JPS6030118A - Leadframe for electronic part - 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 The present invention relates to a lead frame for electronic components, and in particular to an electronic component such as an electrolytic capacitor element, which is connected to an element lead and is pulled out from an exterior member to be soldered. The present invention relates to a terminal member.

In deep-type electrolytic capacitors, the electrolytic solution is impregnated inside the electrolytic capacitor element that is packaged, so the metal that makes up the lead frame causes a chemical reaction with the electrolytic solution.
There is a risk of corrosion. Therefore, it is necessary for the lead frame to be made of a metal material that does not have this effect.
Forming materials are limited. Moreover, in electrolytic capacitors, the airtightness of the exterior member is related to moisture resistance, etc., and directly affects electrical performance, so adhesion with the exterior resin such as epoxy (H resin) becomes a problem.Furthermore, the lead frame If the linear expansion coefficients of the exterior resin and the exterior resin differ greatly, thermal stress will occur, which may impede the airtightness of the exterior member during long-term use.

Conventionally, this type of lead frame uses an aluminum clad material with an aluminum layer formed on the surface of the core material, which enables welding to the aluminum leads of electrolytic capacitor elements and prevents corrosion due to contact with electrolyte. It is prevented.

However, it is difficult to solder a lead frame covered with an aluminum layer like this, and in order to increase the reliability of electrical connection by face bonding, the lead part pulled out from the exterior member is made of a metal that can be soldered. requires plating treatment (post-plating treatment). Such processing involves an increase in manufacturing steps, increases manufacturing time, and increases manufacturing costs.

In addition, in order to make soldering easier and to eliminate the metal plating process that can be soldered to the finished product, the leads are made of a so-called aluminum stripe clad material in which an aluminum layer is formed only on the parts that will be connected to the element leads. When a frame is formed, the aluminum layer is corroded by the post-plating process, making the performance unstable, the plating process is expensive, and the manufacturing process must be interrupted for the 1& plating process. be.

The object of the present invention is to provide a lead frame for electronic components that simplifies the manufacturing process and has stable performance.

This invention divides a lead frame into a first area where element leads are connected and a second area where the element leads are pulled out from the exterior member covering the element and soldered, forming the first area. A weldable metal layer is formed on the surface of the core material,
A solderable metal layer is formed on the surface of the core material forming the second region.

Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings.

1 and 2 show an embodiment of the present invention, with FIG. 1 showing the structure of a lead frame, and FIG. 2 showing a cross section taken along line nn in FIG. 1. In the figure, Lee) - frame 2
In addition to setting a first region @ to weld the element lead directly drawn out from an element such as an electrolytic capacitor element, a second region IIi! is set to allow soldering on both sides of this region. Set 2B. Lead portions 4A and 4B are formed on this lead frame 2 to face each other, and each lead portion 4A and 4B is supported by an arm portion 6. The front edge of each lead frame 4A, 4B is included in the first region, and the rear portion thereof is included in the second region B. The through hole 8 is a space formed for inserting an electrolytic capacitor element during connection. In addition, a through hole 10 is formed at the tip of each lead portion 4A, 4B in order to aid the flow of the exterior resin and improve adhesion with the exterior resin.

Each side of this lead frame 2 has a sprocket hole I that engages a sprocket for continuous transfer.
2.14 are formed at regular intervals.

For the core JA16 of this lead frame 2, one of metal materials such as iron, copper, 42 alloy, Kovar, stainless steel, etc. is selected depending on the elements such as semiconductor elements and electrolytic capacitor elements, as shown in Fig. 2. The surface of the first region A of the core material 16 is made of weldable aluminum, gold,
A metal layer 18 such as silver is formed, and a solderable metal layer 20 such as tin or solder is formed on the surface of the core material 16 included in the second region B. That is, the first region A of the lead frame 2 is made of a raft material so that it can be welded to the element lead, and the second region B is made of a rad material so that it can be soldered. Such a rad treatment is performed on the surface of the core material 6 before the lead frame 2 is molded.

As shown in FIG. 3, the element leads 26A and 126B of the electrolytic capacitor element 24 are overlapped and welded to the surfaces of the lead portions 4A and 4B of the lead frame 2 processed in this manner. Next, the lead parts 4A and 4B are separated from the G-1 frame 2 by press working or the like, and after being impregnated with an electrolytic solution,
The exterior is made of synthetic resin. The electrolytic solution may be injected through a small hole formed in the outer case member after forming the outer case with a synthetic resin.

FIG. 4 shows a chip type electrolytic capacitor using the lead frame 2. As shown in FIG. That is, the element leads 26A, 26
The electrolytic capacitor element 24 from which B has been drawn out is sealed in an internal space 32 of a first exterior member 30 made of pps resin or the like, and the surface of this first exterior member 30 is made of epoxy resin or the like. The second exterior member 34 is laminated.

And a welded part between the lead part 4A and the element lead 26A,
In addition, the welded portion between the lead portion 4B and the element lead 26B is
The lead parts 4A and 4B embedded in the side walls of the first and second exterior members 30 and 34 and exposed from the side walls of the second exterior member 34 are bent along the side walls, and their tips are It is arranged on the lower surface of the second exterior member 34.

In this way, the surface layer of the core material 16 is divided into the first and second regions A,
B, and the weldable metal layer 18 and the solderable metal layer 20 are selectively formed on the surface of the metal layer 18, so that it is possible to omit post-plating treatment etc. in the conventional manufacturing process, and The manufacturing process of electronic components such as electrolytic capacitors can be simplified, and there is no interruption in the manufacturing process, and continuous processing is possible, so manufacturing costs can be reduced.

In particular, plating of metals that can be soldered to exposed leads, which was required in the past, uses strong acid or strong alkaline chemicals in the processing solution, which poses a problem of affecting the elements inside the package. Since the lead frame described above does not require such processing, it is possible to stabilize the product and eliminate inconveniences such as performance deterioration.

Further, in the case of the above embodiment, the weldable metal layer 18 in the first area A was set inside the exterior member 30.34, but as shown in FIG. Even if the weldable metal layer 18 is formed in the first region up to the middle position of the first region, the second region B can be sufficiently covered, so that soldering is not inhibited. Never. As in this embodiment, if an aluminum clad material is used for the metal layer 18 in the portion of the exterior member 30, 34 that passes through the synthetic resin, the adhesion to the synthetic resin will be increased and the moisture resistance can be improved.

Although the embodiments have been explained using an electrolytic capacitor as an example, the lead frame of the present invention can also be used for lead frames of electronic components other than electrolytic capacitors such as semiconductor devices, and in this case, the first and second A metal layer corresponding to the element to be connected is formed in the region.

As explained above, according to the present invention, the manufacturing process can be simplified, and since the product is not exposed to chemicals associated with plating after completion, the product can be stabilized.

[Brief explanation of drawings]

FIG. 1 is a plan view showing an embodiment of the lead frame for electronic components of the present invention, and FIG. 3 is a plan view showing a lead frame to which an electrolytic capacitor element is attached; FIG. 4 is a vertical sectional view showing a chip type electrolytic capacitor according to an embodiment of the present invention; FIG. 5 is a longitudinal sectional view showing a chip type electrolytic capacitor according to another embodiment of the present invention. 2... Lead frame, A... First area, B...
・Second area, 4A, 4B...Lead part, 16°...
Heart material, 18.20... Metal layer, 26A, 26B ・
・ ・Element lead. Figure 1 Figure 2 4B +8 2 1 (J iU Figure 3 2 Figure 4

Claims (3)

[Claims] (1) The lead frame is connected to the first
A weldable metal layer is formed on the surface of the core material forming the first region, and a weldable metal layer is formed on the surface of the core material forming the first region.
A lead frame for electronic components, characterized in that a solderable metal layer is formed on the surface of the core material forming the region. (2) A patent characterized in that in the first region, the surface of the core material is clad with aluminum foil, and in the second region, the surface of the core material is clad with metal foil that can be soldered. A lead frame for electronic components according to claim 1. (3) The lead frame for electronic components according to claim 1, wherein the second region is provided with a solder layer on the surface of the core material.