JPH0782971B2 - Electronic component manufacturing method - Google Patents

Description

The present invention relates to a method for manufacturing a ceramic capacitor used in an electronic circuit and other electronic parts, and more particularly to a method for soldering an electrode terminal to an electrode of an element.

<Prior Art> In a method of manufacturing an electronic component, a soldering iron is used to attach an electrode terminal to an electrode of an element such as a ceramic capacitor, immersion soldering, reflow soldering or conductive adhesion. There are methods such as coating and curing the agent.

As a method to obtain solder by reflow soldering in it,
The electrode terminal 1 as shown in FIG. 5I is dipped in the solder 2 which is melted by heating and liquefied as shown in FIG. II, pulled up, cooled and the solder 2 is attached to the electrode terminal 1 as shown in FIG. A method of attaching and soldering the attached solder 2 to the electrode 4 of the element 3 as shown in IV in FIG. 4 or by attaching the solder 2 to the electrode terminal 1 as shown in FIG. There is a method in which the solder cream 5 is applied by spraying or the like, and the cream 5 is heated and melted and soldered to the electrode 4 of the element 3 as shown in FIG.

<Problems to be Solved by the Invention> In the method of manufacturing an electronic component as described above, the electrode terminal 1
Simply immersing the solder in liquid solder 2 and pulling up
Is attached to the electrode 4 of the element 3 after soldering,
The element 3 is restrained by the frame 6 as shown in FIG.
It can be seen that the attachment strength is low when a so-called tensile test of pulling is performed.

If the mounting strength is low as described above, the reliability is low such that the electrode terminal is detached due to an impact or the like in a subsequent process (cleaning, exterior process, etc.) and the product becomes defective.

Further, the method using solder cream has a high attachment strength but is expensive, resulting in an increase in cost.

An object of the present invention is to provide a manufacturing method having high reliability and low manufacturing cost in order to solve the problems of the conventional manufacturing method as described above.

<Means for Solving the Problems> In order to solve the above problems, the present invention is directed to soldering an electrode terminal to an electrode provided on an element, in which the soldering portion of the electrode terminal has a high liquidus temperature. Then, a solder having a liquidus temperature lower than that of the solder is attached to attach a desired amount of solder to the electrode terminal, and the electrode terminal is soldered to the electrode with the solder. Provide a way.

<Embodiment> An embodiment of the present invention will be described below with reference to FIGS. 1 to 4 of the accompanying drawings.

Sn / Pb = 30/70 solder 12 (liquidus temperature: 258 ° C, which is made liquid by heating the electrode terminal 11 as shown in Fig. 1I as shown in Fig. 2I)
(Solidus temperature: 183 ℃), pull up and cool to solidus temperature, and Sn / Pb = 30 at electrode terminal 11 as shown in Fig. III.
/ 70 Apply solder 12.

As shown in Fig. IV, when this is further immersed in Sn / Pb = 40/60 solder liquid 13 (liquidus temperature: 238 ° C, solidus temperature: 183 ° C) and then pulled up and cooled to the solidus temperature, Sn / Pb = 3 as shown in Fig. V
Sn / Pb = 40/60 solder 13 deposited on 0/70 solder 12 is obtained.

The total amount of the adhered solder becomes twice or more that in the case where the electrode terminals are dipped in a single solder solution and pulled up and cooled to the solidus temperature.

As shown above, the electrode terminals with two solder layers are
As described above, as a result of measuring the mounting strength of the element 3 soldered to the electrode 4 by the method of FIG. 7, the strength is more than double that of the single case, and the reliability is improved.

This is not only the case of Sn / Pb = 30/70 solder and Sn / Pb = 40/60 solder described above, but also Sn / Pb = 50/50 solder 14 as shown in FIG.
Sn / Pb = 60/40 Solder 15 or Sn / Pb = 95/5 as shown in FIG.
Like the solder 16 and Sn / Pb = 65/35 solder 17, the liquidus temperature is 10
It is always applicable when there is a difference of ℃ or more.

Moreover, if the types of solder used are Sn / Pb = 10/90 solder 18, Sn / Pb = 20/80 solder 19, Sn / Pb = 30/70 solder 20 as shown in FIG. It is possible to further increase the amount of solder adhered to the solder.

Similarly, if the number of solder layers used is further increased and the number of solder layers is further increased, the amount of adhesion can be further increased.

<Effect of the Invention> As described above, the method of the present invention performs the operation of attaching the solder having a higher liquidus temperature to the soldering portion of the electrode terminal and then attaching the solder having a lower liquidus temperature than the solder. Therefore, the next solder can be attached without melting the solder that was attached first, and the solder can be attached sufficiently to the electrode terminals. Therefore, the solder can be attached once to the conventional electrode terminals. The amount of solder adhered to the electrode terminals is larger than that in the case of using the above method.

When the electrode terminals to which a large amount of solder is attached are soldered to the electrodes of the element, the mounting strength is increased.

Therefore, there is no possibility that the electrode terminals will be detached due to impact or the like in the subsequent steps (cleaning, exterior steps, etc.), resulting in defective products, and the reliability will be significantly improved.

[Brief description of drawings]

FIGS. 1 to VI, FIG. 2, FIG. 3, and FIG. 4 are front views showing each embodiment of the manufacturing method of the present invention, and FIGS. 5 I to IV are front views showing an example of a conventional method, FIGS. 6, I, II and III are front views showing another example of the conventional method, and FIG. 7 is a partially longitudinal front view showing a tensile strength test. 11 …… Electrode terminal, 12-20 …… Solder 3 …… Element, 4 …… Electrode

Claims (1)

[Claims] 1. When soldering an electrode terminal to an electrode provided on an element, a solder having a higher liquidus temperature is attached to a soldering portion of the electrode terminal, and then a solder having a lower liquidus temperature than the solder is applied. A method for manufacturing an electronic component, characterized in that a desired amount of solder is adhered to an electrode terminal by performing an attaching operation, and the electrode terminal is soldered to the electrode with the solder.