JP2752960B2 - Resin sealing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin sealing apparatus for simultaneously sealing a plurality of small semiconductor devices with a resin to form a resin shell, and more particularly to a resin sealing apparatus having a surface adjustment mechanism for a mold. Related to the device.

[0002]

2. Description of the Related Art When a plurality of small parts such as semiconductor devices are simultaneously resin-sealed, a uniform clamping pressure is required on contact surfaces of upper and lower dies. If it is not uniform, the thickness of the resin flash derived from the resin-sealed semiconductor device varies, and a thick resin flash often occurs. This thick resin burr is difficult to remove. Therefore, it is necessary to adjust the contact surface of the mold before resin sealing.

Usually, the surface adjustment of the mold is performed by adjusting the length of a plurality of support pillars interposed between the mold and a platen or a holder for attaching the mold with a spacer, so that a holder or the like generated at the time of mold clamping is used. Adjustments were made for weak points between the upper and lower dies caused by distortion of the dies.
In addition, in the case of this adjustment method, it is necessary to remove the mold from the apparatus and adjust the contact between the upper and lower molds, and there is a problem that a great deal of man-hour is wasted.

An apparatus for adjusting the contact surface of a mold in which the number of adjustment ports is reduced is disclosed in Japanese Utility Model Laid-Open Publication No. Sho 62-185018. In this device, a sub-plate was installed under either the upper mold or the lower mold, and a plurality of piezoelectric elements were incorporated between this sub-plate and the platen, and were arranged between the contact surfaces of the upper and lower molds. While detecting the mold clamping force between the molds with a pressure detector (not shown), the vertical displacement of the piezoelectric element is adjusted so that the mold clamping force becomes uniform, and the applied voltage is adjusted to adjust the contact surface of the mold. It is characterized by doing.

[0005]

In the above-described device for adjusting the contact surface of the mold, since the sub-plate is interposed between the mold and the piezoelectric element, the deformation of the sub-plate due to the displacement of one piezoelectric element is adjacent. It is difficult to adjust the contact surface precisely because there is no piezoelectric element at the place where you want to strengthen the contact, or it is difficult to determine how much to displace even if there is a piezoelectric element. is there.

Although the number of pressure sensors to be arranged and their relative positions on the plane with respect to the piezoelectric element are not specified, there are dents forming cavities and runners through which molten resin flows on the mold surface. Therefore, the number and the installation position of the pressure detectors are naturally determined. For this reason, there is a disadvantage that many piezoelectric elements are scattered apart from the position on the plane with respect to the positioned pressure sensor, and it takes time to determine which piezoelectric element and how much displacement is given, There is a concern that a piezoelectric element that does not need to be displaced may be displaced, causing an overload and destroying the piezoelectric element. Further, disposing the pressure detector every time the mold is replaced is a cumbersome operation.

Accordingly, it is an object of the present invention to provide a resin sealing device capable of precisely adjusting the contact surface of a mold in a shorter time.

[0008]

A feature of the present invention is that an upper mold and a lower mold in which a cavity for filling and molding an outer shell of a semiconductor device with a resin material and a flow path of the molten resin material are formed are attached. A resin sealing device for a semiconductor device, comprising: an upper die holder and a lower die holder; and an upper platen and a lower platen for attaching the upper die holder and the lower die holder and moving one of them to clamp the upper die and the lower die. A plurality of movable pins which are scatteredly arranged in a region other than where the cavity and the flow path are present in one of the upper mold and the lower mold and which slides perpendicularly to the mold surface; and A plurality of pressure sensors embedded in the holder and in contact with the rear end face of the mold to detect pressure, and a back face and one end of the mold arranged opposite to the movable pin and having no movable pin A plurality of support pillars that can contact and move in the vertical direction, a plurality of piezoelectric elements that are in contact with the rear ends of the support pillars and that are embedded in the holder for mounting the mold, and independently apply a voltage to these piezoelectric elements And a voltage adjusting device. In addition, it is preferable that the piezoelectric element is arranged sparsely at a central portion of the mold surface and densely at a peripheral portion.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings.

FIGS. 1 (a) and 1 (b) are a partial cutaway view of a resin sealing device and a plan view of a mold surface for explaining the resin sealing device according to an embodiment of the present invention. As shown in FIG. 1, this resin sealing device mounts an upper mold 7 and a lower mold 8 in each of which a cavity 14 for molding an outer shell of a semiconductor device and a runner 15 as a flow path of the molten resin material are formed. An upper platen 9 and a lower platen 10 for mounting the upper die holder 5 and the lower die holder 6, mounting the upper die holder 5 and the lower die holder 6, and clamping the upper die 7 and the lower die 8 by the die clamping cylinder 13; Cavity 1 of mold 8
And a plurality of movable pins 3 which are scattered and arranged in a region other than where the runners 4 and the runners 15 are present and slide on the guide plate 12 perpendicularly to the mold surface. A plurality of pressure sensors 4 to be detected and embedded in a lower mold holder 6; and a plurality of support pillars 2 arranged to face the movable pin 3 and movable in the vertical direction by contacting one end with the back surface of the upper mold 7. And this support pillar 2
A plurality of piezoelectric elements 1 that are in contact with the rear end of the upper die holder 5 and are embedded in the plate 11 of the upper die holder 5, and a voltage adjusting device (not shown) that applies a voltage to these piezoelectric elements 1 independently.

The piezoelectric element 1 and the pressure sensor 4 constituting the mechanism for adjusting the contact surface of the mold are paired with each other, as shown in FIG.
As shown in (b), the cavities 14 and the runners 15 are scattered and arranged on the mold surface except for recessed portions. Then, the lower platen 10 is distorted by the pressing of the mold clamping cylinder 13, and the pressing force is weaker at the peripheral portion of the mold surface than at the central portion. Therefore, the pair of the piezoelectric element 1 and the pressure sensor 4 is sparse at the central portion. The periphery is densely arranged.

The piezoelectric element 1 uses a stack type, and the pressure sensor 4 uses a semiconductor sensor with high accuracy. The movable pin 3 for transmitting pressure is made as thin as possible so as to stay within the rated pressure value of the pressure sensor 4 for the purpose of detecting only the pressure difference.

Next, the procedure for adjusting the contact surface of the mold of the resin sealing device will be described. First, the mold is attached and the pot starts to be heated. Then, the mold is clamped, and it is checked whether or not all the pressure sensors 4 indicate a reference value. If there is a pressure sensor 4 that has not reached the reference value, a voltage is applied to the piezoelectric element 1 corresponding to the pressure sensor 4 to make it a reference value.
When the mold reaches the resin sealing temperature, the pressure value of the pressure sensor 4 is checked again. This is because the distortion of the platen changes as the temperature rises. Of course, this check can be performed even during resin sealing.

In this embodiment, the case where the piezoelectric element is disposed on the upper die and the pressure sensor is disposed on the lower die has been described. However, it is needless to say that the same effect can be obtained by mounting the piezoelectric element in reverse. .

[0015]

As described above, according to the present invention, the piezoelectric element displaced to either side of the mold via the support pillar and the piezoelectric element are arranged on the opposite side of the mold and coaxially. By disposing a plurality of pairs with a pressure sensor that detects pressure changes due to the displacement of the piezoelectric element on the mold surface, the displacement of the piezoelectric element can be directly It can be transmitted to any part, and the contact surface of the mold can be adjusted more quickly and precisely. As a result, there is an effect that the number of adjustment steps conventionally performed by trial and error is greatly reduced and the operation rate of the apparatus is increased.

[Brief description of the drawings]

FIG. 1 is a partial cutaway view of a resin sealing device and a plan view of a mold surface for describing the resin sealing device according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Piezoelectric element 2 Support pillar 3 Movable pin 4 Pressure sensor 5 Upper die holder 6 Lower die holder 7 Upper die 8 Lower die 9 Upper platen 10 Lower platen 11 Plate 12 Guide plate 13 Molding cylinder 14 Cavity 15 Runner

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H01L 21/56 B29C 45/14 B29C 45/64 B29C 45/80

Claims (2)

(57) [Claims] An upper mold holder and a lower mold holder for mounting a cavity for filling and molding an outer shell of a semiconductor device with a resin material and an upper mold and a lower mold for forming a flow path of the molten resin material, respectively. In a resin sealing device for a semiconductor device comprising an upper platen and a lower platen for attaching an upper die holder and a lower die holder and moving one of them to clamp the upper die and the lower die, any one of the upper die and the lower die A plurality of movable pins which are scattered and arranged in a region other than where the crab cavity and the flow path are present and which slides perpendicularly to the mold surface; and a pressure is detected by contacting the rear end surface of the movable pin. A plurality of pressure sensors buried in the holder, and a plurality of pressure sensors arranged opposite to the movable pin and capable of moving in the vertical direction by contacting one end with the back surface of the mold having no movable pin. A support pillar, a plurality of piezoelectric elements embedded in the holder for contacting the rear end of the support pillar and mounting the mold, and a voltage adjusting device for independently applying a voltage to the piezoelectric elements. Characteristic resin sealing device. 2. The resin sealing device according to claim 1, wherein the piezoelectric element is disposed so that a central portion of the mold surface is sparsely arranged at a peripheral portion.