JPH05291327A - Method for manufacturing semiconductor device - Google Patents

Abstract

PURPOSE:To prevent generation of crack at a gate part when sealing with resin a lead frame by the transfer mold method and gate from remaining on gate break by resin sealing a projecting protrusion which is formed at the gate while kept adhering to the side surface of a lead frame tie bar. CONSTITUTION:A gate 11 which is a port for pouring resin and is provided for sealing resin to a lead frame 1 by the transfer mold method is placed on a tie bar 2 and a placement piece 4 and a projecting protrusion 11b with a gate width of a gate 11 is stuck to a side surface 2a of the tie bar 2. Resin is poured from the gate 11 and a semiconductor element 3 and lead terminals 6 and 8 on the placement piece 4 are all resin-sealed. In this case, thermal stress accompanying curing of resin is taken care of by the protrusion 11b and is not concentrated at one point, thus preventing thermal stress from being centered only at a thin part of the gate 11 and crack from being generated and the gate from remaining on gate break.

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 semiconductor device for electric power or the like which is resin-sealed using a lead frame.

[0002]

2. Description of the Related Art In a resin-sealed power semiconductor device, a lead frame 1 is formed with a plurality of frames, as shown in FIG.

In each frame, as shown in FIG.
A semiconductor element 68 is die-bonded to the mounting piece 67, and the semiconductor element 68 and each of the lead terminals 70 and 71 are internally connected by a bonding wire 69 to form a circuit.

Then, the lead frame 100 provided with the internal connection is resin-sealed by a transfer molding method. That is, the resin injected from the gate 60 serving as an injection port allows the semiconductor element 68 on the mounting piece 67, the lead terminals 70 and 71, and the bonding wire 69.
Is resin-sealed.

After that, as shown in FIG. 7, the gate 60 is gate-broken, the thin burr 65 and the thick burr 63 are resin-cut, and the tie bars 64, 62, 66 are tie-bar cut to complete the semiconductor device shown in FIG. To do.

[0006]

By the way, according to the conventional technique, when the lead frame is resin-sealed by the transfer molding method as shown in FIG. 6, the gate 60 is thermally contracted by the mold resin before the gate breaks. There is a problem that a crack 60a is generated in 60, and even if the gate is broken, the crack 60a is broken. That is, as shown in FIG.
If it is cracked at 0a, a gate residue is generated, and as shown in FIG. 8, the device becomes a device with poor appearance in which the gate residue is attached, and the quality deteriorates. Further, when the tie bar is cut, if the remaining gate is attached, the tie bar cutting die may be damaged.

The present invention has been made in view of these points, and when a lead frame is resin-sealed by a transfer molding method, a gate crack does not occur before the gate is broken, and the gate break is generated. After that, it is an object of the present invention to provide a method for manufacturing a semiconductor device in which no gate residue occurs.

[0008]

In order to achieve the above-mentioned object, a method of manufacturing a semiconductor device according to the present invention comprises two support tie bars provided at opposite positions, a mounting piece provided between the support tie bars, A lead terminal, and a lead terminal inter-tie tie bar supporting the lead terminal are used together with a lead frame, and the semiconductor element mounted on the mounting piece and the lead terminal are connected to each other, and In a method of manufacturing a semiconductor device in which a resin is injected from a gate provided in the vicinity of one of the support tie bars to perform resin sealing, a protrusion having a convex shape and a width equal to the gate width is provided at a predetermined position of the gate. It is characterized in that it is provided and is resin-sealed in a state where the end face of the protrusion is in close contact with the side face of the one support tie bar.

[0009]

After the resin is injected, the resin is hardened and the thermal contraction causes thermal stress, and particularly when the thermal stress occurs in the longitudinal direction of the gate, the protrusions share the thermal stress. .. Therefore, thermal stress does not concentrate only on the narrowed portion of the gate, and the gate does not crack.

[0010]

EXAMPLE FIG. 5 is an enlarged view of a portion indicated by a broken line of the lead frame 1 shown in FIG. Semiconductor element 3 on mounting piece 4
Is internally connected by the lead terminals 6 and 8 and the bonding wire 5 to form a circuit.

1 to 3 are views for explaining an embodiment of the present invention with time. The (a) figure and the (b) figure of each figure are a top view and its side view, respectively. Embodiments of the present invention will be described below with reference to the drawings.

First, the lead frame 1 with the internal connection shown in FIG. 5 is resin-sealed by the transfer molding method. The gate 11 which is a resin injection port provided for performing the resin sealing is mounted on the tie bar 2 and the mounting piece 4, and the protrusion 11 b having a gate width of the gate 11 has a protrusion 11 b. It is provided in close contact with the side surface 2a. By injecting resin from the gate 11 in this state, the semiconductor element 3 on the mounting piece 4 and the lead terminals 6 and 8 connected by the semiconductor element 3 and the bonding wire 5 are all resin-sealed. And is covered with the sealing resin 12. Also, at the time of this resin sealing,
A thin burr 13 and a thick burr 14 are formed (FIG. 1).

Next, after the sealing resin 12 is cured, the gate 11 is broken. In this process, the gate 11 is gate-breaked with almost no gate left (FIG. 2). Then, the thin burr 13 and the thick burr 14 are resin-cut, and then the tie bars 2, 9 and 10 are tie-bar cut to complete a desired semiconductor device (FIG. 3). A plurality of semiconductor elements shown in the embodiments of the present invention are die-bonded to one lead frame, and each semiconductor element is simultaneously resin-sealed.

In the embodiment of the present invention, since the protrusion 11b formed on the gate 11 is sealed with the resin in close contact with the side surface 2a of the tie bar 2, the thermal stress due to the curing of the resin is shared by the protrusion 11b. Don't concentrate on As a result, a crack does not occur between the molding of the molding resin and the gate break, and a semiconductor device having no gate residue at the time of the gate break is completed.

[0015]

As described above, according to the present invention,
The gate has the gate width, and the resin is sealed with the convex protrusions in close contact with the side surface of the lead frame tie bar. Therefore, between the molding of the resin by the transfer molding method and the gate break. The protrusions share the thermal stress due to the generated thermal contraction. Therefore, thermal stress does not concentrate only on a predetermined point of the gate, and cracks do not occur.

As a result, no gate residue is generated even if the gate is broken, and the appearance of the semiconductor device is not damaged.
Also, the quality is improved. Further, in the manufacturing process, the yield can be improved, and troubles in the process such as damage to the tie bar cutting die can be eliminated.

[Brief description of drawings]

FIG. 1 is a diagram illustrating an embodiment of the present invention.

FIG. 2 is a diagram illustrating an embodiment of the present invention.

FIG. 3 is a plan view of a semiconductor device manufactured according to an embodiment of the present invention.

FIG. 4 is a plan view of a lead frame used in an embodiment of the present invention.

FIG. 5 is a plan view of a semiconductor device used in an embodiment of the present invention before resin sealing.

FIG. 6 is a diagram illustrating a conventional example.

FIG. 7 is a diagram illustrating a conventional example.

FIG. 8 is a plan view of a semiconductor device manufactured by a conventional example.

[Explanation of symbols]

 1 ... Lead frame 2, 9, 10 ... Tie bar 3 ... Semiconductor element 4 ... Mounting piece 5 ... Bonding wire 6, 7, 8 ... Lead terminal 11 ... Gate 11b Protrusion 12 Encapsulation resin

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location B29L 31:34 4F

Claims (1)

[Claims] 1. Two support tie bars provided at opposing positions, a mounting piece provided between the support tie bars, a lead terminal,
And a tie bar between lead terminals for supporting the lead terminal, a lead frame formed integrally with the semiconductor element mounted on the mounting piece and the lead terminal are connected to each other to support the one side. In a method of manufacturing a semiconductor device in which a resin is injected from a gate provided in the vicinity of a tie bar to perform resin sealing, a protrusion having a convex shape and a width equal to the gate width is provided at a predetermined position of the gate, A method for manufacturing a semiconductor device, characterized by encapsulating with resin in a state where an end face of the protrusion is in close contact with a side face of the one support tie bar.