JPH05144988A - Production of semiconductor device, semiconductor producing equipment and lead frame - Google Patents

Abstract

PURPOSE:To improve the flatness and the solder wettability of a lead and improve the mount ability of a plastic IC by compulsorily pressing the lead tip of a lead frame so as to make it thin at the time of bending and narrowing the lead tip. CONSTITUTION:A semiconductor chip is mounted on the stage of a lead frame to which the tip 21 of a lead 2 is connected by a connecting member 4 to be resin-sealed. When the connecting member 4 is removed by cutting, the tip 21 of the lead 2 is cut narrow and the tip 21 of the lead 2 is pressed to be thin when the lead 2 is being bent. In this manner, the tip 21 of the lead 2 is forcibly pressed to be thin, the flatness of the lead is improved and since the tip 21 becomes thin by the press, the solder wettability of the tip 21 is also improved. Since the lead tip 21 is cut narrow, even when the tip 21 pressed to be wide, solder bridge generation at the time of mounting is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a semiconductor device, and more particularly, to a method of manufacturing a plastic IC in which a semiconductor chip is mounted on a lead frame and resin-sealed, and a semiconductor manufacturing apparatus used for manufacturing the same. Regarding lead frame.

[0002]

2. Description of the Related Art FIG. 2A shows a plan view of a lead portion protruding from a resin mold when a semiconductor chip is mounted on a lead frame and resin-sealed, and FIG. 2B is a side view thereof. Indicates. In the figure, 1 is a resin mold, 2 is a lead, 3 is a tie bar, and 4 is a connecting member for connecting the tip portions 21 of the leads 2 to each other.

After the lead portion is plated, the tie bar 3 and the connecting member 4 are cut and removed as shown in FIG. 5, and then the lead 2 is bent and formed as shown in FIG. 5 and 6, (A) is a plan view,
(B) is a side view.

[0004]

When the package after lead bending is placed on a flat plate, some of the leads may float above the flat plate. If this amount of floating is large, soldering failure will occur when it is mounted. Therefore, it is necessary to reduce this amount of floating.
It is difficult to reduce the thickness to 1 mm or less.

Further, since the connecting member 4 of the lead 2 is cut and removed after the solder plating process, the cut surface of the lead tip portion 21 is not plated with solder, resulting in poor solder wettability and poor soldering during mounting. Occurs. As a countermeasure against this, a method of using a lead frame without the connecting member 4 for connecting the tip portions 21 of the leads is conceivable, but there is a drawback that the lead is likely to be deformed during the manufacturing process.

An object of the present invention is to eliminate this drawback, and to provide a manufacturing method for improving the flatness and solder wettability of leads of a plastic IC, and an apparatus and a lead frame used in the method. It is in.

[0007]

Among the above objects, the method for manufacturing a semiconductor device can be achieved by any of the following means. The first means is to mount a semiconductor chip on a stage of a lead frame in which the tip ends (21) of the leads (2) are connected to each other with a connecting member (4) and resin-encapsulate the same, and then perform the above-mentioned connection. In a method of manufacturing a semiconductor device, which includes a step of cutting and removing the member (4) and bending and forming the lead (2), when the connecting member (4) is cut and removed, the lead (2) is removed. A method for manufacturing a semiconductor device, comprising a step of thinly cutting the tip (21) and bending the lead (2) to press and thin the tip (21) of the lead (2). is there. The second means is to mount a semiconductor chip on a stage of a lead frame in which the tip ends (21) of the leads (2) are connected to each other with a connecting member (4) and resin-encapsulate the same, and then the above-mentioned connection. In the method of manufacturing a semiconductor device, which comprises a step of cutting and removing the member (4) and bending the lead (2), the lead (2) is cut before the connecting member (4) is cut and removed. A semiconductor having a step of thinning the tip (21) of the lead (2) by pressing the tip (21) of the lead (2) when the lead (2) is bent It is a method of manufacturing a device.

Among the above-mentioned objects, the semiconductor manufacturing apparatus has a lead connecting member cutting means for cutting and removing the connecting member (4) for connecting the tip portions (21) of the leads (2) of the lead frame to each other and the lead (2). In a semiconductor manufacturing apparatus having a lead forming means for bending and forming a lead), the lead tip cutting means for finely cutting the tip (21) of the lead (2) and the lead tip (21) are pressed to be thin. This is achieved by a semiconductor manufacturing apparatus to which lead tip pressing means is added.

Of the above objects, the lead frame is a lead frame in which the tip portions (21) of the leads (2) are connected to each other by a connecting member (4). Is achieved by the lead frame being narrowed.

[0010]

[Function] When the lead end is forcibly pressed and crushed during or after the lead molding to improve the flatness of the lead, the lead end is crushed and thinned. The property is also improved. Since the lead tip portion 21 is thinly cut when the lead connecting member 4 is cut and removed, even if the tip portion 21 is crushed and spread, the occurrence of a solder bridge at the time of mounting is prevented.

If the lead connecting portion 4 is cut and removed after the lead tip portion 21 is thinly cut and plated, the lead tip portion 21 is also plated with solder on both sides. Therefore, the solder wettability is further improved.

If a lead frame having a thin lead tip 21 is used, a step of cutting the lead tip and a device therefor are unnecessary.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method of manufacturing a semiconductor device, a semiconductor manufacturing device and a lead frame according to the present invention will be described below with reference to the drawings.

First Example FIG. 2 shows the shape of a lead portion after a semiconductor chip is mounted on a lead frame and sealed with resin. Since this shape is the same as that of the conventional example, description thereof will be omitted. In this state, the lead portion is plated.

As shown in FIG. 3, when the tie bar 3 is cut and removed, and then the lead connecting member 4 is cut and removed, the tip portion 21 of the lead 2 is cut very thinly. In addition, the same figure (A)
Is a plan view and (B) is a side view.

Next, as shown in FIG. 1, when the lead 2 is bent, the lead tip 21 is pressed and crushed thinly. Note that FIG. 7A is a plan view and FIG. 8B is a side view.

Second Example As shown in FIG. 4, when the tie bar 3 is cut and removed, the tip portion 21 of the lead 2 is cut into thin pieces and solder plating is performed. Note that FIG. 7A is a plan view and FIG. 8B is a side view.

Next, as shown in FIG. 3, the lead connecting member 4 is cut and removed. Then, as in the first example, as shown in FIG. 1, when the lead 2 is bent, the lead tip 21 is pressed and crushed thinly.

Third Example FIG. 7 shows the shape of the lead portion of the lead frame according to the present invention. Note that FIG. 7A is a plan view and FIG. 8B is a side view. In the figure, 1 is a resin mold, 2 is a lead, and the tip portion 21 is formed thin. Reference numeral 3 is a tie bar, and 4 is a connecting member for connecting the tip portions 21 of the leads to each other.

Fourth Embodiment A semiconductor manufacturing apparatus according to the present invention is a semiconductor manufacturing apparatus having a tie bar cutting means for a lead frame, a lead connecting portion cutting means, and a lead bending forming means. A cutting means and a lead tip pressing means for pressing the lead tip to crush it thinly are added.

[0021]

As described above, in the method of manufacturing a semiconductor device, the semiconductor manufacturing apparatus and the lead frame according to the present invention, the tip of the lead frame is made thin and the tip is forced when the lead is bent. Since the flatness and the solder wettability are improved, the mountability of the plastic IC is significantly improved.

[Brief description of drawings]

FIG. 1 is a lead processing step diagram (3) of a plastic IC according to a first embodiment.

FIG. 2 is a lead processing step diagram (1) of a plastic IC according to the first embodiment.

FIG. 3 is a lead processing step diagram (2) of the plastic IC according to the first embodiment.

FIG. 4 is a lead processing step diagram of a plastic IC according to a second embodiment.

FIG. 5 is a lead processing step diagram (1) of a plastic IC according to the related art.

FIG. 6 is a lead processing step diagram (2) of a plastic IC according to the related art.

FIG. 7 is an external view of a lead frame according to the present invention.

[Explanation of symbols]

 1 Resin mold 2 Lead 21 Lead tip 3 Tie bar 4 Connecting member

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Fumihito Takahashi 1st in Nishigaoka, Murata-cho, Shibata-gun, Miyagi Prefecture

Claims (4)

[Claims] 1. A semiconductor chip is mounted on a stage of a lead frame in which the tip portions (21) of the leads (2) are connected to each other by a connecting member (4) and resin-sealed,
A method for manufacturing a semiconductor device, comprising a step of cutting and removing the connecting member (4) to bend and form the lead (2), wherein when the connecting member (4) is cut and removed, the tip of the lead (2) is removed. Manufacturing of a semiconductor device, characterized in that, when the lead (2) is bent and formed by thinly cutting the portion (21), a tip portion (21) of the lead (2) is pressed to be thin. Method. 2. A semiconductor chip is mounted on a stage of a lead frame in which the tip end portions (21) of the leads (2) are connected to each other by a connecting member (4) and resin-sealed,
A method of manufacturing a semiconductor device, comprising a step of cutting and removing the connecting member (4) to bend and form the lead (2), wherein the lead (2) is removed before the connecting member (4) is cut and removed. The tip (21) is finely cut and plated, and when the lead (2) is bent, the tip (21) of the lead (2) is pressed and thinned. Method for manufacturing semiconductor device. 3. A lead connecting member cutting means for cutting and removing a connecting member (4) for connecting tip portions (21) of leads (2) of a lead frame to each other, and a lead forming means for bending and forming the lead (2). In the semiconductor manufacturing apparatus having: a lead tip portion cutting means for thinly cutting the tip portion (21) of the lead (2) and a lead tip portion pressing means for pressing and thinning the lead tip portion (21). Semiconductor manufacturing equipment characterized by the following. 4. A lead frame in which the tips (21) of the leads (2) are interconnected by a connecting member (4), wherein the tips (21) of the leads (2) are thinned. Characteristic lead frame.