JPH08107170A - Ic lead frame manufacturing method - Google Patents

Abstract

PURPOSE: To prevent tab hanging leads at both sides of a tab from twisting and hold the tab horizontal by twice press-work the hanging leads at the diagonal positions thereof. CONSTITUTION: A diagonal position punching is twice made by a punch and die of a press machine such that the blades A and D or those B and C of tab hanging leads 1 are punched through at the same time. This cancels the twist of the hanging leads 1 to this side with that to that side in the punching step. Hence the punched leads are not twisted due to the punching and the tap 2 is held horizontal. The dab is to mount an IC chip and it is important that the chip is horizontally mounted on the tab of a lead frame. Thus, there is no twist of the leads on the produced IC lead frame, though the manufacturing method, no of steps and material are the same as those used conventionally.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an IC lead frame.

[0002]

2. Description of the Related Art In a manufacturing process of an IC lead frame by press working, as a method of forming tab suspension leads for supporting tabs from both sides by press working, as shown in FIG. It is a general method to form the tab suspension leads by punching out four portions (cuts) of A, B, C, and D that are adjacent "upper and lower" to the left and right tab suspension leads 1 formed on. is there. Here, "cut" means a portion that becomes a punching scrap.

Here, "adjacent to the tab suspension lead" means "adjacent to it" in the direction of the arrow at the right end of FIG. In the following, the direction of this arrow may be referred to as "front side" and the opposite direction may be referred to as "rear side".

In the press working of the tab suspension lead 1, A,
It is most efficient to punch out the "cuts" in the four parts of B, C and D at the same time, and the horizontality of the tab 2 can be maintained, but the width of the tab suspension lead 1 is narrow and It is difficult to perform simultaneous punching because the strength of the bottom part of the die is insufficient and the die may be bent or deformed by repeated punching. Conventionally, it is difficult to perform simultaneous punching in FIG. 2 for punching and "cutting" A and C
Pressing has been carried out in two steps, that is, punching of parts.

[0005]

However, in the above-mentioned conventional press working method, the tab 2 is twisted toward the front side at the time of punching out the portions "B" and "D" in FIG. When punching out parts A and C, it is twisted backward. Therefore, the front-side twist of the tab 2 in the first punching is corrected by the second punching, but the rear-side twist of the tab 2 caused by the second punching remains.

An object of the present invention is to solve the above-mentioned drawbacks of the prior art, and in a method of pressing a tab suspension lead during a manufacturing process of an IC lead frame by press working, a method of manufacturing an IC lead frame in which no twist remains on the tab. To provide.

[0007]

Means for Solving the Problem
This is achieved by the method of manufacturing the C lead frame.

That is, in the method of pressing a tab suspension lead that supports tabs from both sides during the manufacturing process of the IC lead frame by the press processing, the press processing is performed twice for each diagonal position of the tab suspension leads on both front and both sides. Tab suspension leads are formed to prevent twisting of the tab suspension leads and to maintain the horizontality of the tabs.

The tab is a base on which an IC chip is placed. It is important that the IC chip be mounted on the tab of the lead frame while maintaining horizontality. The above-mentioned diagonal position means the positional relationship between "disconnection" A and D or "disconnection" B and C.

The skeleton of the present invention prevents twisting of the lead after punching by performing punching at two diagonal positions in the pressing method of the tab suspension lead that supports the tab from both sides, and by extension, the lead is punched. It is to maintain the horizontality of the tab.

[0011]

EXAMPLE An example of the present invention will be described with reference to FIG. However, the description is for deepening the understanding of the present invention and does not limit the present invention.

FIG. 1 is an explanatory view of a press working method for punching tab suspension leads sandwiching a tab of the present invention.

By means of the punch and die of the press machine, for example, the "cutting" A and D or the "cutting" B and C shown in FIG. When the tab suspension lead is punched by the diagonal position punching method of the present invention, the punching is performed while canceling the twist on the front side and the twist on the rear side, so that the punched lead is not twisted and therefore the horizontality of the tab is maintained. Be done.

[0014]

According to the method of manufacturing an IC lead frame of the present invention, although the number of steps and materials are the same as those of the conventional manufacturing method, the manufactured IC lead frame has no twist of the lead and the tab This is an excellent manufacturing method that maintains horizontality.

[Brief description of drawings]

FIG. 1 is an explanatory view of a press working method of the present invention for punching a tab suspension lead.

[Explanation of symbols]

 1 tab suspension lead 2 tabs A, B, C, D parts (cut)

Claims (1)

[Claims] 1. A method of pressing a tab suspension lead that supports a tab from both sides during a manufacturing process of an IC lead frame by press processing, wherein the press processing is performed twice for each diagonal position of the tab suspension lead on both sides. A method of manufacturing an IC lead frame, comprising forming a tab suspension lead, preventing twisting of the tab suspension lead, and maintaining horizontality of the tab.