JPS6080300A - Method of solder-connecting lead wirings of component - 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 (1) Technical Field of the Invention The present invention relates to a connection between a pattern on a printed circuit board and a lead wire of a component, and particularly to a solder connection between a through-hole plated land and a lead wire 7 of a component. It is.

(2) Background of the technology In order to achieve high integration of components mounted on a printed circuit board, the reference grid of the printed circuit board is set at 50 mil pitch, and solder connections are made between the component glues mounted on the printed circuit board and the through-hole lands. By doing so, it is possible to provide a butt for connecting the leads of the components mounted on the conventional 100 mil pitch grid printed circuit board and the pattern, or to insert the leads of the components into the through-ball holes to make a solder connection. In this method, which increases the mounting density of components by 3 to 4 times compared to the above method, it is required to secure a sufficient amount of solder to ensure the solder connection between the lands and the leads of the components.

(3) Prior art and problems Figure 1 shows a cross-sectional view of a conventional solder connection between a through-hole land and a component lead, Figure 2 shows heating of a through-hole land by BOT air, and ■ indicates a printed board. 1, 2 is a land, 3 is a through-hole plated copper layer, 4 is a solder plated layer, 5 is a through-ball hole, 6 is a component, 7 is a lead wire, 8 is a solder connection, 9 is a bot air, 10 is molten solder.

are shown respectively.

Conventionally, as shown in Figure 1, a laminate plate with a thickness of 2 to 5 fins has a diameter of 0°3.
A through hole 5 is drilled to form a copper layer 3 with a through ball thickness, and a land 2 of 11 m x 1 fin is formed on both end faces of the through ball.
30 on the surface of the land 2 and the copper layer 3 of the through hole.
After obtaining the solder plating layer 4 with a thickness of μm, the lead wire 7 of the component 6 with a thickness of about 0.3 ψ is brought into contact with the land 2, and the contact area is blown with real air 9, and the solder plating layer 4 on the land 2 is
is melted to obtain a solder connection 8. However, when the land 2 is heated with Niposoto air 9, the copper layer of the through hole and the land 2 on the other side are simultaneously heated due to thermal conduction, and the solder plating layer 4 covering it is melted. When the molten solder 10 flows down and accumulates on the land 2 on the bottom surface of the through hole due to the attractive force as shown in FIG. 2, the solder on the land 2 connecting the lead wire 7 of the component 6 on the top surface also flows down at the same time. There was a drawback that the amount of solder in the solder connection 8 was reduced, making the connection between the lead wire 7 and the land 2 unreliable.

(4) Purpose of the Invention In view of the above-mentioned conventional drawbacks, the present invention provides a method for soldering the lead wires of a component, in which the land of the through-hole and the lead of the component are reliably soldered together using plated solder. This is the purpose.

(5) Structure and object of the invention According to the present invention, a component lead wire is soldered by bringing a land on the lower surface of a solder-plated through hole into contact with a lead of the component and soldering the component lead wire. This is achieved by providing a connection method.

(6) Examples of the invention Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 3 shows a cross-sectional view of a solder connection between a through-hole land and a lead of a component according to the present invention.

In the figure, 2A is the land to which the lead wire 7 should be connected, and 2B
denotes a land to which the lead wire 7 is not connected and corresponds to the land 2A.

FIG. 4 shows the solder connection between the lead wire 7 of the component 6 and the land 2A of the through hole according to the present invention. After positioning the component to be removed on the lower surface of the printed circuit board 1 and positioning the land 2A of the printed circuit board 1 and the lead wire 7 of the component 6, the lead wire 7 of the component 6- and the pattern 2A are pressed together. When the pattern 2A, the pattern 2B, and the through-ball copper layer 3 are heated by the bot air 9-, and the solder plating layer 4 on each surface is melted, the solder in the molten solder plating layer 4 becomes in a fluid state, and due to attraction, The solder flows down in the direction of gravity, and the solder on the surface of the pattern 2B, the through hole, and the plated copper layer 3 accumulates on the two patterns, moistens the solder joint 8 between the pattern 2A and the lead wire 7, and the solder between the pattern 2A and the lead wire The amount of solder required for soldering with No. 7 can be sufficiently compensated for.

(7) Effects of the invention As explained in detail above, the amount of solder required to solder connect the through ball pattern of the printed circuit board and the lead wire of the component can be easily obtained, and it is not necessary to replenish solder from another source. When a large number of component lead wires are in close contact with each other, the soldering part does not require replenishment of solder from another source, and the effect is great.

[Brief explanation of drawings]

Fig. 1 shows a cross section of a conventional solder connection between a through-ball land and a component lead, Fig. 2 shows heating of a through-hole land by BOT air, and Fig. 3 shows a through-hole land and a component lead according to the present invention. A cross-sectional view of the solder connection with the lead is shown. In the figure, 2 is a land, 3 is a through-ball plated copper layer, 4 is a solder plated layer, 6 is a component, and 7 is a lead wire.

Claims (1)

[Claims] After making the soldering surface of the printed circuit board the lower surface in the direction of gravity and pressing the component leads and lands, connect the lands to be connected, the lands corresponding to the lands to be connected, and the lands using hot air, etc. A method for soldering 4 lead wires of a component, which is characterized by heating and soldering a through ball.