JPS59150713A - Preheater - Google Patents

Abstract

PURPOSE:To insert resin tablets efficiently into molds by softening nothing but part of the resin tablets supplied to the molds with a heating electrode that takes temperature distribution with a specified inclination. CONSTITUTION:An upper electrode 23 and a lower electrode 24 are provided so that an inclination angle is made between their opposite ends. A plurality of resin tablets 25 to be preheated are preheated by a preheater 20 constructed in this manner. At a specified temperature gradient the resin tablets 25 can be preheated by the upper and the lower electrode 23, 24 that are made uneven in the opposite distance. As a result, in the preheating bodies 25, the lower portion in the pot of the mold is softened and the portion that comes in contact with an upper extruding plunger can be hardened. In this manner, air is not engulfed in the preheating bodies 25 of resin tablets in the mold and voids are prevented from occurring.

Description

[Detailed description of the invention] [Technical field of invention] The present invention relates to a preheater.

[Technical aspect of invention: A rough scene]

In order to manufacture a predetermined semiconductor device, an element is sealed using a resin tablet. Resin tablet? The sealing of the device with 'C is carried out by heating a plurality of resin tablets 1 in advance using a preheater sound as shown in FIG. 1, and supplying them to a mold. Therefore, to preheat the resin tablet l, place it on both the upper and lower sides.
This is carried out by applying a predetermined power supply from the power supply section 4 between the upper electrode 2, the F-type Ti', and the pole 3 which are held between the electrodes 11 and 11. All of the plurality of resin tablets 1 are heated to about 80 to 90° C. by energization.

[Problems with background technology]

Therefore, when the preheated resin tablet 1 is supplied to the mold and the element is attached, air bubbles may be formed in the bath-melted resin tablet 1-1, especially when the mold is large. 1 piece is included. This may lead to open defects in the bonding glands provided in the element, or voids may occur in the resin sealing body in which the element is sealed. As a result, when a thermal shock test was conducted on a resin-sealed product, the probability of causing so-called resin cracks or open bonding wire defects was about 3 at the minimum. The inclusion of air bubbles in the molten resin tablet 1 is thought to occur because air is drawn in when the resin tablet is placed in a preheated molded pot and the plunger is lowered towards it. . That is, it is thought that the resin tablet 1 is pressed by the plunger and breaks down, and the air that was inside the pot is taken into the resin tablet 1 even though it becomes soft.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a preheater that enables molding that prevents the generation of voids.

[Summary of the invention]

The present invention is a preheater that enables molding by heating a resin tablet supplied to a mold to a temperature distribution with a predetermined slope.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 2 is an explanatory diagram showing a schematic configuration of an embodiment of the present invention. This preheater 20 has a power supply section 21 and an electrode section 2.
It is composed of 2. The electrode section 22 is composed of an upper electrode 23 and a D-shaped electrode 24. A plurality of resin tablets, which are objects to be preheated 25, are installed between the upper mold electrode 23 and the knife electrode 24. Lower electrode 2
The opposing interval between the poles 23 and 24 is inclined between both ends of the poles 23 and 24 so that the plurality of objects 25 to be preheated placed i are preheated at a predetermined gradient. is set to .゛-1 Power supply section 2 provided at the bottom of the pole section 220
1 is provided with a timer 26 and an ammeter 27. The timer 26 and ammeter 27 are used to energize the upper electrode 23 and lower electrode 24 for a predetermined customer group.

According to the preheater 20 configured in this way, the plurality of objects to be preheated 25 are arranged so that the opposing intervals are uneven, and
, 23 and 24 can be preheated under a predetermined temperature gradient. As a result, the preheated object 25 is placed in the pot of the mold nozzle 1 (not shown), and placed at a position below it.
It can be supplied with the vertical part in a soft state and the upper part, which is in contact with the plunger, in a hard state. For this reason, the object to be preheated 2 in the pot is heated using the plunger.
It is possible to easily prevent air from being drawn into the object 25 to be preheated when the sheet 1 is put out toward the cavity which is the sealing portion. Therefore, high quality resin sealing with no voids and no open defects in bonding wires.
Building products can be easily obtained.

As a means for heating the plurality of objects 25 to be preheated to a predetermined temperature in a gradient manner, as shown in FIG. 3, upper electrodes 23a...
- 23c was divided according to the number of objects 25 to be preheated. structure may be adopted.

〔Effect of the invention〕

As explained above, according to the gray plate according to the present invention, molding can be easily performed while preventing the generation of voids.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing the schematic configuration of a conventional preheater;
FIG. 2 is an explanatory diagram showing a schematic structure of an embodiment of the present invention;
FIG. 3 is an explanatory diagram showing a schematic configuration of another embodiment of the present invention.

Claims (1)

[Scope of Claims] +11+u An upper mold that holds several objects to be preheated from both upper and lower sides, and includes an electrode section consisting of a pole and a helical electrode, and a power supply section that applies a predetermined capacity of electricity to the electrode section. A preheater characterized in that a control means is provided for energization y, FQ (control means) so as to energize each object to be preheated at a different value of 'f'-N'. (2) The energization discharge control means is , the preheater according to claim 1 is constructed with a structure in which the spacing between the upper electrode and the lower electrode is varied depending on the object to be preheated. Claim 81, wherein the control means is configured by dividing the upper mold electrode corresponding to the object to be preheated.
The preheater according to item 41.