JPH0122732B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention provides a method for resin-sealing each of a plurality of semiconductor element parts mounted on a lead frame.
The present invention relates to a resin encapsulation molding apparatus for semiconductor devices.

[Prior art]

A conventional resin encapsulation molding apparatus of this type for semiconductor devices such as ICs was designed as shown in a schematic vertical cross-sectional view in FIG. The figure shows a state in which the lower mold has been raised and is in contact with the upper mold. Reference numeral 1 denotes an underframe of the press, to which a mold clamping cylinder 2 consisting of a hydraulic cylinder is attached. 3 is fixed to the underframe 1 and extended upwards 4
The upper mold mounting base 4 is fixed at the upper end using a book post. A movable lower mold mount 5 corresponds to the upper mold mount 4 and is guided so as to be vertically movable below the column 3. The movable lower mold mount 5 is connected to the upper end of the piston rod 2a of the mold clamping cylinder 2 and is moved up and down. . Reference numeral 6 denotes an injection cylinder attached to the upper mold mount 4, with a piston rod 7 extending downward and a plunger 8 fixed to the tip.

The upper part is as follows. Reference numeral 9 denotes an upper surface plate, which is mounted and fixed to the lower surface of the upper die mounting base 4 via a heat insulating plate 11 with a plurality of mounting fittings 12 and mounting bolts 13. Reference numeral 14 denotes an upper mold fixed to the lower surface of the upper surface plate 9, and a plurality of cavities 16 are arranged at positions corresponding to each semiconductor element portion of a lead frame (not shown). 14a is a plurality of positioning holes provided on the lower surface of the upper mold 14; 17;
is a chamber that passes through the upper surface plate 9 and the upper mold 14, and is fixed with a collar on both sides, into which the sealing resin is poured from above. Reference numeral 18 designates a number of ejector pins that vertically pass through the upper surface plate 9 and the upper mold 14 and reach the cavity 16 at their lower ends, and the heads at the upper ends are held between the ejector plate 19 and the holding plate 20. has been done. 21 is a receiving piece fixed to the upper surface plate 9 to receive the presser plate 20 and regulate the lowering position of each ejector pin 18; 22 is a compression spring that applies a downward force to the ejector plate 19; It is supported by a spring bolt 23 screwed and fixed to the panel 9. When the lower surface plate 10 has reached the top dead center, the holding plate 20 is slightly lifted from above the receiving piece 21 by a lifting means (not shown) using a lifting pin that is linked to the rise of the lower surface plate, and each ejector pin 18 is lifted. The lower end is aligned with the upper surface within each cavity 16. When the lower mold mounting base 5 starts to descend,
The holding plate 20 is released from being lifted by the lifting means and comes into contact with the receiving piece 21, and each ejector pin 18
The lower end of each protrudes into each cavity 16. 24 is a receiving rod interposed between the upper surface plate 9 and the heat insulating plate 11 to prevent the upper surface plate 9 from deflecting during mold clamping, and 25 is a plurality of positioning seats fixed to the lower surface of the upper surface plate 9. ,
A positioning hole 25a is drilled. A plurality of heaters 26 are inserted into the upper surface plate 9.

The lower mold part is as follows. The lower surface plate 10 is mounted on the movable lower mold mounting base 5 via a heat insulating plate 27, and a plurality of mounting fittings 28 and mounting bolts 29 are attached to the lower surface plate 10.
It is installed and fixed by. 15 is the lower surface plate 10
A lower mold is fixed to the upper surface of the mold, and corresponds to the upper mold 14. Cavities 30 are disposed at a number of positions corresponding to each semiconductor element portion of a lead frame (not shown). On the upper surface of the lower mold 15,
As shown in the plan view in FIG. 2, a pot 31 is provided at a position corresponding to the chamber 17, and a runner 32
A large number of gates 33 are branched out and reach each cavity 30. A plurality of positioning pins 34 are fixed to the lower mold 15, and when the lower mold 15 rises, they are inserted into the positioning holes 14a of the upper mold 14 to position both molds. Returning to FIG. 1, reference numeral 35 denotes a number of ejector pins that vertically pass through the lower surface plate 10 and the lower mold 15 and reach the cavity 30 at their upper ends. Found and maintained.
A compression spring 38 is installed between the lower surface plate 10 and the holding plate 37, and applies a force to push down the ejector plate 36. Reference numeral 39 denotes a knock-out rod fixed on the underframe 1, which passes through the lower die mount 5 and the heat insulating plate 27. When the lower die mount 5 approaches the bottom dead center, its upper end contacts the ejector plate 36 and is compressed. The upper end of each ejector pin 35 is projected into each cavity 30 by being received against the spring pressure of the spring 38 . 40 is the lower surface plate 10
and the heat insulating plate 27 to prevent the lower surface plate 10 from deflecting during mold clamping; 41 is the lower surface plate 10;
A positioning pin fixed to is inserted into the positioning hole 25a and aligned with the upper surface plate 9. 42 is a plurality of heaters inserted into the lower surface plate 10.

Resin-sealing molding of a semiconductor device using the above-mentioned conventional apparatus is performed as follows. First, the lower mold mount 5 is lowered, and a lead frame (not shown) is correctly placed on the lower mold 15 at the lowered position. The upper mold 14 and the lower mold 15 are heated by heaters 26 and 42. The lower mold mount 5 is raised by the mold clamping cylinder 2, and the lower mold 15 and the upper mold 14 are clamped. A tablet-shaped powder solid sealing resin made of thermosetting resin such as epoxy resin or silicone resin is preheated and inserted into the chamber 17, and the plunger 8 is lowered into the chamber 17 by the injection cylinder 6 to soften it. A sealing resin is injected under pressure and press-fitted into each cavity 16, 30 to form a resin sealing body (not shown) in a predetermined shape. When the resin hardens and molding is completed, the lower mold mount 5 is lowered and the lower mold 15 is opened from the upper mold 14. As the lower mold part descends, the action of the lifting means linked thereto is released, and the holding plate 20 is released from lifting and is pushed down by the compression spring 22, and each ejector pin 18 pushes out the resin sealing body of each cavity 16. It is placed on the lower mold 15 and lowered. When the lower die mounting base 5 approaches the bottom dead center, the ejector plate 3 is removed by the knockout rod 39.
6 is received, and each ejector pin 35 releases the resin sealing body of each cavity 30 and the runner 3.
2. The cured resin in the pot 31 is extruded together with the lead frame.

In the conventional resin encapsulation molding apparatus described above, the lower mold 15
The extrusion of the molding resin is limited to the vicinity of the bottom dead center of the lower mold mount 5. For this reason, the knockout rod 39
When the ejector plate 36 is lowered considerably above the bottom dead center, depending on the stopping accuracy of the press, the lower surface plate 10 may be lowered by more than the deflection amount δ of the compression spring 38, damaging the lower mold part. arise. Further, if the knockout rod 39 receives the lowering of the ejector plate 36 at a position very close to the bottom dead center, the amount of thrust of each ejector pin 35 will be insufficient, and the extrusion effect of the molded resin will be insufficient.

In order to ensure that the molded resin is extruded without damaging the lower mold part, the bottom dead center of the lower mold mount 5 must be set with high accuracy, and the height of the knockout rod 39 must be accurately adjusted. In short, both conditions had to be balanced, and the adjustment work was troublesome. In particular, when replacing the mold, the knockout rod 39 must be replaced each time.
This required adjustment work, such as the height.

[Summary of the invention]

In this invention, a push-down device is attached to the ejector plate to push down the ejector plate of the lower mold section with respect to the lower surface plate, and when the lower mold mount is raised, the push-down device pushes the ejector plate against the lower surface plate. Press down, adjust the receiving lowering position with the receiving rod, lower the upper end of the ejector pin to the bottom of the cavity of the lower mold, and when the lower mold mounting base descends to the bottom dead center, release the downward movement by the pressing device. Then, the ejector plate approaches and returns to the lower surface plate using a spring means, and the upper end of each ejector pin protrudes into each cavity of the lower mold to extrude the molded resin, which requires the troublesome adjustment work of the conventional method. It is an object of the present invention to provide a resin encapsulation molding apparatus for a semiconductor device in which molding resin can be reliably extruded from a lower mold without damaging the lower mold part.

[Embodiments of the invention]

3 and 4 are a longitudinal sectional view and a plan view of a lower mold part showing a resin sealing molding apparatus for a semiconductor device according to an embodiment of the present invention, and are 1-3, 9, 14-
18, 25, 28-35, 41, 42, 2a, 2
5a and the upper die portion (not shown) are the same as those of the conventional device described above. The bottom part is as follows. Reference numeral 50 denotes a lower surface plate, which is mounted and fixed onto the movable lower die mounting base 52 via a heat insulating plate 51 with mounting brackets 28 and mounting bolts 29. Reference numeral 53 designates an ejector plate of the lower mold section, which holds a plurality of ejector pins 35 between them and a presser plate 54. Reference numeral 55 denotes a compression spring for pushing up the ejector plate 53 from below to approach the lower surface plate 50 and projecting the upper end of each ejector pin 35 into each cavity 30, and is supported by a spring bot 56 fixed to the lower surface plate 50. ing. Reference numeral 57 denotes a receiving piece fixed on the holding plate 54, which regulates the amount by which the ejector plate 53 and the holding plate 54 are pushed up toward the lower surface plate 50 by the compression spring 55, and sets the extrusion dimension α by the ejector pin 35. There is. Reference numeral 58 denotes a plurality of eject cylinders attached to the ejector plate 53, which constitute a push-down device and are composed of hydraulic cylinders, etc., and have piston rods 59 extending upward, and are activated when the lower mold mounting base 52 is raised. , the piston rod 59 is pushed out and the ejector plate 53 is pushed down by a predetermined distance with respect to the lower surface plate 50, so that the upper end of each ejector pin 35 is lowered to the bottom surface position of each cavity 30. Reference numeral 60 denotes a plurality of receiving rods fixed to the ejector plate 53 and interposed between the heat dissipation plate 51 and regulating the position of the ejector plate 53 to be pressed down with respect to the lower surface plate 50.
3. Prevents accumulation. 61 is interposed between the lower surface plate 50 and the heat insulating plate 51, and is inserted between the lower surface plate 50 and the heat insulating plate 51 during mold clamping.
It has multiple receiving rods to prevent deflection.

The resin-sealing molding of a semiconductor device by the apparatus of the above embodiment is similar to that of the conventional apparatus, but the means for extruding the resin-sealed body in the lower mold section is different. That is, a lead frame (not shown) is placed on the lower mold 15 in the lowered position, and the lower mold mount 52 is raised. At this time, the eject cylinder 58 is operated to push down the ejector plate 53 by a predetermined extrusion dimension α with respect to the lower surface plate 50, and each eject pin 34
The upper end of each cavity 30 is placed at the bottom surface of each cavity 30.
In this way, the chamber 1 of the upper mold 14 is clamped.
At step 7, a tablet-shaped solid powder sealing resin is preheated and inserted into each cavity 16, 30 by pressure injection. When the resin sealing body is molded and cured by heating, it is lowered down the lower mold mount 52 and removed from the lower mold 1.
5 is opened from the upper mold 14. At this time, the upper mold 14
The resin sealing body of each cavity 16 is extruded by each ejector pin 18 of the upper mold part and is placed on the lower mold 15. When the lower mold mount 52 reaches the bottom dead center, the pressing operation of the eject cylinder 58 is released. Then, due to the pressure of the compression spring 55, the ejector plate 53 approaches and returns to the lower surface plate 50 by the extrusion dimension α. As a result, the upper end of each ejector pin 35 protrudes into each cavity 30 and extrudes each resin sealing body together with the integrated lead frame.

In the above embodiment, the ejector plate 5 of the lower mold part
Although the eject cylinder 58 was attached only to the upper die part, a lifting device using an eject cylinder was also attached to the eject plate of the upper mold part, so that the eject plate was lifted when the lower mold part was raised and clamping molding was performed. The conventional lifting means using a lifting pin that lifts the eject plate of the upper mold part in conjunction with the rise of the lower mold part may be omitted.

In addition, although an eject cylinder is used in the above embodiment as a push-down device for pushing down the eject plate 53 with respect to the lower surface plate, the push-down device is not limited to this, and may be a push-down device using a cam means or a lever means attached to the eject plate. may also be used.

〔Effect of the invention〕

As described above, according to the present invention, the ejector plate of the lower mold part is equipped with a push-down device that pushes down the lower surface plate, and when the lower mold mount is raised, the ejector plate is pushed down against the lower surface plate by the push-down device. Push down the plate, adjust the lowering position of the receiver with the retaining rod, lower the upper end of the eject pin to the bottom of the cavity of the lower mold, and after resin casting and molding, when the lower mold mount descends to the bottom dead center,
The push-down operation by the push-up device is released, and the ejector plate is moved back toward the lower surface plate by the spring means,
Since each eject pin extrudes the molding resin from each cavity of the lower mold, there is no need for the troublesome adjustment work required in the past, and the molding resin can be reliably removed from the lower mold without damaging the lower mold part. can be extruded into In addition, there is no need to adjust the height of the knockout rod, which was conventionally necessary, each time the mold is replaced, and work efficiency is improved.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of a conventional resin encapsulation molding apparatus for semiconductor devices, and FIG. 2 is a plan view of the lower mold part of FIG. 1.
FIG. 3 is a longitudinal cross-sectional view showing an apparatus for resin-sealing a semiconductor device according to an embodiment of the present invention, with the upper mold section omitted, and FIG. 4 is a plan view of the lower mold section of FIG. 3. 1...Underframe, 2...mold clamping cylinder, 3...pillar, 4
...Upper mold mounting base, 9...Upper surface plate, 14...Upper mold, 15
...Lower mold, 16...Cavity, 17...Chamber,
18... Ejector pin, 19... Eject plate of upper mold section, 30... Cavity, 35... Ejector pin, 5
0...Lower surface plate, 52...Movable lower die mounting base, 53...Ejector plate of lower die portion, 55...Compression spring, 58...Eject cylinder forming a push-down device, 60...Receiving rod.
Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Scope of Claims] 1. An upper mold mount fixed to the upper part of a plurality of upright columns fixed to the underframe, an upper surface plate attached to the lower surface of the upper mold mount, and an upper surface plate attached to the lower surface of the upper mold mount. an upper mold provided with a plurality of cavities and fixed to the lower surface of the upper surface plate; and an upper mold disposed above the upper surface plate;
The lower ends hold the upper ends of a plurality of ejector pins leading to each of the cavities, and during mold clamping, the lower ends of each of the ejector pins are lifted to the upper surface plate by a lifting means to be pulled up to the upper surface of each of the cavities, When the lower mold part is lowered, the ejector plate of the upper mold part returns down to the upper surface plate and lowers each of the above ejector pins so that the resin sealing body in each cavity is extruded by the lower end, and the lower part of the above-mentioned column. A movable lower mold mount is guided so that it can move up and down, and is raised during molding and lowered after molding by a mold clamping cylinder attached to the underframe, and a movable lower mold mount is mounted on this lower mold mount. A lower surface plate and a plurality of cavities corresponding to the cavities of the upper mold are provided on the upper surface and are fixed on the lower surface plate,
It is disposed below the lower mold on which the lead frame is placed and the lower surface plate, the upper end of which holds the lower ends of a plurality of ejector pins reaching each cavity of the lower mold, and the lower surface plate is used during mold clamping molding. The upper end of each ejector pin of the lower mold section is lowered to the bottom of each cavity of the lower mold, and after molding, when the lower mold mount is lowered, it approaches the lower surface plate upward and lowers each ejector pin of the lower mold section. The ejector pin is attached to the ejector plate of the lower mold part, which allows the upper end of the ejector pin to protrude into each cavity of the lower mold and extrude the resin sealing body, and is attached to the ejector plate of the lower mold part, and is activated during mold clamping molding. The ejector plate is then lowered relative to the lower surface plate, and when the lower mold mount is lowered after molding, the operation is released, and the ejector plate of the lower mold section is raised and returned to the lower surface plate by spring means. and a plurality of retaining rods interposed between the lower mold mounting base and the ejector plate of the lower mold part and regulating the lowering position of the ejector plate. Molding equipment. 2. The resin sealing molding apparatus for a semiconductor device according to claim 1, wherein the push-down device comprises an eject cylinder. 3. The resin sealing molding apparatus for a semiconductor device according to claim 1 or 2, wherein an eject cylinder is attached to the ejector plate of the upper mold as a lifting means.