JPH1012789A - Lead frame processing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow all resin within a dam to fall by removing dam-part resin including thin burr resin remaining in the dam-part of a lead frame through dam punching operation of a dam-punch for the dam to break the dam-part resin at about central part thereof. SOLUTION: The tip part 20a of a dam-punch 20 is formed in a quadr angular pyramid shape. The dam-punch 20, having comb-tooth like members for punching the resin of a dam-part 7, is fixed in the upper part. A plurality of through-openings, through which the dam-punch 20 is moved upwardly and downwardly, are provided in a dam-punch guide 11-3, and the comb-tooth parts of the dam-punch 20 are inserted through the openings to be capable of upward and downward sliding motion. The dam-part 7 resin including thin burr resin remaining in the dam-part 7 of a lead frame is removed by dam punching operation of this dam-punch 20. Thus, the dam-part 7 resin is broken at about central part thereof by the dam-punch 20 so that all resin within the dam can be made to fall.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device lead frame processing apparatus for forming a semiconductor device by performing resin molding.

[0002]

2. Description of the Related Art Conventionally, techniques in such a field include:
JP-A-63-98649, JP-A-5-10996
There was one disclosed in Japanese Patent Publication No. FIG. 4 is a plan view showing an example of a lead frame shape before molding for resin-sealing such a conventional semiconductor element, and FIG. 5 is a plan view showing an example of a lead frame shape after molding.

[0003] As shown in these figures, an island portion 2 for mounting a semiconductor element is provided at a central portion between the pair of outer frames 1 which are provided side by side. A large number of external leads 3 (lead frames) are provided symmetrically with the outer frame 1 on both sides with the island portion 2 at the center.
Internal lead 4 connected to the innermost end of external lead 3
(Lead frame) is directed toward the island portion 2.

In order to support the leads composed of the external leads 3 and the internal leads 4, the inner ends of the external leads 3 are connected by tie bars 5.
The external leads 3 at the four corners near the outer frame 1 are connected to the outer frame 1 via tie bars 5. The dashed line in FIG. 4 indicates the planned boundary of the resin mold package 6, and the lead frame is molded by a mold, and as shown in FIG. The inside of the boundary is covered with the resin mold package 6.

[0005] After this forming, in the lead processing step, punching of the dam portion 7 → punching out of the tie bar 5 → cutting of the external lead 3 and bending of the external lead 3 are performed simultaneously with the island support 10, as shown in FIG. A semiconductor device having the appearance shown in FIGS. FIG. 7 is a schematic view showing an example of the lead processing step. First, as shown in FIG. 7A, in a first step, a comb-shaped dam punch 11 is inserted into a dam portion 7.
Punch out unnecessary resin parts. Next, as shown in FIG. 7B, in the second step, the tie bar punch 12 is
Punch out. Next, as shown in FIG. 7C, in a third step, an intermediate portion 16 (see FIG. 4) for connecting the external leads 3 to each other to separate the semiconductor device (see FIG. 4).
Are separated by a lead cutting punch 13, and the island support 10 and the outer frame 1 are separated by an island support cutting punch 14. Next, as shown in FIG. 7D, in a fourth step, the external lead 3 is formed by the bending roller 15, and the lead processing step is completed.

[0006]

However, in the above-mentioned conventional method for manufacturing a lead frame, a sagging surface occurs during the lead frame manufacturing process due to press punching, and resin remains after punching out the dam, resulting in later lead processing. There has been a problem that lead resin adheres in the process and quality is deteriorated.

Here, the dam removal in the first step will be described. FIG. 8 is a diagram showing a first step of removing a dam in a conventional lead process. FIG. 8A is an enlarged plan view showing a portion where an unnecessary resin of a dam portion is to be punched by a punch for removing a dam, and FIG. b) is a side view thereof, and FIG.
FIG. 8D is a partially enlarged view of FIG. 8D, and FIG.
It is A 'line sectional drawing.

A dam punch punch guide 11-3, which guides the dam punch 11-1 and is slidable up and down by a coil spring force (not shown), is attached. A punch guide 11-3 for damping abuts on a lead frame mounted on the die for die removal 11-2, contacts the internal lead 4 and the diver 5, and is held between the die for die removal 11-2. The dam punch 11-1 descends while pressing the dam punch punch guide 11-3 by the coil spring pressure, and punches the resin of the dam portion 7.

At this time, the resin of the dam portion 7 has the same thickness as the lead frame. The clearance (gap) between the dam portion 7 of the frame and the dam punch 11-1 is 0.1
The thin flash resin 7b inside the dam remains on the side surface of the external lead 3 as shown in FIG. In addition, the dam guide punch guide 11-3 punches out unnecessary resin of the dam portion 7 while holding down the resin on the lead frame sagging surface, and the sagging surface and the resin of the dam portion 7 are sheared,
The thin burr resin 7b at the sag remains. In addition, 7a
Is a dam removal scum.

FIG. 9 is a view showing a tie bar punching step of a second step in the conventional lead processing. FIG. 9 (a) is an enlarged plan view showing a place where the tie bar is to be punched by a tie bar punch, and FIG. 9) is a side view thereof, FIG. 9 (c) is a partially enlarged view of FIG. 9 (a), and FIG. 9 (d) is an A-
It is A 'line sectional drawing. Without tie bar, internal lead 4
(Clearance) between the tie bar punch 12-1 and the tie bar
Is usually about 0.03 to 0.05 mm, and as shown in the enlarged views of FIGS. 9C and 9D, the thin flash resin 7b adhered to the frame sagging surface is as shown in FIG. As shown in d), it cannot be completely removed even after the dam bar is removed. Note that in FIG. 9, reference numeral 5a denotes a dam bar removal scum.

This resin residue peels off in the lead bending step in the subsequent step, adheres to the solder surface of the lead, and is crushed when the lead is bent, leading to poor lead bending, poor appearance, and poor solder adhesion during board mounting. There was a problem of doing. The present invention is to provide a lead frame processing apparatus capable of performing highly reliable lead processing by removing the above problems and removing thin flash resin adhered to a frame sagging surface in a dam removing step. Aim.

[0012]

In order to achieve the above object, the present invention provides: [1] A lead frame having a plurality of leads connected to a tie bar and sealing a semiconductor device is mounted on a die. And
A plurality of dam punches, which are arranged so as to be able to move up and down in the upward direction of the die, and oppose a dam portion punching scheduled portion, are projected downward from the lower surface, and are slid vertically in relation to the dam punch, and movably mounted. In a lead frame processing apparatus provided with a dam punch punch guide that presses and fixes the lead frame, a dam punch is formed in which a tip portion is formed in a protruding body. The dam resin including the thin burr resin remaining in the dam portion of the lead frame is removed.

[2] In the lead frame processing apparatus according to the above [1], the projecting body has a quadrangular pyramid shape. [3] The lead frame processing apparatus according to the above [1] or [2], wherein the dam punch is provided with a concave relief portion on the outer periphery of the dam portion. [4] A lead frame having a plurality of leads connected to the tie bar and sealing the semiconductor device is placed on the die,
A plurality of dam punches, which are arranged so as to be able to move up and down in the upward direction of the die, and oppose a dam portion punching scheduled portion, are projected downward from the lower surface, and are slid vertically in relation to the dam punch, and movably mounted. A lead frame processing apparatus having a dam punch punch guide for pressing and fixing the lead frame, wherein a dam punch punch guide having a concave relief portion provided on the outer periphery of the dam portion is provided. The thinning resin remaining on the dam portion of the lead frame is also removed by the punching operation.

[5] In the lead frame processing apparatus according to the above [3] or [4], a plurality of air blowing holes are provided in a concave relief portion of the dam punch.

[0015]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows the first embodiment of the present invention.
It is a figure which shows the dam removal process in the lead processing which shows an Example, FIG.1 (a) is a plane enlarged view showing the place where the unnecessary resin of a dam part is punched out by a dam removal punch, FIG.1 (b).
FIG. 1C is a side view, and FIG. 1C is an enlarged perspective view of the tip of the dam punch. Note that the same parts as those in the related art are denoted by the same reference numerals, and description thereof will be omitted.

In this embodiment, as shown in FIG. 1C, the tip 20a of the punch 20 is formed in a quadrangular pyramid shape. First, on the upper part, a dam punch 20 having a comb blade shape for punching the resin of the dam portion 7 is fixed. A plurality of through-holes are provided for the dam punch 20 to penetrate the dam punch punch guide 11-3 and go up and down, and are inserted into the comb blades of the dam punch 20 and slidably mounted vertically. I have.

The dam punch punch guide 11-3 acts so as to be pushed downward by a coil spring pressure (not shown). Lead frame is resin mold package 6
The lower projecting portion of the die is accommodated in the mold portion and the
2 at a predetermined position. Hereinafter, this dam removal will be described.

First, the lead frame is removed from the die 11
-2 at a predetermined position. At this time, the dam portion 7 is provided with a dam removing die 11-2 corresponding to the blade of the dam removing punch 20.
Is placed on the concave mold part. Next, punch 2 without dam
0, when the punch punch guide 11-3 is lowered, first, the punch guide 11-3
-2 Reach the upper surface and fix the lead frame.

Even after the dam-pulling punch guide 11-3 reaches the dam-pulling die 11-2 and stops, the dam-pulling punch 20 continues to descend while sliding on the dam-pulling punch guide 11-3. Unnecessary resin is punched out and falls. In this case, the tip 20a of the
Since it is formed in the shape of a pyramid, the resin of the dam portion 7 is broken from the substantially central portion by the tip portion, and the resin inside the dam falls without being left.

When the dam punch 7 starts to move up after the resin is punched out of the dam portion 7, the dam punch punch guide 11-3 is pressed downward by the coil spring force. Only rise. Therefore, the lead frame is pressed by the punch punch guide 11-3 onto the die 11-2 to fix the lead frame.
It does not rise with zero.

The dam removing punch 20 is completely removed from the lead frame, and the dam removing punch 20 and the dam removing punch guide 11-3 move up and separate from the dam removing die 11-2. As described above, after the dam is removed by the lead frame processing apparatus, the process proceeds to the next step of removing the tie bar. As described above, according to the first embodiment, the tip is
Since the dam punch formed in the shape of a pyramid is used, the dam punch is broken from substantially the center of the resin of the dam portion, and the resin inside the dam can be completely dropped.

As described above, when the dam is removed, the thin burr resin also falls together with the resin inside the dam, so that slant leads (leads having an uneven pitch) and coplanarity (flatness) in the subsequent process due to the remaining resin of the dam portion are formed. Degree: Uneven flatness of the tip of the lead due to poor bending of the lead) can be prevented, and reliability during lead processing can be improved.

The hatched portion shown in FIG. 1A indicates a position where the punch guide 11-3 presses the lead frame by the coil spring pressure. As can be seen from this figure, a part of the resin of the dam portion 7 is sandwiched by the dam punch punch guide 11-3. Next, a second embodiment of the present invention will be described.

FIG. 2 is a view showing a dam removing step in lead processing according to a second embodiment of the present invention. FIG. 2 (a) is a plan view showing a portion where an unnecessary resin in a dam portion is to be punched by a dam removing punch. FIG. 2B is an enlarged view of FIG.
(C) is an enlarged view of a main part of the tip of the punch without dam. Note that the same parts as those in the related art are denoted by the same reference numerals, and description thereof will be omitted.

In this embodiment, a dam punch punch guide 21 having a concave relief portion 21a on the outer periphery of the dam portion is provided. That is, the hatched portion shown in FIG.
The position where the dam punch punch guide 21 presses the lead frame by the coil spring pressure is shown. As shown in FIG. 2 (a), in the dam portion 7 of the lead frame, the outer periphery of the lead frame pressing portion of the dam removing punch guide 21 has a predetermined size so that the dam removing punch 20 does not press the resin portion on the sagging surface of the frame. It has a missed structure.

Therefore, first, the lead frame 4 is placed at a predetermined position on the dam removal die 11-2. At this time, the dam portion 7 is placed on the concave mold portion of the dam removing die 11-2 corresponding to the blade of the dam removing punch 20. Next, when the dam removing punch 20 and the dam removing punch guide 21 are lowered, first, the dam removing punch guide 21 is moved to the dam removing die 1.
1-2 The upper surface is reached. At this time, the dam removing punch guide 21 abuts on the hatched portion of FIG. 2A except for the resin portion of the dam portion 7 to fix the lead frame 4.

Even after the dam punch punch 21 has reached the dam punch die 11-2 and has stopped, the dam punch 20 is still in the same position.
Continues descending while sliding on the punch guide 21 without dam, and the unnecessary resin of the dam portion 7 falls. After the resin punching of the dam portion 7, when the dam punching punch 20 starts to rise, the dam punching guide 21 is pressed downward by the coil spring force, so that only the dam punching punch 20 rises. Accordingly, the lead frame does not rise together with the punch 20 because the punch guide 21 presses and fixes the lead frame on the die 11-2. The dam removing punch 20 is completely removed from the lead frame, the dam removing punch 20 and the dam removing punch guide 21 are raised, separated from the dam removing die 11-2, and the first step of removing the dam is completed. Proceed to the punching process.

As a result, as shown in the enlarged view of the main part of FIG. 2C, the thin burr resin of the dam portion falls together with the resin inside the dam portion. According to this embodiment, a concave relief portion is formed on the punch guide for dam removal corresponding to the thin burr resin on the sagging surface of the lead frame dam portion. Since the resin is dropped together with the resin, it is possible to prevent the lead resin from adhering to the resin due to the remaining resin of the dam portion and to prevent the solder adhesion from being defective when the semiconductor device is mounted on the substrate, thereby improving the reliability of the lead processing.

Particularly, in the case of a lead frame formed by press punching, a thin flash resin is easily generated. In such a case, according to this embodiment, the thin flash resin can be easily peeled off. In the second embodiment, the tip portion 20a of the dam punch 20 is formed in the shape of a quadrangular pyramid. However, the present invention is not limited to this. The tip portion 20a is flat as in the related art. It may be shaped.

Next, a third embodiment of the present invention will be described. FIG. 3 is a view showing a dam removing step in lead processing according to a third embodiment of the present invention, and FIG. 3 (a) is an enlarged plan view showing a portion where an unnecessary resin of a dam portion is to be punched by a dam removing punch. FIG. 3B is a side view thereof. Note that the same parts as those in the related art are denoted by the same reference numerals, and description thereof will be omitted.

In this embodiment, in addition to the above-described first and second embodiments, as shown in FIGS. 3 (a) and 3 (b), a concave portion of the dam portion of the punch guide 22 is provided. A plurality of air blowing holes 23 are provided in the escape portion 22a. Therefore, the dam punch 20 continues to descend while sliding on the dam punch guide 22, and simultaneously punches out the resin of the dam portion 7 with the dam punch 20,
By blowing air from a plurality of air blowing holes 23 provided in the concave relief portion 22a of the dam punching guide 22, the resin remaining in the dam portion 7 falls down reliably together with the thin burr resin.

As described above, according to the third embodiment, since a plurality of air blowing holes 23 are provided in the concave escape portion 22a of the punch guide 22, the strong thin burr resin adhering to the dam portion 7 can be removed. It can be blown off and completely dropped downward, thereby preventing a reduction in quality due to thin burr resin. Further, a dam removing punch 20 having a quadrangular pyramid-shaped tip portion as described in the first embodiment, a dam removing punch guide 21 in which the outer periphery of the dam portion is concavely released as described in the second embodiment, or a third embodiment. By combining the punch guides 22 provided with a plurality of air blowing holes 23 with the concave relief portions 22a of the punch guide 22 for dam removal described in the example, the thin flash resin adhered to the dam portion 7 can be dropped downward. As a result, it is possible to prevent a decrease in quality due to the thin burr resin.

The present invention has the following usage modes. In the above embodiment, DIP (Dual Inlin)
ePackage) type semiconductor device has been described, but a QFP (Quad) having leads extending from four directions is described.
Fract Package and QFJ (Quad F
(Lact J-leaded package) and the like and electronic parts having the same shape. Further, the dam portion has been described, but the present invention can be applied to other unnecessary resin portion punching.

Further, in the above embodiment, an example was shown in which the tip of the dam punch was formed in a quadrangular pyramid shape. However, the present invention is not limited to this, and the tip of the dam punch is a projecting body. Any shape can be used, and various modifications are possible. It should be noted that the present invention is not limited to the above embodiment, and various modifications can be made based on the gist of the present invention, and these are not excluded from the scope of the present invention.

[0035]

As described above, according to the present invention, the following effects can be obtained. [A] According to the first aspect of the present invention, since a dam punch having a protruding tip portion is used, the resin of the dam portion is broken from the substantially central portion by the dam punch. Therefore, it is possible to drop all the resin inside the dam.

[B] According to the second aspect of the present invention, since a dam punch having a quadrangular pyramid-shaped tip is used, the dam punch is used to break the resin substantially from the center of the dam resin. In other words, the resin inside the dam can be dropped without leaving. As described above, when the dam is removed, the thin burr resin also falls along with the resin inside the dam, thereby preventing slant leads and coplanarity defects in the subsequent process due to the remaining resin of the dam portion, and improving reliability in lead processing. be able to.

[C] According to the third or fourth aspect of the present invention, a concave relief portion is formed in the punch guide for punching out the dam corresponding to the thin burr resin on the sag surface of the lead frame dam portion. The thin burr resin falls along with the resin inside the dam when the dam is pulled out, preventing lead resin from adhering to the resin in the subsequent process due to residual resin from the dam and poor solder adhesion when mounting the semiconductor device on the board. Performance can be improved.

[D] According to the fifth aspect of the present invention, since a plurality of air blowing holes are provided in the concave relief portion of the punch guide for punching out the dam, strong thin burr resin adhering to the dam portion is blown off. , And can be completely dropped downward, thereby preventing quality deterioration due to thin burr resin.

[Brief description of the drawings]

FIG. 1 is a view showing a dam removing step in lead processing according to a first embodiment of the present invention.

FIG. 2 is a view showing a dam removing step in lead processing according to a second embodiment of the present invention.

FIG. 3 is a view showing a dam removing step in lead processing according to a third embodiment of the present invention.

FIG. 4 is a plan view showing an example of a conventional lead frame shape before molding for resin-sealing a semiconductor element.

FIG. 5 is a plan view showing an example of a conventional lead frame shape after molding for resin-sealing a semiconductor element.

FIG. 6 is a diagram illustrating an appearance of a conventional semiconductor device.

FIG. 7 is a schematic view showing an example of a conventional lead processing step.

FIG. 8 is a diagram showing a dam removing step of a first step in the conventional lead processing.

FIG. 9 is a view showing a tie bar removing step of a second step in the conventional lead processing.

[Description of Signs] 4 Lead frame 6 Resin mold package 7 Dam portion 11-2 Dam removal die 11-3, 21, 22 Dam removal punch guide 20 Dam removal punch 20a Tip end portion 21a, 22a of dam removal punch Concave relief portion 23 Air outlet

Claims (5)

[Claims] 1. A lead frame having a plurality of leads connected to a tie bar and encapsulating a semiconductor device is mounted on a die, and is disposed so as to be able to move up and down in the die. A plurality of dam punches projecting downward from the lower surface, and are vertically slid with respect to the dam punch, movably attached to the punch, and a dam punch punch guide for pressing and fixing the lead frame. In the lead frame processing apparatus, a dam removing punch having a tip formed in a protruding body is provided, and the dam removing operation of the dam removing punch removes the dam resin including the thin flash resin remaining in the dam of the lead frame. A lead frame processing apparatus characterized in that it is removed. 2. The lead frame processing apparatus according to claim 1, wherein the protrusion has a quadrangular pyramid shape. 3. The lead frame processing apparatus according to claim 1, wherein a concave relief portion is provided on the outer periphery of the dam portion in the dam punch. 4. A lead frame having a plurality of leads connected to a tie bar and encapsulating a semiconductor device is mounted on a die, and is arranged so as to be able to ascend and descend in an upward direction of the die. A plurality of dam punches projecting downward from the lower surface, and are vertically slid with respect to the dam punch, movably attached to the punch, and a dam punch punch guide for pressing and fixing the lead frame. In the lead frame processing apparatus, a dam removing punch guide provided with a concave relief portion on the outer periphery of the dam portion is provided, and by the dam removing operation of the dam removing punch, the thin flash resin remaining in the dam portion of the lead frame is removed. A lead frame processing apparatus characterized in that a lead frame is also removed. 5. The lead frame processing apparatus according to claim 3, wherein a plurality of air blowing holes are provided in a concave relief portion of the dam punch.