JP2000043096A - Resin sealing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin sealing device which is free from the positional deviation of a lead frame when a semiconductor device positions a bonded lead frame and sets the lead frame on the cavity block of a bottom force of a resin sealing mold. SOLUTION: Vacuum suction holes opened 31 in the first surface of a cavity block 21 with which the second surface of a lead frame 51 is brought into contact, are perforated in the cavity block 21. The lower ends of the vacuum suction holes are connected to vacuum piping through a vacuum line. When set pins 29 implanted in the cavity block 21 are fitted into the positioning holes 59 of the lead frame 51 and set together, the lead frame 51 is vacuum-sucked by the cavity block 21 so that the lead frame 51 is not out of place.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin sealing device for a semiconductor device, and more particularly, to a resin sealing device which does not cause a displacement between a lead frame and a cavity block during resin sealing. .

[0002]

2. Description of the Related Art In general, semiconductor devices have been commercialized by transfer molding in order to protect them from the outside. That is, a semiconductor device is die-bonded and wire-bonded lead frame is positioned and set in a lower cavity block of a mold heated to a predetermined temperature of a resin sealing device,
A tablet-like resin, for example, epoxy resin, preheated from the pot is charged and closed with the upper mold.When the resin receives heat from the mold and the viscosity decreases, the resin is pressed from above or below the pot with a plunger and the cavity is pressed. In this case, the positioning of the lead frame with respect to the cavity block is performed in such a manner that a plurality of set pins (pilot pins) provided on the surface of the cavity block are provided corresponding to the lead frame. This is done by fitting the positioning holes provided.

FIG. 9 shows a chase 10 'which is exchangeably attached to a lower mold of a mold of a conventional resin sealing device, and a lead frame 51 set in a cavity block 21'. It is a partial perspective view shown. That is, a chase 10 ′ includes a center block 11 in which pots 12 each having a plunger are arranged in a row, not shown, and cavities 2 on both sides thereof.
The cavity block 21 'provided with 3 is heated to a temperature of 170C to 180C during resin sealing. Three set pins 29 are attached to the surface of the cavity block 21 ′ in contact with the back surface of the lead frame 51, and the semiconductor device to be sealed is die-bonded and wire-bonded to the lead frame 51.
(The semiconductor device 50 is shown surrounded by a dashed line) is positioned and set by fitting the positioning holes 59 to the set pins 29, and the semiconductor device 50 is housed in the cavity 23.

Then, the pot 1 of the center block 11
The pre-heated tablet-like resin is put into 2 and the upper mold is closed. When the resin melts and loses its viscosity due to the heat of the mold, the resin is pressed by a lower plunger (not shown) and pressed into the cavities 23 of the cavity blocks 21 'on both sides. That is, the molten resin flows into the cavity 23 via the runner 22, but at this time, the air in the cavity 23 escapes from the air vent 24 formed at a position facing the runner 22.

[0005] As a prior art of a resin molding apparatus, a "resin molding apparatus" disclosed in JP-A-63-162206 is disclosed.
There is disclosed an apparatus in which a vacuum evacuation hole communicating with a cavity portion of an upper mold or a lower mold is provided so that warpage of a substrate can be corrected.

[0006]

As described above, the positioning of the lead frame 51 with respect to the cavity block 21 is performed by fitting the positioning holes 59 of the lead frame 51 into the set pins 29 of the cavity block 21. The set pin 29 may have a height of 2 to 3 mm, and after the positioning hole 59 is fitted into the first set pin 29, the second and third set pins 29 are set.
When the positioning hole 59 is fitted to the first set pin 29, the positioning hole 59 may come off from the first set pin 29 fitted first. Then, due to the resin sealing being performed with the positioning hole 59 being detached, a product with a misalignment defect sometimes occurs. In addition, the positioning hole 59
When re-inserted into the set pin 29, the bonding wire connecting the semiconductor device 50 may be broken and an open defective product may be generated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and a semiconductor device is die-bonded and a wire-bonded lead frame is positioned and set in a mold cavity block for resin sealing of the semiconductor device. It is therefore an object of the present invention to provide a resin sealing device that does not cause a setting failure.

[0008]

Means for Solving the Problems The above-mentioned object can be attained by the structure of claim 1. According to the means for solving the problem, the resin sealing device of the present invention is such that the semiconductor device is die-bonded and wire-bonded. Positioning and setting the lead frame in the lower mold cavity block of the mold, and injecting molten resin into the cavity formed by closing the upper mold to seal the semiconductor device,
One or a plurality of vacuum suction holes are formed in the cavity block and open on the surface of the cavity block with which the back surface of the lead frame is in contact, and the vacuum suction holes are connected to a vacuum exhaust system.

A resin sealing apparatus having a lower cavity block provided with such a vacuum suction hole is provided with a lead pin when the positioning hole of the lead frame is fitted to a set pin provided in the cavity block. Since the frame is vacuum-sucked to the cavity block, there is no trouble that the lead frame is sealed with the resin while being separated from the set pins.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The resin sealing device of the present invention is a device in which one or a plurality of vacuum suction holes opened on the surface of a lower mold block are formed in a cavity block and connected to a vacuum exhaust system. The location where the opening of the vacuum suction hole is provided may be any location as long as the back surface of the lead frame contacts the surface of the cavity block. It is desirable to arrange the contact portions at intervals. Since the vacuum suction holes are opened in the surface of the cavity block, it is easy to make the holes if the cavity block is vertically penetrated. Further, by providing a seat around the opening of the vacuum suction hole and fitting a heat-resistant gasket, the vacuum seal at the contact surface between the lead frame and the cavity block is further ensured.

When the cavity block is exchangeably fixed on a base block having a side wall contacting the side surface thereof, a vacuum line is provided in the base block, and a vacuum suction hole, a vacuum pump and the like are provided through the vacuum line. It is desirable to connect the vacuum exhaust system. As a vacuum line provided in the base block, for example, a groove formed on the surface of the base block with which the bottom surface of the cavity block is in contact with the lower end of the vacuum suction hole, and the side surface of the cavity block is connected to the groove. A side wall through hole penetrating the side wall of the base block that is in contact with the base block may be provided. Since the groove of the vacuum line is formed on the contact surface between the cavity block and the base block, for the purpose of vacuum sealing, around the connection point between the lower end of the vacuum suction hole and the groove and on both sides of the groove. By providing a seat on one side and sandwiching a gasket between the cavity block and the base block, the connection point and the vacuum line are vacuum-sealed.

A vacuum line may be formed by providing a through-hole extending downward from the lower end of the vacuum suction hole in the base block and penetrating to the side. In this case, a seat is provided around the upper end of the through hole, and a gasket or a hollow metal O-ring is fitted therein to perform vacuum sealing at a connection point between the vacuum suction hole and the through hole. As the gasket, a heat-resistant resin or heat-resistant rubber that can withstand a mold temperature of 170 to 180 ° C., or a flexible metal such as lead or aluminum can be used. In addition, it goes without saying that a vacuum line other than those described above may be set.

In the above case, the vacuum suction hole is connected to the evacuation system via a vacuum line provided in the base block, but it is desirable that the vacuum in the vacuum suction hole can be arbitrarily interrupted. . By releasing the vacuum after the resin sealing is completed in the molding cycle of the resin sealing, the release of the lead frame from the cavity block becomes easy.

[0014]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a resin sealing apparatus according to the present invention.

(Embodiment 1) FIG. 1 is a partial perspective view of a lower chase 10 of a resin-sealing mold in a resin-sealing apparatus of an embodiment, and corresponds to FIG. 9 of a conventional example. . That is, the configuration in which the cavity blocks 21 are arranged on both sides of the center block 11 is the conventional chase 10 ′.
Therefore, the description is omitted. The difference between the chase 10 of the embodiment and the chase 10 'of the conventional example is that the lead frame 51 is arranged at a predetermined interval on the surface of the cavity block 21 on which the back surface thereof is placed in contact. Lead hole which is set by fitting a positioning hole 59 into a set pin (pilot pin) 29 of the cavity block 21 because a vacuum suction hole 34 having an opening 31 formed in the cavity block 21 is vertically formed. The positioning hole 59 of the lead frame 51 once fitted does not come off the set pin 29 by the vacuum suction of the 51.

FIG. 2 is a plan view schematically showing a lower mold to which the chase 10 shown in FIG. 1 is exchangeably fixed, and FIG. 3 is a sectional view taken along the line [3]-[3] in FIG. is there. The elements corresponding to those in FIG.
2 is fixed on an upper base block 41 having side walls of a base block including an upper base block 41 and a lower base block 42, and the chase 10 including a cavity block 21 on both sides of the center block 11 is fixed to a long side. Stoppers 43 are applied to both ends to enclose four circumferences. By the way, the width of chase 10 is 100
mm and the length is 180 mm.

As shown in FIG. 2, the cavity block 2
1 has three set pins 29 attached to one side, and an opening 31 of a vacuum suction hole 34 is provided adjacent to each set pin 29. In the first embodiment, the diameter of the opening 31 is 1.65 mm. Also,
As shown in FIG. 3, the vacuum suction hole 34 penetrates the cavity block 21 up and down, and the upper base block 41
4 formed on the surface of the groove and communicating with the lower end of vacuum suction hole 34
5 and the side wall through-hole 46 penetrating the side wall of the upper base block 41 as a vacuum line.
And a vacuum pipe 61 is screwed to each side. FIG. 4 is a cross-sectional view taken along the line [4]-[4] in FIG. 3, and a groove 45 and a through hole 4 formed in the upper base block 41 corresponding to each vacuum suction hole 34.
FIG. 6 is a diagram showing a state in which a single vacuum pipe 61 is provided on the side of the upper base block 41 and connected to a vacuum pump 64 attached to the resin sealing device. Vacuum piping 61
A three-way valve, which is opened and closed by a control device (not shown), is mounted in the middle of the apparatus, so that the vacuum in the vacuum suction hole 34 can be switched on and off at an arbitrary timing.

FIG. 5 is an enlarged view of a portion marked with A in FIG. A seat 32 is formed around the opening 31 of the vacuum suction hole 34, a gasket 33 is fitted therein, and vacuum sealing is performed between the seat 32 and the back surface of the lead frame 51 to be set. As a material of the gasket 33, a heat-resistant polymer, a heat-resistant rubber, or a flexible metal that can withstand a mold temperature of 170 to 180 ° C. is preferable. FIG. 6A is an enlarged view of the portion marked with ＢB in FIG. 3, and FIG. 6B is [B]-[B] in FIG.
It is sectional drawing of a line direction. The lower end of the vacuum suction hole 34 and the groove 45
Seats are provided on the periphery of the connection point with the gasket, and on both sides of the groove 45, and a gasket 44 made of aluminum or lead is fitted therein and vacuum sealed.

In the case where the semiconductor device is resin-sealed by the mold of the resin sealing device as described above, the semiconductor device 50 is attached to the set pin 29 provided on the cavity block 21 of the lower mold of the mold. The positioning hole 59 of the lead frame 51 to which the bonding and the wire bonding are performed is fitted. At this time, the lead frame 51 has an opening 31 in the surface of the cavity block 21, and the lead frame 51 is evacuated by the vacuum suction hole 34 formed in the cavity block 21. Since it is sucked and fixed, the fitted positioning hole 59 does not come off from the set pin 29, so that the resin is not sealed while the lead frame 51 and the cavity block 21 are misaligned. In addition, there is no occurrence of defective products with misalignment.

(Embodiment 2) FIG. 7 is a sectional view of a lower mold of a mold in a resin sealing device of Embodiment 2, and corresponds to FIG. 3 in Embodiment 1. The difference from the first embodiment is that in the upper base block 41 ′, a through hole 47 extending downward from the lower end position of the vacuum suction hole 34 of the cavity block 21, penetrating sideways and leading to the side surface of the upper base block 41 is provided. A vacuum line is bored as a vacuum line, and the vacuum pump 6
4 is connected. A three-way valve (not shown) is mounted in the middle of the vacuum pipe 61 and is opened and closed by a control device so that the vacuum in the vacuum suction hole 34 can be switched on and off at an arbitrary timing.

FIG. 8 is an enlarged view of the portion marked with "C" in FIG. A seat 43 is provided around the upper end of the through hole 47, and a stainless steel hollow ring 48 is fitted therein. A vacuum seal is performed at a connection point between the lower end of the vacuum suction hole 34 and the upper end of the through hole 47. .

The through-hole 47, which is a vacuum line of the vacuum suction hole 34 in the resin sealing device of the second embodiment, requires a complicated process for forming the through-hole 47, but the vacuum sealing is easy.

The resin sealing device according to the embodiment is constructed and operates as described above, but of course the present invention is not limited to these, and various modifications are possible based on the technical idea of the present invention. .

For example, in the present embodiment, the case where a vacuum suction hole is provided in a cavity block of a resin sealing device whose cavity block is replaceable has been exemplified. Needless to say, the effect is obtained.

Further, in this embodiment, the opening of the vacuum suction hole is provided near the set pin, but may be any of the surface of the cavity block as long as the back surface of the lead frame is in contact with the back surface. . Further, in the present embodiment, three openings of the vacuum suction holes are provided for one cavity block, but the number of openings may be one and the number is not particularly limited.

In this embodiment, the case where the vacuum pipe is connected to the vacuum pump attached to the resin sealing device is exemplified, but it may be connected to a common vacuum line laid in the building.

[0027]

The present invention is embodied in the form described above, and has the following effects.

According to the first aspect of the present invention, when the positioning pin of the lead frame is fitted and set on the set pin provided in the cavity block, the lead frame is suction-fixed by the vacuum suction hole opened on the surface of the cavity block. Therefore, there is no defective product with misalignment due to resin sealing with the lead frame being disengaged from the set pin.

According to the second aspect of the present invention, vacuum sealing at the contact surface between the lead frame and the cavity block is facilitated, and the lead frame is securely fixed.

According to the third aspect of the present invention, it is easy to lay a vacuum line connecting the vacuum suction hole and the vacuum pipe, and the connection portion and the vacuum line are securely sealed by the fourth aspect of the invention. .

According to the fifth aspect of the present invention, the vacuum of the vacuum line connecting the vacuum suction hole and the vacuum pipe is easily maintained, and the connection portion is securely sealed by the sixth aspect of the present invention.

According to the seventh aspect of the present invention, since the vacuum of the vacuum suction hole can be arbitrarily interrupted, the release of the lead frame after the completion of the resin sealing is facilitated, and the sealing operation is streamlined.

[Brief description of the drawings]

FIG. 1 is a partial perspective view of a lower chase of a mold in a resin sealing device according to a first embodiment.

FIG. 2 is a plan view of a lower mold of a mold of the resin sealing device according to the first embodiment.

FIG. 3 is a sectional view taken along line [3]-[3] in FIG.

FIG. 4 is a sectional view taken along the line [4]-[4] in FIG.

FIG. 5 is an enlarged view of a portion marked with A in FIG. 3;

6A is an enlarged view of a portion marked with “B” in FIG. 3, and FIG. 6B is a cross-sectional view taken along the line [B]-[B] in FIG. 6A.

FIG. 7 is a cross-sectional view of a lower mold of the mold according to the second embodiment;
FIG. 4 is a diagram similar to FIG. 3 of the first embodiment.

8A is an enlarged view of a portion marked with ○ C in FIG. 7, and FIG. 8B is a cross-sectional view taken along the line [B]-[B] in FIG. 8A.

FIG. 9 is a partial perspective view of a lower chase and a lead frame of a resin sealing mold in a conventional resin sealing device.

[Explanation of symbols]

10 ... Chase, 11 ... Center block, 21 ...
... Cavity block, 29 ... Set pin (pilot pin), 31 ... Opening of vacuum suction hole, 34 ... Vacuum suction hole, 41 ... Top base block, 51 ... Lead frame, 59 ... Positioning hole, 61 .... Vacuum piping, 64
……Vacuum pump.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) // B29K 105: 20 B29L 31:34

Claims (7)

[Claims] A lead frame to which a semiconductor device is die-bonded and wire-bonded is positioned and set in a lower cavity block of a resin sealing mold;
In a resin sealing device for injecting a molten resin into a cavity formed by closing with an upper mold and sealing the semiconductor device, one or a plurality of openings are formed on a surface of the cavity block with which a back surface of the lead frame abuts. A vacuum suction hole is drilled in the cavity block and connected to a vacuum exhaust system, and the set lead frame is vacuum-sucked to prevent displacement between the lead frame and the cavity block. A resin sealing device characterized by the above-mentioned. 2. A seat is provided around the opening of the vacuum suction hole, a heat-resistant gasket is fitted therein, and a vacuum seal is performed on a contact surface between the lead frame and the cavity block. The resin sealing device according to claim 1, wherein: 3. The vacuum block, wherein the cavity block is exchangeably fixed on a base block having a side wall contacting on a side surface thereof, and a bottom surface of the cavity block is formed on a surface of the base block abutting on the base block. The vacuum suction hole is connected to the vacuum exhaust system with a groove communicating with the lower end and a side wall through-hole formed in a side wall of the base block connected to the groove as a vacuum line. Item 2. The resin sealing device according to Item 1. 4. A gasket is fitted around a connection point between the lower end of the vacuum suction hole and the groove and seats formed on both sides of the groove, and the connection point and the vacuum line are vacuum-sealed. The resin sealing device according to claim 3, wherein: 5. The vacuum block, wherein the cavity block is exchangeably fixed on the base block, and the vacuum suction hole is formed as a vacuum line extending from a lower end of the vacuum suction hole to a side surface of the base block through the inside of the base block. The resin sealing device according to claim 1, wherein the resin sealing device is connected to the vacuum exhaust system. 6. A gasket or an O-ring is fitted into a seat formed around a connection point between a lower end of the vacuum suction hole and an upper end of the through hole, and the connection point is vacuum-sealed. The resin sealing device according to claim 5 which performs. 7. The vacuum of the vacuum suction hole can be arbitrarily intermittently controlled, and the vacuum suction is controlled so that the vacuum suction is released when the lead frame, which is completed with resin sealing, is released from the cavity block. The resin sealing device according to claim 1, wherein: