JPH01144616A - Method of mounting lead terminal - Google Patents

Abstract

PURPOSE:To improve bonding strength, by employing a series of processes in which an element body of electronic component is held between the lead terminals in which bow sections are respectively formed in the positions in contact with electrodes, and under this condition the element body is dipped into a solder vessel, and the element body is then pull up, thereby solder pools being formed in the bow sections. CONSTITUTION:In the head section of a lead terminal, both a bow section and a section to hold an element body of electronic component are formed in the position to contact with the electrode of the component. The plate-shaped element body 1 of electronic component is held between the lead terminals 2 and 3. Under this condition, a holder 4 is to lowered dip the element body 1 of electronic component into a solder vessel 5. Subsequently, the whole holder 4 is pull up, and cooling is then performed in order to complete soldering. If necessary, each the component is dipped into a resin vessel with being held by the holder 4, and the lead terminals are thereafter divided. Therefore, even if a straight type lead terminal or a lead terminal of fine wire is employed, the bonding strength of lead terminal can be sufficiently maintained.

Description

DETAILED DESCRIPTION OF THE INVENTION (Al Industrial Field of Application) The present invention relates to a method for attaching lead terminals to a plate-shaped electronic component element by a solder dipping method.

Tb) Prior Art Conventionally, when electrodes are formed on both main surfaces of a plate-shaped electronic component body, such as a ceramic capacitor with lead terminals, and lead terminals are attached to both electrodes, the solder dipping method is used.

FIG. 3 shows the structure of this type of electronic component after lead terminals are attached. In the figure, reference numeral 1 indicates an electronic component element having electrodes formed on both principal surfaces of a disc-shaped dielectric ceramic, and reference numerals 2 and 3 indicate lead terminals. As shown in the figure, one ends 2a and 3a of the lead terminals 2 and 3 are bent to sandwich the electronic component body 1 and soldered by a solder dipping method.

(C) Problems to be Solved by the Invention In order to attach the lead terminals to the electrodes formed on both main surfaces of the plate-shaped electronic component element, one end of the lead terminal is attached to the electronic component element. It can be easily removed by holding it in place and immersing it in a solder bath. However, the conventional REIT terminal attachment method has the following problems.

- For electronic components with lead terminals, a certain level of insertion strength is required in consideration of compatibility with automatic electronic component insertion machines and impact resistance after circuit board removal. Electronic components to which lead terminals are attached by the conventional method have particularly low solder strength at the root portion of the lead terminal relative to the electronic component body, that is, in the region A shown in FIG. 3. This is because when the lead terminal holding the electronic component body is pulled out of the solder bath, the amount of solder that adheres to the lead terminal and the electrode surface of the electronic component body is small.

In particular, stress is concentrated at the root portion of the straight type, which has no crimp portion in the drawer portion, and the aforementioned low amount of solder adhesion becomes a problem.

Also, when manufacturing positive temperature coefficient thermistors, lead terminals are attached using the same method, but in the case of current control positive temperature coefficient thermistors used for demagnetizing color cathode ray tubes, lead terminals are attached in order to reduce the steady current. Although it is necessary to make the REET terminal thinner to prevent heat dissipation, there is a problem in that if the REET terminal is made thinner, the soldering strength of the REET terminal to the PTC thermistor body further decreases.

The purpose of this invention is to use the solder dipping method when attaching lead terminals to a plate-shaped electronic component body, and to improve the strength of attaching the lead terminal to the electronic component body. Our goal is to provide the following.

(Means for Solving Problem d1) The method for attaching lead terminals to electronic components according to the present invention is a method for attaching lead terminals to electrodes formed on both main surfaces of a plate-shaped electronic component body, and includes: a lead terminal forming step of forming a curved portion at a portion in contact with the electrode; and the curve B11 of the lead terminal by sandwiching the electronic component body between lead terminals, immersing it in a solder bath, and pulling it out. The method is characterized in that the lead terminal is removed by a soldering process in which a solder pool is formed in the electrode and the lead terminal is attached in half to the picture electrode.

(21 Action Number of lead terminals of electronic component of this invention) In the method, a curved portion is formed in a part of the lead terminal in contact with the electrodes formed on both main surfaces of the plate-shaped electronic component body by the lead terminal forming step. In the soldering process, the plate-shaped electronic component body is immersed in a solder bath with both electrodes sandwiched between the lead terminals and pulled up.At this time, a solder pool is formed on the curved portion of the lead terminal. Ru.

Since the lead terminal with the curved portion formed in this way is pulled up from the solder bath while in contact with the electrode of the electronic component body, the amount of solder adhering to the lead terminal and the electrode of the electronic component body increases, increasing the bonding strength. improves.

([) Embodiment FIG. 2 is a plan view showing the shape of an electronic component with a 1F terminal manufactured according to an embodiment of the present invention. In the figure 1
is a disk-shaped electronic component body, and electrodes are formed on both main surfaces thereof. 2 and 3 are lead terminals, respectively -Oi+it2a.

3a sandwich the electronic component element body 1. Electronic component body 1
Bent portions 2b,
3b is formed, a solder pool S is formed in this curved portion, and a relatively thin solder film is formed on the electrode surface of the electronic component body and the tip of the lead terminal.

The electronic component with lead terminals shown in FIG. 2 can be manufactured by the following procedure.

(1) First, as shown in FIG. 2, a curved portion and a portion for sandwiching the electronic component body are formed at the tip of the lead terminal at a location where it comes into contact with the electrode of the electronic component body.

In this case, it is possible to adopt a method in which the two lead terminals are constructed from one conductor wire and then separated later. FIG. 1(A) shows a state in which a plate-shaped electronic component body is sandwiched between lead terminals formed by this lead terminal forming process. In the figure, reference numeral 4 denotes a holder through which a plurality of lead terminals are inserted and held.

(2) As shown in FIG. 1(A), the plate-shaped electronic component body 1 is sandwiched between the lead terminals 2 and 3 and immersed in a solder bath. In the figure, 5 is a solder bath, and 6 is a wave of molten solder. The bolt 4 is lowered from the state shown in Fig. 1 (A) and the first
As shown in FIG. 1(B), the entire electronic component body is immersed in a solder bath, and then, as shown in FIG. 1(C), the entire holder 4 is pulled up and cooled to perform soldering.

In the manner described above, an electronic component with lead terminals shown in FIG. 2 is obtained. In addition, when applying resin coating around the electronic component body as necessary, immerse each component in the resin bath while holding it in the holder, and then apply lead coating.
Divide the dumplings.

+g) Effects of the Invention As described in -1-, according to the present invention, a solder pool is formed at the root portion of the lead terminal to the electronic component body, and the solder joint strength is improved. Even when a quiz lead terminal is used or a thin wire lead terminal is used, the bonding strength of the lead terminal can be maintained, and an electronic component with a lead terminal having excellent reliability and characteristics can be manufactured.

[Brief explanation of the drawing]

Figures 1 (A) to (C) are diagrams showing the procedure of a method for attaching lead terminals to electronic components, which is an embodiment of the present invention, and Figure 2 is a diagram showing the procedure for attaching lead terminals to an electronic component according to an embodiment of the present invention. FIG. 3 is a plan view showing the shape of an electronic component manufactured by a conventional method. 1-Plate electronic component body, 2.3-Lee I/terminal, 2b, 3b--curved portion, 4-holder, 5-solder bath, 6-? Capacitive solder wave, S-solder puddle.

Claims (1)

[Claims] (1) A method for attaching lead terminals to electrodes formed on both main surfaces of a plate-shaped electronic component body, comprising: a lead terminal forming step of forming a curved portion at a portion of the lead terminal that contacts the electrodes; a soldering step of sandwiching a component element between lead terminals, immersing it in a solder tank and pulling it up to form a solder pool on the curved portion of the lead terminal, and soldering the lead terminal to both electrodes; How to attach lead terminals to parts.