JPH04263408A - Lead-attached electronic part - Google Patents

Abstract

PURPOSE:To provide a lead-attached electronic part with which the formation of solder bridge between the adjacent lead terminals will be prevented. CONSTITUTION:A lead-attached electronic part, on which an insulating protective coating 2 is provided on the upper surface and both side faces of a lead terminal 1 protruding from the side face of the main body of an electronic part as shown in the diagram, is obtained.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to leaded electronic components, and more particularly to leaded electronic components that prevent the formation of solder bridges between adjacent lead terminals.

0002

[Prior Art] For example, when an electronic component with leads is brought into contact with an electrode of a circuit board and joined by soldering, cream solder is coated on the electrode of the circuit board in advance, and then cream solder is coated on the electrode of the circuit board. The lead terminals are placed at appropriate positions, and then soldered together using a reflow oven or the like. At this time, the lead terminal 10 of the leaded electronic component is shown in FIG.
As shown in FIG. 2, solder plating 12 is formed on the entire outside of the cross section 11 of the lead terminal in order to improve solder wettability at the circuit board electrode portion (not shown).

0003

[Problems to be Solved by the Invention] However, in the above-described configuration, the solder between the lead terminal 10 and the adjacent leads of the leaded electronic component may be damaged due to variations in the amount of cream solder on the electrodes of the circuit board. There was a problem in that it was easy to cause solder bridges that caused connections.

In particular, in recent years there has been a tendency for the number of lead terminals protruding from the main body of electronic components to increase, and the lead pitch has become narrower accordingly, so this problem has become extremely important in improving the reliability of solder joints. This is becoming an important issue.

[0005] In view of the above problems, the present invention has been developed to provide a connection between lead terminals of adjacent leaded electronic components.
The purpose of the present invention is to provide an electronic component with leads in which it is extremely difficult to form a solder bridge where solder is connected.

[0006]

[Means for Solving the Problems] In order to solve the above problems, the leaded electronic component of the present invention is provided with an insulating protective coating on the top and both sides of the lead terminal protruding from the side of the electronic component body. The lower surface of the lead terminal is plated with solder, and a groove is formed on the lower surface of the lead terminal.

[0007]

[Function] The electronic component with leads of the present invention has the above-described structure, and by applying an insulating protective coat to the top and both sides of the lead terminals and applying solder plating to the bottom surface, the insulating layer is coated between adjacent leads. The protective coat repels the solder and prevents the formation of solder bridges. Further, by forming a groove on the lower surface of the lead terminal, the solder sinks into the lower surface of the lead terminal by capillary action, and the solder does not protrude to the side surface and form a solder bridge.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A leaded electronic component according to an embodiment of the present invention will be described below with reference to the drawings.

(Embodiment 1) In the first embodiment shown in FIG. 1, 1 is a lead terminal, 2 is an insulating protective coat formed on the upper surface and both sides of the lead terminal 1, and 3 is the lead terminal 1.
This is solder plating formed on the bottom surface of the .

In FIG. 2, 4 is an electronic component body, and 5 is a lead terminal thereof. The flowchart in FIG. 3 shows the steps for forming an insulating protective coat and solder plating on the lead terminals 5.

In FIG. 3, first, the lower surface of the lead terminal is masked, and then an insulating protective coat is applied to the upper surface and both side surfaces of the lead terminal.

Next, the masking is removed from the lower surface of the lead terminal, and finally, solder plating is applied to the lower surface of the lead terminal.

By using the electronic component with leads constructed as described above, the solder is repelled by the insulating protective coat 2 between the lead terminals 5, and no solder bridge is formed, resulting in a highly reliable solder joint. can be formed.

(Embodiment 2) Next, a second embodiment shown in FIG. 4 will be described.

In FIG. 4, 6 is a lead terminal, 7 is an insulating protective coat formed on the upper surface and both side surfaces of the lead terminal 6, and 8 is a solder plating formed on the lower surface.

Reference numeral 9 denotes a groove formed on the lower surface of the lead terminal 6 by pressing or half etching.

By using the leaded electronic component constructed as described above, solder is repelled by the insulating protective coat 7 between the lead terminals, and furthermore, the solder is repelled between the lead terminals 6.
The groove 9 on the bottom surface causes the solder to sink into the solder plating formed on the groove 9 on the bottom surface of the lead terminal 6 by capillary action, thereby preventing the formation of solder bridges and improving adhesion to the board (not shown). It can be improved.

Note that the groove 9 in the second embodiment shown in FIG.
It goes without saying that the shape may be any other shape, such as a semicircle or V-shape, as long as it does not adversely affect the capillarity of the solder or the adhesion of the leads to the substrate.

[0019]

[Effects of the Invention] As is clear from the above description of the embodiments, according to the leaded electronic component of the present invention, the upper surface of the lead terminal,
By applying an insulating protective coat on both sides and solder plating on the bottom surface, the insulating protective coat repels the solder between adjacent lead terminals, resulting in highly reliable solder joints that do not form solder bridges. It has the effect of making it possible. Furthermore, by forming a groove on the bottom surface of the lead terminal, the solder sinks into the solder plating of the groove formed on the bottom surface of the lead terminal due to capillary action, and by preventing the solder from protruding to the side surface, a solder bridge is formed. It also has the effect of preventing this and improving adhesion to the substrate.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a lead terminal of a leaded electronic component in a first embodiment of the present invention.

[Figure 2] Perspective view showing the appearance of an electronic component with leads

[Figure 3]
Flowchart showing the procedure for forming an insulating protective coat and solder plating on lead terminals

FIG. 4 is a sectional view of a lead terminal according to a second embodiment of the present invention.

[
Figure 5: Cross-sectional view of a lead terminal of a conventional leaded electronic component

[Explanation of symbols]

1 Lead terminal 2 Insulating protective coat 3 Solder plating

Claims (2)

[Claims] 1. An electronic component with a lead, in which an insulating protective coat is applied to the upper surface and both side surfaces of a lead terminal protruding from a side of an electronic component body, and a solder plating is applied to the lower surface of the lead terminal. 2. The leaded electronic component according to claim 1, wherein a groove is formed on the lower surface of the lead terminal.