JP2576645B2 - Manufacturing method of IC lead frame - Google Patents

Description

The present invention relates to a method for manufacturing an IC lead frame. ICs that prevent deformation and displacement of inner leads
The present invention relates to a method for manufacturing a lead frame.

[Conventional technology]

An IC lead frame usually has a structure as shown in FIG. 3, and since the inner lead 21 is often elongated, the deformation and deformation of the inner lead 21 in the mounting process as well as in the handling and plating processes between processes. Displacement often occurs.

Many of the deformation and displacement of the inner lead are caused by the internal stress of the material and the processing distortion at the time of press working for forming the inner lead, and are called so-called rampage. Conventionally, the following processing method has conventionally been used for the purpose of preventing this rampage.

(1) After punching, "striking" is inserted into the inner lead where the rampage has occurred. That is, the lead is subjected to plastic working, and the lead is returned to a normal position.

(2) After performing a heat treatment for removing distortion with the tip of the inner lead connected, the tip of the inner lead is cut off (for example, a method described in JP-B-62-44422).

(3) With the tip of the inner lead connected, the vicinity of the tip of the inner lead is fixed with an insulating tape or the like, and the tip of the inner lead is cut off.

Japanese Patent Application Laid-Open No. Sho 62-224055 discloses a structure in which a resin is filled in a gap between the tips of the inner leads in order to prevent displacement of the inner leads.

[Problems to be solved by the invention]

However, in the method of tapping in the above (1), since the internal stress of the material is not constant and the processing distortion changes due to wear of the cutting edge of the mold, etc., it is necessary to adjust the tapping strength. Yes, which reduces work efficiency.

The method (2) of applying a heat treatment requires a long time for the heat treatment and requires equipment for the heat treatment.

The method (3) for fixing the vicinity of the tip of the inner lead with an insulating tape or the like takes a long time because it is fixed for each piece. That is, it must be performed separately before the tip of the inner lead is cut off.

Even if the above processes (1) to (3) are not performed, there is a case where there is no problem of lead deformation in the press working. However, as mentioned above, many inner leads are elongated,
It is not rare that the inner leads are deformed and displaced during handling, plating, mounting and the like between processes. As described in JP-A-62-224055, a resin filled in the gap at the tip of the inner lead cannot sufficiently prevent deformation and displacement in the mounting process, etc. When the resin is injected, the resin easily adheres to the inner leads. To prevent or remove the resin, the efficiency of the manufacturing process decreases, and the manufacturing cost increases.

An object of the present invention is to prevent inner lead runaway caused by internal stress and processing strain of a material at the time of press working of an IC lead frame without special equipment and without performing a time-consuming process, An object of the present invention is to provide a method of manufacturing an IC lead frame in which dimensions and positions of inner leads are stable.

[Means for solving the problem]

In order to achieve the above object, according to the present invention, the inner lead of the IC lead frame is punched with an insulator having a shape of a cutting blade, and the insulator is fitted between the inner leads.

As the insulator, for example, a ceramic chip or the like can be used.

[Action]

According to the present invention, punching is performed in a die during press working with an insulating chip having a predetermined hardness and a cutting edge shape, and the insulating material is embedded in a gap between lead frames. Also, the inner lead does not run out due to the processing distortion, and the work of correcting the deformation as in the related art is not required.

In the IC lead frame manufactured according to the present invention, since the insulator chip having the shape of the cutting blade is held between the inner leads, the inner leads are less likely to be deformed and displaced during handling in the mounting process.

 Hereinafter, the present invention will be described in detail with reference to examples.

〔Example〕

FIGS. 1A and 1B show cross sections of a mold used in the method of the present invention. The gold pendant includes an upper mold 1, a lower mold 2, a punch 3, a taper pin 4, a spring 5, and a slide pin 6. First
1A shows a state in which the upper mold 1 is separated from the lower mold 2 and the material 9 to be pressed thereon, and FIG. 1B shows a state in which the upper mold 1 is in contact with the material 9 on the lower mold 2. Is shown. The upper end of the spring 5 is fixed to the upper mold 1, and the taper pin 4
Is biased downward. The tapered pin 4 has an inclined slide surface 4a at an upper end and an engaging portion 4b adjacent below the inclined slide surface 4a. Since the taper pin 4 is urged downward by the spring 5, when the upper die 1 is separated from the lower die 2 and the material 9, it protrudes downward from the upper die 1 as shown in FIG. The engaging portion 4b engages with the engaging portion 7. The slide pin 6 is inserted into the upper die 1 so as to be slidable left and right, and is urged rightward by a spring (not shown). With this bias, the right end 6a of the slide pin 6 is in contact with the inclined slide surface 4a at the upper end of the tapered pin 4.

When the upper mold 1 is lowered, the lower end of the tapered pin 4 comes into contact with the lower mold 2 as shown in FIG. The taper pin 4 rises with respect to the upper mold 1 as the upper mold 1 descends.
Right end of slide pin 6 in contact with inclined slide surface 4a
6a is pushed to the left while sliding on the inclined slide surface 4a.
As a result, the slide pin 6 is pushed leftward, and the left end 6b pushes one of the insulator chips 8 directly below the punch 3 as shown in FIG. 1 (B). Next, when the punch 3 descends, the insulating material chip 8 becomes a punching blade to punch out the material 9. The punch 3 stops with the insulator chip 8 embedded in the material 9. The stamped material 9a is accumulated in the opening 2a of the lower mold 2.

In this way, the material 9 is punched into a predetermined shape by the insulator tip 8, and at the same time, the insulator tip 8 is embedded in the punched portion 9a. In this example, since the insulator tip 8 is used as a punching blade, a ceramic having high hardness and having a sharp lower end is used. By using the insulator tip as the punching blade, wear and damage of the punch cutting blade of the mold can be prevented.

When the punch 3 is raised and then the upper mold 1 is raised,
The right end 6a of the slide pin 6 biased rightward moves to the right while abutting on the inclined slide surface 4a of the tapered pin 4, and the entire slide pin 6 slides to the right. When the upper mold 1 is further raised, the engaging portion 4b of the tapered pin 4 becomes
And returns to the state of FIG. 1 (A).

FIG. 2 shows an example of an IC lead frame manufactured by the method of the present invention. In this IC lead frame, the tip of the inner lead 21 has an insulating chip 8 having a cutting edge shape.
Since the inner lead 21 is fixed, the inner lead 21 can be prevented from running out, and subsequent deformation and displacement are unlikely to occur.

Although the example in which the insulator chip 8 is embedded at the tip of the inner lead 21 is shown, the same effect can be obtained by embedding it at the root of the inner lead 21 or entirely.

〔The invention's effect〕

In the IC lead frame manufactured by the manufacturing method of the present invention, deformation or displacement of the inner lead hardly occurs during handling in the mounting process.

According to the manufacturing method of the IC lead frame of the present invention, the inner lead is processed and fixed by the insulating chip at the time of the press working, so that the deformation and displacement of the inner lead due to the internal stress of the material and the processing strain, the lead shift, etc. Does not occur, and a high quality IC lead frame can be manufactured.

Further, since the work of correcting the deformation of the inner lead as in the related art is not required at the time of press working, the time required for manufacturing is reduced, and the production efficiency is increased. Also, since no equipment for correcting the deformation is required, capital investment can be reduced.

[Brief description of the drawings]

1 (A) and 1 (B) are explanatory views showing cross sections in different states of a mold used in an embodiment of a method for manufacturing an IC lead frame according to the present invention, and FIG. 2 is manufactured by a manufacturing method according to the present invention. Plan view showing an example of an assembled IC lead frame, FIG.
FIG. 1 is a plan view showing a conventional IC lead frame. DESCRIPTION OF SYMBOLS 1 ... upper die 2 ... lower die 2a ... lower die opening 3 ... punch 4 ... taper pin 4a ... inclined slide surface 4b ... engagement part 5 ... spring 6 … Slide pin 6a… Right end of slide pin 6 6b… Left end of slide pin 6… Engagement part 8… Insulator chip 9… Material 9a… Punched material 21… Inner lead

Claims (1)

(57) [Claims] When an inner lead of an IC lead frame is punched, an insulating lead deformation preventing member having a predetermined hardness and a cutting blade shape is disposed immediately below a punch, and the insulating lead deformation is performed. Using the prevention member as a punching blade, the punch is lowered to punch out the work material, and the lowering of the punch is stopped in a state where the insulating lead deformation prevention member is embedded in the work material. A method for manufacturing an IC lead frame, comprising manufacturing an IC lead frame having an insulating lead deformation preventing member having a predetermined hardness and a cutting edge shape.