JPH04261092A - Connection method for terminal of electric component - Google Patents

Abstract

PURPOSE:To prevent the generation of a bridge at the time of soldering and to prevent solder layers from being oxidized by a method wherein parts, at which first and second terminals come into contact to each other, are covered with a film having a heat resistance and the solder layers are heated. CONSTITUTION:A silicone rubber or the like is applied thin from joints 5 to the surface which is situated on the peripheries of the joints 5, of a substrate 3 to form a coating film 8. After that, a reflow for heating by infrared rays, a laser or a thermal tool is performed to fuse leads and substrate terminal solder layers 9 and 10 and the leads are firmly bonded to the layers 9 and 10. Thereby, a semiconductor device 1 is linked to an electric circuit 7 and at the same time, is mechanically fixed on the substrate 3. At this time, as the joints 5 are covered with the film 8, the solder layers 9 and 10 never flow out. Moreover, the joints 5 are isolated from the air on their peripheries by the film 8 and the solder layers are not oxidized.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a method of connecting terminals of electrical components by soldering.

0002

2. Description of the Related Art FIG. 4 is a plan view of an electrical component showing a conventional terminal connection method. A plurality of leads serving as first terminals have solder applied to their surfaces to form a solder layer (not shown). 3 is a board which is a second electrical component on which an electric circuit (not shown) is formed; 4 is a board terminal as a second terminal provided on the board 3, which is connected to the above electric circuit; A solder layer (not shown) is formed on. 5 is lead 2
This is a joint where the board terminal 4 and the board terminal 4 are in contact with each other.

Next, a terminal connection method will be explained. First, the leads 2 and the board terminals 4 are aligned so that they are in contact with each other. That is, the leads 2 are superimposed on the board terminals 4. Then, by reflowing using infrared rays or the like, both the solder layers of the leads 2 and the board terminals 4 are heated and melted to fuse them, thereby electrically connecting the semiconductor device 1 to the board 3.
A mechanical connection is obtained.

By the way, when the solder layer is heated, as a result of melting and flowing, adjacent board terminals 4 may be short-circuited. FIG. 5 is an elevational view of the joint 5 seen from the right or left side of FIG. 4. The protruding solder 6 short-circuits the board terminals 4, causing a defect called a "bridge." Furthermore, the surfaces of the solder layers of the leads 2 and the board terminals 4 are oxidized, resulting in incomplete bonding between them. To prevent this, a flux consisting of a strong acid must be used.

[0005]

[Problem to be Solved by the Invention] Since the conventional terminal connection method for electrical components is as described above, heated and molten solder protrudes from the first and second terminals, causing a bridge between adjacent terminals. First, due to oxidation,
There was a problem that the bonding of the second terminal would be incomplete, and in order to prevent this, it was necessary to use a flux made of strong acid. This invention was made to solve the above-mentioned problems, and an object thereof is to provide a terminal connection method that can prevent bridging and oxidation during soldering.

[0006]

[Means for Solving the Problems] A method for connecting terminals of electrical components according to the present invention is such that the portion where the first and second terminals are in contact with each other is covered with a heat-resistant film and the solder is heated. It is something.

[0007]

[Operation] The method for connecting terminals of electrical components in this invention is as follows:
The membrane covers the part where the first and second terminals touch each other.
Solder oxidation and leakage are prevented.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1 and 2 are a side view and a plan view of an electrical component showing a terminal connection method according to the present invention, and FIG. 3 is a sectional view of a joint 5 seen from the right or left side of FIG. 1. In these figures, 1 to 5 are the same as in the case of FIG. 4, so their explanation will be omitted. Reference numeral 7 denotes an electric circuit formed on the substrate 3 and connected to the substrate terminal 4, and 8 a coating film covering the joint portion 5, which is made of an insulating material having heat resistance and elasticity, such as silicone rubber. 9 is a lead solder layer which is solder applied to the surface of the lead 2, and 10 is a board terminal solder layer formed on the surface of the board terminal 4.

Next, a terminal connection method will be explained. First, as in the case of FIG. 4, the leads 2 and the board terminals 4 are aligned. Subsequently, a coating film 8 is formed by thinly coating silicone rubber or the like from the bonding portion 5 to the surface of the substrate 3 around the bonding portion 5, as shown in FIGS. 1 to 3. After that,
Reflow heating using conventional infrared, laser, or thermal tools is performed to melt and bond the lead and board terminal solder layers 9, 10 together. As described above, the semiconductor device 1 is connected to the electric circuit 7 and is mechanically fixed to the substrate 3.

[0010] At this time, the joint portion 5 where soldering is performed
Since it is covered with the coating film 8, the solder does not flow out from here. Further, since the joint portion 5 is isolated from the surrounding air by the coating film 8, the solder is not oxidized.

Although the lead solder layer 9 and the board terminal solder layer 10 are provided in the above embodiment, the solder may be applied only to the lead solder layer 9. Alternatively, the first electrical component may be a board 3, the first terminal may be a board terminal 4, the second electrical component may be a semiconductor device 1, the second terminal may be a lead 2, and the solder applied may be only the board solder layer 9. good.

0012

[Effect of the invention] As described above, according to this invention, the first
Since the part where the second terminals are in contact with each other is covered with a film to heat the solder, the molten solder does not flow out from the part where the two terminals contact each other, so that no bridge occurs between the terminals. Further, since the portion where the two terminals are in contact with each other is isolated from the surrounding air by the film, the solder is not oxidized and a good bond can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a side view of an electrical component showing a terminal connection method according to the present invention.

FIG. 2 is a plan view of the electrical component shown in FIG. 1.

FIG. 3 is a cross-sectional view showing a joint of the electrical component in FIG. 1;

FIG. 4 is a plan view of an electrical component showing a conventional terminal connection method.

FIG. 5 is an elevational view showing a joint of the electrical component of FIG. 4;

[Brief explanation of symbols]

1 Semiconductor device 2 Lead 3 Board 4 Board terminal 5 Joint part 8 Coating film 9 Lead solder layer

Claims (1)

[Claims] Claim 1: A plurality of first terminals provided on a first electrical component and having solder applied to their surfaces and a plurality of second terminals provided on a second electrical component are in contact with each other. a step of aligning, a step of covering the portion where the first and second terminals touch each other with a heat-resistant film, and a step of heating the solder to solder the first and second terminals to each other. Terminal connection method for electrical components consisting of