JPS62263603A - Electronic parts - 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 Field of Industrial Application The present invention relates to an electronic component having a resin mold type surface mounting exterior structure.

Conventional technology In recent years, as electronic devices have become more multifunctional, home appliances.

2. Description of the Related Art Computerization and miniaturization are progressing in the fields of information communication equipment and industrial equipment. Due to this.

Electronic components are also becoming smaller, and their mounting methods are shifting to surface mounting using solder reflow. Among these, surge absorbers that protect semiconductor elements and electronic devices from abnormally high voltages are also being miniaturized as single-sided mounting electronic components.

Here, a description will be given using a surface mount surge absorber as an example.

FIG. 4 shows an example of a conventional surge absorber. Fourth
In the figure, numeral 1 denotes a plate-shaped varistor, which is generally made of ceramics whose main raw material is lead oxide, strontium titanate, or the like. 2&.

2b is a counter electrode formed at opposing positions on the front and back sides of the varistor 1 by baking silver paste or the like. 31L
, 3b are the counter electrodes 2 & , 2b and metal electrode plates 4a, 4
b, l! :'ji Electrical 1 Conductive adhesive for mechanical connection 1 Usually, an epoxy adhesive containing silver powder is used. The above metal electrode plate, 4L, 4b
To ensure proper soldering with external wiring, apply approximately 3.
~20 μm solder plating is applied. Reference numeral 5 is made of a resin material in which the main parts such as the varistor 1 are molded, except for the parts that will become external terminals of the metal electrode plates 4 & 4b.

6 and 6 are schematic views of the process of bending the metal electrode plates 4a and 4b'ii of the conventional surge absorber shown in FIG. 6 is a metal electrode plate, and 7 is a molded resin material. 8 is a metal fitting for bending the metal electrode plate 6;
Move in the direction of the arrow in FIG. In FIG. 6, the radius of curvature of the bent portion H of the metal electrode plate 6 bent in this way is small (1), for example, the thickness of the metal electrode plate 6 is 0.
．． In the case of In, the part corresponding to the outer diameter of the radius of curvature is 0.2
It is about fl.

Problems to be Solved by the Invention In the conventional configuration as described above, when the folded metal electrode plate 6 has a solder plating thickness of 6 μm and 8 degrees, the plated solder is wrinkled on the surface corresponding to the inner diameter of the bent portion. Therefore, the solder cracks on the surface corresponding to the outer diameter. Further, when the solder plating thickness is 10 μm or more, the plating may peel off. Therefore, if the metal electrode plate is left in such a state for a long period of time, there is a risk that the metal electrode plate material will be oxidized and corroded, and there is also a problem that the properties of the metal electrode plate may deteriorate.

The present invention is an attempt to solve such problems, and aims to provide an electronic component that does not interfere with the damage of bent metal electrode plates and that ensures perfect soldering performance. It is something.

Means for Solving the Problems In order to solve the above problems, the present invention provides a molded resin material with a stepped opening for taking out the metal electrode plate.
This maintains the radius of curvature of the bent portion of the metal electrode plate to a size that does not affect solder plating.

Effect: According to this configuration, the radius of curvature of the bent portion of the metal electrode plate is maintained at a size of about 416, as described above, and cracking and soldering of the solder plating on the bent portion of the metal electrode plate is easily prevented. This will prevent deterioration.

Embodiment FIG. 1 shows an embodiment in which the electronic component of the present invention is employed in a surge absorber, and this figure is a sectional view thereof.

In FIG. 1, reference numeral 9 denotes a plate-shaped varistor whose main raw material is zinc oxide or the like, 10fL, and 10b counter electrodes provided opposite to each other on the front and back sides of the varistor 9, and 11tL.

11b is a counter electrode 1oa, 1ob and a metal electrode plate 12
2L, 12b"i is a conductive adhesive to be connected, and 13 is a resin material in which the main parts such as the varistor 9 are molded, except for the parts that will become the external terminals of the metal electrode plates 12&, 12b. There is a step at the outlet, and there are 12 metal electrode plates.

In the bending direction of 12b, the molded resin material 13 is lowered only in the portion along which the metal electrode plates 121L and 12b extend.

2 and 3 are schematic views of the process of bending the metal electrode plates 12a and i2b'e of the surge absorber in FIG.
14 is a metal electrode plate, 15 is a molded resin material, and 16 is a metal fitting for bending the metal electrode plate 14, which moves as shown by the arrow in FIG. This basic configuration is the same as the metal electrode plate bending process of the conventional surge absorber shown in FIGS. When the solder plating thickness is 5 μm, the outer diameter of the radius of curvature at the bent portion R of the metal electrode plate is 0.2 in the conventional example shown in FIG.
m18, and cracks have occurred in the solder plating, but in the example shown in Fig. 3, the outer diameter of the radius of curvature at the bent portion R' is approximately 0.4 mm, and no cracks have occurred in the solder plating. do not have.

Note that the present invention can be applied to other electronic components other than surge absorbers as described above.0 Effects of the Invention As described above, according to the present invention, at the outlet of the metal electrode plate in the molded resin material, By lowering the molding resin material in the bending direction of the metal electrode plate only in the part along the metal electrode plate, the bent outer diameter of the gold plate can be maintained at a size that does not affect the solder plating. Oxidation corrosion and soldering of the plate material can prevent deterioration of properties.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of the electronic component of the present invention applied to a surge absorber, FIGS. 2 and 3 are schematic diagrams illustrating the bending process of the metal electrode plate in FIG. 1, FIG. 4 is a sectional view showing an embodiment of a conventional surge absorber, and FIGS. 6 and 6 are schematic diagrams illustrating the bending process of the metal electrode plate in FIG. 4. 9... Element (varistor), 10&, 10b...
...electrode (counter electrode), 11&, 11b...
・Conductive adhesive, 12L, 12b, 14・-
...-Metal electrode plate, 13°16...Mold resin material. Name of agent: Patent attorney Toshio Nakao and 1 other person9-
11 Balliskutsu 072 no oh - spear qp and tinnitus x no j - mall) - a fat material 21st! l Figure 3 Figure 5

Claims (1)

[Claims] The main parts of the elements, electrodes, etc. are molded and covered with a resin material, and the external terminal part of the metal electrode plate is solder-plated and bent along the molded resin material, and the molded resin material is coated with the metal electrode plate. An electronic component that has a step lower than the outlet of the metal electrode plate in the bending direction.