JPS58108681A - Soldering device - 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 soldering device for soldering a board terminal, a lead wire, and a pattern formed on a flexible resin board, and particularly relates to a soldering device that uses a board that is susceptible to cracking due to thermal expansion. When I did,
Soldering is related to the heating method used.

An object of the present invention is to prevent rapid thermal expansion of the board and eliminate cracking of the board by providing a heating element for preheating the board in the soldering device.

Another purpose is to improve the solder wettability of the terminal part and provide reliable soldering.Another purpose is to increase the thermal efficiency of the heat chip and improve work efficiency. be.

Conventionally, the method of soldering lead wires to board terminals was to apply preliminary solder to the lead wires, heat the board terminals and leads with the tip of a soldering iron, and solder the leads.

However, with the current demand for higher density, it has become difficult to attach a lead wire to each terminal.Currently, it is possible to use a flexible resin-based wiring board (C or PPC). It's becoming more common. 1st. The conventional method will be explained with reference to FIG. Terminals 2 are formed on the substrate 1. The connection leads are attached to the flexible resin board 3 with terminals 4 having the same pitch as the terminals 2.
is formed. To solder these terminals,
After applying the solder coach 2 ink to either or both of the terminals 2 and 4 in advance, the terminals are placed on the pedestal 6 of the stacking device, and a part or the entire surface of the terminal is heated by the heat chip 95 and soldered. Do the following. In the soldering method described above, the heat chip is heated from the opposite side of the FPC pattern, so in order to melt the solder, the temperature must be set to a fairly high temperature. Assuming that the heat chip is pressed for seconds, the bath melting temperature is 180℃,
The temperature must be raised to 370°C. This monetary system is large;
If the temperature is raised too much, the FPC board will be burnt, and the adhesive material used to attach the pattern 4 to the board 3 will also deteriorate, resulting in extremely unreliable soldering. Also, if you look at the soldered part, you can see that the heat is flowing through terminal 2.
This may lead to a situation where the solder escapes to the pattern leading to the terminal and the board 1, and the solder has poor wettability and is connected to a part of the terminal. Furthermore, since heat is applied locally, if a substrate made of glass or the like is used, rapid thermal expansion may cause cracks in multiple terminals, resulting in the product itself being defective.

31 The present invention eliminates this drawback and will be explained with reference to FIG.

Place the boards 1 and 3 and the terminals 2 and 4 on top of each other on the pedestal 6,
The soldering device is the same as the conventional one in that the terminal part is held down by a heat chip 5, but a heater 7 is embedded in the pedestal 6. In this case, the material of the pedestal 7 is preferably aluminum, which has good thermal conductivity, but is not particularly specified.The pedestal 6 heated by the heater 7 also heats the substrate 1. base'4
When heating of the heat chip 5 starts in a state where Fi] is heated, since the substrate 1 is already heated, less heat escapes from the heat chip, and the heat efficiency to the terminals 2 and 3 becomes very high. Therefore, heating with the heat chip can be done at a low temperature and in a short time. Experimental results show that soldering can be completed in 3 seconds at 280°C.

Listing other effects of preheating the substrate l:
Because the temperature of the heat chip is low, FPC board material,
Less impact on adhesive material. Furthermore, since the solder wettability of the terminal 1 is reduced, strong soldering can be achieved. Furthermore, although the terminal is heated at the extreme end, the temperature does not rise sharply, so thermal expansion is gradual, and even when a substrate material such as glass is used, cracking of the glass terminal can be prevented.

As a method of heating the substrate 1 in acid 1 according to the present invention, the pedestal 6
Although the explanation has been made by burying the heater 7 inside, there are other methods, such as a method in which the pedestal 6 is a resistor and generates heat by directly applying electricity, or a method in which a surface heater that generates heat by running a resistance wire is used in the pedestal.

As mentioned above, in equipment that uses heat chips to solder, installing a separate heat source that heats the board that the heat chip touches and the board that is paired with it increases reliability and short-term soldering. Soldering can finish the work.

[Brief explanation of the drawing]

FIG. 1 is a perspective view illustrating how the terminals of the board overlap each other. Fig. 2 is a perspective view of a conventional heat chip during heating soldering. Figure 3 shows the heat chip applicant Suwa Sayakosha Co., Ltd. when another heating element is attached according to the present invention.

Claims (1)

[Scope of Claims] [11] In an apparatus for soldering lead wires to terminals formed on a substrate such as glass that is prone to cracking due to rapid thermal expansion, the solder processed on the lead wires is soldered to a heat chip. 1. A soldering device characterized by having a separate heat source for preheating said board when said board is melted in a bath and soldered to said terminal. (2) The soldering device according to claim 1, wherein the lead wire is a board wired to a flexible resin.