JPH10163394A - Semiconductor lead molding equipment - Google Patents

Abstract

(57) [Problem] To provide a semiconductor lead molding apparatus capable of reducing the generation of defective products as much as possible and improving the productivity. SOLUTION: There is provided a molding table 1 for fixing a semiconductor device 7 from which a lead 9 covered with solder is drawn out, and a molding table punch 3 for pressing the lead 9 against the molding table 1 and molding it into a predetermined shape. Semiconductor lead molding equipment
A groove 5 is provided in an area on the molding table 1 where the lead 9 contacts and moves at the time of molding, and when the tip of the lead 9 contacts and moves on the molding table 1, the peeled solder is not dragged by the groove 5 portion. By doing so, the peeled solder is prevented from being deposited on the molding table 1, especially near the bent portion of the lead 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor lead molding apparatus for molding a lead drawn from a semiconductor device into a shape suitable for a use.

[0002]

2. Description of the Related Art In general, in order to enable a packaged semiconductor device to be mounted on a substrate, it is necessary to form a lead drawn from the semiconductor device and covered with solder into a shape suitable for the intended use. is there. As shown in FIG. 10, there are several types of shapes formed by this forming step. One of the shapes is a gull wing molding (FIG. 10B) in which a lead is formed in a gull wing (gull wing) shape. )).

FIGS. 11 (A) to 11 (C) are schematic cross-sectional views showing a process when gull wing molding is performed by a conventional semiconductor lead molding apparatus.

In FIG. 11A, a packaged semiconductor device 7 to be processed is fixed on a molding table 11. Leads 9 are drawn out of the semiconductor device 7, and the entire surface of the leads 9 is covered with solder (not shown). The molding table 1 is located above the lead 9 in the figure.
1 is provided with a molding punch 3 that can be moved up and down.
Although the leads 9 are drawn out from the four sides around the semiconductor device 7, the structure is the same on the four sides.
In the following description, one of them will be described.

[0005] First, from the state of FIG.
When the molding punch 3 approaches the molding table 11 as shown in FIG. 11, the vicinity of the root of the lead 9 is bent, and its tip comes into contact with the molding table 11 (FIG. 11B). When the molding punch 3 further approaches the molding table 11, the molding punch 3
The portion from the center to the tip of the lead 9 is substantially L
When the lead 9 is bent into a letter shape and finally the lead 9 is pressed against the molding table 11, the gull wing molding is completed as shown in FIG.

During the gull wing molding, the tip of the lead 9 which has contacted the molding table 11 moves from the position shown in FIG. 11B to the position shown in FIG. . Here, FIG. 12 is an enlarged view of the area a of the molding table 11 that has moved in contact as shown in FIG. As shown in FIG. 12, when the lead 9 makes contact with and moves on the molding table 11, a part of the solder that has been packaged on the surface of the lead 9 comes off, and the solder 13 moves in the direction of the arrow in FIG. And is deposited near the bent portion of the lead.

In addition to the above gull wing molding,
As shown in FIG. 10C, there is curling molding for molding a lead into a curl shape.

FIGS. 13A and 13B are schematic cross-sectional views showing a process of performing curling molding in a conventional semiconductor lead molding apparatus.

FIG. 13 shows the final step of the curling molding. In the preceding step, the root and the tip of the lead 19 are each bent by 90 degrees by another molding stand (not shown). In FIG. 13 (A), the semiconductor device 17 is
It is fixed in a state sandwiched from above and below by 1a and the molding table 21b. The molding table 21b controls the upward movement of the lead 19 during molding by pressing the base of the lead 19.

When a molding punch 23 having a shape as shown in FIG. 13B approaches the molding table 21a from the lateral direction from the state of FIG. 13A, the tip of the lead 19 and the molding of the molding punch 23 are formed. Part 23a comes into contact with the
3 approaches the molding table 21a, the tip of the lead 19 is substantially J
It is bent into a letter shape. Then, when the lead 19 is finally pressed against the lower surface of the semiconductor device 17, the curling molding is completed as shown in the figure.

[0011]

As described above, in a conventional semiconductor lead molding apparatus for performing gull wing molding,
Since the tip of the lead contacts and moves on the molding table until the molding is completed, a part of the solder that has been packaged on the lead peels off and deposits on the molding table, especially near the bent portion of the lead. Then, the deposited solder adheres to a newly formed lead in a whisker-like manner, and this leads to a problem that the lead becomes defective. By the way, since the gull-wing type lead is used by cutting the tip end finally, there is no problem even if the solder adheres to the tip end, but the solder attached near the bent portion remains as it is.

Similarly, in the curling molding, the tip of the lead 19 which has come into contact with the molding portion 23a of the molding punch 23 moves in contact with the upper portion of the molding portion 23a. Is peeled off, and solder is applied to the molded portion 23a in the same manner as in the case of the gull wing molding described above.
Deposits on top of In particular, in the configuration of FIG.
9 and the molded portion 23a have a large amount of friction.
Since the upper part of a was concave, solder was easily deposited.

Further, in any of the molding apparatuses, it is necessary to temporarily stop the molding system in order to prevent such a defective product and to remove the solder deposited on the molding table or the molding punch. Was causing the decrease.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to make it difficult to deposit solder on a molding table or a molding punch so that defective products can be generated. It is an object of the present invention to provide a semiconductor lead molding apparatus capable of improving the productivity as well as reducing the cost.

[0015]

According to a first aspect of the present invention, there is provided a first molding table for fixing a semiconductor device from which a lead coated with solder is drawn out, and the lead is pressed against the molding table to form a predetermined shape. In a semiconductor lead molding apparatus provided with a second molding table for molding, a groove is provided in a region on the first molding table where the lead contacts and moves during molding.

In the first aspect of the present invention, when the tip of the lead contacts and moves on the molding table, even if the peeled solder is dragged along with the movement of the lead, it is not dragged in the groove portion. Solder does not deposit on the molding table, especially near the bent portion of the lead.

According to a second aspect, in the first aspect,
At least a part of the corner of the groove that comes into contact with the lead during the contact movement of the lead is a curved surface.

In the second aspect of the present invention, even if the lead contacts the corner of the groove, the angle of the groove does not hit the surface of the lead at an acute angle. Is weaker than the case where

According to a third aspect of the present invention, there is provided a first molding table for fixing a semiconductor device from which a solder-covered lead is drawn out, and a second molding table for pressing the lead to a predetermined position and molding the lead into a predetermined shape. And a plurality of guide members are provided in an area on the second molding table where the lead contacts and moves during molding.

In the third aspect, the lead is the second type.
When the lead is pressed to a predetermined position by the molding table, the tip of the lead is bent while being guided by the guide member, and is formed into a predetermined shape. At this time, since the lead moves on the surfaces of the plurality of guide members by point contact, the distance of contact and movement between the lead and the surface of the guide member becomes shorter than before.

According to a fourth aspect, in the third aspect,
A groove is provided below the guide member.

In the fourth aspect, the peeled-off solder does not fall on the molding table but in the groove, and does not accumulate in the area on the second molding table where the lead contacts and moves.

According to a fifth aspect, in the third or fourth aspect, the guide member is a roller.

In the fifth aspect of the present invention, when the lead makes contact with the surface of the guide member, the roller serving as the guide member is rotated. The shock at the time is reduced.

According to a sixth aspect of the present invention, there is provided a first molding table for fixing a semiconductor device from which a lead coated with solder is drawn out, and a second molding table for pressing the lead to a predetermined position and molding the lead into a predetermined shape. And a groove is provided in a region on the second molding table where the lead contacts and moves during molding.

In the sixth aspect of the present invention, when the lead contacts and moves on the molding table, the peeled-off solder falls not in the molding table but in the groove, and on the second molding table where the lead contacts and moves. Does not accumulate in the area.

According to a seventh aspect, in the first to sixth aspects, a suction means is provided in a part of the groove.

In the seventh aspect, the solder that has entered the groove is sucked by the suction means, so that the inside of the groove is always kept clean.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a semiconductor lead molding apparatus according to the present invention will be described below with reference to the drawings.

FIGS. 1A to 1C are schematic sectional views showing a process of performing gull wing molding by the semiconductor lead molding apparatus according to this embodiment.

This semiconductor lead molding apparatus comprises a molding table 1 for fixing the semiconductor device 7 and a molding punch 3 which can be moved up and down with respect to the molding table 1. A groove 5 is provided. Other configurations and operations are the same as those in FIG. 11, and the same parts as those in FIG. 11 are denoted by the same reference numerals.

FIG. 2A is a schematic plan view of the molding table 1.
FIG. 2B is a side view of the same. The molding table 1 is provided with a groove 5 for each side corresponding to leads extending from four sides of a semiconductor device (not shown). Also,
A hole (not shown) is provided at the center of the groove 5 in the longitudinal direction, and is connected to a dust collector described later.

To perform gull wing molding using such a semiconductor lead molding apparatus, first, as shown in FIG.
The semiconductor device 7 packaged on the molding table 1 is fixed. Next, as shown in FIG. 1B, the molding punch 3 is moved downward to approach the molding table 1. Then, the vicinity of the root of the lead 9 is bent by the molding punch 3, and the tip thereof contacts the molding table 1 near the groove 5. Further, as shown in FIG. 1C, when the molding punch 3 approaches the molding table 1, the vicinity of the tip of the lead 9 is bent into a substantially L-shape, and the lead 9 is finally pressed against the molding table 1. Gull wing molding is completed.

Here, in the process from FIG. 1 (B) to FIG. 1 (C), when the tip of the lead 9 which has come into contact with the molding table 1 starts to move, the solder peeled off at the tip of the lead 9 is removed. 9 is dragged on the molding table 1 as it moves.
Since the solder drops downward at the groove 5, the peeled solder does not accumulate on the molding table 1, especially near the bent portion of the lead.

As described above, in the semiconductor lead molding apparatus according to this embodiment, the peeled solder hardly accumulates on the molding table 1, especially near the bent portion of the lead 9. The occurrence of defective products due to the deposited solder can be reduced as much as possible. Also,
Since the number of times the molding system is stopped to remove the solder on the molding table 1 can be reduced, the productivity can be greatly improved.

Next, the position of the groove 5 provided on the molding table 1 will be described. FIG. 3 is a schematic sectional view of the lead 9 and the molding table 1 after the gull wing molding is completed.

In the same figure, θ ₁ and θ ₂ are the respective central axes of the lead 9 bent near the tip, and R ₁ is the R (curved portion) of the curved portion at the intersection of these θ ₁ and θ _2. The radius of the circle) and L ₁ indicate the end points of the curved portion on the lead tip side, respectively. Position L of one end of groove 5
_2, the are from the position of L ₁ is set to a position obtained by adding the length of the R _1, position L ₃ at the other end at a tip of the lead 9 in Figure 1 (B) in contact with the molding table 1 position Is set to a position close to 1 mm toward the curved portion side. The hatched portion at the tip of the lead indicates a portion to be cut after molding.

[0038] The position L ₁ and L ₂ of the groove 5, which has been theoretically calculated in consideration of the state of the lead 9 after Gullwing molding completion, leads of the semiconductor device the position of the L ₁ and L ₂ The groove 5 can be provided according to each product by obtaining from the length, bending dimension, and the like.

In FIG. 3, R ₂ is a curved surface R provided at one corner of the groove 5. This R is provided to prevent the surface of the lead 9 from being rubbed at the corner of the groove 5 during the contact movement of the lead 9. When the curved surface R is provided, even if the lead 9 contacts the corner of the groove 5, the groove 5
Does not hit sharply, so that the solder on the lead surface is less likely to peel off.

FIG. 4 is a schematic configuration diagram of a dust collection system provided in the semiconductor lead molding apparatus according to this embodiment. The bottom surface of the groove 5 is inclined from both ends in the longitudinal direction toward the center, and a hole 15 for collecting the solder dropped into the groove 5 is formed in the center. A dust collector 17 is connected downstream of the hole 15. The dust collector 17 is a device for sucking the air in the groove 5 and discharging the air to the outside, and a filter (not shown) for capturing the sucked solder is provided at the air discharging portion.
According to this dust collection system, the solder that has fallen into the groove 5 during molding moves to the center along the slope provided on the bottom surface, where it is further sucked from the hole 15 by the dust collector 17 and discharged out of the apparatus. You. Note that the suction by the dust collector 17 is always performed, and when the molding punch 3 in FIG. 1 is lowered to the bottom dead center to be in a vacuum state, the solder in the groove is collected. By providing the dust collection system in this manner, the inside of the groove can be always kept clean without frequently stopping the molding system.

In the above dust collecting system, most of the solder peeled off from the leads can be collected.
Since it is difficult to collect the solder that has adhered as a certain mass in the groove, the molding system is stopped when the specified number of moldings is reached, and the solder accumulated in the groove is removed. I have.

Next, another embodiment of the semiconductor lead forming apparatus will be described.

FIG. 5 is a schematic cross-sectional view showing the process of performing curling molding by the semiconductor lead molding apparatus according to this embodiment, and the same parts as those in FIG.

FIG. 5 shows the final step of the curling molding, and its basic structure and operation are described in FIG.
3 (B). That is, also in this semiconductor lead molding apparatus, the root and the tip of the lead 19 are each bent by 90 degrees by another molding stand (not shown) in the preceding step. The semiconductor device 17 is mounted on a molding table 21a.
The molding base 21b is fixed in a state sandwiched from above and below, and the upward movement of the lead 19 during molding is restricted by the molding base 21b. And the molding punch 25
When approaching the molding table 21a from the side, the lead 1
9 is bent into a substantially J-shape, and finally the lead 19 is bent.
Is pressed against the lower surface of the semiconductor device 17, the curling molding is completed as shown.

In the semiconductor lead molding apparatus of this embodiment, three rollers 27 are provided as guide members in the molding part 25a of the molding punch 25. This roller 2
Reference numeral 7 denotes an ultra-hard metal roller having a diameter of 1.2 mm, and both ends in the longitudinal direction are rotatably supported by a molding portion 25a. The roller 27 is shown in FIG.
Are arranged at 45 ° intervals. However, the arrangement of the rollers 27 is determined according to the actual molding pattern.

A groove 29 is formed below the roller 27. As shown in FIG. 7, which is a schematic plan view of the molding punch 25, the groove 29 is opened between the rollers, and is configured so that the solder peeled from the lead 19 during molding is collected. Also in this embodiment, a hole (not shown) is formed on the bottom surface of the groove 29, and the dust collection system shown in FIG. 4 is connected. In FIG. 7, reference numeral 31 denotes a rib for supporting the roller 27 at an intermediate portion.

In order to perform curling molding using such a semiconductor lead molding apparatus, first, the semiconductor device 17 packaged on the molding table 21a is fixed (see FIG. 13A), and then the above-described FIG. The molding punch 25 having the shape shown in FIG.
Then, the tip of the lead 19 and the molding part 25 of the molding punch 25
a, and when the molding punch 25 approaches the molding table 21a, the tip of the lead 19 is bent into a substantially J-shape.

Here, the leads 19 come into contact with the rollers 27 provided on the molding punch 25. Since the leads 19 move on the surface of each roller 27 by point contact, the leads 19
The distance over which the lead and the surface of the roller 27 move in contact is shorter than in the conventional case in which the lead and the molded portion move while making surface contact. At the time of contact, each roller 27
Is rotated, so that the impact at the time of contact is reduced as compared with the case where the surface of the guide member is fixed. Accordingly, the amount of the peeling-off of the solder coated on the lead 19 during molding is greatly reduced as compared with the conventional example shown in FIG.

Further, most of the solder peeled off from the lead 19 falls into the groove 29 provided below the roller 27 and hardly accumulates on the molding portion 25a (there is very little on the surface of the roller 27). Small amount of solder adheres), to remove the solder deposited on the forming punch,
The number of times the molding system is stopped is reduced, and productivity can be greatly improved.

As described above, in the semiconductor lead molding apparatus according to this embodiment, the solder can be hardly peeled off from the surface of the lead 19 during molding.
The occurrence of defective products due to the solder deposited on the molded portion 25a can be reduced as much as possible. Also in this embodiment, by collecting the solder by a dust collection system (not shown), the inside of the groove can be always kept clean without frequently stopping the molding system.

In the above dust collecting system, most of the solder that has peeled off from the lead 19 can be collected, but the solder that has adhered to the surface of the roller 27 and a certain amount of clumps have adhered in the grooves. Since it is difficult to collect dust from the solder, the molding system is stopped when a predetermined number of moldings is reached, so that the solder accumulated in the groove is removed.

Further, in this embodiment, an example in which a rotatable roller is used as the guide member has been described. However, a non-rotatable member can be used as the guide member, and they can function equally. If so, its shape, structure, dimensions, arrangement, etc. can be changed as appropriate.

Next, the productivity of the semiconductor lead molding apparatus according to this embodiment and the conventional semiconductor lead molding apparatus will be described.

First, as common conditions of the molding process, the operating time of the system per day is 21.75 hours, and the semiconductor device 1
The time (M / C index) required for manufacturing individual pieces is 3.5
Seconds, the system downtime per cleaning is 0.
5H, the number of operating days per month was 22 days. The measurement results of each device were as follows.

1. Conventional semiconductor lead molding device (cleaning frequency is 1 time / 2000 punches) Production number per day 22371 Number of times of cleaning per day 11.2 times Number of losses due to cleaning per day 5760 Cleaning loss time per month 0.5 × 11.2 × 22 = 123H Number of losses per month 5760 × 22 = 126720 Semiconductor lead molding apparatus of the present embodiment (cleaning frequency is 1 time / 6000 punches) Production number per day 26213 cleaning times per day 3.73 times loss number due to cleaning per day 1918 cleaning loss time per month 0.5 × 3.73 × 22 = 41H Number of losses per month 1918 × 22 = 42202 pieces The number of losses due to cleaning per day is
It shows the number that would have been produced without a stop due to cleaning.

When comparing the cleaning loss time per month between the conventional apparatus and the present apparatus based on these results, 123H-41H = 82H as shown in FIG. In addition, based on this, the number of production per month (KP /
Month), as shown in FIG.
It was 492 KP = 84 KP / month, and it was confirmed that the production number was improved by about 17% as compared with the conventional case.

[0057]

According to the semiconductor lead molding apparatus according to the first aspect of the present invention, the groove is provided in the area on the molding table where the lead contacts and moves during molding, so that the tip of the lead contacts and moves on the molding table. At this time, even if the peeled solder is dragged with the movement of the lead, the solder is not dragged at the groove. Therefore, the peeled solder does not accumulate on the molding table, especially near the bent portion of the lead, and the occurrence of defective products due to the peeled solder adhering to the lead can be reduced as much as possible. Further, since it is not necessary to frequently remove the deposited solder, productivity can be significantly improved.

In particular, according to the second aspect, in the first aspect, at least a part of the corner of the groove that makes contact with the lead is curved, so that even if the lead makes contact with the corner of the groove, the surface of the lead is formed. Since the corner of the groove does not hit sharply,
It is possible to make it difficult for the solder coated on the lead surface to peel off.

According to the third aspect of the present invention, the plurality of guide members are provided in the area on the second molding table where the leads contact and move during molding, so that the leads and the surfaces of the guide members contact each other during molding. The moving distance is shorter than before, and the solder on the lead surface is less likely to peel off. Therefore, the occurrence of defective products due to the peeled solder adhering to the leads can be reduced as much as possible. Further, since it is not necessary to frequently remove the deposited solder, productivity can be significantly improved.

In particular, according to the fourth aspect, in the third aspect, the groove is provided below the guide member, so that most of the peeled-off solder falls into the groove, and the lead contacts and moves. There is no accumulation in the area on the second molding table. Therefore, the possibility that the peeled-off solder adheres to the lead can be further reduced.

According to a fifth aspect of the present invention, in the third or fourth aspect, the guide member is constituted by a roller. Therefore, when the lead contacts and moves on the surface of the guide member, The roller as a guide member rotates, and the impact at the time of contact is reduced as compared with the case where the surface of the guide member is fixed. Therefore, it is possible to make it more difficult for the solder provided on the lead surface to peel off.

According to the sixth aspect of the present invention, since the groove is provided in the area on the second molding table where the lead contacts and moves at the time of molding, the solder which has come off when the lead contacts and moves on the molding table is formed. Most fall into the groove and do not accumulate in the area on the second molding table where the lead contacts and moves. Therefore, the occurrence of defective products due to the peeled solder adhering to the leads can be reduced as much as possible. Further, since it is not necessary to frequently remove the deposited solder, productivity can be significantly improved.

According to the seventh invention, in the first to sixth inventions, a suction means is provided in a part of the groove, so that the solder entering the groove is sucked by the suction means. . Therefore, the inside of the groove can always be kept clean.

[Brief description of the drawings]

FIGS. 1A to 1C are schematic sectional views showing a process of performing gull wing molding by a semiconductor lead molding apparatus according to an embodiment.

2A is a schematic plan view of the molding table shown in FIG. 1,
(B) is the side view.

FIG. 3 is a schematic cross-sectional view of a lead and a molding table after gull wing molding is completed.

FIG. 4 is a schematic configuration diagram of a dust collection system provided in the semiconductor lead molding device according to the embodiment.

FIG. 5 is a schematic cross-sectional view showing a process of performing curling molding by the semiconductor lead molding apparatus according to the embodiment.

FIG. 6 is a partial sectional view of the roller shown in FIG. 5;

FIG. 7 is a schematic plan view of a molding punch.

FIG. 8 is an explanatory diagram showing the cleaning loss time per month of the conventional apparatus and the apparatus of the present embodiment.

FIG. 9 is an explanatory view showing the number of production per month (KP / month) of the conventional apparatus and the apparatus of the present embodiment.

FIGS. 10A to 10C are schematic views showing the shape of a lead formed by a conventional forming step.

11 (A) to 11 (C) are schematic cross-sectional views showing a process when gull wing molding is performed by a conventional semiconductor lead molding apparatus.

FIG. 12 is an enlarged view of a region a shown in FIG.

FIGS. 13A and 13B are schematic cross-sectional views showing a process of performing curling molding in a conventional semiconductor lead molding apparatus.

[Explanation of symbols]

 1, 21a, 21b Molding table 3, 25 Molding punch 5, 29 Groove 7, 17 Semiconductor device 9, 19 Lead 25a Molding part 27 Roller

Claims (7)

[Claims] 1. A semiconductor device comprising: a first molding table for fixing a semiconductor device from which a solder-covered lead is drawn out; and a second molding table for pressing the lead against the molding table and molding the lead into a predetermined shape. The semiconductor lead molding device according to claim 1, wherein a groove is provided in a region on the first molding table where the lead contacts and moves during molding. 2. The semiconductor lead molding apparatus according to claim 1, wherein at least a part of the corner of the groove that contacts the lead when the lead moves in contact is a curved surface. 3. A semiconductor device comprising: a first molding table for fixing a semiconductor device from which a solder-covered lead is drawn out; and a second molding table for pressing the lead to a predetermined position and molding the lead into a predetermined shape. A semiconductor lead molding apparatus, wherein a plurality of guide members are provided in an area on the second molding table where the lead contacts and moves during molding. 4. The semiconductor lead molding apparatus according to claim 3, wherein a groove is provided below said guide member. 5. The semiconductor lead molding apparatus according to claim 3, wherein said guide member is a roller. 6. A first molding stand for fixing a semiconductor device from which a solder-covered lead is drawn out, and a second molding stand for pressing the lead to a predetermined position and molding the lead into a predetermined shape. A semiconductor lead molding apparatus, wherein a groove is provided in an area on the second molding table where the lead contacts and moves during molding. 7. The semiconductor lead molding apparatus according to claim 1, wherein suction means is provided in a part of said groove.