been used to efficiently dissipate heat generated from electronic components mounted on printed wiring boards, for example, heat-generating components such as high-current output power transistors. . In connection with this, the terminal connection structure for fixing terminal members, such as a power supply terminal, to a metal base board was developed and proposed (for example, refer to patent documents 1). This is because the circuit conductor is formed on the surface of the metal plate via an insulating layer, a metal base substrate provided with a through hole, and a protrusion that closes the circuit conductor side opening of the through hole is provided. Is inserted, the projecting portion is insulatively bonded to the circuit conductor, and the projecting portion and the circuit conductor are soldered.

In addition, it has also been proposed to form a hole in the metal base substrate, press-fit a fixing fitting into the hole, and attach an actual equipment (see, for example, Patent Document 2). In this method, a metal pin is provided in the housing portion of the surface mount connector, and is held and fixed by press-fitting into the hole of the metal base substrate.
Japanese Utility Model Publication No. 4-8467 Japanese Patent Laid-Open No. 3-13876

  In the terminal mounting structure in which the metal base substrate is connected only by soldering, the mechanical strength of the terminals is ensured by the mechanical strength of the solder and the peel strength of the conductive pattern and the non-conductive pattern. Therefore, there is a problem that connection failure occurs when external stress is applied to the terminal.

  Further, in the structure in which the fixing metal fitting is press-fitted into the substrate, the insulating substrate portion needs a certain thickness. The metal base board aims at exhausting heat generated from the mounted parts on the board part through the metal part. Therefore, if the insulating board part is thickened, the thermal conductivity is lowered and the heat exhausting performance is deteriorated. .

  Therefore, an object of the present invention is to provide a terminal connection structure to a metal base substrate that can sufficiently ensure mechanical strength and insulation in order to solve the above-described problems.

According to one aspect of the present invention, a metal base substrate having a through hole formed by bonding a conductive pattern portion to a metal base via an insulating substrate;
A terminal member disposed on the conductive pattern portion side of the metal base substrate and facing the through hole;
The terminal member and the metal base substrate are mechanically connected by an insulating member through the through hole, and the terminal member and the conductive pattern portion are electrically connected. A terminal connection structure to a metal base substrate is provided.

Further, according to one aspect of the present invention, a metal base substrate having a through hole formed by bonding a conductive pattern portion to a metal base via an insulating substrate;
A conductive pattern portion side of the metal base substrate, and a terminal member that is disposed facing the through hole and subjected to threading,
The terminal member and the metal base substrate are mechanically connected through an insulating screw through the through hole, and the terminal member and the conductive pattern portion are electrically connected by soldering. A terminal connection structure to a metal base substrate is provided.

  Further, in the terminal connection structure to the metal base substrate of the present invention, the terminal member is countersunk around the screw hole or is flattened to ensure a creeping distance for insulation. And

  Further, in the terminal connection structure to the metal base substrate of the present invention, a space distance for insulation is secured by separating the through hole and the conductive pattern portion by a predetermined distance.

  In the terminal connection structure to the metal base substrate of the present invention, the insulating member is an insulating screw.

  In the terminal connection structure to the metal base substrate of the present invention, the insulating screw is a flat head screw.

  In the terminal connection structure to the metal base substrate of the present invention, the insulating substrate is FR-4.

  In the terminal connection structure to the metal base substrate of the present invention, the terminal member is brass or phosphor bronze.

  According to the present invention, mechanical strength can be ensured, the metal base substrate can be thinned, and thermal conductivity can be improved. Moreover, insulation can be arbitrarily ensured.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, the same portions are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 1 is a schematic cross-sectional view showing a terminal connection structure to a metal base substrate according to the present embodiment. As shown in FIG. 1, this terminal connection structure is roughly composed of a terminal 1, a metal base substrate 3, an insulating screw 4, and solder 2.

  First, the metal base substrate 3 has a configuration in which an insulating base 3b is bonded to a metal plate 3d by an insulating adhesive 3c, and the substrate 3a is formed on the insulating base 3b.

  The metal plate 3d is preferably the same as the material of the housing that houses the electronic device. For example, the metal plate 3d is made of aluminum having a good heat dissipation property and a plate having a thickness of 3 mm.

  Insulating base material 3b is, for example, FR-, which is a copper-clad laminate having a general heat resistance made of a flame-retardant glass cloth base epoxy resin, from the viewpoint of high reliability of insulation. A material such as 4 is preferred.

  As the insulating adhesive 3c, for example, an epoxy adhesive is suitable.

  The substrate 3a is formed of a conductive pattern, and the material is preferably, for example, copper or aluminum.

  The layer configuration of the insulating base material 3b and the substrate 3a is not necessarily a single-sided substrate, and may be a double-sided substrate or a multilayer substrate.

  A through hole 3 e is formed in the metal base substrate 3. In addition, countersunk processing that matches the inclination of the screw head is applied to the portion of the metal plate 3d of the metal base substrate 3 so that the countersunk screw 4 is screwed into the through hole 3e and the screw head is embedded in the metal plate 3d. It has been subjected. The countersunk screws 4 are preferably so-called engineering plastics in order to ensure heat resistance of about 150 ° C., for example. For example, an insulating screw such as PPS (polyphenylene sulfide) is suitable. PPS is a crystalline heat-resistant polymer, has a high melting point of about 280 ° C. and chemical resistance, and has a non-flammable property that exhibits self-extinguishing properties without adding a flame retardant.

  Terminals 1 are arranged at positions facing the through holes 3 e of the metal base substrate 3. The terminal 1 is preferably a conductive material plated with tin, for example. This is because the terminal 1 can be soldered to the substrate 3 a of the metal base substrate 3. The terminal 1 is preferably made of brass or phosphor bronze, for example. The terminal 1 has a counterbore hole on the side facing the metal base substrate 3. A female screw is cut into the hole so that the countersunk screw 4 is screwed. Therefore, the terminal 1 and the metal base substrate 3 are mechanically connected by the insulating screw 4. The counterbore may be a flat plate process, and is intended to ensure a creepage distance. Here, the creepage distance is a distance measured along the surface of the insulator that separates both the insulated conductors. For example, in order to use a combination of devices having different potentials, it is necessary to provide an insulating portion for separating the ground. The insulation and withstand voltage conditions vary depending on the operating voltage of the device, the usage environment, and the like. Therefore, if the spatial distance, which is the linear distance between the insulated conductors, is sufficient, the counterbore can be omitted.

  As the solder 2, either lead-containing solder or lead-free solder can be selected. The terminals 1 and the substrate (conductive pattern) 3a are electrically connected by soldering.

  Next, the operation of the above terminal connection structure will be described. A through-hole is provided in the metal base substrate 3, the terminal 1 is mechanically connected by the insulating screw 4, and the terminal 1 and the conductive pattern 3 a are electrically connected by the solder 2. As a result, the mechanical strength almost depends on the strength of the non-conductive screw, so that no stress is applied to the solder and the conductive pattern 3a, and a robust structure is obtained even if an external stress is applied to the terminal. Moreover, since the insulating screw is made of a material having high heat resistance, it can be subjected to solder reflow while the terminals are connected, so that there is no need for retrofitting and the manufacturing cost can be reduced.

  In addition, when the space distance for insulation between the metal 3d and the electroconductive pattern 3a is required, it can ensure by separating | separating the distance between penetration screws and the electroconductive pattern 3a. Moreover, when the creeping distance for insulation between the metal 3d and the terminal 1 is required, the distance can be ensured by spotting or flattening the terminal 1.

  According to this embodiment, by providing a through hole in the metal base substrate, connecting the terminal with an insulating screw, and connecting the terminal and the conductive pattern with solder, the mechanical strength is increased by the insulating screw. It is dependent on the strength of the wire, and it has a robust structure. The insulating property can be arbitrarily ensured by the distance between the through hole and the conductive pattern, the countersink on the terminal, or the dishing.

  The present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. For example, the mechanical connection between the metal base substrate 3 and the terminals 1 is not limited to a countersunk screw when there is no problem even if a screw head comes out from the back surface of the metal base substrate. It may be a round countersunk screw or pan head screw. Various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

It is a schematic sectional drawing which shows the terminal structure to the metal base substrate concerning this embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Terminal, 2 ... Solder, 3 ... Metal base substrate, 3a ... Conductive pattern, 3b ... Insulating base material, 3c ... Insulating adhesive, 3d ... Metal, 4 ... Insulating screws.

Claims (8)

A metal base substrate having a through hole formed by bonding a conductive pattern portion to the metal base via an insulating substrate;
A terminal member disposed on the conductive pattern portion side of the metal base substrate and facing the through hole;
The terminal member and the metal base substrate are mechanically connected by an insulating member through the through hole, and the terminal member and the conductive pattern portion are electrically connected. Terminal connection structure to metal base substrate. A metal base substrate having a through hole formed by bonding a conductive pattern portion to the metal base via an insulating substrate;
A conductive pattern portion side of the metal base substrate, and a terminal member arranged to face the through hole and subjected to threading,
The terminal member and the metal base substrate are mechanically connected through an insulating screw through the through hole, and the terminal member and the conductive pattern portion are electrically connected by soldering. A terminal connection structure to a metal base substrate.   The terminal connection structure to a metal base substrate according to claim 2, wherein the terminal member is countersunk around the screw hole or is flattened to ensure a creeping distance for insulation. .   The terminal connection structure to a metal base substrate according to claim 3, wherein a space distance for insulation is secured by separating the through hole and the conductive pattern portion by a predetermined distance.   The terminal connection structure to the metal base substrate according to claim 2, wherein the insulating member is an insulating screw.   6. The terminal connection structure to a metal base substrate according to claim 5, wherein the insulating screw is a flat head screw.   3. The terminal connection structure to a metal base substrate according to claim 2, wherein the insulating substrate is FR-4.   The terminal connection structure to a metal base substrate according to claim 2, wherein the terminal member is brass or phosphor bronze.

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