JPH09167782A - Method for manufacturing semiconductor device - Google Patents

Abstract

(57) [Abstract] (Correction) [Problem] To prevent the formation of resin burrs during the molding process of resin-sealing the semiconductor element electrically connected to the lead-out terminal for external lead-out, and to improve the moldability and the usage efficiency of the resin. A method for manufacturing a semiconductor device is provided. A molding die 1 includes an upper die and a lower die. The upper mold 1a has a plurality of upper cavities 2a which serve as a resin filling portion for forming a resin package and a pot 3 which serves as an injection port for the filling resin and a predetermined number of cavities (cavities), and the lower mold 1b has an upper cavity. A lower cavity 2b which is a resin filling portion at a position opposite to the lower cavity 2; 5 and a lead frame mounting portion 6. After mounting the lead frame 10 to which the semiconductor element 7 on the stage 8 and the lead terminal for external connection is connected on the lower mold placement part 6, the upper and lower molds are closed and resin is injected from the pot to mold the resin into the cavity. Are filled and sealed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a semiconductor device, and more particularly to a method of manufacturing a semiconductor device having a molding step of encapsulating a semiconductor element electrically connected to a lead terminal led to the outside with a resin package. Regarding The above-mentioned molding process is performed by filling a mold with a molten resin, but it is necessary to prevent the occurrence of resin burr due to the exudation of the resin from the mold.

[0002]

2. Description of the Related Art As a conventional method of manufacturing a semiconductor device,
There are a molding method using a multi-plunger type molding die and a molding method using a conventional type molding die. FIG. 5 is a cross-sectional view of a mold for explaining a multi-plunger molding method, and FIG. 6 is a cross-sectional view of a mold for explaining a conventional molding method.

In the multi-plunger system, as shown in FIG. 5, a pot 53 located at the center of a predetermined number of cavities 52, a gate 55 connecting the pots 53 to each other, and a gate 55 connecting the cavities 52 to each other. 'When,
Lead frame mounting portion 56 including a plurality of cavities 52
It is performed by using a molding die 51 having Although not shown, the molding die 51 is composed of an upper die and a lower die, and after mounting the lead frame on which the semiconductor device is mounted on the lead frame mounting portion 56, the mold is closed. After that, the molten resin is injected from the pot 53 to fill the gates 55, 55 '.
The resin is filled in the plurality of cavities 52 via the.

In the case of FIG. 5, multi-stage lead frames are arranged on both sides of the pot 53.
The resin is filled in the 3 to 8 cavities. The multi-plunger type molding method described above improves the efficiency of resin use by shortening the distance from the pot 53 to the cavity 52. , This method is the mainstream.

On the other hand, in the conventional system, as shown in FIG. 6, a plurality of cavities 62, a pot 63 located at the center, a plurality of runners 64 extending from the pot 63 to the vicinity of the cavity 62, a runner 64 and a cavity. This is performed using a molding die 61 having a gate 65 that connects 62 to each other and a lead frame mounting portion 66 including a plurality of cavities 62.

Although not shown, the molding die 61 is composed of an upper die and a lower die, and after mounting the lead frame on which the semiconductor device is mounted on the lead frame mounting portion 66, the mold is closed. Then, a molten resin is injected from the pot 63 to fill the plurality of cavities 62 with the resin via the runner 64 and the gate 65. In the case of FIG. 6, six runners 64 extend from one pot 63, and each runner 64 has five cavities 62 on each side.
The resin is injected through the gate 65.

The conventional molding method is suitable for mass production because many moldings can be sealed at one time.

[0008]

In both the multi-plunger system and the conventional system, a gap is partially formed between the upper die and the lower die by the thickness of the lead frame. Therefore, the cavity is formed in the gap. The resin oozes out from the resin, causing resin burr. FIG. 7 is a plan view of a lead frame showing a resin burr after resin sealing,
The lead frame 70 has a resin package 73 formed on both sides of the runner resin 74 and the gate resin 75 in the center.

As shown in FIG. 7, the exuding resin 76 is generated in the peripheral portion of the in-gate resin 75, and the exuding resin 76 is generated in the runner resin 74 and the in-gate resin 7.
After 5 is removed, it remains and becomes resin burr. Such a resin burr causes adhesion of foreign matter in the subsequent exterior plating process, and troubles such as conveyance in the mold and lead deformation in the cutting and molding process.

In order to prevent the above troubles, a step of removing the resin burr must be performed after the mold sealing step, but this step must be performed manually or a large jig must be prepared. It becomes troublesome. It is also possible to prevent the resin from seeping out by changing the shape of the mold, etc., but in the case of the multi-plunger method, provide a protrusion in the peripheral area of each gate, or Since a pseudo runner must be provided so as to overlap with the mold, the mold processing becomes complicated, or the distance from the pot to the cavity becomes long, resulting in deterioration of moldability and deterioration of resin use efficiency.

Even in the case of the conventional system,
By overlapping the side of the lead frame and the runner, the exudation of resin can be prevented, but the distance from the pot to the cavity also becomes extremely long and moldability deteriorates.
Also, the use efficiency of the resin deteriorates. SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems and prevent the occurrence of resin burrs, and improve moldability and resin use efficiency.

[0012]

DISCLOSURE OF THE INVENTION The present invention for solving the above problems provides a semiconductor element encapsulated in a resin package mounted on a stage of a lead frame and electrically connected to the semiconductor element. In a method of manufacturing a semiconductor device having a lead terminal led out of a resin package, a plurality of upper cavities 2a to be a resin filling portion for forming the resin package, and the upper cavity 2
an upper mold 1a which serves as an injection port for the resin to be filled in a and has one pot 3 provided for a predetermined number of cavities;
It is located at a position facing the upper cavity 2a and crosses the lower cavity 2b, which serves as a resin filling portion for forming a resin package, and directly below the pot 3, and the resin injected into the pot 3 is placed above and below the pot. A lower part having a runner 4 which flows into the vicinity of the cavity 2, a gate 5 which causes the resin to flow from the runner 4 into the upper and lower cavities 2, and a lead frame mounting portion 6 whose one side corresponds to the side of the runner 4. A mold 1 including a mold 1b is used, and a lead frame 10 in which a semiconductor element 7 is mounted on a stage 8 and the semiconductor element 7 and lead terminals for external connection are electrically connected to each other is provided. The lower mold 1b
Of the upper die 1a after being mounted on the lead frame mounting portion 6 of
And the lower mold 1b are closed, and a resin sealing step of filling the resin into the upper and lower cavities 2 by injecting a molten resin from the pot 3 is included.

According to the method for manufacturing a semiconductor device of the present invention, in the resin sealing step, one side of the lead frame 10 and one side of the runner 4 which is the resin flow path to the gate 5 are aligned with each other. Since the cavity 2 is filled with the resin, no resin bleeding gap is formed around the gate 5. Further, since the runner 4 is located immediately below the pot 3 and the lead frame mounting portion 6 is also aligned with the side of the runner 4, both the runner 4 and the gate 5 can be shortened.

Therefore, the distance from the pot 3 to the cavity 2 is shortened, and the resin usage efficiency is improved. Further, since the distance from the pot 3 to the cavity 2 is short and the variation in the distance is small, it becomes easy to control the pressure and the like at the time of resin filling, so that the moldability of the resin package can be improved.

[0015]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a mold die diagram for explaining an embodiment of a molding method according to the present invention.
1 (a) is an upper sectional view, and FIG. 1 (b) is A in FIG. 1 (a).
It is -B sectional drawing.

However, in FIG. 1 (a), the upper die and the lower die are overlapped with each other to show all the main parts. (Invisible in an actual sectional view) The molding die 1 used in the molding process of the present embodiment is
As shown in FIG. 1 (a), a plurality of cavities 2 filled with resin, one pot 3 provided for each of the eight cavities 2 at the resin injection port, and a cavity located immediately below the plurality of pots 3. 2 is a runner 4 that flows in resin to the vicinity of 2, a gate 5 that branches from the runner 4 and serves as a resin flow path to each cavity 2, and a lead frame mounting portion 6 (thick And a frame portion). The thick frame is for clarifying the lead frame mounting portion 6, and only one is shown.

The molding die 1 as described above is shown in FIG.
As shown in the sectional view of (b), it is composed of an upper mold 1a and a lower mold 1b, and in the case of this embodiment, the cavity 2 is composed of an upper cavity 2a and a lower cavity 2 in upper and lower molds, respectively.
It is provided so as to face each other as b and the pot 3 is the upper mold 1a.
In addition, the runner 4, the gate 5, and the lead frame mounting portion 6 are provided on the lower mold 1b.

A semiconductor element is sealed with a resin using such a molding die, and a plurality of semiconductor elements are mounted on a long lead frame. FIG.
As shown in (b), a plurality of stages 8 and stage 8
First, an adhesive such as silver paste is applied on the stage 8 to the lead frame 10 provided with a large number of external connection lead terminals 9 provided around the periphery of the lead frame, and then the semiconductor element 7 is mounted on the stage 8. To do.

Further, a plurality of electrodes of the semiconductor element 7 and the lead terminals 9 for external connection are electrically connected via wires 11. And upper mold 1a and lower mold 1b
The lead frame 10 having the plurality of semiconductor elements 7 mounted thereon is mounted on the lead frame mounting portion 6 shown by the thick frame (FIG. 1a) of the lower mold 1b. Then, upper mold 1
1a and the lower mold 1b are closed to obtain the state shown in FIG. 1b.

In the state shown in FIG. 1 (b), a molten resin is injected from the pot 3 of the upper mold 1a, and the plurality of cavities 2 (2a, 2b) are filled with the resin via the runner 4 and each gate 5. . In this embodiment, the runner 4 and one side of the lead frame 10 are aligned with each other, and there is no gap between the upper mold 1a and the lower mold 1b in the peripheral portion of the gate 5, so that the resin bleeds from the periphery of the gate 5. There is no sticking out.

After the resin has cooled and solidified, the upper and lower molds are opened, and the lead frame 10 in which the semiconductor element 7 is sealed with resin is taken out. FIG. 2 is a plan view showing the lead frame after the above molding process. However, the number of elements, size, and the like do not correspond to the mold of FIG. As shown in the figure, in the lead frame 10, the semiconductor element portion is covered with the resin package 12, and the lead terminals 9 (partially shown) are led out to the peripheral portion thereof. In addition, the cradle 13 of the lead frame 10 according to the present embodiment includes the pot 3 of the mold 1.
It has a pot notch 14 for escaping.

Although not shown, in order to prevent the resin from not being filled due to air remaining in the cavity 2, a portion corresponding to the outer cradle 13 'of the lead frame 10 of the mold 1 is provided. A dummy cavity may be provided. 3A and 3B are plan views showing another configuration of the lead frame used in the present invention.

FIG. 3A shows a lead frame 20 in which a slit (cutting groove) 22 is provided in a cradle 21.
It has a structure in which the slit 22 is cut at the time of releasing from the mold after the resin is sealed with the molding die shown in FIG. At the stage of resin sealing, the resin 23 in the runner 4 of the molding die 1 exists along the cradle 21 as shown by the dotted line, but by cutting the slit 22, this unnecessary It is possible to remove such a resin, that is, the resin 23 in the runner.

FIG. 3B shows a lead frame 30 in which a cradle 31 is plated with silver 32 which has poor adhesion to resin.
It is. According to such a lead frame 30, as shown in FIG.
After performing resin sealing with the mold die shown in, the resin 33 in the runner corresponding to the runner of the die remains as shown by the dotted line, but it can be easily removed because the silver plating 32 is applied. You can

FIGS. 4 (a) and 4 (b) are plan views of lead frames of still another structure used in the present invention.
Is a lead frame before resin sealing, and FIG. 4B is a lead frame after resin sealing. The lead frame 40 of this embodiment is shown in FIG.
As shown in (a), the cradle 41 located on the gate side of the molding die is characterized in that a through hole 42 having a shape obtained by dividing a circle into four is provided at a position corresponding to the pot of the molding die. (Refer to FIG. 1 for the molding die.) After preparing two such lead frames 40 and mounting semiconductor elements on them, as shown in FIG. 4A, molding is performed so that the through holes 42 face each other. Set in the mold. At this time, the two lead frames 40 are in contact with each other at one side thereof.

The actual lead frame 40 of this embodiment is
In FIG. 4A, although a lead terminal is provided on the stage on which the semiconductor element is mounted and in the periphery thereof, it is omitted in FIG. As described above, after the lead frame 40 is set in the molding die, the resin is injected from the pot of the molding die to fill the resin in the cavity and seal the semiconductor element with the resin package.

FIG. 4 (b) shows the lead frame after this resin sealing, in which a resin package 44 is formed in the semiconductor element portion and a resin is formed in the through hole 42 corresponding to the pot. Shaped culls 45 are formed. Cal 45
The two lead frames 40 are connected to each other by entering the through holes 42 of the two lead frames 40 and covering the peripheries thereof.

As described above, when the lead frame 40 of this embodiment is used, the two lead frames are connected after the resin sealing, and they are simultaneously conveyed in the subsequent steps such as the plating step and the marking step. It is possible to improve efficiency. Since the cull 45 can be removed together with the cradle 41 during the cutting process of the lead frame 40, the cutting process is not particularly complicated.

[0029]

According to the semiconductor device manufacturing method of the present invention described above, in the resin sealing step, the inside of the cavity is aligned with one side of the lead frame and one side of the runner that is the resin flow path to the gate. Because it is filled with resin,
Since there is no gap between the upper and lower molds in the peripheral portion of the gate, the resin does not exude and the subsequent steps are not affected.

Further, since the runner is located directly below the pot and the lead frame mounting portion is also aligned with the runner side, both the runner and the gate can be shortened. Therefore,
Since the distance from the pot to the cavity can be shortened and the pressure at the time of resin filling can be easily controlled, the moldability of the resin package and the efficiency of use of the resin can be improved.

[Brief description of the drawings]

FIG. 1 is a mold diagram for explaining a molding method according to the present invention.

FIG. 2 is a plan view of a lead frame after a molding process according to the present invention.

FIG. 3 is a plan view of a lead frame having another structure used in the present invention.

FIG. 4 is a plan view of a lead frame having still another structure used in the present invention.

FIG. 5 is a plan view of a mold for explaining a conventional multi-plunger molding method.

FIG. 6 is a plan view of a mold for explaining a conventional conventional molding method.

FIG. 7 is a plan view of a lead frame after a conventional molding process.

Claims (6)

[Claims] 1. A semiconductor element which is mounted on a stage of a lead frame and sealed in a resin package,
A method of manufacturing a semiconductor device having a lead terminal electrically connected to the semiconductor element and led out of a resin package, comprising: a plurality of upper cavities (2a) serving as a resin-filled portion for forming the resin package; Upper cavity (2
It is an injection port for resin to be filled in a) and has an upper mold (1a) having one pot (3) provided for a predetermined number of cavities, and a position opposite to the upper cavity (2a). The lower cavity (2b), which serves as a resin filling portion for forming the resin, is located just below the pot (3), and the resin injected into the pot (3) is placed near the upper and lower cavities (2). A runner (4) to flow in, a gate (5) to flow resin from the runner (4) into the upper and lower cavities (2), and a lead frame mounting part (one side of which corresponds to the side of the runner (4) ( A mold die (1) including a lower die (1b) having a semiconductor element (6) is used. The semiconductor element (7) is mounted on the stage (8) and is used for external connection with the semiconductor element (7). Lead terminal After mounting the lead frame (10) in the state of being electrically connected to the lead frame mounting portion (6) of the lower mold (1b), the mold of the upper mold (1a) and the lower mold (1b) A method of manufacturing a semiconductor device, comprising a resin sealing step of closing and filling a resin into the upper and lower cavities (2) by injecting a molten resin from the pot (3). 2. The gate-side cradle (13) of the lead frame (10) is provided with a pot notch (14) for avoiding the pot (3) of the molding die (1). The method of manufacturing a semiconductor device according to claim 1, wherein 3. The gate side cradle (21) of the lead frame (20) is characterized in that a cutting groove (22) for removing an end of the cradle (21) is formed. The method for manufacturing a semiconductor device according to claim 1. 4. The material (32) having poor adhesion to a resin is applied to the surface of the gate side cradle (31) of the lead frame (30).
The manufacturing method of the semiconductor device described in the above. 5. The through hole (42) is formed in the gate side cradle (43) of the lead frame (40) at a position corresponding to the pot of the molding die. 1. The method for manufacturing a semiconductor device according to 1. 6. The lead frame (40) according to claim 5.
The two through holes (42) are opposed to each other, and the two halves are resin-sealed with one side of the cradle (41) in contact with each other, and the through holes (42) are coated with resin. The method for manufacturing a semiconductor device according to claim 5, wherein the two are connected to each other.