JP2003174052A - Mold for manufacturing semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mold for manufacturing semiconductor device which can smoothly exhaust air from the mold at the time of compression molding and can prevent the occurrence of void in resin after molding. <P>SOLUTION: Sealing resin is stored in a cavity M formed of a frame-like mold 53 and a compression mold 54. A molded article 1 is sandwiched by a first mold 51 and a second mold 52, and the cavity M is sealed. When a forced evacuation means such as a vacuum pump is operated and air in the cavity M is evacuated through an exhaust hole 12, pressure in the cavity is reduced and air included in resin is also evacuated. The cavity M is evacuated to a prescribed pressure level, and a pin 11 is moved to block the exhaust hole 12 connected to the forced evacuation means. The compression mold 54 is elevated, resin is melted/pressurized and the molded article 1 is sealed. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device manufacturing die used for sealing a wiring board (substrate, lead frame) or the like on which a semiconductor chip is mounted with a resin.

[0002]

2. Description of the Related Art FIG. 10 shows a compression molding die conventionally used as a die for manufacturing a semiconductor device. As shown in FIG. 10, the conventional compression molding die is
A first die 51, a frame-shaped die 53 arranged to face the first die 51 and having an opening 52, and the opening 5
The second mold 55 is composed of a compression mold 54 that fits in 2 and can move up and down inside the first mold 5.
The first and second molds 55 are operated by an elevating mechanism 56 (not shown).

The first and second molds 51,
An object to be molded 57 to be processed is arranged between 55, and the peripheral edge of the wiring board of the object to be molded 57 is clamped by the first mold 51 and the frame-shaped mold 53. After that, by moving the compression mold 54 on which the sealing resin 58 is placed relatively to the first mold 51 side by the elevating mechanism 56,
The sealing resin 58 that has been heated and melted on the compression mold 54 is pressed against the article 57 to be molded, and as shown in FIG. 11, the resin is sealed by compression molding.

In the case of compression molding as described above, a molded product 57 is placed between the first and second molds 51 and 55,
By sandwiching the molded product 57 with both molds, the space M formed by the molded product 57 and the second mold 55 is sealed. Then, the compression mold 54, which is a constituent member of the second mold 55, is lifted to the first mold 51 side to pressurize and flow the molten sealing resin, thereby removing the air in the space M. Push it to the outer periphery.

A narrow groove-shaped gap (air vent) is formed on the surface of the frame-shaped mold 53, which is a component of the second mold 55, and the molded product 57 is placed on the second mold. The air vent communicates with the outside even when it is placed on the substrate and sandwiched by the first mold, and the air moved to the outer peripheral portion by the molten resin during the molding process is discharged from the air vent.

[0006]

However, in the conventional compression molding method as described above, the molding die 57 and the second molded article 57 and the second molded article 57 are crushed by the compression mold 54 which is moved up and down to cause the fluidized tip to flow. Since the air in the space M sealed by the mold 55 is discharged to the outside, the resistance is large when exhausted only from the air vent, and the air is trapped at the flow front end, or the air outside the air vent is left behind. There was a problem.

In addition, due to the recent thinning of semiconductor devices, when a conventional tablet-shaped resin is compressed and molded in sealing some semiconductor devices, the flow distance of the molten resin becomes long in the molding process. , The cavity could not be filled completely. As a means for solving such a problem, a method has been proposed in which crushed particles of the tablet or a granular resin before molding the tablet is used, and the granular resin is supplied so as to be distributed over the entire cavity surface to perform molding. There is. However, in the conventional compression molding method, the resin starts to melt before exhaustion proceeds, and air is trapped in the melted granular resin, which may remain in the molded product to form a void.

In order to solve such problems, as used in the conventional transfer mold,
A seal for sealing between the first and second molds is provided, and an exhaust hole is provided at a position on the first or second opposing surface where the resin cannot come into contact with the first and second molds. A method of discharging air between the molds can be considered.

However, this method has the following problems. The exhaust from the air vent takes a long exhaust time because the exhaust hole has a small cross-sectional area and exhaust efficiency is poor. In order to improve the exhaust efficiency, the operation of the first and second molds in the opposing direction may be stopped at a position where only the seal is in contact, and the circuit board may be sandwiched after the exhaust is performed. Thus, when the intermediate mold clamping for stopping the operation of the mold is performed during the molding work, as a result, the space for exhausting becomes large, and the capacity of the forced exhaust means, for example, the capacity of the vacuum pump is required to be large. Was getting bigger.

The present invention has been proposed in order to solve the above-mentioned problems of the prior art, and an object thereof is to enable smooth exhaust from the mold during compression molding, An object of the present invention is to provide a mold for manufacturing a semiconductor device, which can prevent the generation of voids in the resin after molding.

[0011]

According to a first aspect of the present invention, there is provided a first mold, and a frame-shaped mold which is arranged so as to face the first mold and has an opening at a central portion thereof. A second compression die that is fitted in the opening and can move up and down in the opening
A mold cavity is formed by a space surrounded by the molds, the molded product is arranged between the first mold and the second mold, and In a mold for manufacturing a semiconductor device, in which a mold is raised and lowered and a molded product is sealed with a resin housed in a cavity of a frame-shaped mold,
An exhaust path for forcibly exhausting the gas in the cavity to the outside of the mold, and an opening / closing mechanism for opening and closing the exhaust path are provided in the second mold. According to the invention of claim 1 having such a configuration,
Since the gas in the cavity can be forcedly exhausted to the outside,
It is possible to suppress entrapment of air by the resin during molding. Further, by exhausting the inside of the cavity in advance, the gas existing between the granular or powdery resins can be eliminated, and the generation of voids due to the gas trapped in the molten resin can be prevented.

The invention of claim 2 is characterized in that, in the invention of claim 1, the exhaust path is formed in the frame-shaped mold, and one end thereof is an exhaust hole opened in the cavity. . According to the second aspect of the present invention, the exhaust path is provided in the frame-shaped mold that is fixed to the substrate during molding, so that the exhaust path does not interfere with the molding operation, and the opening / closing mechanism is arranged and It is easy to operate.

According to a third aspect of the present invention, in the first aspect of the invention, the exhaust passage is formed in the compression mold, and one end of the exhaust passage is an exhaust hole opened in the cavity. According to the invention of claim 3, the exhaust path is provided in the compression mold disposed in the center of the second mold, whereby the frame-shaped mold can be downsized, and the frame-shaped mold can be formed depending on the shape of the molded product. This is suitable when the exhaust opening area required for the mold cannot be obtained.

According to a fourth aspect of the present invention, in the invention according to the second or third aspect, the opening / closing mechanism is slidably fitted in a part of the exhaust hole, and the exhaust hole is moved depending on the sliding position. It is a pin that opens and closes. This claim 4
According to the invention, the exhaust hole can be opened and closed with a simple configuration in which the pin is simply slid. In particular, since the exhaust hole and the pin are parallel to the operation direction of the compression mold, it is possible to interlock with the operation of the compression mold, and it is possible to open and close the exhaust hole without independently driving the pin. .

According to a fifth aspect of the present invention, in the first aspect of the present invention, a part of the exhaust path is a groove formed on a surface of the frame-shaped die facing the first die. Is characterized by. According to the invention of claim 5, the exhaust passage can be provided at a position apart from the ascending / descending portion of the compression mold, a larger exhaust passage can be provided, and the exhaust efficiency can be improved.

According to a sixth aspect of the present invention, in the first aspect of the present invention, the exhaust path is formed in the frame-shaped mold, and one end thereof is an exhaust hole opened in the cavity, and the opening / closing mechanism is The exhaust hole opened in the cavity is opened and closed by the vertical movement of the compression mold in the opening. According to the invention of claim 6, since the compression mold itself which moves up and down acts as an opening / closing mechanism for the exhaust hole without providing a dedicated opening / closing mechanism such as a valve or a pin, the configuration of the entire apparatus can be simplified. Can be achieved.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention (hereinafter referred to as embodiments) will be specifically described below with reference to the drawings. The same members as those of the conventional type shown in FIGS. 10 and 11 are designated by the same reference numerals, and the description thereof will be omitted.

(1) First Embodiment (1-1) Structure In the present embodiment, as shown in FIGS. 1 and 2, it is surrounded by a molded article 1, a frame-shaped mold 53 and a compression mold 54. The opening inside the frame-shaped mold is a cavity M for resin molding
Is formed. In the cavity forming portion 10, which is the frame portion of the frame-shaped mold 53, a horizontal step portion 10a is formed in accordance with the rising position of the compression mold 54. An exhaust hole 12 serving as an exhaust path for forcibly exhausting gas such as gas inside the cavity or air to the outside is formed inside the frame-shaped mold 53, and one end of this exhaust hole 12 has the step portion 10a. It has an opening on the surface. As shown in the enlarged view of FIG. 3, the exhaust holes 12 are the first exhaust holes 12 communicating with the inside of the cavity.
a and a second exhaust hole 12b formed by branching from the first exhaust hole 12a.

As shown in FIG. 3, the first exhaust hole 12a is provided with a pin 11 that slides up and down in the inside to open and close the exhaust hole 12, and from the start of the filling of the resin into the cavity. The exhaust hole 12 is configured to be closed until the filling is completed. Further, the second exhaust hole 12b communicates with the outside of the mold, and a forced exhaust means such as a vacuum pump (not shown) is connected to the second exhaust hole 12b.

A pin 11 arranged in the exhaust hole 12a
Has a shape as shown in FIG. 3 as an example, and its base is connected to an operating mechanism (not shown). Pin 11
Although not shown, the inside of the first exhaust hole 12a is interlocked with the vertical movement of the first and second molds 51, 55 or by a predetermined operation mechanism connected to the base of the pin 11 as described above. Is configured to slide up and down.

Although the number of the exhaust holes 12 is one in FIGS. 1 and 2, it goes without saying that a plurality of exhaust holes 12 may be installed.
Further, the installation position of the exhaust hole 12 may be anywhere in the cavity forming portion 10 of the frame-shaped mold 53, but as shown in FIG.
If the structure is such that air is exhausted from below the frame-shaped mold 53, the pin 1
It becomes easy to arrange the opening / closing mechanism such as 1.

On the other hand, on the surface of the frame-shaped mold 53, an airtight member 3 is provided to ensure airtightness between the peripheral edge of the wiring board of the molded product 1 to be processed, and the molded product. The inside of the cavity M can be made airtight by clamping the peripheral portion of the first wiring board by the first and second molds 51 and 55.

(1-2) Operation / Effect The following is a method of sealing a wiring board having a semiconductor chip mounted thereon with a resin using the mold of this embodiment having the above structure.

That is, as shown in FIG. 1, a powder or granular sealing resin is contained in a cavity M formed by a frame-shaped mold 53 and a compression mold 54, and an airtight member is provided on the peripheral portion. The periphery of the molded product 1 is arranged on the frame-shaped mold 53 in which 3 is arranged, and the semiconductor chip mounted on the surface (lower surface in the figure) of the molded product is accommodated in the cavity M. In this state, the first mold 51 and the second mold 52
By sandwiching the molded product 1 by, the cavity M formed by the molded product 1 and the second mold 55 is sealed. At this time, it is assumed that the compression mold 54 is located at a position where the resin does not contact the molding target.

In this state, when the forced exhaust means such as a vacuum pump is operated to discharge the air in the cavity M from the exhaust hole 12b, the inside of the cavity is decompressed and the air surrounded by the powder or granular resin is also removed. Is discharged. After the inside of the cavity M is exhausted to a predetermined pressure, the pin 1
1 is raised as shown in FIG. 2 and is moved to a position where its shaft portion closes the exhaust hole 12b connected to the forced exhaust means.

After that, the compression mold 54 constituting the second mold 55 is raised to the first mold 51 side to pressurize the sealing resin in the cavity M heated and melted by a heater (not shown). , The semiconductor chip arranged on the surface of the molded product is sealed.

It is preferable that the air in the cavity M is discharged before the resin melts. The reason is that not only the air existing between the particles of the powdery or granular resin can be removed, but also the air can be prevented from being trapped in the melted resin. Further, the forced exhaust may be continued even while the air inside the cavity M is being exhausted by raising the compression mold 54 after the resin is melted. However, if the air is evacuated to a certain extent, there is no air that escapes to the outside when the compression mold 54 rises, so the exhaust hole 12 can be closed.

As described above, in this embodiment, since the exhaust hole 12 is provided in the cavity, the airtight area can be made smaller than that in the case where the exhaust hole is provided outside the resin flow path. The size of the die and the entire sealing device including the die can be reduced. Further, since the airtight volume is also reduced, it is possible to shorten the gas or air discharge time. Further, as the airtight volume is reduced, the capacity of the discharging means such as a vacuum pump can be reduced, so that the device configuration can be reduced.

Further, by providing a movable pin in the exhaust hole, the exhaust hole can be surely closed at the beginning of the resin filling in the vicinity of the exhaust hole. Therefore, the exhaust hole should have a necessary and sufficient cross-sectional area. The intermediate mold clamping is unnecessary.

(2) Second Embodiment This embodiment is a modification of the first embodiment described above and is shown in FIG.
As shown in FIG. 5, the opening / closing mechanism capable of forcibly discharging air and gas in the cavity through the groove 21 formed on the surface of the frame-shaped mold 20 and closing a part or the whole of the groove 21. The forced discharge path is opened and closed by 22. In this case, as shown in an enlarged manner in FIGS. 5 and 6, the groove 21 is communicated with an exhaust hole 23 formed vertically in the frame-shaped mold 20, and the pin 24 and the like are provided in the exhaust hole 23. An opening / closing mechanism is provided.

In the present embodiment having the above-mentioned structure, since the opening / closing mechanism of the exhaust hole 23 can be arranged at a position apart from the sliding portion of the compression mold 54, a larger discharge passage is provided. Therefore, the exhaust efficiency can be improved. For example, when it is difficult to provide an exhaust hole or an opening / closing mechanism in that part due to dimensional restrictions of the molded product or when the size of the exhaust hole cannot be increased, the exhaust hole and the opening / closing mechanism are connected to the sliding portion of the compression mold 54. Since it can be arranged at a position away from, a larger discharge flow path can be provided, and exhaust efficiency can be improved.

(3) Third Embodiment This embodiment is a modification of the first embodiment described above and is shown in FIG.
As shown in FIG. 5, the air and gas in the cavity are forcibly discharged using the exhaust hole 31 formed in the sliding portion of the frame-shaped mold 30. The position of the exhaust hole 31 is such that when the compression mold 54 is in the lowered position as shown in FIG. 7, the exhaust hole 31 and the cavity communicate with each other, and as shown in FIG. The exhaust hole 31 is set to be closed by the side surface of the compression mold 54 when the stop resin 58 is melted and the resin filling in the vicinity of the exhaust hole 31 starts.

According to the present embodiment having such a structure, the exhaust hole 31 is moved by moving the compression mold 54 up and down.
Since it is opened and closed, there is no need to provide a special opening and closing mechanism for opening and closing the exhaust hole 31, and the structure can be greatly simplified.

In the present embodiment, the exhaust hole 31
Is configured to open and close so as to be “open” before molding and “closed” during molding or after molding by the elevating operation of the compression mold 54. In the first and second embodiments, The exhaust hole 31 can also be opened and closed by an opening / closing mechanism that is provided exclusively as shown. In that case, since the opening / closing timing can be adjusted, molding can be performed under optimum conditions.

(4) Fourth Embodiment This embodiment is a modification of the first embodiment described above and is shown in FIG.
As shown in FIG. 7, the compression die 42 is provided with the exhaust hole 41 provided with the opening / closing mechanism by the pin 11 described in the first embodiment. Also in this case, as in the first embodiment, it is possible to forcibly exhaust the air inside the cavity prior to molding the resin. In particular, in the present embodiment, the exhaust passage and its opening / closing mechanism are not provided in the frame-shaped mold part, but are provided in the central compression mold, so that only the exhaust opening necessary for the frame-shaped mold is provided depending on the shape of the molded product. This is effective when the area cannot be obtained.

(5) Other Embodiments The present invention is not limited to the above-described embodiments, but also includes the following modifications. That is, in each of the above-described embodiments, the elastic body is used as the airtight member 3 provided in the molding target 1. However, even if the elastic body is not used as the airtight member, the airtight effect can be obtained only by clamping with the mold. In some cases In this case, the elastic body of the airtight member can be reduced, and the die can be simplified.

Further, in each of the above-described embodiments, the compression mold of the second mold, which is the lower one of the first and second molds, is lifted to move the molded product 1 to be molded. Although the substrate is clamped and molding is performed, conversely, the same effect can be obtained by lowering the first mold disposed on the upper side.

[0038]

As described above, according to the present invention, by forcibly exhausting the air or gas inside the cavity, the molding operation can be speeded up and the quality of the product can be improved, and only the cavity portion can be hermetically sealed. Since it is sufficient to secure the property, the amount of exhaust gas is small, the gas can be quickly exhausted, and the forced exhaust means such as a vacuum pump can be downsized and downsized.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing the configuration of a first embodiment of a semiconductor device manufacturing die according to the present invention, showing a state during exhaust from a cavity.

FIG. 2 is a cross-sectional view showing the configuration of a first embodiment of a semiconductor device manufacturing die according to the present invention, showing a state in which exhaust from the cavity is stopped.

FIG. 3 is an enlarged sectional view of an exhaust hole portion shown in FIG.

FIG. 4 is a cross-sectional view showing the configuration of a second embodiment of a die for manufacturing a semiconductor device according to the present invention.

5 is an enlarged perspective view of the groove portion shown in FIG.

FIG. 6 is an enlarged cross-sectional view of the groove portion shown in FIG.

FIG. 7 is a cross-sectional view showing the configuration of a third embodiment of a semiconductor device manufacturing die according to the present invention, showing a state during exhaust from the cavity.

FIG. 8 is a cross-sectional view showing a configuration of a third embodiment of a semiconductor device manufacturing die according to the present invention, showing a state in which exhaust from the cavity is stopped.

FIG. 9 is a cross-sectional view showing the structure of a semiconductor device manufacturing die according to a fourth embodiment of the present invention, showing a state during exhaust from the inside of the cavity.

FIG. 10 is a cross-sectional view showing a configuration of a conventional die for manufacturing a semiconductor device, showing a state before resin molding.

FIG. 11 is a cross-sectional view showing the structure of a conventional die for manufacturing a semiconductor device, showing a completed state of resin molding.

[Explanation of symbols]

1 ... Molded product 3 ... Airtight member 10 ... Cavity forming part 10a ... Step 11 ... pin 12 ... Exhaust hole 12a ... first exhaust hole 12b ... second exhaust hole 20 ... Frame-shaped mold 21 ... Groove 22 ... Opening / closing mechanism 23 ... Exhaust hole 24 ... Ball valve 30 ... Frame-shaped mold 31 ... Exhaust hole 41 ... Exhaust hole 42 ... Compression mold 51 ... First mold 52 ... Aperture 53 ... Frame-shaped mold 54 ... Compression mold 55 ... second mold 56 ... Lifting mechanism 57 ... Article to be molded 58 ... Sealing resin

Continued front page    F-term (reference) 4F202 AD03 AG03 AH37 CA09 CB01                       CB12 CB17 CK52 CL02 CP01                       CP06 CQ01                 5F061 AA01 BA01 CA22 DA01 DA06                       DA08

Claims (6)

[Claims] 1. A first mold, a frame-shaped mold which is arranged so as to face the first mold and has an opening in a central portion thereof, and which is fitted in the opening to move up and down in the opening. A second mold comprising a possible compression mold, the cavity of the mold being formed by the space surrounded by these molds, between the first mold and the second mold. In the mold for manufacturing a semiconductor device, in which the molded product is placed, and the compression mold is moved up and down to seal the molded product with the resin housed in the cavity of the frame-shaped mold, the gas in the cavity is forced. A die for manufacturing a semiconductor device, wherein the second die is provided with an exhaust path for discharging the material to the outside of the die, and an opening / closing mechanism for opening and closing the exhaust path. 2. The mold for manufacturing a semiconductor device according to claim 1, wherein the exhaust path is formed in the frame-shaped mold, and one end thereof is an exhaust hole opened in the cavity. 3. The mold for manufacturing a semiconductor device according to claim 1, wherein the exhaust passage is formed in the compression mold, and one end thereof is an exhaust hole opened in the cavity. 4. The opening / closing mechanism is a pin which slidably fits into a part of the exhaust hole and opens and closes the exhaust hole depending on the sliding position. A mold for manufacturing a semiconductor device according to 1. 5. The semiconductor device manufacturing apparatus according to claim 1, wherein a part of the exhaust path is a groove formed on a surface of the frame-shaped mold that faces the first mold. Mold. 6. The exhaust path is formed in the frame-shaped mold, and one end of the exhaust path is an exhaust hole opened in the cavity, and the opening / closing mechanism moves up and down the compression mold in the opening. The mold for manufacturing a semiconductor device according to claim 1, wherein an exhaust hole opened in the cavity is opened and closed.