JP2012199464A - Manufacturing method of semiconductor device and lead frame - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a semiconductor device capable of surely removing an unnecessary sealing resin without leaving it in a lead frame.SOLUTION: A manufacturing method of a semiconductor device includes: a step of mounting a semiconductor chip 100 on a die pad 210 of a lead frame 200; a molding step of placing the lead frame 200 in a mold and sealing the frame with a sealing resin; a step of taking out the sealed lead frame 200 from the mold; and a removal step of removing an unnecessary part 600 of the sealing resin. Before the molding step, a semi-punching part 260 enclosed by a groove is formed at least on one surface of a support frame 240 of the lead frame 200. The removal step removes the unnecessary part 600 by removing the semi-punching part 260.

Description

  The present invention relates to a method for manufacturing a semiconductor device and a lead frame.

  In a step of molding a lead frame on which a plurality of semiconductor chips are mounted with a sealing resin, a method is adopted in which the sealing resin is caused to flow into individual cavities via runners. In this method, when the mold is filled with the sealing resin and cured, the sealing resin remaining on the runner is fixed on the lead frame, so that the sealing resin in the runner portion is surely removed. Is desired.

  For example, Patent Document 1 proposes a method of removing unnecessary portions by extruding a sealing resin at a runner portion with a pin from an opening hole provided in a lead frame.

Japanese Patent Laid-Open No. 03-184351

  However, in the method described in Patent Document 1, when the adhesion between the runner and the lead frame is strong, a part of the sealing resin of the runner cannot be peeled off even if pushed out by a punching pin, and remains on the surface of the lead frame. There was a possibility.

According to the present invention,
Mounting a semiconductor chip on the die pad of the lead frame;
A molding step of placing the lead frame in a mold and sealing with a sealing resin;
Removing the sealed lead frame from the mold;
A removal step of removing unnecessary portions of the sealing resin;
Have
Before the molding step, the method includes a step of forming a half punched portion surrounded by a groove on at least one surface of the support frame of the lead frame,
In the molding step, a runner that guides the sealing resin into a cavity that encloses the semiconductor chip is disposed so as to pass over the half-punched portion,
The unnecessary portion is the sealing resin remaining in the runner,
In the removing step, a method of manufacturing a semiconductor device is provided in which the unnecessary portion is removed by removing the half-punched portion.

According to the present invention,
At least one die pad;
A suspension lead for supporting the die pad;
A support frame for supporting the suspension leads;
Have
The support frame is provided with a lead frame having a half-punched portion surrounded by a groove on at least one side.

According to the present invention, before the molding step, a half-cut portion surrounded by the groove is formed on at least one surface of the support frame of the lead frame, and is fixed to the sealing resin remaining on the runner. In the subsequent removal step, the half-punched portion is cut. Thereby, an unnecessary part can be removed easily. As described above, unnecessary sealing resin can be reliably removed without leaving the lead frame.

  According to the present invention, unnecessary sealing resin can be reliably removed without leaving the lead frame.

It is a figure which shows the manufacturing method of the semiconductor device which concerns on 1st embodiment. It is sectional drawing which shows the manufacturing method of the semiconductor device which concerns on 1st embodiment. It is a top view which shows the manufacturing method of the semiconductor device which concerns on 1st embodiment. It is sectional drawing which shows the manufacturing method of the semiconductor device which concerns on 1st embodiment. It is sectional drawing which shows the manufacturing method of the semiconductor device which concerns on 1st embodiment. It is a top view for demonstrating the effect of 1st embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, the same reference numerals are given to the same components, and the description will be omitted as appropriate.

(First embodiment)
FIG. 1 is a diagram showing a method for manufacturing a semiconductor device according to the first embodiment. A lead frame 200 used in the first embodiment will be described with reference to FIG. The lead frame 200 of this embodiment includes at least one die pad 210, a suspension lead 220 that supports the die pad 210, and a support frame 240 that supports the suspension lead 220. The support frame 240 has a half-punched portion 260 surrounded by a groove on at least one side. As will be described later, the half-punched portion 260 adheres to the sealing resin remaining on the runner (340 in FIG. 3). Details will be described below.

  FIG. 1 shows a lead frame 200 on which a semiconductor chip 100 is mounted. FIG. 1A is a plan view. Moreover, FIG.1 (b) is the sectional view on the AA 'line of Fig.1 (a). Moreover, FIG.1 (c) is sectional drawing to which the C section of FIG.1 (b) was expanded. As shown in FIG. 1A, the lead frame 200 includes a die pad 210, suspension leads 220, leads 230, and a support frame 240.

  The die pad 210 is supported by the suspension leads 220. The semiconductor chip 100 is fixed on the die pad 210. The lead 230 is connected to an electrode pad (not shown) on the semiconductor chip 100 by a bonding wire 120.

  As shown in FIG. 1A, the support frame 240 is formed with a half punched portion 260 surrounded by a groove on at least one side. In addition, the solid line part surrounding the half punching part 260 in FIG. 1A corresponds to a groove forming part.

  Further, as shown in FIG. 1C, in this embodiment, grooves are formed from both sides of the support frame 240. Thereby, the half-punched part 260 is formed. As will be described later, the half-cutting portion 260 is formed by, for example, pressing.

  Further, as shown in FIG. 1B, the lead frame 200 is formed with a plurality of half-punched portions 260 and openings 280 alternately and repeatedly along the first direction. Moreover, a 1st direction is an extending | stretching direction of the runner (340) which guides sealing resin mentioned later, for example.

  Next, the manufacturing method of the semiconductor device of the first embodiment will be described with reference to FIGS. FIG. 1 is a diagram illustrating a method for manufacturing a semiconductor device according to the first embodiment, and FIGS. 2 to 5 are cross-sectional views illustrating a method for manufacturing a semiconductor device according to the first embodiment. The manufacturing method of the semiconductor device of this embodiment includes the following steps. First, the semiconductor chip 100 is mounted on the die pad 210 of the lead frame 200. Next, the lead frame 200 is placed in a mold and sealed with a sealing resin (molding process). Next, the sealed lead frame 200 is taken out from the mold. Next, the unnecessary portion 600 of the sealing resin is removed (removal process). Here, before the molding process, the half-cut processing portion 260 surrounded by the groove is formed on at least one surface of the support frame 240 of the lead frame 200. Next, in the molding process, a runner 340 that guides the sealing resin into the cavity 380 that encloses the semiconductor chip 100 is disposed and sealed so as to pass over the half-blanking part 260. Further, the unnecessary portion 600 is sealing resin remaining on the runner 340. Further, in the removing step, the unnecessary portion 600 is removed by removing the half-punched portion 260. Details will be described below.

  FIG. 2A to FIG. 2D show a process of forming the half blanking portion 260. At least prior to the molding process, the following process of forming the half-punched portion 260 is performed.

  First, as shown in FIG. 2A, the lead frame 200 is placed on the die 740 so that the support frame 240 comes to a predetermined pressing position.

  Next, as shown in FIG. 2B, press working is performed from one side of the lead frame 200 with a punch 720. At this time, pressing is performed from 30% to 50% of the thickness of the support frame 240 from one side. By performing press working within this range, a half-punched portion 260 described later can be fixed to the support frame 240 until the molding step. Further, in the removing step, the half-punched portion 260 can be easily removed.

  Next, as shown in FIG. 2 (c), pressing is performed from the opposite direction to FIG. 2 (b). Thereby, the support frame 240 is flattened.

  In this way, as shown in FIG. 2D, the half-cut processing portion 260 surrounded by the groove is formed on at least one side (both sides in the present embodiment) of the support frame 240. Note that the process of forming the half-punched portion 260 may be performed after the process of mounting the semiconductor chip 100 described later on the lead frame 200.

  Next, as shown in FIG. 1A, the semiconductor chip 100 is mounted on the die pad 210 of the lead frame 200. Next, the electrode pads (not shown) on the semiconductor chip and the leads 230 are connected by the bonding wires 120.

  Next, a molding process is performed as follows. First, the lead frame 200 is put into a mold. Here, FIG. 3 shows the lead frame 200 arranged in the mold.

  FIG. 4A shows a cross-sectional view taken along line AA ′ of FIG. FIG. 4B is a sectional view taken along line BB ′ in FIG. 3 and 4 indicate the shape of the inner wall of the mold. As shown in FIGS. 3 and 4B, a runner 340 that guides the sealing resin to the cavity 380 that encloses the semiconductor chip 100 is disposed so as to pass over the half-blanked portion 260.

  Next, the sealing resin is filled from the cull 320 to the cavity 380 by the plunger 460 of FIG. Next, the sealing resin is cured by heating. At this time, as illustrated in FIG. 4A, the runner 340 is disposed so as to pass over the half-punched portion 260 and the opening 280. For this reason, in the support frame 240 main body, the portion fixed to the sealing resin remaining on the runner 340 is small.

  Next, after the sealing resin is cured, the upper mold 420 and the lower mold 440 are removed, and the lead frame 200 is taken out.

  Next, a removal process of the unnecessary portion 600 is performed as follows. FIG. 5A and FIG. 5B show a case where the unnecessary portion 600 is separated in the removing process in the first embodiment. Here, the unnecessary portion 600 is the sealing resin remaining in the runner 340.

  As shown in FIG. 5A, a punching pin 540 having a large cross section within a range that can be inserted into the half-punched portion 260 and the opening 280 is disposed immediately above the half-punched portion 260 and the opening 280. Next, the pusher plate 520 is lowered. Thereby, the punching pin 540 cuts the half-punched portion 260 and pushes out the unnecessary portion 600.

  At this time, as described above, the portion of the support frame 240 that adheres to the sealing resin is small. Here, in the main body of the support frame 240, “the portion that adheres to the sealing resin” remaining on the runner 340 is a portion that contacts the support frame 240 other than the half-punched portion 260, and a gate (not connected) to the cavity 380. It is a part in contact with the figure. In addition, since the above-mentioned “part fixed to the sealing resin” has a small fixing area, it can be easily peeled off only by applying a weak force. Further, the portion that adheres to the sealing resin on the back surface of the half-punched portion 260 is removed together with the half-punched portion 260 by cutting the half-punched portion 260.

  In this way, by cutting the half-punched portion 260, the sealing resin (unnecessary portion 600) of the runner 340 can be easily removed.

  Therefore, as shown in FIG. 5B, it is possible to accurately remove only the unnecessary portion 600 while leaving the semiconductor package portion 620 on the lead frame 200.

  Thereafter, the suspension leads 220 and the leads 230 in the lead frame 200 are cut to obtain respective semiconductor devices.

  Next, the effect of this embodiment is demonstrated using FIG. FIG. 6 shows a plan view after the above-described unnecessary portion 600 removal step. As a comparative example, FIG. 6A shows a case where the half-punched portion 260 as in this embodiment is not provided, and FIG. 6B shows a case of this embodiment.

  As shown in FIG. 6A, in the comparative example, the half-punched portion 260 is not formed. Thereby, in a mold process, the part fixed to sealing resin among the support frame 240 main bodies is large. For this reason, in the removal process, there is a case where even if the punching pin 540 provided in the opening 280 is pushed out, it cannot be completely peeled off. In this way, a part of the sealing resin (remaining portion 640) remains on the support frame 240. In a state where there is such a remaining portion 640, there is a possibility that a conveyance failure occurs in a later process. Further, when the remaining portion 640 is peeled off at an unintended time after the removal process, there is a possibility that a defect such as a foreign matter adheres to the semiconductor package portion 620 may occur.

  On the other hand, according to the present embodiment, before the molding process, the half blanking portion 260 surrounded by the groove is formed on at least one surface of the support frame 240 of the lead frame 200. Next, in the molding process, the half-punched portion 260 is fixed to the sealing resin remaining on the runner 340. Thereby, the part fixed to sealing resin among the support frame 240 main bodies becomes small.

  Therefore, as shown in FIG. 6B, the unnecessary portion 600 can be easily removed without causing the remaining portion 640 by cutting the half-punched portion 260 in the removing step.

  As described above, according to the present embodiment, unnecessary sealing resin can be reliably removed without leaving the lead frame 200.

  As described above, in the present embodiment, the case where the half-cut processing portions 260 surrounded by the grooves are formed on both surfaces of the support frame 240 of the lead frame 200 has been described. Good. Further, for example, the groove may be formed by half-etching on one side.

  Further, in the present embodiment, the case of forming the half blanking portion 260 surrounded by the groove has been described, but a through opening may be provided in a part of the groove. In the present embodiment, the case where the half-punched portion 260 is rectangular has been described, but the shape is not limited and may be, for example, a circle.

  As mentioned above, although embodiment of this invention was described with reference to drawings, these are the illustrations of this invention, Various structures other than the above are also employable.

100 Semiconductor chip 120 Bonding wire 200 Lead frame 210 Die pad 220 Suspended lead 230 Lead 240 Support frame 260 Half-cut processing part 280 Opening 320 Cull 340 Cavity 420 Upper mold 440 Lower mold 460 Plunger 520 Pusher plate 540 Punching pin 600 Unnecessary portion 620 Semiconductor package portion 640 Remaining portion 720 Punch 740 Die

Claims (3)

Mounting a semiconductor chip on the die pad of the lead frame;
A molding step of placing the lead frame in a mold and sealing with a sealing resin;
Removing the sealed lead frame from the mold;
A removal step of removing unnecessary portions of the sealing resin;
Have
Before the molding step, the method includes a step of forming a half punched portion surrounded by a groove on at least one surface of the support frame of the lead frame,
In the molding step, a runner that guides the sealing resin into a cavity that encloses the semiconductor chip is disposed so as to pass over the half-punched portion,
The unnecessary portion is the sealing resin remaining in the runner,
A method of manufacturing a semiconductor device, wherein in the removing step, the unnecessary portion is removed by removing the half-punched portion. In the manufacturing method of the semiconductor device according to claim 1,
A method of manufacturing a semiconductor device, wherein in the step of forming the half punched portion, after pressing from 30% to 50% of the plate thickness of the support frame from one side, pressing is performed from the opposite side to flatten. At least one die pad;
A suspension lead for supporting the die pad;
A support frame for supporting the suspension leads;
Have
The support frame is a lead frame having a half punched portion surrounded by a groove on at least one side.

Images