JPH09293741A - Punch for manufacturing semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor device with excellent abrasion resistance and strength by fixing cemented carbide chip which is made of a metallic member whereupon a super abrasive layer is baked, on the leading edge by brazing. SOLUTION: A cemented carbide chip 11 is junctioned to the leading edge of a punch base metal 10 by silver brazing S. The loading edge of this carbide chip 11 is divided into comb shape by wire discharge process etc., so that the metallic medium of diamond powder, Co, etc., with diameters of several - scoresμm may be applied to the loading edge of the carbide chip base metal 11a to sinter a super abrasive layer meeting the production requirements of 1400-1500 deg.C, 50.000 atmospheric pressure for the formation of a 500μm-thick diamond sintered body layer 11b. Through these procedures, the title semiconductor device in excellent abrasion resistance and strength can be manufactured.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an IC, an LSI, a V
The present invention relates to various punches used in a semiconductor device package manufacturing process such as LSI, for example, a punch for removing burrs generated in a resin-sealed package by punching.

[0002]

2. Description of the Related Art In a resin-sealed package of a semiconductor device, a semiconductor element is mounted on multiple lead frames which are etched or press-molded, and after wire bonding, a large number of epoxy- or silicon-based resins are molded at once. It is formed by

The molded semiconductor element is separated from the frame by gate cutting in the next process, and becomes an individual semiconductor device.

Here, when the lead frame is molded, the resin exudes from a slight gap between the lead frame and the mold, and the space surrounded by the outer lead and the dam bar corresponds to the thickness of the lead frame. Filled with resin,
These are called Bali.

FIG. 5 shows the state of occurrence of such burrs.
In the figure, 50 is a molding resin, 51 is an outer lead, 52 is a dam bar, 55 is a burr that has exuded, and 56 is a burr.
Indicate burrs filled in the spaces of the outer lead 51 and the dam bar 52, respectively.

Such burrs may be peeled off even with a weak impact. Particularly, when the burrs are peeled off after the exterior treatment, the base material of the lead frame is exposed and the solder wettability and corrosion resistance of the outer leads are impaired. It is necessary to thoroughly remove burrs before processing.

Conventionally, as a burr removal method, a high pressure water method or a liquid honing method has been employed to remove the burr 55 that has exuded. High pressure water method has an inner diameter of 0.2 mm
A few hundred kg / cm ² of water is sprayed on the burr from the nozzle at the top to remove it. In the liquid honing method, the inner diameter is 8 to 10
A few kg of water mixed with media from a nozzle of about mm / c
The burr is removed by spraying with a pressure of m ² .

On the other hand, the outer lead 51 and the dam bar 5
The burr 56 filled in the space of No. 2 is disclosed in JP-A-3-5085.
4, Japanese Patent Laid-Open No. 2-30152, Japanese Patent Laid-Open No. 5-3
No. 26798 and the like, and using a comb tooth-shaped punch as shown in FIG.
Removed with 2.

[0009]

This punch has hitherto been
It is formed of cemented carbide or ultrafine grained cemented carbide having relatively excellent wear resistance. However, in recent years, the punch wear has become particularly severe due to the finer punch members due to the higher integration of semiconductor devices and the addition of silica as a filler in the resin. Need to be replaced.

As a countermeasure against this, it is conceivable to form a diamond sintered body layer or a CBN sintered body layer having excellent wear resistance at the tip of the punch, but these sintered bodies are the base material of the punch. Hard cannot be brazed directly and requires extensive equipment, in an inert atmosphere or in a vacuum,
It is necessary to use special brazing methods with active metals. Therefore, it is difficult to apply a diamond sintered body having excellent wear resistance to a punch.

In addition to this, CVD is performed on the surface of the base material made of cemented carbide or the like.
(Chemical vapor position
It is also conceivable to form a TiC film, a diamond film or the like by using the n) method or the like. However, the TiC layer formed in this case is at most about several μm, and a thickness of this level does not lead to a significant improvement in the durability of the punch, which is subject to severe wear due to repeated repetition.

In addition to the above-mentioned problems, such a problem is caused by a gate (cut) punch, an outer casing, which is used for punching a gate at the time of resin molding.
It is used in a set with a resin punch that punches out only the burr that flows out between the leads, a diver cut punch that punches out the burr and tie bar (dam bar) that flow out between the outer leads with the die, and a bending die, and the outer lead is specified. Cutting and bending punch that cuts and bends to the length of
The same also applies to a lead cut punch that cuts only the lead frame. In the present invention, the punch includes all of the above punches.

The present invention solves the above problems in various punches used in a semiconductor device package manufacturing process, and provides a punch which is relatively easy to manufacture, has excellent wear resistance, and has excellent strength. An object is to improve the productivity of semiconductor devices.

[0014]

In order to solve the above problems, the present invention provides a punch for cutting or bending used in a package manufacturing process of a semiconductor device, in which a metal member is preliminarily super-abrasive at a tip portion. It is characterized in that a cemented carbide chip formed by baking a grain layer is fixed by a brazing method.

The diamond sintered body and the CBN sintered body are
Although it is far more excellent in wear resistance than conventional punch materials such as cemented carbide or ultrafine particle cemented carbide, diamond sintered bodies and cemented carbide have problems such as difficulty in brazing in the atmosphere. By using a cemented carbide tip obtained by baking and molding the above-mentioned diamond sintered body layer and CBN sintered body layer to a metal member (carbide member) as a backing with a thickness of about 500 μm in advance, the bonding to the punch base material is performed in the atmosphere. It becomes possible by brazing inside.

A cemented carbide chip having a diamond sintered body layer is filled with a cemented carbide plate serving as a base material, a diamond powder having a diameter of several μm to several tens of μm, and a metal medium such as Co in a capsule to form a diamond powder. 1400 to 15 that is the generation condition
By sintering under the conditions of 00 ° C. and 50,000 atm, the abrasive grain layer can be fixedly formed on the surface of the base material.

The grain size of the superabrasive grains is not particularly limited, but in the case of diamond grains, it is 5 μm or less, 8 to 15 μm.
m, 20 to 30 μm, and a metal (Co or the like) as a binder are mixed and used in a volume ratio of about 9: 1.

The CBN abrasive grains are not particularly limited, but those having a grain size of 5 μm or less are used, Co or ceramics is used as a binder, and a mixture thereof is used in a ratio of about 9: 1 to 5: 5. can do.

Here, the joining position between the cemented carbide tip and the base material is set to be 0.5 mm or more than the depth of the comb teeth on the base material side, whereby the joining strength is increased and the cemented carbide tip and the base material are joined. Peeling can be effectively prevented.

The limit of use due to abrasion of the punch tip is generally up to about 80 μm, and the thickness of the superabrasive layer is preferably thicker than this, and in consideration of correction and use, 200 μm or more is desirable. .

Wire-cut electric discharge machining or the like can be used to form such a cemented carbide chip having a diamond sintered body layer formed on the cemented carbide tip, which is the punch base material, in the shape of a comb tooth. .

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below in detail based on the embodiments shown in the drawings. FIG. 1 is a front view of a burr punching punch showing an embodiment of the present invention. In the figure, 10 is a punch base material made of carbide, and 11 is a carbide tip joined to the tip of the punch base material 10 by silver brazing S. The cemented carbide tip 11 is formed in the shape of a comb tooth with a divided tip and is made of cemented carbide.
A diamond sintered body layer 11b having a thickness of about 500 μm is formed at the tip of a.

In the present embodiment, the punch groove depth h
= 10 mm, pitch P = 1.8 mm, punch width W = 0.
It is 6 mm, and the joint surface S between the punch base material 10 and the cemented carbide chip 11 is on the side of the 2 mm punch base material 10 with respect to the groove.

Next, a method for manufacturing the punch for burr punching will be described. Referring to FIG. 2 showing a manufacturing process of a cemented carbide chip having a superabrasive grain layer, first, as shown in FIG. 2A, a diamond abrasive grain 20a and a binder (Co) 2 are added.
2b of the mixture of 0b and the cemented carbide base material 21 shown in FIG.
Fill the inside of the capsule 22 as shown in FIG. Then, this is subjected to ultra-high pressure sintering at a temperature of 50,000 atm and 1400 ° C. or higher using an ultra-high pressure apparatus 23 as shown in FIG. 2 (c).

As a result, as shown in FIG.
A diamond sintered body core 25 having a diamond sintered body layer 24 fixed to the surface of the cemented carbide base material 21 is formed.
The same procedure can be used when CBN abrasive grains are used as the superabrasive grains.

Next, this is cut into a chip of an arbitrary size according to the product size by using a wire cut electric discharge machining method or the like.

Further, this is brazed with silver to the front end of the punch base material 10 and processed into a predetermined comb tooth shape using a wire cut electric discharge machining method or the like to complete the burr punching punch shown in FIG.

With such a structure, the durability is dramatically improved, the frequency of exchanging the punch in the semiconductor manufacturing apparatus is reduced, and the productivity is improved as compared with the conventional punch made of super-hard or ultra-fine-grain super-hard. be able to.

FIG. 3 is a front view showing a tip portion of a punch showing another embodiment of the present invention. In this embodiment, as a cemented carbide tip 15, diamond firing is performed only on the working point side of the tip base material 15. The united layer 15b is formed. This cemented carbide tip 15 can also be manufactured according to the above method. Thus, by providing the sintered body layer 15b only on the working point side, an expensive sintered body layer can be economically used.

[0030]

EXAMPLE A punch shown in the above-mentioned embodiment was used as Example 1, a punch having a cemented carbide tip having a length of 3 mm and a joint portion being an upper portion of a groove was used as Example 2, and a conventional punch was used as a comparative example. A punch made of a super hard member was used to deburr a semiconductor device.

In the comparative example, the result is about 80 after 3 months of use.
Abrasion of μm was observed, and it became impossible to maintain a predetermined processing accuracy, and continuous use was impossible. On the other hand, in both Example 1 and Example 2, no wear was observed after 3 months of use, and continuous use was possible. However, in Example 2, although no wear was observed, peeling was observed at the joint between the cemented carbide tip and the punch base metal.

Based on this result, the length of the cemented carbide tip was changed little by little, and the joint strength with the punch base material was tested. When the length of the cemented carbide tip was shorter than the punch groove, That is, it was confirmed that the strength was weak in the case of joining at the teeth of the comb of the punch, and that the joining strength was sufficient in the case of joining at the punch base material side of 0.5 mm or more than the groove.

FIG. 4 is a graph showing the relationship between the length and the strength of the cemented carbide tip. When the teeth of the comb at the tip are joined, the joining area is small, so the joining strength is weak, and the joining depth is 0.5 m less than the groove depth.
The strength increased sharply from the point where m was exceeded, and thereafter, there was almost the same tendency.

[0034]

According to the present invention, the following effects can be obtained.

(1) A cemented carbide tip, which is formed by baking a superabrasive grain layer consisting of a diamond sintered body layer or a CBN sintered body layer on a metal member in advance, is joined by brazing to the tip of the punch, thereby being relatively manufactured. It is possible to provide a punch that is simple and has excellent wear resistance, which can improve the productivity of semiconductor devices.

(2) By setting the thickness of the abrasive grain layer to 200 μm or more, it becomes possible to use the product for a relatively long period of time without impairing the quality of the product.

(3) By setting the joining position of the cemented carbide tip to the base material side by 0.5 mm or more from the depth of the comb teeth, peeling at the joint portion of the cemented carbide tip and the base material even with a relatively small cemented carbide tip Can be effectively prevented.

[Brief description of drawings]

FIG. 1 is a front view of a punch for burr punching according to the present invention.

FIG. 2 is a diagram showing a manufacturing process of a cemented carbide chip having a superabrasive grain layer.

FIG. 3 is a side view of a punch showing another embodiment.

FIG. 4 is a graph showing the relationship between the length and strength of a cemented carbide tip.

FIG. 5 is an explanatory diagram showing a burr occurrence state.

FIG. 6 is a front view of a conventional burr punching punch.

[Explanation of symbols]

 10 Punch base material 11,15 Carbide chip 11a, 15a Chip base material 11b, 15b Diamond sintered body layer 50 Mold resin 51 Outer lead 52 Dam bar 55, 56 Burr

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshikazu Shigenaga 210 Takeno, Ota, Marumachi, Ukiha-gun, Fukuoka Noritake Diamond Co., Ltd. In the company

Claims (4)

[Claims] 1. A punch for cutting or bending used in a semiconductor device package manufacturing process, wherein a cemented carbide chip having a superabrasive grain layer pre-baked and formed on a metal member is fixed to the tip portion by a brazing method. A punch for manufacturing a semiconductor device, which is characterized in that 2. The punch for manufacturing a semiconductor device according to claim 1, wherein the tip portion is formed in the shape of a comb tooth. 3. The superabrasive layer is a diamond sintered body layer or a CBN sintered body layer.
2. A punch for manufacturing a semiconductor device as described in 2 above. 4. The punch according to claim 1, wherein the abrasive grain layer has a thickness of 200 μm or more.