JPH09260570A - Lead frame for semiconductor device, and manufacture of mold type semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a lead frame for a resin-sealed type semiconductor device which not only can avoid the abrasion, damage, etc., of a die-cutting punch, but also can surely secure the electric insulation between leads, and a highly reliable resin-sealed type semiconductor device. SOLUTION: For a lead frame for a semiconductor device, the width 6' of each of the regions that a tie bar 6 couples and unites is set in stepped width or swelling to the width of an inner lead or width of an outer lead 6b, in a lead frame for a semiconductor device which has a group of leads 6 where inner leads 6a and outer leads 6b are connected in succession and besides arranged in parallel, and tie bars 6 which couple and unite the adjacent leads 6 with each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lead frame for a semiconductor device and a method of manufacturing a mold type semiconductor device using this lead frame.

[0002]

2. Description of the Related Art For example, semiconductor devices such as IC elements are
In general, a resin mold is used as a sealing material to mount and mount (or bond) on a lead frame or the like, and protect the environment (environment) and ensure a stable function. FIG. 4 is a plan view showing a generally used lead frame for a semiconductor device.

In FIG. 4, reference numeral 1 denotes a lead portion, an inner lead 1a having one end connected to the input / output terminal side of an IC element to be mounted and mounted, and an outer lead 1b connected / extended to the other end of the inner lead 1a. Is formed by. Here, the width of the inner lead 1a on the other end side gradually increases as compared with the input / output terminal side of the IC element to be mounted and mounted, and the outer lead 1b has the inner lead 1a on the side connected to the inner lead 1a. The lead portion 1 has a width substantially the same as that of the lead portion 1 and is narrowed on the other end side. A plurality of the lead portions 1 are arranged and formed in parallel so as to correspond to the input / output terminals of the IC element to be mounted and mounted. In addition, the lead portions 1 adjacent in parallel are connected and integrated by a tie bar 2 at a wide portion (enlarged portion) of the lead, and after the IC element to be mounted / mounted is molded and sealed, the diver is provided. 2 is selectively cut and removed to separate the outer lead 1b, and stability is achieved by plating.

On the other hand, the manufacturing of a resin mold-sealed semiconductor device using the above lead frame is performed in the following procedure. First, a semiconductor element is mounted and mounted on the semiconductor device lead frame, and the mounted and mounted semiconductor element including the inner lead 1a region is resin-molded by, for example, a transfer molding method. FIG. 5 is a plan view schematically enlarging and showing the state of the main part after the resin molding, 3 is a resin mold region, 4 is an outer lead
1b is a lattice-shaped resin burr bulged on the extension side.

That is, the resin mold seals the mounted and mounted semiconductor element and the inner leads 1a with resin 3, and a lattice-like space formed between the outer leads 1b and the tie bars 2 interconnecting each other. Part of the molding resin flows out to the portion 4 ', and the lattice-shaped resin burr 4 is bulged and formed. Next, as shown in the enlarged schematic view of the essential parts in FIG. 6, the tie bar 2 together with a part of the lattice-shaped resin burr 4 is selectively cut and removed by a punch 5 to remove the lead 1 (outer lead 1b). A mold type semiconductor device is manufactured by separating.

[0006]

However, the following inconveniences often occur in the means for manufacturing a resin-sealed semiconductor device using the lead frame for a semiconductor device having the above structure. That is, when the tie bar 2 is cut and removed by the punching punch 5 after the resin molding, a step of simultaneously punching out a part of the lattice-shaped resin burr 4 is adopted. By the way, the mold sealing resin is generally
For example, since it has a form in which silica powder or the like is dispersedly contained, the punching punch 5 is likely to be worn and the sharpness tends to be reduced. When the tie bar 2 of the plated lead frame is cut while the sharpness is reduced in this way, the plating film protrudes like a beard from the cut surface and a short circuit occurs between adjacent outer leads 1b. There is a risk of

To cope with the problem that the plating film protrudes like a mustache from the cut surface, a lead frame without plating treatment is used, and after the resin molding, the tie bars 2 are cut and removed to be separated from each other, and then the outer It has also been attempted to perform plating treatment on the lead 1b, but this not only lowers productivity but also requires a new dedicated die,
This greatly increases the manufacturing cost. Further, in this plating treatment, there is also a problem that solder residue or the like is likely to adhere to the separated outer lead 1b surface and cause a short circuit between adjacent outer leads 1b.

The present invention has been made in consideration of the above circumstances, and not only can avoid wear and damage of punching punches, but also can surely secure electrical isolation between leads. An object of the present invention is to provide a lead frame for a mold semiconductor device and a manufacturing method capable of manufacturing a highly reliable resin-sealed semiconductor device at low cost.

[0009]

According to a first aspect of the present invention, a group of leads in which inner leads and outer leads are connected to each other and arranged in parallel with each other are integrated by connecting the adjacent leads to each other. In a lead frame for a semiconductor device having a tie bar, a lead width of a region where the tie bar is connected and integrated is set to be a stepped wide width with respect to an inner lead width and an outer lead width. It is a lead frame for a semiconductor device.

According to a second aspect of the present invention, there is provided a semiconductor device having a lead group in which inner leads and outer leads are connected and arranged in parallel, and a tie bar which connects and integrates the adjacent leads. In a lead frame for a semiconductor device, a lead width of a region where the tie bars are connected and integrated is bulged in a width direction in a stepped shape with respect to an inner lead width and an outer lead width. It is a frame.

According to a third aspect of the present invention, in the lead frame for a semiconductor device according to the first or second aspect, the inner leads are in the resin region to be molded. The invention of claim 4 is the lead frame for a semiconductor device according to any one of claims 1 to 3, characterized in that the tie bar is formed and arranged apart from the inner lead.

According to a fifth aspect of the present invention, a semiconductor element is mounted on a lead frame for a semiconductor device in which inner leads and outer leads are connected to each other and adjacent leads formed in parallel are connected and integrated by a tie bar. Mounting and mounting process, resin molding of the mounted and mounted semiconductor element including the inner lead region, and tie bar with part of the lattice-shaped resin burr bulged on the outer lead extension side by the resin molding And a step of selectively cutting and removing the lead to separate the lead, wherein the lead frame has an inner lead width and an outer lead width in a region where the tie bars are connected and integrated. The width of the stepped type is set to the width, and the wide part is almost outer at the same time when cutting and removing the tie bar. A method of manufacturing molded semiconductor device characterized by cutting shaping aligned in over de width.

According to a sixth aspect of the present invention, the semiconductor element is mounted on a lead frame for a semiconductor device in which inner leads and outer leads are connected to each other and adjacent leads formed in parallel are connected and integrated by a tie bar. Mounting and mounting process, resin molding of the mounted and mounted semiconductor element including the inner lead region, and tie bar with part of the lattice-shaped resin burr bulged on the outer lead extension side by the resin molding And a step of selectively cutting and removing the lead to separate the lead, wherein the lead frame has an inner lead width and an outer lead width in a region where the tie bars are connected and integrated. The width is set so that it bulges in the widthwise direction with respect to the width, and the bulging portion is set at the same time when the tie bar is cut and removed. URN is a method for manufacturing a molded semiconductor device characterized by cutting shaping aligned to the outer lead width. In the present invention, the inner lead and the outer lead, which are connected to form a lead, are set corresponding to the pitch of the input / output terminals of the semiconductor element to be mounted / mounted. Here, the lead frame is, for example,
The main body is made of 42Ni-Cu alloy, etc., and the surface is plated.

The tie bar forming / connecting portion for connecting / integrating adjacent leads is an outer lead portion connected to the inner lead and outside the resin molding planned region. The tie bar forming / connecting portion is a stepped type with respect to the inner lead width, and also has a stepped width with respect to the width of the region or portion which actually functions as the outer lead even on the outer lead side, Or it is characterized in that it is huge. Here, the width or the degree of expansion of the stepped die is, for example, such that the punch punch can punch the side portions of the lead at the same time when the tie bar is punched, cut and removed, and separated. It is generally 0.10 to 0.20 mm, but it is desirable that the width is stepwise or enormous, depending on factors such as the size.

According to the first to fourth aspects of the invention, when the lead frame is configured as described above, when the outer lead is separated by cutting and removing the diver in the region widened to the stepped type, for example, a resin mold. After that, the blade of the punching punch of the punching tool not only distinguishes between the portion that abuts the lattice-shaped resin burr and the portion that abuts the metal surface, but also suppresses / prevents the occurrence of misalignment. That is,
The blade of the punching punch contacts the surface to be cut substantially horizontally, so that there is no risk of misalignment and the cutting can be performed with high precision.

Also, it is avoided that the punching punch blades are cut off and separated from the outer lead group by the punching punch blades whose target regions are selected and are worn or damaged due to cutting of the resin layer containing dispersed silica powder or the like. Resolve.
Therefore, the risk of plating film burrs and the like occurring due to cutting and removal of the diver is completely eliminated, and the problem of short-circuiting between outer leads adjacent in parallel is eliminated.

According to the fifth and sixth aspects of the present invention, the lead frame is used for forming the resin-sealed semiconductor device. Therefore, when the outer lead is separated by cutting and removing the diver of the lead frame, the punching tool is punched. The punch blade not only distinguishes between a portion that contacts the lattice-shaped resin burr and a portion that contacts the metal surface, but also suppresses or prevents the occurrence of misalignment. In other words, the punch punch blade is
Since the blade edge portion is in contact with the surface to be cut almost horizontally, there is no risk of misalignment and highly accurate cutting is possible.

Further, it is also avoided that the punching punch blade has a target area selected, and the punching punch blade, which is worn or damaged by cutting the resin layer containing dispersed silica powder or the like, cuts and separates the outer lead group. Resolve.
Therefore, the possibility of plating film burrs and the like occurring due to cutting and removal of the diver is completely eliminated, and the short circuit problem between outer leads adjacent in parallel is solved, and a highly reliable resin-sealed semiconductor device is obtained. Can be provided at low cost and with high yield.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment will be described below with reference to FIGS.

FIG. 1 is a plan view showing a main part of a constitutional example of a lead frame for a semiconductor device. Reference numeral 6 is a lead in which an inner lead 6a and an outer lead 6b are connected and arranged in parallel. , 7 are tie bars that connect and integrate the adjacent leads 1. Here, the lead frame for a semiconductor device is made of, for example, 42Ni-Cu alloy, has a 0.01 mm thick exterior plating layer on its surface, and the tie bar 7 connecting adjacent outer leads 6b has a width. 0.2mm, thickness 0.15mm, this tie bar 7
The stepped wide region 6a ′ connected to each other is set to 0.46 mm. Further, the inner lead 6a and the outer lead 6b are provided on the side continuously provided with the stepped wide region 6a ′,
The pitch is 0.65 mm, the lead width is 0.3 mm, and the lead thickness is 0.15 mm.

That is, the lead frame for a semiconductor device of this embodiment is different from the conventional lead frame for a semiconductor device in the inner lead 6a and the original outer lead.
In contrast to 6b, a part of the outer lead 6b is formed into a stepped type, and the width thereof is widened or enlarged, and the widened or enlarged region 6a 'is used as a region for connecting and integrating with the tie bar 7. Further, in this embodiment, the width of the punching position is set to 0.16 mm wide (in an enlarged state) in consideration of the deviation of the punching position (cut eccentricity) when cutting and removing the tie bar 7. In addition, in FIG. 1, 8 is a slit part.

Next, an example of manufacturing a resin-sealed semiconductor device using the semiconductor device lead frame having the above-described structure will be described.

First, the lead width of the area 6'where the tie bars 7 connect and integrate the adjacent leads 6 with each other is set to be wider (or larger) with a step than the inner lead 6a and the original outer lead 6b. Then, a lead frame for a semiconductor device is prepared in which the inner leads are connected and formed in parallel as a part of the outer leads 6b using the stepped wide (or enormous) area, and the lead frame for the semiconductor device is prepared. A semiconductor element (for example, an IC element) is mounted and mounted on. Next, the lead frame on which the semiconductor element is mounted and mounted is set in a predetermined mold,
For example, transfer molding is performed by a transfer molding device to resin-mold the mounted and mounted semiconductor element including the inner lead 6a region. After this resin molding, the mold is removed from the transfer mold device, and the molded body is taken out from the mold.

The molded body (resin-encapsulated semiconductor device) resin-molded in the above series of steps extends from the resin-molded region (sealing portion) 9 to the outer lead 6b as shown in FIG. Since the lattice-shaped resin burr 10 is bulged in the side slit 8a and the outer leads 6b are connected and integrated with each other by the tie bar 7, for example, the lattice-shaped resin burr is punched by a punching punch.
The tie bar 7 along with a part of 10 is selectively cut and removed to separate the lead 6. FIG. 3 (a) is a plan view schematically showing the execution state of this punching process, and FIG. 3 (b) is a partial sectional view.

In the step of selectively cutting and removing the tie bar 7 to separate the leads 6, a punching punch 11 made of an ultra-hard material (for example, Toshiba Tungaloy Co., Ltd., trade name EM10) has a lattice-like resin on the tip width direction side. While abutting on the burr 10 and a part of the adjacent stepped wide portion 6 ′, the side of the punched punch 11 in the tip length direction contacts the side portion of the stepped wide portion 6 ′ connected by the tie bar 7. In contact with each other, a part of the lattice-shaped resin burr 10 and the tie bar 7 are selectively cut and removed, and the leads 6 are separated while narrowing the width of the wide portion 6'with all the steps. And
In the process of cutting and removing the tie bar 7, the plating residue attached to the lead 6 is removed (in the width and length directions in FIG. 3 (a)), or the plating residue is crushed (in FIG. 3 (b)). The risk of a short circuit between the leads 6 due to plating residue is also eliminated. In addition, in FIG. 3 (b),
12 is a super hard material (eg Toshiba Tungaloy, trade name EM1
A diver cutting table made of 0), 13 is a stripper made of die steel, for example.

The resin-encapsulated semiconductor device mass-produced by the above-mentioned means was subjected to a visual evaluation and a characteristic evaluation by a conventional test method. It was confirmed that each of the separated leads 6 maintains a good insulating property, and a highly reliable resin-sealed semiconductor device can be manufactured with a high yield. When the tie bar 7 is cut and removed, the abutting / cutting portion of the punching punch 11 is sharply divided into a grid-shaped resin burr 10 region and a REIT 6 region. Therefore, it is possible to easily eliminate the risk of burrs of the plating film due to wear and damage of the punching punch 11, so that no dedicated or expensive processing tool is required, and there are many points in terms of cost and productivity. The benefits are recognized.

The present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the invention. For example, the lead frame components, lead frame dimensions and structure, etc.
It can be appropriately selected according to the semiconductor device to be mounted. That is, it is usually sufficient to change a part of the lead frame used for the resin-encapsulated semiconductor (the lead width of the diver connecting portion is widened or enlarged to a stepped type).

[0028]

According to the invention of claims 1 to 4, when the tie bar is cut and removed after the resin molding to separate the outer leads, the punching blade of the punching punch which is worn or damaged due to the cutting of the mold resin burr is removed. Since it is no longer involved in the cutting portion of the lead, burrs of the plating film will not occur and sharp cutting can be maintained. In other words, from the viewpoint of sharp cutting and separation of the lead caused by cutting and removing the tie bar, the durability of the blade of the punching punch (usage limit due to wear and damage) is about 10 times that of the conventional one. Also,
Completely avoiding the occurrence of plating film burrs and the like in the punching process of the tie bar also eliminates the possibility of short-circuiting between leads, which greatly contributes to the provision of a highly reliable semiconductor device.

According to the inventions of claims 5 to 6, the effect of the inventions of claims 1 to 4 is eliminated, that is, the necessity of plating after the tie bar punching process is eliminated (the tie bar can be punched after the plating process. ), It is possible to avoid complication of the process, and there is no need for a device or jig dedicated to tie bar cutting, and in combination with the improvement of the usage limit due to the above-mentioned wear and damage, the production of resin-sealed semiconductor devices. There are many advantages in terms of both sex and cost.

[Brief description of drawings]

FIG. 1 is a plan view showing a main part configuration of a semiconductor device lead frame according to an embodiment.

FIG. 2 is an enlarged schematic plan view of a resin-molded state of the lead frame of FIG.

FIG. 3 is an enlarged schematic view showing the state of cutting and removing the tie bar of the resin-molded lead frame of FIG.
(a) is a plan view, (b) is a partial sectional view.

FIG. 4 is a plan view showing a main part configuration of a conventional semiconductor device lead frame.

5 is an enlarged schematic plan view showing a resin-molded state of the lead frame of FIG. 4. FIG.

6 is an enlarged schematic plan view of the resin-molded lead frame of FIG. 5 with the tie bar cut and removed.

[Explanation of symbols]

 1,6 ...... Lead 1a, 6a …… Inner lead 1b, 6b …… Outer lead 2,7 …… Tie bar 3,9 …… Resin mold area (resin encapsulation part) 4,9 …… Lattice resin burr 5 , 11 …… Punch punch 6 ′ …… Wide wide part (enlarged part) 8 …… Slit 8a …… Slit where lattice-shaped resin burr is formed

Claims (6)

[Claims] 1. A lead frame for a semiconductor device, comprising: a lead group in which inner leads and outer leads are connected to each other and arranged in parallel; and a tie bar for connecting and integrating the adjacent leads. A lead frame for a semiconductor device, wherein a lead width of a region where the tie bars are connected / integrated is set to be a stepped type wider than an inner lead width and an outer lead width. 2. A lead frame for a semiconductor device, comprising: a lead group in which inner leads and outer leads are connected and arranged in parallel, and a tie bar that connects and integrates the adjacent leads. A lead frame for a semiconductor device, wherein a lead width of a region where the tie bars are connected / integrated is bulged in a width direction in a stepped shape with respect to an inner lead width and an outer lead width. 3. The lead frame for a semiconductor device according to claim 1, wherein the inner lead is in a resin region to be molded. 4. The lead frame for a semiconductor device according to claim 1, wherein the tie bar is formed and arranged apart from the inner lead. 5. A step of mounting and mounting a semiconductor element on a lead frame for a semiconductor device, in which inner leads and outer leads are connected to each other and adjacent leads formed in parallel are connected and integrated by a tie bar. And a step of resin-molding the mounted and mounted semiconductor element including the inner lead region, and selectively cutting the tie bar together with a part of the lattice-shaped resin burr bulged on the outer lead extension side by the resin molding. A method of manufacturing a molded semiconductor device, comprising: a step of removing the leads to separate the leads, wherein the lead frame has a step in which a lead width in a region where the tie bars are connected and integrated is different from an inner lead width and an outer lead width. It is set to the wide width of the attached type, and the wide part is aligned with the outer lead width at the same time when the tie bar is cut and removed. A method of manufacturing a mold-type semiconductor device, which comprises cutting and shaping. 6. A step of mounting and mounting a semiconductor element on a lead frame for a semiconductor device in which an inner lead and an outer lead are connected to each other and adjacent leads formed in parallel are connected and integrated by a tie bar. And a step of resin-molding the mounted and mounted semiconductor element including the inner lead region, and selectively cutting the tie bar together with a part of the lattice-shaped resin burr bulged on the outer lead extension side by the resin molding. A method of manufacturing a molded semiconductor device, comprising: a step of removing the leads to separate the leads, wherein the lead frame has a step in which a lead width in a region where the tie bars are connected and integrated is different from an inner lead width and an outer lead width. It is set to bulge in the width direction on the attached mold, and the bulging part is almost outer at the same time when cutting and removing the tie bar. A method for manufacturing a mold-type semiconductor device, which comprises cutting and shaping in accordance with the width of the mold.