JPS6146051B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a resin sealing device for resin-sealed electronic components such as semiconductor devices, and particularly relates to supplying a resin material to a sealing mold.

2. Description of the Related Art Conventionally, resin sealing devices for resin-sealed electronic components, such as resin-sealed semiconductor devices, have generally been of a transfer type. First, this method will be explained based on FIGS. 1 and 2. 1 is a resin portion remaining in the resin supply section, and 2 is a resin portion remaining in the resin transfer path (runner), both of which are portions that will not become a product. The resin passes through the gate 3 and fills the cavity 4 in which the semiconductor element is housed.

Note that 5 is a lead frame. Furthermore, the mechanism of transfer molding will be briefly explained with reference to FIG. Taking epoxy resin as an example, a preheated resin tablet (pressure molded product) is introduced into the resin material injection hole 7 of the upper mold 6 heated to 150° to 190°C, and when the plunger 8 pressurizes and injects it, The epoxy resin softens and becomes a fluid that flows through runners fitted into the mold.

A narrow gap called a gate 3 is formed on the side surface of the runner 2, and this gate 3 communicates with a cavity 4. The cavity 4 consists of a space cut into upper and lower molds, and a lead frame 5 on which a semiconductor element is placed is fixed in the cavity while being held between the upper and lower molds. The mold is provided with a plurality of cavities 4, and resin is press-fitted to fill these cavities 4. After press-fitting,
The mold is held in place for several minutes until the resin hardens. After that, the mold is opened and the product in the state shown in Figure 1 is taken out. The above is the mechanism of the transfer molding method.

The problems with this method are: 1. There are many runner parts, and the utilization rate of resin in the product is low.

2. In order to improve mass production, a large number of molds are sealed at once, which requires advanced ability to maintain and manage precision over the entire surface of the mold, making automation and unmanned operation difficult.

3 In 2, the larger the mold is made to improve mass production, the longer the sealing time becomes.

4. When the thin metal wire 11 connecting between the semiconductor element substrate 9 and the tip 10' of the external lead wire 10 shown in FIG. Or the wire may break, causing quality problems such as shorts.

It can be summarized as follows. For this reason, maintaining and controlling the accuracy of the mold required human skills and was difficult to automate, and it also became a key process for continuous production in the semiconductor element assembly process.

The present invention relates to a resin sealing device that can eliminate the above-mentioned problems, and in particular, provides a device that can solve the problem of stabilizing the supply of resin pellet material.

An embodiment of the present invention will be described below.

4 and 5, first, the means for preheating the comb material 5 in which the semiconductor device is incorporated and the means for supplying it to the sealing mold will be explained. 19 is the comb material 5
20 is a motor, 21 is a comb material transfer loader that can move vertically and horizontally, 22 is a comb material drawer pin attached to the comb material transfer loader 21, 2
3 is a preheat rail incorporating a heater 24, and 25 is a comb material chucking device attached to the comb material transfer loader 21.

In the above configuration, the comb material transfer loader 21
As the magazine stocker 19 moves vertically and horizontally, the uppermost comb material 5a of the magazine stocker 19 is pulled out onto the preheat rail 23 by the pull-out pin 22. At the same time, the comb material 5 already on the preheat rail 23 and heated by the heater 24
b is supplied to the lower mold 17 by the comb material chucking device 25. Magazine stock car 19
After the above operations are completed, the comb material 5b is raised by a predetermined pitch by the motor 20, and the comb material 5b drawn out onto the preheat rail 23 is immediately heated by the heater 24 and prepared for the next cycle. Therefore, by the operation of the comb material transfer loader 21, the comb material 5a is pulled out from the magazine case 19,
Two operations of supplying the preheated comb material 5b to the lower mold 17 can be performed simultaneously. Further, there is an effect that the comb material 5b can be prepared for heating during sealing molding. In this embodiment, when the comb material 5 is supplied, it is pulled out from the magazine stocker 19 onto the preheat rail 25 using the comb pull-out pin 22, but the comb material 5 is directly pulled out onto the preheat rail 25 by a conveyor or the like.
3 may be supplied above.

Next, the molding means will be explained. 6 is an upper mold, and 17 is a lower mold, each of which has a built-in heater 24'. 26 is a lower die plate that fixes the lower mold 17, 27 is a mold clamping cylinder that provides thrust to the lower die plate 26, 28 is a tie bar shaft,
One end is fixed to the upper die plate 29 and serves as a sliding guide for the lower die plate 26.

The upper mold 6 has resin injection holes 16 and heating heaters 24'' corresponding to the number of semiconductor elements incorporated in the comb material 5c, and is fixed to the upper die plate 29. It is a molded cylinder that gives

In the above configuration, when the preheated comb material 5c is supplied to the lower mold 17, the lower mold 17 rises while further heating the comb material 5c by the heater 24', and the lower mold 17 and the upper mold 6 are heated. Dokking and mold tightening. Next, resin material pellets 18 are charged into the resin material injection hole 16 of the upper mold 6,
The plunger 9 descends and the resin material heated and melted by the heating heater 24'' is injected under pressure into the cavity to perform sealing.

Next, a take-out means for taking out the encapsulated comb material 5c (hereinafter referred to as comb molded product) from the mold;
Also, a means for taking out the comb molded product 5d from which the gate residue has been removed will be explained.

31 is a chucking device for taking out the comb molded product 5c from the lower mold 17, 32 is a chucking device for taking out the comb molded product 5d from which gate residue has been removed, and 33 is a molded comb taken out from the lower mold 17. A rail 34 for receiving the material 5d is a take-out loader that moves the chucking devices 31, 32 vertically and horizontally. After the sealing molding is completed in the above configuration and the lower mold 17 is lowered, the take-out loader 34 moves into the mold, grips the comb molded product 5c with one chuck device 31, and removes the rail 33 with the other chuck device 32. The comb molded product 5d from which the gate residue has been removed is held at the top and taken out.

Therefore, one operation of the take-out loader 34 can simultaneously take out the comb molded product 5c and the comb molded product 5d from which the gate residue has been removed.

Next, regarding the resin pellet supply device of the present invention,
This will be explained in detail based on FIGS. 4 and 5. In FIG. 4, 35 is a hopper that stores a large number of resin pellets 18, 36 is a fixed pipe chute with both ends open, and 40 is a drive cylinder. The resin pellets 18 inside are inserted into the pipe chute 36 in alignment. The process up to supplying the resin pellets 18 aligned in the pipe chute 36 to the resin material injection hole 16 of the upper mold 6 will be explained based on FIG. In the figure, numeral 37 is a disk with a hole capable of intermittent rotational movement at a predetermined angle, 38 is a through hole provided in the disk with hole 37 for guiding the resin pellets 18, and 39 is a supply for guiding a plurality of resin pellets 18. It's a block. 41 is a disc with a hole 3
This is a fixing plate to prevent the resin pellets 18 guided to the supply block 39 from falling.
A through hole is made in the part that matches. 4
Reference numeral 2 denotes an intermittent rotation actuator that rotates the circular plate 37 with holes at predetermined intervals. In the above configuration,
Resin pellets 1 arranged in pipe chute 36
8 is transferred from the pipe chute 36 to the through hole 38 of the holed disc 37, and is guided while maintaining its posture in the through hole 38. When the holed disk 37 is rotated by a predetermined angle by the intermittent rotary actuator 42, only one resin pellet 18 is separated, and the resin pellet 18 in the pipe chute 36 is not supplied by the holed disk 37. will be stopped. One resin pellet 18 falls again in the next through hole 38 of the holed disc 37, and the resin pellets 18 are separated one by one. The resin pellets 18 are delivered to the guide hole 39a of the supply block 39 at the opening of the fixed plate 41. Supply block 39
In conjunction with the intermittent rotational movement of the circular plate 37 with holes, the rotational movement of the drive motor 43 is moved intermittently linearly through the pole screw 44 by a stroke corresponding to the pitch P of each hole. All the resin pellets 18 are put into each of the guide holes 39a. When a predetermined number of resin pellets 18 have been guided, the supply block 39 is rapidly moved to a position facing the upper mold 6, and then the cylinder 45
, and stops at a position where the resin material injection hole 16 of the upper mold 6 and the guide hole 39a match. Thereafter, the shutter plate 46 slides under the thrust of the cylinder 47 while being guided by two long holes 48 and a guide pin 49, releases the holding of the resin pellets 18, and injects the entire number of resin pellets 18 at the same time. It is dropped into the hole 16.

In this embodiment, the hopper 35 that moves up and down is used to supply the resin material, but other supply devices such as a vibrating parts feeder may also be used.
Also, when separating the resin material, although the intermittently rotating holed disk 37 is used, other devices such as a direct-acting reciprocating slider may be used.

Note that FIG. 6 is a partial sectional view showing in more detail the structure of the upper and lower mold parts shown in FIG. 4.

In this figure, the lead frame 5 is the upper mold 6.
and the lower mold 17, and is connected to the cavity 4. A resin material pellet 18 is inserted into a resin material injection hole 16 provided in the upper mold 6, and a plunger 9 is arranged above the resin material injection hole 16 so as to be movable up and down. .
The resin material pellet 18 is a thermosetting resin,
This amount is enough to fill 4 cavities 4.
The resin material pellets 18 charged into the resin material injection hole 16 are melted by the heat of the heated molds 6 and 17, and are press-fitted into the cavity 4 by the pressing force of the plunger 9.

FIG. 7 is an enlarged view of a part of the lead frame 5 after resin sealing is completed using the resin sealing mold of FIG. 6, and FIG. 8 is a view showing the whole. The resin residue 14 at the gate portion and the resin residue 13 within the supply portion are connected to the molded resin outer grain 15.

As described above, according to the present invention, it is possible to simultaneously and reliably feed a plurality of resin pellets to a resin sealing mold, and in a resin sealing device, the process from supplying comb material and resin pellets to sealing molding and combing is possible. A major problem in automatic and continuous processing up to the removal of molded products has been solved. Furthermore, its industrial effects are extremely large, as it enables continuous and integrated production of semiconductor element assembly processes.

In the example, a single in-line type semiconductor device was molded, but it is also possible to resin-seal a dual-in-line type semiconductor device.
It is also possible to resin-seal various other resin-sealed electronic components.

[Brief explanation of the drawing]

Figure 1 is a plan view showing the state of a semiconductor device immediately after resin encapsulation using a conventional transfer molding method;
The figure is a diagram for explaining the mechanism of transfer molding in the conventional method, Figure 3 is a diagram for explaining the internal state of a resin-sealed semiconductor device, and Figure 4 is a diagram for explaining the resin-sealed semiconductor device related to the present invention. FIG. 5 is a perspective view showing an embodiment of the resin pellet feeding device of the present invention, and FIG. 6 is a resin sealing device used in the resin sealing device shown in FIG. 4. FIG. 7 is an enlarged perspective view showing a part of the resin-sealed lead frame; FIG. 8 is a plan view showing the overall shape of the resin-sealed lead frame. It is. 6...Upper mold, 16...Resin material injection hole, 17...
... lower mold, 35 ... storage means, 37 ... separation supply means, 39 ... supply block, 39a ... guide hole,
46...Means for transferring.

Claims (1)

[Claims] 1 storage means for storing a large number of resin pellets;
It is equipped with a separation supply means that separates the resin pellets sent from the storage means one by one and sequentially supplies them to a fixed position, and a plurality of guide holes for receiving the resin pellets, and sequentially supplies the resin pellets supplied by the separation supply means. A supply block that is received in the plurality of guide holes, an upper mold that corresponds to each guide hole of this supply block and has a resin material injection hole through which the plunger is passed, and a lower mold that forms a capi- ty with the upper mold. The mold consists of a resin sealing mold for resin-sealing the electronic component structure, a resin sealing mold for holding each pellet received in the separation and supply means, and a guide hole of the separation and supply means and an upper mold of the resin sealing mold. A resin pellet supply device comprising means for releasing the holding of each pellet in the separation supply means at a position where the resin material input holes of the mold coincide with each other and simultaneously transferring the pellets to the upper mold.