JP3314771B2 - Lead forming apparatus and semiconductor device holding method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lead forming apparatus for bending and forming a lead projecting outward from an outer body of a semiconductor device.

[0002]

2. Description of the Related Art In lead molding of a semiconductor device, when mounting the semiconductor device on a printed wiring board, it is necessary to ensure the flatness of the tip of the lead so as not to cause a connection failure.
Therefore, in order to ensure the flatness, various lead forming apparatuses have been conventionally proposed (for example, Japanese Patent Application Laid-Open No. 3-295261). In these conventional examples, when molding the leads, the semiconductor device is held by horizontally aligning and sandwiching the roots of all the leads formed by the upper mold and the lower mold of the lead molding apparatus. .

However, the outer shell of the semiconductor device molded by resin sealing may be warped by contracting heat after the resin sealing. In this case, in the conventional holding method, after the lead is formed, the formed lead may be warped following the warp of the outer body (spring back), and the tips of the leads may become uneven. Therefore, the flatness of the tip of the lead could not be secured.

As a configuration for solving such a problem, Japanese Patent Laid-Open Publication No. Hei 7-106484 discloses that when forming a lead, the root of the lead protruding following the warpage of the outer body of the semiconductor device is separated from the bending blade portion by an amount corresponding to the warpage. There is disclosed a lead molding die having an upper bottom means for placing an outer shell. Also,
When performing lead molding, a plurality of protrusions are brought into contact with the upper and lower surfaces of an outer body of the semiconductor device, and the plurality of protrusions are urged against resin surfaces above and below the semiconductor device to hold the semiconductor device. It has been disclosed.

Therefore, when a lead is formed by using such a lead forming apparatus, the semiconductor device is held by applying pressure to the upper and lower surfaces of the outer body instead of holding the semiconductor device with the root of the lead interposed therebetween. Therefore, the fulcrum of the lead bent by the punch changes following the warpage of the semiconductor device. Therefore, after the lead is formed, the flatness of the tip of the lead can be ensured without the conventional formed lead warping following the warpage of the outer shell.

However, the above-mentioned conventional example is compatible with a QFP having a relatively large package size, and applies pressure to the resin surface above and below the chip for a package having a relatively thick resin covering the chip. Is a structure for holding a semiconductor device. However, recent thin products (for example, T
When a lead molding die according to SOP or the like is applied, since the resin covering the chip is thin, the chip sealed inside the resin may be damaged by the pressure applied to the resin surface above and below the chip.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a lead molding apparatus which can cope with warpage of a semiconductor device and can be applied to a thin package. .

[0008]

According to a first aspect of the present invention, there is provided a semiconductor device comprising: a semiconductor chip having a lead protruding outward from an outer body comprising an upper outer body and a lower outer body of a semiconductor chip. An upper die having an upper holding portion for contacting the body and pressing the semiconductor device, and a punch located outside the upper holding portion; and a lower supporting portion for supporting the semiconductor device by contacting the lower outer body. A lead die having a lower die having a die positioned outside of the lower support and a holding mechanism for holding a semiconductor device with the upper holder and the lower support, wherein the upper holder and the The pressing part of the semiconductor device pressed by the lower holding part is small.
At least the side of the upper shell and the lower shell
It is set on the peripheral part including the side part, and the upper holding part and the front part
The lower holding portion has a projection with a curved end.
The lead forming device is characterized in that the projections are held in point contact with the pressing portion .

Therefore, according to the lead forming apparatus of the first invention of the present application, the pressing portion is formed in the vicinity of the periphery of the upper shell including the side of the upper shell and the lower shell including the side of the lower shell. by set in the vicinity of the peripheral portion, sealing directly under
Enables holding without a stopped chip and sealing
This has the advantage that the damage of the chip that has been cut is reduced. Ma
In addition, the tips of the upper holding part and the lower supporting part are curved.
Even if the semiconductor device is warped, the curved surface
Holds semiconductor devices at the tip with safe and reliable point contact
There is an advantage that can be.

According to a second aspect of the present invention, there is provided the lead forming apparatus according to the first aspect of the present invention, wherein the protrusion is spherical.
A lead forming apparatus according to claim Rukoto.

The third invention of the present application is a first invention of the present application.
In the lead forming apparatus of the present invention or the second application of the present invention , a nib for absorbing a force applied to the upper pressing portion from the semiconductor device through a contact point at which the upper outer body contacts the upper pressing portion. A lead forming apparatus comprising a mechanism provided in the upper holding portion.

Therefore, according to the lead forming apparatus of the third invention of the present application, since a relief mechanism for absorbing the force applied from the semiconductor device to the upper pressing portion is provided, excessive pressure is applied to the semiconductor device from the upper pressing portion. There is an advantage that the semiconductor device can be flexibly held without being added.

According to a fourth aspect of the present invention, there is provided the lead forming apparatus according to the third aspect of the present invention, wherein a support having a pad for controlling a movement amount is provided at a lower end portion, and a cam portion for guiding rotation of a punch is provided on a side surface. A plunger attached to the support via a spring, a holding blade for holding the lead, a cam follower moving along a cam portion at one upper end, and rotatably attached to the support. A lead gap, and a predetermined gap is set between the upper surface of the root portion of the lead and the pad.

Therefore, according to the lead forming apparatus of the fourth invention of the present application, a predetermined gap is provided between the upper surface of the root portion of the lead and the plunger. The force trying to return the semiconductor device tends to lift the semiconductor device upward. Further, since the lead forming apparatus of the fifth invention of the present application is provided with a relief mechanism in the upper holding part, the relief mechanism determines a difference between a force for pressing the semiconductor device from the upper part and a force for lifting the semiconductor device from the lower part. As a result, the semiconductor device can be held in a well-balanced manner. By such holding, a lead having a small curvature can be formed. Therefore, there is an advantage that the flatness (coplanarity) of the tip of the lead can be easily ensured since the influence of springback is not so large after the lead is formed.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1 Hereinafter, an embodiment of a lead forming apparatus according to the present invention will be described with reference to FIGS. 1, 2, 3 and 4. FIG. The semiconductor device holding method according to the present invention is realized by the present embodiment. FIG. 1 is a front view showing a lead forming apparatus according to Embodiment 1 of the present invention. FIG. 2 is a partial bottom view and a partial side view showing the arrangement of the protrusions according to the first embodiment of the present invention. FIG. 3 is a partial top view and a partial side view showing the arrangement of the clamper according to the first embodiment of the present invention.

As shown in FIG. 1, a lead forming apparatus according to a first embodiment of the present invention includes a lower mold 11 on which a semiconductor device 1 is mounted, and a semiconductor device 1 located above the semiconductor device 1 from above. It consists of an upper die 12 to be pressed. Lower mold 11
Is a die 4 located at the center of the base 14 for molding the semiconductor device 1, a plurality of protrusions 5 installed in the depressions on the die 4 to support the semiconductor device 1, and the base 14 sandwiching the die 4. And pad stoppers 13 located at both ends to stop the upper mold 12 from descending. The upper die 12 is disposed so as to face the die 4, and has a support 16 having a pad 15 for controlling the movement amount at a lower end thereof, and a cam portion for guiding the rotation of the punch 7 on a side surface, and a spring. A punch 7 having a plunger 10 attached to the support 16, a pressing blade for pressing the lead 3, and a cam follower moving along a cam portion at one upper end, and rotatably attached to the support 16; A clamper 6 having a plurality of springs 8 is provided below the plunger 10.

As shown in FIGS. 1, 2 and 3, the projection 5 and the clamper 6 each have a spherical tip, and each side face of the lower outer body 2a and the upper outer body 2b of the semiconductor device 1 is formed. They are arranged so as to be in contact with the slope to be formed and to face each other. The clamper 6 is attached to the plunger 10 by a pin 9 and has a configuration in which the clamper 6 can rotate with the pin 9 as a fulcrum. Further, a spring 8 for transmitting the force of the plunger 10 is provided on the tip side. Thus, the tip of the clamper 6 has a relief mechanism and acts on the upper outer body 2b.
In addition, the protrusion 5 and the clamper 6 are respectively arranged at two points on each side of the semiconductor device 1 having the leads 3.

Next, an operation of forming a lead using the lead forming apparatus according to the first embodiment of the present invention will be described. FIG. 4 is a front view showing the lead forming apparatus according to Embodiment 1 of the present invention during lead forming.

The supply of the semiconductor device 1 to the lead forming apparatus of the first embodiment is performed by an automatic machine having feed pins or by hand, and the positioning is provided in a positioning hole provided in a lead frame and a lower die. The positioning pin.
As shown in FIG. 1, the supplied semiconductor device 1 makes point contact with a plurality of protrusions 5 having a spherical tip on each slope of the side surface of the lower outer body 2a. At this time, the semiconductor device 1 is supported by at least three protrusion tips, including the case where the semiconductor device 1 is warped.

After the semiconductor device 1 is mounted on the lower mold 11,
The upper mold 12 starts lowering, and accordingly, the clamper 6 simultaneously starts lowering according to the punch 7, the pad 15, and the plunger 10. Thereafter, as shown in FIG.
As the clamper 6 descends, the clamper 6 is moved to the upper outer body 2 of the semiconductor device 1.
The oblique side of b is point-pressed to hold the semiconductor device 1. Then, immediately after that, the punch 7 comes into contact with the lead 3 of the semiconductor device 1 and the plunger 10
When the punch 7 pushes down the lead 3 along the cam curve provided in the step 3 and descends, and the pad 15 stops at the pad stopper 13, the pushing and bending process of the lead 3 is completed.

When the lead 3 is formed by the punch 7, the lead 3 of the semiconductor device 1 is set so that a slight space is left between the upper surface of the lead 3 and the plunger 10.
Therefore, since the clamper 6 has a relief mechanism by the spring 8, the upper die 12
As the semiconductor device 1 descends, the semiconductor device 1 is deformed in a shape corresponding to the shape of the semiconductor device 1, and serves to prevent PGK damage due to overload on the semiconductor device 1.

Further, at the time of forming the lead, the force for returning the lead 3 to the original shape tends to lift the semiconductor device 1 upward. However, the clamper 6 presses the semiconductor device 1 from above, and the spring 8 compensates for the difference between the force pressing the semiconductor device 1 from the upper portion and the force trying to lift the semiconductor device 1 from the lower portion. The device 1 can be held.

[0023]

According to the first embodiment of the present invention, as described above.
In this lead forming apparatus, the clamping force is dispersed by point-pressing the slope provided on the side surface of the outer body, and the semiconductor device conforming to the shape can be held. Therefore, the influence of springback after lead molding is reduced. or,
It is possible to hold the semiconductor device without the sealed chip directly below, thereby reducing damage to the sealed chip. Further, the lead forming apparatus according to the first embodiment of the present invention is merely an example, and the same effects as in the case of a spherical shape can be obtained by forming the protrusions and the ends of the clamper into arc shapes.

[Brief description of the drawings]

FIG. 1 is a front view showing a lead forming apparatus according to Embodiment 1 of the present invention.

FIG. 2 is a partial bottom view and a partial side view showing an arrangement of protrusions according to the first embodiment of the present invention.

FIG. 3 is a partial top view and a partial side view showing an arrangement of a clamper according to the first embodiment of the present invention.

FIG. 4 is a first embodiment of the present invention during lead molding.
It is a front view which shows the lead forming apparatus in FIG.

[Explanation of symbols]

 Reference Signs List 1 semiconductor device 2a lower outer body 2b upper outer body 3 lead 4 die 5 protrusion 6 clamper 7 punch 8 spring 9 pin 10 plunger 11 lower mold 12 upper mold 13 pad stopper 14 base 15 pad 16 support

Claims (4)

(57) [Claims] An upper holding portion for pressing the semiconductor device by contacting the upper outer body of a semiconductor device having a lead projecting outward from an outer body including an upper outer body and a lower outer body of a semiconductor chip; A lower die having an upper die having a punch located outside the upper holding part, a lower support part supporting the semiconductor device in contact with the lower outer body, and a die located outside the lower support part. In a lead forming apparatus including a mold, a holding mechanism for holding a semiconductor device with the upper holding portion, and the lower supporting portion, a pressing portion of the semiconductor device pressed by the upper holding portion and the lower holding portion has at least the upper portion. Side of outer shell
And a peripheral portion including a side portion of the lower outer body ,
The upper holding part and the lower holding part have a curved end at the tip.
Having a pointed contact with the pressing portion.
A lead forming apparatus characterized by holding . 2. The lead forming apparatus according to claim 1, wherein said projection is spherical . 3. The upper holding portion has a relief mechanism for absorbing a force applied to the upper holding portion from the semiconductor device through a contact point at which the upper outer body and the upper holding portion come into contact with each other. The lead forming apparatus according to claim 1 or 2, wherein : 4. A support having a pad for controlling the amount of movement at a lower end thereof, a plunger which is provided on a side surface thereof with a cam for guiding rotation of a punch and is attached to the support via a spring, and A presser blade for pressing down, a cam follower that moves along a cam portion at an upper end, and a punch rotatably attached to the support, between the upper surface of the root portion of the lead and the pad. The lead forming apparatus according to claim 3 , wherein a predetermined gap is set in the lead forming apparatus.