JPS6395635A - Resin sealing of semiconductor device - Google Patents

Abstract

PURPOSE:To carry out resin sealing under the same condition of molding and ensure a uniform package molding by measuring the degree of vacuum in a template on the occasion of causing a plunger to advance, thereby controlling a starting time of the plunger according to the measured value. CONSTITUTION:The insides of templates 21 and 27 are vacuum-exhausted by placing resin tablets into a transfer pot in the template 21 and also by using a suction system 25 and after that, the resin tablets are pressure-fed into cavities 23 and 29 by causing a plunger 26 to move forward to perform a resin sealing. In such a case, on the occasion of making the plunger 26 move forward, the degrees of vacuum in the templates 21 and 27 are measured by a vacuum gauge 24 a starting time of the plunger 26 is controlled according to the measured values. Under these situation, once the inside of the template comes to a prescribed vacuum state, this device permits the plunger 26 to move forward and the resin tablets to be fed under pressure in the cavities 23 and 29.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for resin-molding a semiconductor device using a transfer molding press.

[Conventional technology]

Generally, resin sealing equipment for semiconductor devices is known to perform molding by clamping two upper and lower mold plates attached to a transfer molding press, and then force-feeding the resin tablet in the transfer pot into a cavity using a plunger. ing.

Usually, this type of resin sealing equipment for semiconductor devices includes a fixed side template that has a transferbot in the center of which a plunger for pressurizing the tablet advances and retreats, and a cavity that forms one package, and this template. a movable mold plate having a cavity that is movable downwardly and retractably to form the other package, and an ejector turbine that is housed in this mold plate and the fixed mold plate and that moves forward and backward into each cavity. A device equipped with a mechanism is used.

In the resin sealing device for semiconductor devices configured in this way, the transfer pot has a structure that opens to the outside, so the air that flows into the transfer pot when the plunger is inserted will melt the resin due to the pressurization of the plunger. This has the drawback that the particles get mixed into the package, resulting in voids being formed inside the package.

Therefore, in this type of resin sealing equipment for semiconductor devices, by driving the intake device to reduce the pressure inside the cavity and transfer pot during resin sealing,
Efforts are being made to prevent air from entering the package.

Conventionally, a resin sealing device for this type of semiconductor device has been constructed as shown in FIG. To explain this based on the same figure, in the same figure, the reference numeral 1 indicates a mold consisting of two upper and lower template plates (not shown), and 2 is a plan attached to this mold 1 for pressurizing the resin. A transfer pot 3 in which a jar (not shown) moves forward and backward is an intake device connected to the transfer pot 2 and the mold 1 by a pipe 4 and having a vacuum gauge 5 and a vacuum pump 6. Further, 7 and 8 are vacuum gauges for measuring the degree of vacuum inside the mold l and the transferbot 2. In addition, 9
and 10 are a solenoid valve and a filter of the intake device 3.

Next, a resin sealing method for the semiconductor device configured as described above will be explained.

First, the mold 1 is heated to a predetermined temperature. Next, a resin tablet (not shown) heated to a predetermined temperature is put into the transfer pot 2, and then a plunger (not shown) is inserted. Then, the suction device 3 is driven to evacuate the inside of the mold 1 and fill the inside of the cavity (not shown) with molten resin.

In this way, the semiconductor chip (not shown) in the mold 1 can be sealed with resin.

[Problem that the invention seeks to solve]

By the way, in conventional resin encapsulation methods for semiconductor devices, there is no control over the starting time of a plunger (not shown), and for this reason, resin encapsulation cannot be performed under the same molding conditions. There was a problem in that variations occurred in the package molded product (not shown) of the device.

In other words, check the degree of vacuum inside the mold l and press the plunger (
This is because the degree of vacuum within the mold 1 is not constant because the suction device 3 is driven at a rate of 1 mm until it is operated (not shown).

The present invention has been made in view of the above circumstances, and provides a method for resin-sealing a semiconductor device, which can be resin-sealed under the same molding conditions, thereby molding a uniform pancage. .

[Means for solving problems]

In the resin sealing method for a semiconductor device according to the present invention, the degree of vacuum within the template is measured when the plunger is moved forward, and the time when the plunger is started is controlled based on this measured value.

[For production]

In the present invention, when the inside of the template reaches a predetermined vacuum state, the plunger is moved forward to force-feed the resin tablet into the cavity. be able to.

〔Example〕

FIG. 1 is a block diagram showing a resin sealing apparatus for semiconductor devices used in the resin sealing method according to the present invention. In the figure, reference numeral 21 denotes a stationary template, which is attached to the upper platen 22, and a cavity 23 forming an upper package (not shown) for semiconductor chip enclosing is formed on its parting surface 21a. ing. A vacuum gauge 24 for measuring the degree of vacuum within the template and a suction device 25 for suctioning the interior of the template are connected to the template 21, and a plunger 26 for pressurizing the tablet moves back and forth inside the template. A transfer pot (not shown) is attached. Reference numeral 27 denotes a movable template, which is provided below the template 21 so as to be able to move forward and backward, and is attached to the lower platen 28, with a lower package for sealing the semiconductor chip on its parting surface 27a. A cavity 29 (not shown) is formed. 30 is a controller that controls when the plunger is started, the vacuum gauge 24.degree., the intake device 25. It is connected to the plunger 26 and the lower platen 28. The controller 30 can control the injection timing and injection rate of the molten resin into the cavity 23, 29.

Next, a method of sealing a semiconductor device configured as described above using a resin sealing device will be described.

First, a resin tablet (not shown) is placed inside a transfer pot (not shown) in the template 21 . Next, after the inside of the mold plates 21 and 27 are evacuated by the suction device 25, a resin tablet (not shown) is placed in the cavity 23 and 29 by moving the plunger 26 forward.
is pumped and sealed with resin. In this case, plunger 26
When moving the template 2 forward, the vacuum gauge 24
The degree of vacuum within 1°27 is measured, and the starting time of the plunger 26 is controlled by this measured value.

In this manner, the semiconductor chip knob (not shown) within the template 21.27 can be sealed with resin.

Therefore, when the inside of the template 21.27 reaches a predetermined vacuum state, the plunger 26 is moved forward at point A of the curve shown by the dashed line (conventional example: broken line) in FIG. Tablets (not shown) can be pumped.

In addition, in the same figure, the solid line is a characteristic diagram showing pressure changes within both mold plates 21 and 27.

〔Effect of the invention〕

As explained above, according to the present invention, the degree of vacuum inside the mold plate is measured when moving the plunger that pressurizes the resin tablet forward, and the time of starting the plunger is controlled based on this measurement value, so that the inside of the mold plate is When a predetermined vacuum condition is achieved, a resin tablet can be force-fed into the cavity. Therefore, since resin sealing can be performed under the same molding conditions, a uniform semiconductor device package can be molded.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing a resin sealing device for a semiconductor device used in the resin sealing method according to the present invention, and Fig. 2 is a characteristic diagram showing pressure changes and resin filling amount in the same resin sealing method for semiconductor devices. , FIG. 3 is a block diagram showing a resin sealing apparatus for a semiconductor device used in a conventional resin sealing method. 21... fixed side template, 23... cavity,
24... Vacuum gauge, 25... Intake device, 26...
... Plunger, 27 ... Movable side template, 29.
...Cavity, 30...Controller. Agent Masuo Oiwa Figure 1 21: Fixed side 1° type box 29: Roasted

Claims (1)

[Claims] A resin tablet is placed inside a template in which a plunger for pressurizing the tablet advances and retreats, and after the interior of the template is evacuated, the plunger is moved forward to place the resin tablet into the cavity of the template. In a resin sealing device for a semiconductor device that pressure-feeds and seals with resin, the degree of vacuum in the template is measured when the plunger is moved forward, and the plunger starting time is controlled based on this measured value. Characteristic resin encapsulation method for semiconductor devices.