JP2011009589A - Resin sealing die, and resin sealing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress occurrence of a resin mold flash caused by intrusion of a liquid resin between an end face of a substrate with a chip mounted thereon and an inner surface of a molding die by using a simple mechanism.SOLUTION: An upper die 2 provided with a cavity 16, and a lower die 1 facing the upper die 2 are provided. In a predetermined region 9 with a substrate 20 arranged therein on a die surface of the lower die 1, a guide pin 11 having a slope 12 is arranged on the side opposite to an inner surface 10 of the lower die 1 against which the right end face of the substrate 20 is pressed, and an O-ring 13 formed of an elastic member having appropriate hardness and appropriate elasticity is fitted in the root of the guide pin 11. The substrate 20 is arranged in the predetermined region 9 after the left end face lowers along the slope 12 of the guide pin 11. The left end face of the substrate 20 is pressed by the compressed O-ring 13 in this state, whereby the right end face of the substrate 20 is pressed against the inner surface 10 of the lower die 1.

Description

  The present invention relates to a resin sealing mold and a resin sealing method used when a chip made of one or a plurality of semiconductor chips mounted on a substrate is resin-sealed by transfer molding.

  Transfer molding is widely used when one or more chips are mounted on one main surface of a substrate such as a lead frame or a printed circuit board and the one or more chips are resin-sealed. . For the transfer molding, an upper mold and a lower mold that are opposed to each other are used, the upper mold has a cavity and a resin flow channel communicating with the upper mold, and the lower mold has a region where a substrate is disposed. Is provided. In addition, the lower mold is provided with a pot for storing a resin tablet, which is a raw material of the flowable resin injected into the cavity via the resin flow path, and a plunger disposed so as to be movable up and down in the pot. It has been.

  According to the configuration described above, the substrate is arranged in the lower mold region and the plunger presses the resin tablet in a state where the upper mold and the lower mold are clamped, so that the resin tablet is melted to generate a fluid resin. The Then, when the plunger presses the fluid resin, the fluid resin is injected into the cavity via the resin flow path. As a result, the fluid resin flows across the gap formed between the inner side wall of the region (hereinafter referred to as “inner side wall”) and the end face of the substrate (for example, Patent Documents). 1 (see FIG. 1 (2)).

Japanese Patent Laying-Open No. 2005-260026 (3rd page, 6th page, FIGS. 1-2)

  However, according to the conventional configuration, when the chip is resin-sealed using a low-viscosity resin material that has been widely adopted in recent years, the following problems have occurred. That is a problem that a low viscosity (in other words, high fluidity) fluid resin enters a gap generated between the inner wall and the end face of the substrate, and a resin beam is generated in the gap. This resin flash causes the following problems. The first problem is that it is difficult to take out a sealed substrate that is resin-sealed. The second problem is that the resin substrate dropped from the gap is injected into the cavity to make the sealed substrate defective. These problems have become more prominent when the LED chip is resin-sealed using a low-viscosity translucent resin material.

  Here, there has been proposed a mold in which a pin-shaped movable member provided on the upper mold has a function of pressing the substrate against the inner wall (see, for example, FIG. 2 of Patent Document 1). According to this, it is possible to prevent a gap from being generated between the inner wall and the end face of the substrate. However, this movable member causes another problem that the configuration of the mold is complicated. In addition, this movable member may cause wrinkles in a release film that is used in close contact with mold surfaces in the cavity and the resin flow path in order to facilitate release of the sealed substrate. Therefore, the movable member causes another problem that it is difficult to use the release film.

  An object of the present invention is to provide a resin-sealed mold and a resin-sealed mold that prevent a gap from occurring between the inner wall of the lower mold and the end face of the substrate with a simple configuration and facilitate the use of a release film. Is to provide a method.

  Hereinafter, the reference numerals in parentheses in the descriptions of “means for solving the problems” and “effects of the invention” are described for the purpose of facilitating the comparison between the terms in the description and the components shown in the drawings. It is. Further, these symbols and the like do not mean that “the meaning of the terms in the description is limited to the components shown in the drawings”.

  In order to solve the above-described problems, the resin-sealed mold according to the present invention includes an upper mold (2) provided with a cavity (16) in which a chip (21) mounted on a substrate (20) is to be accommodated. The lower mold (1) facing the upper mold (2), the predetermined region (9) where the substrate (20) is disposed on the mold surface of the lower mold (1), and the first of the substrate (20) The upper die (2) and the lower die (1) are provided with an inner surface (10) of the lower die (1) against which the end face is pressed, and a passage (15) communicating with the cavity (16) in the upper die (2). Resin sealing used when resin-sealing the chip (21) by hardening the fluid resin (22) filled in the cavity (16) through the passage (15) with the mold clamped Guide member (11) which is a mold (3) and has a guide surface (12) provided on the mold surface of the lower mold (1) And the elastic member (13) provided at the base of the guide member (11), and the passage (15) is in the lower die (1) with the upper die (2) and the lower die (1) being clamped. The elastic member is compressed in a state where the substrate (20) is disposed in the predetermined region (9) after the substrate (20) descends along the guide surface (12) across the inner surface (10) of the substrate. The first end surface is pressed toward the inner surface (10) of the lower mold (1) by pressing the second end surface facing the first end surface of the substrate (20) by (13). It is characterized by.

  The resin-sealed mold according to the present invention is the above-mentioned resin-sealed mold (3), in which the upper mold (2) and the lower mold (1) are clamped by the upper mold (2) with the substrate ( 20) is pressed so that the first end surface is pressed toward the inner surface (10) of the lower mold (1).

  The resin-sealed mold according to the present invention is characterized in that, in the above-mentioned resin-sealed mold (3), the elastic member (13) is an annular member (13) made of rubber.

  The resin-sealed mold according to the present invention is characterized in that, in the above-mentioned resin-sealed mold (3), the elastic member (13) is a columnar member or a massive member made of rubber.

  The resin-sealed mold according to the present invention is characterized in that in the above-mentioned resin-sealed mold (3), a release film (24) is stretched along at least the inner surface of the cavity (16). .

  The resin sealing method according to the present invention includes an upper mold (2) provided with a cavity (16) in which a chip (21) mounted on a substrate (20) is to be accommodated, and an upper mold (2). The opposed lower mold (1), the predetermined area (9) where the substrate (20) is disposed on the mold surface of the lower mold (1), and the lower mold on which the first end surface of the substrate (20) is pressed Using the resin-sealed mold (3) comprising the inner surface (10) of (1) and the passage (15) communicating with the cavity (16) in the upper mold (2), the upper mold (2) and the lower mold (2) A resin sealing method in which the chip (21) is resin-sealed by curing the fluid resin (22) filled in the cavity (16) through the passage (15) with the mold (1) being clamped. Then, the step of arranging the substrate (20) in the predetermined region (9) and the upper mold (2) and the lower mold (1) are clamped. Flowing into the cavity (16) through the passage (15), pressing the first end face of the substrate (20) toward the inner surface (10) provided on the lower mold (1), and A step of filling the flowable resin (22), a step of curing the flowable resin (22), a step of opening the upper mold (2) and the lower mold (1), and a flowable resin (22 ) Is filled in the cavity (16) with the flowable resin (22) through the passage (15) arranged so as to cross over the inner surface (10) of the lower mold (1). In the step of pressing the end face of 1, the elastic member (13) provided at the base of the guide member (11) presses the second end face of the substrate (20) facing the first end face, thereby lowering the lower mold Pressing the first end face toward the inner surface (10) of (1) And features.

  The resin sealing method according to the present invention is the above-described resin sealing method, wherein the upper die (2) presses the substrate (20) when the upper die (2) and the lower die (1) are clamped. Thus, the first end face is pressed against the inner surface (10) of the lower mold (1).

  The resin sealing method according to the present invention is characterized in that, in the above-described resin sealing method, the elastic member (13) is an annular member (13) made of rubber.

  The resin sealing method according to the present invention is characterized in that, in the above-described resin sealing method, the elastic member (13) is a columnar member or a massive member made of rubber.

  Moreover, the resin sealing method according to the present invention is characterized in that in the above-described resin sealing method, a step of stretching the release film (24) along at least the inner surface of the cavity (16) is provided.

  According to the present invention, first, the guide surface (12) of the guide member (11) guides the substrate (20) toward the inner surface (10) of the lower mold (1). Second, the second end face of the substrate (20) is pressed by the elastic member (13) provided at the base of the guide member (11). By these, the 1st end surface of a board | substrate (20) can be pressed on the inner surface (10) of a lower mold | type (1). Accordingly, the generation of a gap between the first end surface of the substrate (20) and the inner surface (10) of the lower mold (1) can be suppressed without providing a special movable member.

FIGS. 1A and 1B are cross-sectional views showing a state in which the substrate is carried in between the lower die and the upper die and a state in which the substrate is in contact with the inclined surface of the guide pin in the first embodiment. It is. 2 (1) and 2 (2) show the state in which the substrate was pressed against the inner wall by the O-ring of the guide pin in Example 1, and the fluid resin was injected into the cavity after the mold was clamped. FIG. 3 (1) and 3 (2) show a state in which the substrate is carried in between the lower die and the upper die and a state in which the substrate is pushed by the O-ring of the guide pin in Example 2, respectively. It is sectional drawing shown. 4 (1) and 4 (2) show a state in which the release film is stretched between the lower mold and the upper mold and the substrate is loaded in Example 3, and the mold is released on the mold surface of the upper mold. It is sectional drawing which each shows the state which the film contact | adhered and the board | substrate was pressed by the inner wall. 5 (1) and 5 (2) show the state in which the tip of the guide pin has a hole in the release film and the state in which the fluid resin is injected into the cavity after the mold is clamped in Example 3 in FIGS. FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  Example 1 of the resin sealing mold and the resin sealing method according to the present invention will be described with reference to FIGS. 1 and 2. As shown in FIG. 1, a lower mold 1 and an upper mold 2 facing each other are provided. The lower mold 1 and the upper mold 2 together constitute a molding mold for resin sealing, that is, a resin sealing mold 3. The lower mold 1 is provided with a pot block 4 constituting a part of the lower mold 1 so as to protrude from the mold surface of the lower mold 1 by a predetermined height. The pot block 4 is provided with a pot 5 that is a cylindrical space. A cylindrical plunger 6 is provided in the pot 5 so as to be movable up and down. The plunger 6 is connected to a drive mechanism (not shown) via a rod 7 and moves up and down as needed inside the pot 5.

  A cylindrical resin tablet 8 is disposed on the plunger 6 inside the pot 5. The resin tablet 8 is made of, for example, a thermosetting resin. Specifically, the resin tablet 8 is made of an epoxy resin, a silicone resin, or the like. The resin tablet 8 is heated by heaters (not shown) provided in the lower mold 1 and the upper mold 2 respectively. Thereby, the resin tablet 8 is melted to become a fluid resin (described later).

  The mold surface of the lower mold 1 is provided with a predetermined region 9 in which a substrate (described later) is arranged. At one end of the predetermined region 9 (right end in the figure), the inner surface 10 of the lower mold 1 protrudes by a predetermined height. In each embodiment, the inner side surface 10 is constituted by the side surface of the pot block 4. A guide pin 11 is provided at the other end (the left end in the figure) of the predetermined region 9. The guide pin 11 has a truncated cone shape or a truncated cone shape. Therefore, the side surface of the guide pin 11 is constituted by the slope 12. Further, an elastic member having an appropriate hardness and an appropriate elasticity, that is, an O-ring 13 is fitted at the base of the guide pin 11. As the elastic member constituting the O-ring 13, for example, heat resistant rubber such as silicone rubber and fluorine rubber is preferable.

  The upper die 2 is provided with a recess, that is, a cull 14 at a position facing the pot 5 of the lower die 1. Then, a resin flow path 15 in which the fluid resin flows and a cavity 16 into which the fluid resin is injected are provided in communication with the cull 14 in sequence. Further, the upper die 2 is provided with a guide pin storage portion 17 that is a space in which the guide pin 11 is to be stored when the lower die 1 and the upper die 2 are clamped.

  A transport mechanism 18 for transporting the substrate to a predetermined region 9 of the lower mold 1 is inserted between the lower mold 1 and the upper mold 2. The transport mechanism 18 is retracted to a position outside the lower mold 1 and the upper mold 2 except when the substrate is carried in / out between the lower mold 1 and the upper mold 2. The transport mechanism 18 is provided with a suction path 19 connected to a suction mechanism (not shown) such as a decompression tank. Then, the transport mechanism 18 transports the substrate 20 to the predetermined region 9 of the lower mold 1 while adsorbing the substrate 20 through the suction path 19.

  On the upper surface of the substrate 20, a chip 21 made of a semiconductor chip such as a CPU, a memory, a transistor, an LED, or a chip-like electronic component other than a semiconductor is mounted. The terminals of the substrate 20 and the terminals of the chip 21 are electrically connected using a conductive material (not shown) such as wires and bumps. Here, FIG. 1 shows an example in which one chip 21 is mounted on one substrate 20. Not limited to this, a plurality of chips 21 may be mounted on a single substrate 20.

  Hereinafter, Example 1 of the resin sealing method according to the present invention will be described with reference to FIGS. 1 and 2. First, as shown in FIG. 1A, in a state where the lower mold 1 and the upper mold 2 are opened, the substrate 20 is interposed between the lower mold 1 and the upper mold 2 using the transport mechanism 18. Carry in. Here, the substrate 20 is carried in such that the left end surface of the substrate 20 is positioned directly above the inclined surface 12 of the guide pin 11.

  Next, as shown in FIG. 1B, the transport mechanism 18 is lowered. Thereby, the left end surface of the substrate 20 is brought into contact with the inclined surface 12 of the guide pin 11. In this state, the suction of the substrate 20 by the transport mechanism 18 is released.

  Next, as shown in FIG. 2 (1), the substrate 20 whose suction has been released is lowered along the inclined surface 12 of the guide pin 11. Thus, the inclined surface 12 of the guide pin 11 functions as a surface for guiding the substrate 20 toward the side surface of the pot block 4, that is, the inner surface 10 of the lower mold 1. The left end surface of the substrate 20 is pressed by an O-ring 13 provided at the base of the guide pin 11 and having appropriate hardness and elasticity. Accordingly, the right end surface of the substrate 20 can be pressed against the side surface of the pot block 4, that is, the inner side surface 10 of the lower mold 1 (see the right-pointing arrow shown in FIG. 2A). As a result, the generation of a gap between the right end surface of the substrate 20 and the inner surface 10 of the lower mold 1 can be suppressed. Here, the inclined surface 12 only needs to be substantially inclined to such an extent that the substrate 20 from which the adsorption has been released can slide down along the inclined surface 12.

  Next, as shown in FIG. 2B, the lower mold 1 and the upper mold 2 are clamped. Further, the resin tablet 8 is heated by heaters (not shown) provided in the lower mold 1 and the upper mold 2 respectively. In addition, by raising the plunger 6, the resin tablet 8 is melted to produce the fluid resin 22. Subsequently, the fluid resin 22 is pressed by the plunger 6. Thus, the fluid resin 22 is injected and filled into the cavity 16 via the resin flow path 15 (see FIG. 2 (1)). Here, since no gap is generated between the right end surface of the substrate 20 and the inner side surface 10 of the lower mold 1, it is possible to prevent the occurrence of resin flash in this gap.

  Next, the fluid resin 22 is heated from the state shown in FIG. As a result, the fluid resin 22 made of a thermosetting resin is cured to produce a cured resin (not shown). Through the steps so far, the resin sealing of the chip 21 mounted on the substrate 20 is completed. Thereafter, the lower mold 1 and the upper mold 2 are opened, and the sealed substrate having the substrate 20, the chip 21, and the cured resin is moved between the lower mold 1 and the upper mold 2 using the transport mechanism 18. Remove from between.

  As described above, according to the present embodiment, first, the inclined surface 12 of the guide pin 11 functions as a surface for guiding the substrate 20 toward the side surface of the pot block 4, that is, the inner surface 10 of the lower mold 1. To do. Second, the left end surface of the substrate 20 is pressed by an O-ring 13 provided at the base of the guide pin 11 and having appropriate hardness and appropriate elasticity. As a result, the right end surface of the substrate 20 can be pressed against the inner surface 10 of the lower mold 1. Therefore, the generation of a gap between the right end surface of the substrate 20 and the inner surface 10 of the lower mold 1 can be suppressed without providing a special movable member.

  A second embodiment of the present invention will be described below with reference to FIG. This embodiment is characterized in that a columnar guide pin 23 is used. In this embodiment, as shown in FIG. 3 (1), an O-ring 13 having appropriate hardness and elasticity is fitted at the base of a cylindrical or prismatic guide pin 23.

  In this embodiment, as shown in FIG. 3 (2), the suction of the substrate 20 is released when the left end surface of the substrate 20 contacts the O-ring 13 after descending along the peripheral surface of the guide pin 23. To do. As a result, the right end surface of the substrate 20 contacts the mold surface of the lower mold 1, and the left end surface of the substrate 20 that is lowered by its own weight is pressed by the O-ring 13. Therefore, since the substrate 20 is pressed by the O-ring 13, the right end surface of the substrate 20 can be pressed against the side surface of the pot block 4, that is, the inner surface 10 of the lower mold 1. As a result, the generation of a gap between the right end surface of the substrate 20 and the inner surface 10 of the lower mold 1 can be suppressed.

  As described above, according to the present embodiment, the same effects as those of the first embodiment can be obtained. In addition, according to the present embodiment, since the guide pin 23 having a simple shape without a slope is used, the resin sealing mold 3 can be configured at a lower cost.

  In this embodiment, the left end surface of the substrate 20 that is lowered by its own weight is pressed by the O-ring 13. Not only this but from the state shown in FIG. 3 (2), the upper mold 2 presses the substrate 20 when the lower mold 1 and the upper mold 2 are clamped, whereby the inner surface 10 of the lower mold 1 is obtained. The right end surface of the substrate 20 may be pressed toward the surface.

  Embodiment 3 of the present invention will be described below with reference to FIGS. In the present embodiment, the conical or pyramidal guide pins 25 are provided corresponding to the case where the release film 24 is brought into close contact with the mold surface of the upper mold 2 (at least along the inner surface of the cavity 16) and resin-sealed. It is characterized by using. The release film 24 is in close contact with the mold surface of the upper mold 2 by a known means such as adsorption (not shown). In the present embodiment, as shown in FIG. 5 (1), an O-ring 13 having appropriate hardness and elasticity is fitted at the base of a conical or pyramidal guide pin 23. And the top part 26 of the guide pin 23 is formed sharply.

  According to the present embodiment, as shown in FIGS. 5 (1) to (2), the release film 24 stretched in close contact with the mold surface using the sharp top portion 26 of the guide pin 23. Can be pierced. As a result, even when the release film 24 is brought into close contact with the mold surface of the upper mold 2 and resin-sealed, the same effects as those of the first embodiment can be obtained. In other words, according to the present embodiment, even when the release film 24 is used, a gap between the right end surface of the substrate 20 and the inner surface 10 of the lower mold 1 is not provided without a special movable member. Occurrence can be suppressed.

  In addition, in each Example so far, the inner wall 10 provided in the lower mold | type 1 demonstrated the example comprised by the side surface of the pot block 4. FIG. However, the present invention is not limited to this, and the present invention can also be applied to the case where the inner wall 10 is constituted by the inner wall of a recess provided in the lower mold 1 and accommodating the substrate 20.

  Further, an O-ring 13 fitted into the base of the guide pin 11 was used as an elastic member having appropriate hardness and appropriate elasticity and pressing the left end face of the substrate 20. However, the elastic member may be a columnar or massive elastic member fitted in a space provided at the base of the guide pin 11 as an elastic member. In other words, this elastic member is a member fixed to the base of the guide pin 11, and when the left end surface of the substrate 20 contacts the elastic member, the substrate 20 can be pressed toward the right side. Any member can be used. Thereby, even when the elastic member formed of the O-ring 13 or the like is damaged or worn, the lower mold 1 and the upper mold 2 can be opened and the elastic member can be easily replaced.

  Further, when it is desired to adjust the strength of pressing the substrate 20, in other words, the strength of pressing the right end surface of the substrate 20 against the inner surface 10 of the lower mold 1, the hardness of the elastic member including the O-ring 13 and the like What is necessary is just to change elasticity suitably. In addition, by using an elastic member having appropriate hardness and appropriate elasticity, an effect of preventing the substrate 20 from being damaged can be obtained.

  In addition, the present invention is not limited to the above-described embodiments, and may be arbitrarily combined, changed, or selected as necessary without departing from the spirit of the present invention. It can be done.

DESCRIPTION OF SYMBOLS 1 Lower mold | type 2 Upper mold | type 3 Resin sealing type | mold 4 Pot block 5 Pot 6 Plunger 7 Rod 8 Resin tablet 9 Predetermined area | region 10 Inner side surface 11, 23, 25 Guide pin (guide member)
12 Slope (guide surface)
13 O-ring (elastic member, annular member)
14 Cal 15 Resin channel (passage)
16 Cavity 17 Guide Pin Storage 18 Transport Mechanism 19 Suction Path 20 Substrate 21 Chip 22 Flowable Resin 24 Release Film 26 Top

Claims (10)

An upper mold provided with a cavity in which a chip mounted on the substrate is to be accommodated; a lower mold facing the upper mold; a predetermined region where the substrate is disposed on a mold surface of the lower mold; and the substrate An inner side surface of the lower mold against which the first end surface of the upper mold is pressed, and a passage communicating with the cavity in the upper mold, and the upper mold and the lower mold are clamped through the passage. A resin-sealing mold used when resin-sealing the chip by curing the fluid resin filled in the cavity,
A guide member provided on the lower mold surface and having a guide surface;
An elastic member provided at the base of the guide member,
With the upper mold and the lower mold clamped, the passage crosses over the inner surface of the lower mold,
In a state where the substrate is disposed in the predetermined region after the substrate is lowered along the guide surface, the second end surface of the substrate facing the first end surface is pressed by the compressed elastic member. By doing so, the first end surface is pressed toward the inner surface of the lower mold. The resin-sealed mold according to claim 1,
When the upper mold and the lower mold are clamped, the first end surface is pressed toward the inner surface of the lower mold by the substrate being pressed by the upper mold. Resin sealed type. The resin-sealed mold according to claim 1 or 2,
The resin-sealed mold wherein the elastic member is an annular member made of rubber. The resin-sealed mold according to claim 1 or 2,
The resin-sealed mold, wherein the elastic member is a columnar member or a massive member made of rubber. The resin-sealed mold according to any one of claims 1 to 4,
A resin-sealed mold, wherein a release film is stretched along at least the inner surface of the cavity. An upper mold provided with a cavity in which a chip mounted on the substrate is to be accommodated; a lower mold facing the upper mold; a predetermined region where the substrate is disposed on a mold surface of the lower mold; and the substrate The upper mold and the lower mold are molded using a resin-sealed mold including an inner side surface of the lower mold against which the first end surface of the lower mold is pressed and a passage communicating with the cavity in the upper mold. A resin sealing method for resin-sealing the chip by curing the fluid resin filled in the cavity through the passage in a tightened state,
Disposing the substrate in the predetermined region;
Clamping the upper mold and the lower mold;
Pressing the first end surface of the substrate toward the inner surface provided in the lower mold;
Filling the cavity with the flowable resin through the passage;
Curing the flowable resin;
A step of opening the upper mold and the lower mold; and
In the step of filling the fluid resin, the fluid resin is filled into the cavity through the passage arranged so as to cross over the inner surface of the lower mold,
In the step of pressing the first end surface, the elastic member provided at the base of the guide member presses the second end surface of the substrate that faces the first end surface, so that the inner surface of the lower mold is pressed. The resin sealing method, wherein the first end face is pressed against the resin. A resin sealing method according to claim 6,
Resin sealing characterized in that when the upper mold and the lower mold are clamped, the upper mold presses the substrate to press the first end surface toward the inner surface of the lower mold. Method. A resin sealing method according to claim 6 or 7,
The resin sealing method, wherein the elastic member is an annular member made of rubber. A resin sealing method according to claim 6 or 7,
The resin sealing method, wherein the elastic member is a columnar member or a massive member made of rubber. It is the resin sealing method described in any one of Claims 6-9,
A resin sealing method comprising a step of stretching a release film along at least the inner surface of the cavity.

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