JPH0684985A - Transfer mold - Google Patents

Abstract

PURPOSE:To prevent flow of a foreign matter such as resin flash to a photoreceiving surface of an optical semiconductor device at the time of molding. CONSTITUTION:A transfer mold for an optical semiconductor comprises ejector pins 106a, 107a of a cull and a runner disposed on protrusions 110, 110a not on a way for mainly feeding resin. Thus, an imaging malfunction of an optical semiconductor device at the time of molding is reduced to improve its yield.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer mold which is particularly effective as a mold for an optical semiconductor device, and is mainly made of a transparent resin for an optical semiconductor.
It is used in the field of molding technology.

[0002]

2. Description of the Related Art A conventional transfer mold for an optical semiconductor is composed of an upper mold and a lower mold, and plan views thereof are shown in FIGS. 11 (a) and 11 (b). As shown in the plan view of the die, the lower die cull portion eject pin 206a and the lower die runner portion eject pin 207a are connected to the lower die cull portion 20.
6 and the lower die runner portion 207, and the upper die runner portion eject pin 213a in the upper die runner portion,
Each of them is arranged mainly in the flow path of the resin.
Reference numeral 208 is a cavity, 208a is a cavity eject pin, and 209 is a gate.

12 to 18 are a sectional view and a schematic view of steps of a conventional upper and lower molds. Hereinafter, a conventional transfer mold molding process of an optical semiconductor device will be described in detail.

First, the structure of the upper and lower molds in the mold open state will be described with reference to FIG. The upper die eject pin 213a of the upper die 212 is the upper die eject pin plate 21.
It is fixed to 2a and is pushed down by a spring 212b together with the eject pin plate. Therefore,
In the mold open state, the upper mold eject pin 213a projects from the upper mold parting surface 213. Lower mold 2
Although the lower die cull portion eject pin 206a and the lower die runner portion eject pin 207a of 11 are fixed to the lower die eject pin plate 211a, they do not have any springs and are not opened. In the state, the lower mold cull part 20
6. The lower die runner portion 207 does not protrude from the bottom surface.

Next, as shown in FIG. 13, by clamping the mold, the upper mold eject pin column 213b is moved to the lower mold part.
Eject pin plate for grounding to the mounting surface 214
It is lifted together with the door 212a. Therefore, in the mold clamped state,
The upper die eject pin 213a is retracted to the same surface as the upper die parting surface 213. The lower die cull portion eject pin 206a and the lower die runner portion eject pin 207a are the same as in the mold open state.
6 and the lower die runner portion 207 does not protrude from the bottom.

As shown in FIGS. 14 and 15, a transparent resin tablet 216 is put in from the pot portion 215 in the mold clamped state, and is poured into the runner, gate, and every corner of the cavity by the transfer 217, and the mold is held for a certain period of time. After tightening and curing, the mold is opened. As shown in FIG. 16, the upper mold eject pin 213a is pushed down by the spring 212b together with the upper mold eject pin plate 212a and protrudes from the upper mold parting surface 213. As a result, the molded product 218 and the upper die 212 are released from each other. Finally,
As shown in FIG. 17, the lower die cull portion eject pin 20
6a and lower die runner-section eject pin 207a
Is lifted by the hydraulic mechanism 219 together with the lower die eject pin plate 211a, and the molded product 218 is pushed up from the lower die 211 and released. As shown in FIG. 18, after the molded product 218 is removed, the hydraulic pressure is released, and the lower die cull portion eject pin 206a and the lower die runner portion eject pin 207a are lowered to the original position and compressed air is used. Remove the resin burr adhering to the mold surface with an air blower.

[0007]

In the series of molding processes, when the conventional mold shown in FIG. 11 is used, the eject pin 213a and the eject pin 213a provided right above the upper mold runner at the time of mold clamping are used. The resin burr is extruded from the gap of the inner wall of the hole, and is caught in the molten resin to form the gate 2
It will flow into the cavity 208 through 09. Similarly, for the lower die cull portion 206 and the lower die runner portion 207, the eject pin 206a for the lower die cull portion of the previous shot, or the eject pin and the eject pin hole when the lower die runner portion eject pin 207a operates. If the resin burr extruded from the gap of the inner wall cannot be removed sufficiently with an air blower, it will be caught in the molten resin and the gate 2
It passes through 09 and flows into the cavity 208.

As a result, the resin burr which has flowed into the cavity 208 has a very high possibility of flowing into the light receiving surface of the optical chip, and if it is cured as it is, there is a problem that black defects occur in the imaging test and the yield is reduced.

A resin burr is also generated from the inner wall of the cavity eject pin 208a of the upper and lower molds, but this resin burr is made to flow to the corner of the cavity 208 by the molten resin injected from the gate 209. There is no problem as it hardens.

The present invention provides a transfer mold which solves the above problems in the conventional mold.

[0011]

[Means for Solving the Problems] In the conventional die, the eject pin which has been arranged in the cull portion and the runner portion mainly in the passage through which the resin flows is replaced by a protrusion capable of disposing the eject pin in the cull portion and the runner portion. Parts are provided and the mold is improved so that the protrusions eject the molded product.

That is, the present invention provides a transfer mold having a cull portion, a runner portion, and a cavity portion, and an eject pin for assisting the mold release from a resin molded product. The transfer mold is characterized in that a projecting portion is provided on the base plate and the eject pin is arranged on the projecting portion.

[0013]

According to the transfer mold of the present invention, even when the molten resin passes through the cull portion and the runner portion, the eject pin does not exist in the passage in which the molten resin mainly flows and the cull portion and the runner portion are not present. The resin burr generated from the inner wall of the eject pin stays at the protrusion because it is on the protrusion provided at the minus portion, and does not flow onto the light receiving surface of the optical chip of the cavity.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 2 shows an assembly flow chart of a manufacturing process of an optical semiconductor device, and FIG. 3 is a sectional view of an optical semiconductor device molded by a transfer mold.

The embodiments of the present invention will be described in detail below based on the assembly flow chart.

First, the wafer on which a desired pattern is formed is diced (not shown) to be in the chip 1 state (step T1).

Next, the separated chip 1 is die-bonded to the lead frame 2 using a die-bonding adhesive (step T2).

Die-bonded lead frame 2
Then, the Au wire-3 is bonded (step T
3).

Die-bonded and wire-bonded releas
The dray frame 2 is washed to remove foreign matters adhering to the chips and the lead frame (step T4).

After washing the lead frame 2, a transfer mold is used to mold the transparent mold resin 4 (step T5).

After molding (step T5), the company name and serial number are marked on the back surface of the molding package.
(Step T6). When the marking is completed, the lead 5 is cut into a predetermined size and bent (step T7). When the forming is completed, it is tested whether or not the electrical characteristics and the imaging characteristics meet the specifications (step T8), and the optical semiconductor device is completed. However, if a foreign matter such as a resin burr is present on the light receiving surface 4a of the optical chip during the image pickup test, a black defect occurs.

The mold molding process (step T5) using the mold of the present invention will be described in detail below.

The transfer mold for optical semiconductors in this embodiment is composed of an upper mold and a lower mold, and plan views thereof are shown in FIGS. 1 (a) and 1 (b).

As shown in the plan view of the die, the lower die cull portion eject pin 106a and the lower die runner portion eject pin 107a are connected to the lower die cull portion 106 and the lower die runner.
The protrusion pins 110, 110a provided on the portion 107, and the runner portion eject pin 113a of the upper die are provided on the protrusion portion 110b provided on the upper die runner portion. The upper and lower molds have been modified to eject molded products. Protrusions 110 and 11
0a and 110b are not mainly arranged in the flow path through which the resin flows. Reference numeral 108 is a cavity, reference numeral 108a is a cavity portion eject pin, and reference numeral 109 is a gate.

4 to 10 are a sectional view of the upper and lower molds of the present invention and a schematic view of the transfer molding process. Hereinafter, the transfer molding process of the optical semiconductor device will be described in detail.

First, the structure of the upper and lower molds in the mold open state will be described with reference to FIG. The upper die eject pin 113a of the upper die 112 is the upper die eject pin plate 112.
It is fixed to a and is pushed down by the spring 112b together with the eject pin plate. Therefore, in the mold open state, the upper mold eject pin 113a projects from the upper mold parting surface 113. Lower mold 11
The lower die cull portion eject pin 106a and the lower die runner portion eject pin 107a of 1 are fixed to the lower die eject pin plate 111a, but no spring is inserted and the die opening In the state, the lower mold cull portion 106,
It does not protrude from the bottom surface of the lower die runner portion 107.

Next, as shown in FIG. 5, the upper die eject pin plate 112a is lifted because the upper die eject pin column 113b is grounded to the lower die parting surface 114 by clamping the die. Therefore, in the mold clamped state, the upper mold eject pin 113a retracts to the same surface as the upper mold parting surface 113. The lower die cull portion eject pin 106a and the lower die runner portion eject pin 107a are the same as in the mold open state, and the lower die cull portion 2
06 and the lower die runner portion 207 does not protrude from the bottom surface.

As shown in FIGS. 6 and 7, a transparent resin tablet 116 is loaded from the pot portion 115 in the mold clamped state, and is poured into every corner of the runner, gate, and cavity by the transfer 117, and the mold is held for a certain period of time. After tightening and curing, the mold is opened. As shown in FIG. 8, the upper die eject pin 113a is pushed down by the spring 112b together with the upper die eject pin plate 112a, and the upper die eject pin 113a is pushed down.
It projects from the tongue 113. As a result, molded product 11
8 and the upper die 112 are released.

When the upper and lower molds of the present invention are used, when the mold is clamped, the resin burr is pushed out from the gap between the upper mold eject pin 113a and the inner wall of the eject pin hole, and even if the molten resin is injected, the resin burr is projected. It stays in 110 b and does not flow into the cavity 108. Similarly, for the lower die cull portion and the runner portion, the lower die cull portion eject pin 10 is operated during the operation of the lower die eject pin of the previous shot.
6a and lower die runner-section eject pin 107a
Even if the resin burr extruded from the gap between the inner wall of the eject pin hole and the eject pin hole is not sufficiently removed by the air blower, the resin burr stays on the protrusions 110 and 110a, and the cavity 10
It does not flow into 8. As a result, a good molded product can be obtained.

Finally, as shown in FIG. 9, the lower die cull portion eject pin 106a and the lower die runner portion eject pin 107a are connected to the eject pin plate 111a.
The whole is lifted by the hydraulic mechanism 119, and the molded product 118 is pushed up from the lower mold 111 and released. As shown in FIG. 10, after removing the molded product 118, the hydraulic pressure is released, and the lower die cull portion eject pin 106a and the lower die runner portion eject pin 107a are lowered to the original position and compressed air is used. Remove the resin burr adhering to the mold surface with an air blower.

The present invention is not limited to the above embodiment.

[0032]

As described in detail above, with the mold according to the present invention, foreign matter is prevented from flowing onto the light receiving surface of the optical chip during molding, and image pickup defects during testing are reduced.
The yield of the optical semiconductor device can be improved.

[Brief description of drawings]

FIG. 1A is a plan view of an upper die according to an embodiment of the present invention. (B) is a plan view of a lower mold in one embodiment of the present invention.

FIG. 2 is an optical semiconductor assembly flow chart.

FIG. 3 is a cross-sectional view of an optical semiconductor device.

FIG. 4 is a cross-sectional view showing a state where upper and lower molds are opened in an embodiment of the present invention.

FIG. 5 is a cross-sectional view showing a state in which the upper and lower molds are clamped in the same example.

FIG. 6 is a cross-sectional view showing a state in which a transparent resin tablet is put in the pot portion in the example.

FIG. 7 is a cross-sectional view showing a state where transparent resin is injected in the same example.

FIG. 8 is a cross-sectional view showing a state in which the upper and lower molds are opened after being molded in the example.

FIG. 9 is a cross-sectional view showing a state in which a molded product is pushed up by a lower mold eject pin in the example.

FIG. 10 is a cross-sectional view showing a state where the lower die eject pin is lowered to the original position in the same embodiment.

FIG. 11A is a plan view of a conventional upper mold.
(B) is a top view of the conventional lower mold.

FIG. 12 is a cross-sectional view showing a state in which the upper and lower molds are opened with a conventional technique.

FIG. 13 is a cross-sectional view showing a state where upper and lower molds are clamped by a conventional technique.

FIG. 14 is a cross-sectional view showing a state in which a transparent resin tablet is put in a pot portion according to a conventional technique.

FIG. 15 is a cross-sectional view showing a state in which a transparent resin is injected by a conventional technique.

FIG. 16 is a cross-sectional view showing a state where the upper and lower molds are opened after molding according to the conventional technique.

FIG. 17 is a cross-sectional view showing a state in which a molded product is pushed up by a lower die eject pin according to a conventional technique.

FIG. 18 is a cross-sectional view showing a state where the lower die eject pin is lowered to the original position in the conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Optical semiconductor chip 2 Lead frame 3 Au wire-4 Transparent mold resin 4a Optical semiconductor chip light-receiving surface 5 Lead 106 Lower mold cull part 106a Lower mold cull part Eject pin 107 Lower mold runner Part 107a Lower mold runner part Eject pin 108 Cavity 108a Cavity part Eject pin 109 Gate 110, 110a, 110b Protrusion part 111 Lower mold 111a Lower mold eject pin plate 112 Upper mold 112a Upper mold eject Pin plate 112b Spring 113 Upper mold parting surface 113a Upper mold ejecting pin 113b Upper mold ejecting pin column 114 Lower mold parting surface 115 Pot part 116 Transparent resin tablet 117 Transfer 118 Molded product 119 Hydraulic mechanism

Claims (1)

[Claims] 1. A transfer mold having a cull part, a runner part, and a cavity part, and an eject pin for assisting the mold release from a resin molded product, wherein the cull part and the runner part have protrusions. And a structure in which the eject pin is arranged on the protrusion, and a transfer mold die.