JPS5928047B2 - Hermetic sealing method for semiconductor devices - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of hermetically sealing or molding semiconductor devices using photocurable resins.

Conventionally, when molding light-emitting diodes, transistors, diodes, etc., first a semiconductor chip 2 is bonded to a lead member 1 as shown in FIG. 1, and then this is molded into a predetermined shape as shown in FIG. It was placed in a mold 3, injected with, for example, an epoxy resin 4, and then heated and cured to form a molded element 5 as shown in FIG.

This type of mold is made using a two-part mixture of an epoxy base material and a hardening agent, so there are problems such as air bubbles entering during mixing, expanding during heating and curing, and remaining air bubbles having an adverse effect on the characteristics of the semiconductor element. be. For example, if bubbles remain in a light-emitting element, it will impede the identification of the light-emitting display, and in general semiconductor elements, it will cause a drop in withstand voltage. If a photocurable resin is used instead of a thermosetting epoxy resin, there is no need for mixing, which reduces air bubbles.

In addition, unlike epoxy resins, there is no restriction on the usage time after mixing, so it can be stored for a long time in a sufficiently defoamed state.
Furthermore, the growth of bubbles due to heating is limited.
Therefore, molding with a photocurable resin is more advantageous than molding with a thermosetting resin in terms of air bubbles, etc. but,
Even when molded with a photocurable resin, it is impossible to avoid the generation of bubbles, and problems arise due to bubbles. SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a method for molding a semiconductor device, that is, a method for hermetically sealing a semiconductor device to obtain a molded device with fewer bubbles.

That is, the present invention includes wrapping a predetermined portion of a semiconductor element in a predetermined shape with a partially cured photocurable resin, and keeping at least a portion of the periphery of the photocurable resin having the predetermined shape in a non-exposed state. A semiconductor device characterized in that the semiconductor device is hermetically sealed by exposing the remaining portion to light to form a cured portion and a partially cured portion, and removing the portion that is the partially cured portion. By using such a step, air bubbles can be removed extremely easily, and a semiconductor element with fewer air bubbles can be provided.
Next, a molding method according to an embodiment of the present invention will be described with reference to the drawings.

FIGS. 4 to □ show a method of molding a light emitting device according to an embodiment of the present invention in the order of steps.

For this mold, first, as shown in FIG. 4, a glass plate 12 with a mask 11 in a predetermined pattern is placed using a support frame 10 to prevent the mold resin from adhering to the glass plate 12. A transparent film 13 is placed thereon. This transparent film 13 is suitably a polyester or polypropylene film with a thickness of 10 to 30 microns. The lead member 15 to which the light emitting diode chip 14 is adhered is positioned using the lower jig 16, the upper jig 17, and the pins 18 of the support frame 10. The lower and upper jigs 16 and 17 are preferably made of Al or polyethylene that can withstand acetone cleaning. By sequentially arranging the mask glass plate 12, the transparent film 13, the lower jig 16, the lead member 15, and the upper jig 17 using the pins 18 of the support frame 10, the side walls are formed by the jigs 16 and 17. The light emitting diode chip 14 and part of the lead member 15 are placed in the recess 19 whose bottom surface is formed of the transparent film 13. In this state, for example, a photocurable resin 20 called Sonne KPMlO46 manufactured by Kansai Paint Co., Ltd. is placed in the recess 1.
Inject approximately 10% more volume than No. 9. Next, cover the transparent film 21 of the same quality as the lower transparent film 13, and
9 is placed on the transparent film 21, and the roller 2 is moved from one end of the recess 19 to the other end so as to remove the photocurable resin 20 protruding from the recess 19.
Roll 2. As a result, the upper part of the photocurable resin 20 where the bubbles are present is removed. When the upper surface of the photocurable resin 20 is made flat by rolling the roller 22, the glass plate 24 having the mask 23 is positioned on the transparent film 21 using the pins 18, as shown in FIG.

The pattern of the mask 23 is the same as the pattern of the lower mask 11, and the width of the light-transmissible window 25 is smaller than the width of the recess 19. peripheral portion 26 of
is designed not to be exposed to light. The width L of the non-exposed peripheral portion 26 of the photocurable resin 20 is preferably a value obtained by adding 0.3 um to the depth of the recess 19, that is, 1/10 of the thickness of the photocurable resin 20. In this case, the depth of the recess 19 is 4.
mW! Therefore, it is 0.7 mm. Note that this width L corresponds to a region where bubbles are likely to occur when the photocurable resin 20 is injected into the recess 19. After completing the mask alignment shown in FIG.
The photocurable resin 20 is irradiated for 0 minutes.

This ultraviolet ray irradiation can be carried out using, for example, two 30W chemical lamps arranged at a spacing of 4cr1L, and a distance of 5cm from the mask.
? The illuminance is approximately 30 lux. This generates parallel light rays 27 and enables exposure while keeping the peripheral edge 26 in an unexposed state. When the exposure is completed, the mask glass plate 24
, the transparent film 21 and the upper jig 17 are removed, and the chip 14 and the lead member 15 wrapped in the photocurable resin are taken out. FIG. 6 shows the molded light emitting element 28 that has been taken out, and in this state, there is a hardened part 29 of the photocurable resin that has been hardened by exposure and a peripheral part 26 that has not yet been cured by not being exposed to light.
There is. The partially cured peripheral edge portion 26 is a portion in contact with the jigs 16 and 17, and is therefore a portion in which a relatively large number of bubbles 30 are present. Next, the light emitting element 28 is washed with acetone, and the partially cured peripheral portion 26 is dissolved and removed, leaving only the cured portion 29 as shown in FIG.

Thereafter, the photocurable resin is placed in a constant temperature bath for about 30 minutes to completely cure the cured portion 29 of the photocurable resin, thereby completing the light emitting device 28.

Figures 4 to 7 contain chips 14 for ease of understanding.
Although the lead member 15 is schematically shown, in reality, the lead member 15 is made of a lead frame as shown in FIG. 8, and a plurality of chips 14 are bonded thereto in correspondence with a plurality of display segments. .

Therefore, after curing, the lead member 15 is cut as shown in FIG. 9 and shaped into the shape shown in FIG. 10. If a light emitting element is formed using the above method, not only will there be fewer bubbles compared to epoxy molding, but the peripheral edge 26 of the injected photocurable resin, where bubbles are likely to be generated, will be kept in a non-exposed state and the final Since the bubbles are removed, the number of bubbles is extremely reduced.

Therefore, it is possible to provide a light emitting element whose light emitting state is easy to observe. Further, since an extra photocurable resin 20 is placed in the recess 19 and the upper part where air bubbles exist is removed by rolling the roller 22, a light emitting element without air bubbles can be provided in the upper part. Although one embodiment of the present invention has been described below, the present invention is not limited to the above-described embodiment and can be further modified.

For example, instead of leaving the peripheral edge part 26 corresponding to the side surface of the photocurable resin 20 unexposed, the peripheral edge part corresponding to the upper and lower surfaces of the chip 14 may be left unexposed and removed. Moreover, it is applicable not only to molds for light emitting elements but also to molds for phototransistors, diodes, transistors, and the like. In short, it is applicable to the manufacture of any element that is optically or electrically affected by the presence of bubbles.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIGS. 1, 2, and 3 are schematic sectional views sequentially showing conventional molding methods, and FIGS. 4, 5, 6, and 7 are 8, 9, and 1 are schematic cross-sectional views showing a molding method for a light emitting device according to an embodiment of the present invention in the order of steps.
FIG. 0 is a plan view and a perspective view, respectively, showing the configuration of a specific light emitting element.

Claims (1)

[Scope of Claims] 1. Wrapping a predetermined portion of a semiconductor element in a predetermined shape with a partially cured photocurable resin, and keeping at least a part of the periphery of the photocurable resin in a non-exposed state to The semiconductor element is hermetically sealed by exposing a portion other than the semiconductor element to light to form a cured portion and a partially cured portion, and removing the portion that is the partially cured portion. A method for hermetically sealing semiconductor devices. 2. The method for hermetically sealing a semiconductor device according to claim 1, wherein the semiconductor device is a light emitting device. 3. The method for hermetically sealing a semiconductor device according to claim 1 or 2, wherein the portion is a portion where bubbles are likely to occur.