JPS6221254B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a lead soldering method.

Conventionally, lead wires are soldered to electrodes of electrical (electronic) components by passing the lead wires in contact with the electrodes of the electrical component through a solder bath for about 2 to 3 seconds. As shown in FIG. 1, the solder bath is made by blowing air to form a partially raised molten solder raised part 10, and the electrical component 11 described above is passed through this raised part 10, and the lead wire is soldered to the electrode. (This is called "jet soldering").

For example, in the case of a small ceramic capacitor, as shown in FIG. Keep in touch. Thereafter, the folded portions of the leads 14 of a large number of capacitors having such a structure are supported on a jig 15, such as adhesive tape, at regular intervals.
Next, as described above, the jig 15 is passed through the raised portion 10 of the solder bath to perform jet soldering. After soldering, the ends of the folded portions of the leads 14 are cut to obtain a ceramic capacitor 16 as shown in FIG. This is then painted or coated with a moisture-proof coating. In addition, in FIG. 3, 17 indicates the adhered solder.

In such conventional soldering methods, the solder adheres differently depending on the solder surface, and the solder flows, so that uniform soldering cannot be achieved. Also,
The disadvantage is that the silver in the electrode is removed to the solder side (so-called silver eaten by the solder), which changes the characteristics of the component. Furthermore, since the solder is exposed to air at high temperatures for a long period of time, air oxidation of the solder occurs, resulting in loss.

The present invention has been made in view of the above-mentioned drawbacks, and it is possible to solder the leads to the electrodes, terminals, etc. of electrical parts without passing through a solder bath while holding tape-shaped solder in advance. The present invention provides a lead soldering method that eliminates this.

Hereinafter, one embodiment of the present invention will be described in detail with reference to FIG. 4 and the following drawings.

In the method of the present invention, a solder tape 20 as shown in FIG. 4A is used. 21 is a reel on which the tape-shaped solder 20 is wound. Tape-shaped solder 20
It may be flux-containing or non-flux-containing, and when used, it is cut into a single solder body 22 of a certain size as shown in FIG. 4B. This solder cutting can be easily done using an automatic machine. The cut solder unit 22 must have a size and quantity necessary and sufficient for soldering leads to electrodes, terminals, etc. of electrical components. Therefore, the width, thickness, cut length, etc. of the solder tape 20 are selected depending on the dimensions of the electrode or terminal and the lead.

Next, the cut solder unit 22 having a certain size is temporarily fixed to a portion of an electrical component to be soldered, such as an electrode or a terminal. As an example, the present invention will be described in the case where it is applied to a small ceramic capacitor, but it goes without saying that it can be similarly applied to other electrical components (including electronic components). Single solder 22
For temporary fixing, for example, as shown in FIG.
This can be achieved by sandwiching the solder element 22 between the free end portion of the solder member 3 and the free end portion of the solder member 3. In this case, an adhesive or a thermosetting resin may be used in combination. Of course, temporary fixing may be performed by other suitable means. The folded portions of the leads 23 of a large number of capacitors constructed in this manner are supported at regular intervals on a jig 26, such as adhesive tape, as shown in FIG. After that, jig 26
For example, as shown in FIG.
It passes through a heated atmosphere configured to blow out higher-temperature hot air 28. This heating atmosphere is preferably one that locally heats the temporary solder single body 22 portion. In addition to hot air, a heated atmosphere formed by any heating device such as a heater (seed wire) or an infrared lamp can be used. By passing through the heated atmosphere, the solder element 22 is welded, and the free end of the lead 23 and the silver electrode 25 are reliably soldered. After soldering is completed, the ends of the folded portions of the leads 23 are cut and then painted to complete the desired ceramic capacitor.

According to the above-mentioned method of the present invention, since the solder alone is sandwiched between the electrode or terminal of the electrical component and the lead, only the required amount of solder is used, resulting in less loss. , and also allows for reliable soldering. Furthermore, since the position of the solder can be determined accurately, it is efficient. Furthermore, since the soldering time is short and the solder can be heated locally, the silver of the electrode is not eaten away, and the characteristics of the component are therefore constant. Furthermore, since the solder is not exposed to air at high temperatures for long periods of time, there are many excellent advantages such as no solder oxidation and no loss.

In the above embodiments, the present invention was explained for the case where the leads were soldered to the silver electrodes of a small ceramic capacitor, but the present invention can also be applied to the case where the leads are soldered to the electrodes, terminals, etc. of other electrical components. Needless to say.

[Brief explanation of the drawing]

Figure 1 is a schematic diagram to explain the conventional jet soldering method, Figure 2 is a schematic diagram to explain a process of continuous soldering of small ceramic capacitors, and Figure 3 is a diagram after soldering. FIG. 4A is a schematic perspective view showing a ceramic capacitor obtained by cutting the lead folded portion; FIG. 4A is a schematic perspective view showing an example of tape-shaped solder used in the method of the present invention; FIG. 4B
1 is a schematic perspective view showing a single piece of solder obtained by cutting a solder tape to a certain length, and FIGS. 5 to 7 are schematic views for explaining each process of the method of the present invention. 20: Tape-shaped solder, 22: Single solder, 23:
Lead, 24: Small porcelain capacitor, 25: Silver electrode of porcelain capacitor, 26: Jig, 27: Pipe, 28: Hot air.

Claims (1)

[Claims] 1. Cut a solder tape with the required width and thickness to a certain length, hold the cut solder on the part of the electrical component to be soldered, and heat the solder while supporting the lead on the solder. A lead soldering method characterized by passing the solder through an atmosphere and heating and fusing the solder alone.