JP4031881B2 - Resin sealing device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
In the present invention, the sealing resin is formed by intensively heating the molding recess while burying the substrate having the semiconductor chip mounted on one surface in the molding recess where the semiconductor chip is filled with the sealing resin. The present invention relates to a resin sealing device that hardens and performs resin sealing.
[0002]
[Prior art]
2. Description of the Related Art Conventional resin molding apparatuses such as transfer molding apparatuses are equipped with mold dies vertically on a resin sealing portion having a movable platen that can be opened and closed and a fixed platen. A lead frame or substrate on which a semiconductor chip is mounted as a product to be molded is loaded into a mold mold opened by a loading device such as a loader, clamped at a high pressure by the mold mold, and loaded into a pot Resin sealing is performed by pressure-feeding a sealing resin such as a tablet to a cavity by a plunger. The resin-sealed molded product is released by pushing up the ejector pin from the mold mold that has been opened, taken out by an unloading device such as an unloader, and gate-breaked to collect only the molded product. The molded product was cut into individual pieces by removing resin burrs and the like in a T / F (Trimmig and Forming) apparatus in a subsequent process.
[0003]
Further, as proposed by the present applicant in JP-A-8-142105, JP-A-8-142106 and the like, a release film is stretched on the parting surface including the resin molding part of the mold, thereby forming a molded product. It has also been realized that the mold can be easily released from the mold.
[0004]
[Problems to be solved by the invention]
In the above conventional resin sealing device, the resin is sealed by feeding the sealing resin into the cavity with the plunger, so wire flow and voids are likely to occur regardless of the size of the package and the molding quality of the package is reduced. It was a factor to make. In addition, according to the resin sealing device using a release film, the ejector pin normally provided in the mold can be omitted, so that the configuration of the mold can be simplified and the molded product can be easily released. Although it has become possible to reduce the resin burrs generated in the mold, there is a similar problem in the molding quality of the package.
In addition, in the case where the surface of the mold is coated with a fluororesin, it is possible to improve the flowability of the resin and temporarily improve the molding quality, but the durability tends to decrease. When the resin coating is peeled off, the flowability of the resin and the release property of the molded product are lowered.
[0005]
An object of the present invention is to provide a resin sealing device that solves the above-described problems of the prior art, improves the molding quality of the molded product, and facilitates the release of the molded product from the mold.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the present invention comprises the following arrangement.
That is, a substrate holding means for transporting to a lower mold while holding a substrate on which a semiconductor chip is mounted, an upper mold for pressing a heater block against the substrate and clamping between the lower mold and heating, and the semiconductor chip A releasable mold formed with a molding recess filled with a sealing resin for resin sealing , and a lower mold provided with a base plate having a heater that supports the peelable mold and heats the molding recess mainly An upper mold provided with a heater block is mounted on a lower mold by burying the semiconductor chip in a molding recess filled with a sealing resin while the substrate is held by the substrate holding means. and wherein the sealing resin is cured the resin sealing is performed by downward movement to intensively heat the molding recess by the heater block and the heater by clamping between the lower mold the substrate To do.
Also, a plurality of semiconductor chips are mounted on the substrate, the resin sealing means may be provided with a plurality of mold dies, and the substrate holding means is preferably equipped with a heater.
Further, the peelable mold is preferably made of a fluororesin or an insert block surface-treated with a fluororesin. In this case, the fluororesin may be PTFE (polytetrafluoroethylene) or ETFE (polytetrafluoroethylene polymer). ) Is preferably used.
Moreover, you may provide the drive source which can push a peelable metal mold | die to a board | substrate from the opposite side to a shaping | molding recessed part.
[0007]
As another means, heated and clamped between an elongated substrate on which the semiconductor chip is mounted on one surface and a substrate conveying means for Feeding into the lower mold, the lower mold a substrate heater An upper mold having a block, a center block for forming a bottom surface of a molding recess for filling a sealing resin for sealing the semiconductor chip and a surrounding block for forming a side surface, and the center block and the surrounding block The resin sealing means having the lower mold provided with a base plate having a heater for supporting the molding and heating the molding recesses preferentially, and the release film is fixedly fed to the parting surface including the molding recesses formed in the lower mold and provided with a release film carrying means for stretched, feeding the substrates Ri by said substrate conveying means, wherein the molding recess sealing resin is filled through the release film Is mounted on the lower mold by buried conductors chip, intensively heating the shaped recess by the heater block and the heater by clamping between the lower mold the substrate and the upper mold is moved downward with a heater block and wherein said sealing resin is cured the resin sealing is performed by.
In addition, a plurality of semiconductor chips may be mounted on the substrate, and the resin sealing means may include a plurality of mold dies.
Also, of the mold, the insert block which forms a shaped recess has preferably that the center block having a high thermal conductivity than the surrounding blocks are equipped.
The center block may be a copper block including the bottom surface of the molding recess, and the surrounding block may be a steel block including the side surface of the molding recess.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
In this embodiment, a resin sealing device for resin-sealing a single-sided mold type semiconductor device will be described.
FIGS. 1A and 1B are an explanatory view of the resin sealing device according to the first embodiment as viewed from the front and a top view of a mold, and FIG. 2 is a description of a multi-cavity type resin sealing device. FIGS. 3 and 3 are explanatory views seen from the front showing another example of the resin sealing device of FIG. 1A, and FIGS. 4A and 4B are views of the resin sealing device according to the second embodiment from the front. It is the explanatory drawing which looked, and the top view of a mold die.
[0009]
First, a schematic configuration of the resin sealing device according to the first embodiment will be described with reference to FIGS. Reference numeral 1 denotes a handler which is an example of a substrate holding means, and a hand-shaped strip 3 such as a lead frame or a wiring board on which a semiconductor chip 2 is mounted on one surface (the lower surface side in FIG. While being held, it is reciprocated in the left-right direction in FIG. An auxiliary heater 5 for heat-curing the sealing resin 14 is built in the handler 1.
[0010]
Reference numeral 6 denotes a resin sealing portion as a resin sealing means. The substrate 3 is transported while being held by the handler 1 and mounted on the mold 7. The mold 7 includes an insert block 10 in which a molding recess 9 which is a peelable mold is formed on a base plate 8 mounted on a fixed platen provided on the lower mold side, and a chase block for positioning the insert block 10 11 is supported. The insert block 10 may be a material having good resin peelability, for example, a block body made of fluororesin, or an insert block body surface-treated with fluororesin. As this fluororesin, PTFE (polytetrafluoroethylene) or ETFE (polytetrafluoroethylene polymer) is preferably used. Fluorocarbon resin has excellent strength at high temperatures (the maximum continuous use temperature for PTFE is about 260 ° C) and has a low coefficient of friction. Therefore, the resin has good flowability, weather resistance, and chemical resistance. Therefore, since the durability is very good, it is suitable as the insert block 10. Further, the base plate 8 incorporates a heater 12 for preferentially heating the molding recess 9. In addition, a heater block 13 for preferentially heating the molding recess 9 is provided on a movable platen (not shown) provided on the upper mold side so as to be movable up and down.
[0011]
A liquid resin 14 as a sealing resin is supplied to the molding recess 9 of the insert block 10 by potting. As the liquid resin 14, a liquid resin may be supplied in advance, or a liquid resin that has been liquefied by supplying granular or powdered resin and preheating may be used. When the substrate 3 held by the handler 1 is placed on the insert block 10, the semiconductor block 2 is buried in the molding recess 9 filled with the liquid resin 14, and the heater block 13 equipped on the upper mold moves downward to move the substrate 3. The substrate 3 is lightly clamped between the lower mold by pressing against the upper surface side. At this time, the liquid resin 14 is cured resin sealing is performed by intensively heated by the molding recess 9 the heater 1 2及 beauty heater block 13.
[0012]
According to the above configuration, the semiconductor chip 2 is buried in the liquid resin 14 filled in the molding recess 9 and the molding recess 9 is heated preferentially, thereby curing the liquid resin 14 and sealing with resin. Therefore, there is no possibility that voids are generated in the wire flow of the semiconductor chip 2 or the molded product, and the molding quality of the semiconductor device can be improved. In particular, since resin sealing is performed using the insert block 10 made of a fluororesin, it is very easy to release the molded product from the mold 7, and it is possible to improve the releasability without using an ejector pin. Moreover, the durability of the mold 7 can be improved. In addition, since a pot insert and a plunger are basically unnecessary for the mold 7, it is possible to reduce the size of the mold 7.
Further, since the resin sealing can be performed simply by lightly clamping the mold 3 while holding the substrate 3 by the handler 1, the resin sealing can be performed while feeding the substrate 3 at a constant length. / F can also be used as a press device, and by connecting the resin sealing device and the T / F device, the molded product after resin sealing can be transferred to the T / F process continuously, and the resin burrs can be used. The device configuration can be made smaller and streamlined compared to the conventional case where the resin sealing process is performed using a dedicated machine and the T / F process is performed using a dedicated machine. Manufacturing costs can be significantly reduced.
[0013]
In the above embodiment, the case where the semiconductor chips 2 are sealed with the resin one by one has been described. However, since a plurality of semiconductor chips 2 are mounted on the substrate 3, a multi-chip that can be sealed with a resin at a time. It is also possible to use a cavity type resin sealing device. In FIG. 2, a plurality of fluororesin insert blocks 10 are supported on a base plate 8 on the lower mold side of the mold 7. Each of the molding recesses 9 of the insert block 10 is filled with the liquid resin 14, and the semiconductor chip 2 mounted on one surface of the substrate 3 is buried in the molding recess 9 and heated intensively once. Alternatively, each liquid resin 14 may be cured and sealed with resin. In this case, productivity of the semiconductor device is improved, and mass production can be performed at low cost.
[0014]
As shown in FIG. 3, a drive source 19 that pushes the block 10 against the substrate 3 from the opposite side to the molding recess 9 of the fluororesin insert block 10 is provided at the bottom of the base plate 8. Also good. In this case, the insert block 10 is slightly deformed due to the plastic but elastically deforms. By utilizing this, it becomes possible to finely adjust the amount of resin supplied to the molding recess 9, and further, by slightly pressurizing the resin sealing portion, voids are reduced and adhesion of the sealing resin to the substrate 3 is increased. be able to. As this drive source 19, various things, such as a pneumatic cylinder, a hydraulic cylinder, an electric motor, are applicable, for example.
[0015]
Next, a resin sealing device according to a second embodiment will be described with reference to FIGS. In addition, the same number is attached | subjected to the same member as a 1st Example, and description shall be used.
In FIG. 4A, a semiconductor chip 2 is mounted on one surface (lower surface side) of a long substrate 3 such as a tape substrate using a lead frame or a polyimide film, and the substrate 3 is not shown. It is fed in a fixed direction in the direction of the arrow by a substrate transfer means such as an arm. The substrate 3 is positioned in the mold 7 by pilot pins 16 provided upright on the chase block 15.
[0016]
The mold 7 supports an insert block 17 in which a molding recess 9 is formed in a base plate 8 provided on a fixed platen provided on the lower mold side, and a chase block 15 that guides both sides thereof. A center block 17 a including the bottom surface of the molding recess 9 is fixed to a part of the insert block 17. As the center block 17a, one having higher thermal conductivity than the surrounding block 17b including the side surface of the molding recess 9 is preferably used. In this embodiment, the center block 17a is made of copper and the surrounding block 17b is made of steel. Each block is used.
[0017]
A release film 18 is stretched on the parting surface of the mold 7 including the molding recess 9 of the insert block 17. The release film 18 is fixedly fed in the direction of the arrow in FIG. 4A between the reels by a release film conveying means (not shown) along the parting surface of the lower insert block 17 substantially parallel to the substrate 3. . As the release film 18, a known FEP film, PET film, ETFE film, PTFE film, polypropylene film, polyvinylidene chloride film, fluorine-impregnated glass cloth film, or the like is used. The release film 18 is sucked through a suction hole 15a (see FIG. 4B) formed so as to surround the insert block 17 on the surface of the chase block 15 during resin molding or a clearance provided around the bottom surface of the molding recess 9. To be adsorbed.
[0018]
Similarly to the first embodiment, the base plate 8 has a built-in heater 12 for preferentially heating the molding recess 9. On the movable platen (not shown) provided on the upper mold side, a heater block 13 for clamping the substrate 3 and heating the molding recess 9 with priority is provided so as to be movable up and down.
A liquid resin 14 as a sealing resin is supplied to the molding recess 9 of the insert block 17 by potting. As the liquid resin 14, a liquid resin may be supplied in advance, or a liquid resin that has been liquefied by supplying granular or powdered resin and preheating may be used. When the substrate 3 that has been fixedly fed by the substrate conveying means is placed on the insert block 17 on which the release film 18 that has been fixedly fed by the release film conveying means is previously sucked, the semiconductor chip 2 is filled with the liquid resin 14. It is buried in the molding recess 9. Then, the heater block 13 provided in the upper mold moves downward to pressurize the other surface (upper surface side) of the substrate 3 to clamp the substrate 3. At this time, the resin molding is performed by curing the liquid resin 14 by intensively heating the molding recess 9 with the heater 12 and the heater block 13.
[0019]
According to the above configuration, the semiconductor chip 2 is buried in the liquid resin 14 filled in the molding recess 9 and the molding recess 9 is heated preferentially, thereby curing the liquid resin 14 and sealing with resin. Therefore, there is no possibility that voids are generated in the wire flow of the semiconductor chip 2 or in the molded product, and the center block 17a has higher thermal conductivity than the surrounding block 17b, so that the curing speed of the sealing resin filled in the molding recess 9 is increased. Can be uniformly cured without causing unevenness, and the molding quality of the molded product can be improved. Moreover, since the molded product can be easily released from the mold by the release film 18, the ejector pins can be omitted.
[0020]
In the above embodiment, the case where the semiconductor chips 2 are sealed with the resin one by one has been described. However, since a plurality of semiconductor chips 2 are mounted on the substrate 3, a resin that can be sealed with the resin at once. It is also possible to use a sealing device. That is, as in FIG. 2, a plurality of fluorine insert blocks 17 are supported on the base plate 8 on the lower mold side of the mold 7, and the liquid resin 14 is placed in each molding recess 9 of the insert block 17. Each liquid resin 14 is cured at once and sealed with resin by filling and filling each of the semiconductor chips 2 mounted on one surface of the substrate 3 in the molding recesses 9 and heating them intensively. May be.
[0021]
The present invention is not limited to the first and second embodiments described above, and the material of the fluororesin insert block 10 and the material of the center block 17a having high thermal conductivity can be appropriately changed. Needless to say, the mold 7 may be provided with a plunger for performing direct molding, and more modifications can be made without departing from the spirit of the invention.
[0022]
【The invention's effect】
In the present invention, as described above, the semiconductor chip is embedded in the sealing resin filled in the molding recess and the molding recess is intensively heated, so that the sealing resin is cured and resin-sealed. There is no possibility that voids or the like occur in the wire flow of the semiconductor chip or the molded product, and the molding quality of the semiconductor device can be improved. In particular, since resin sealing is performed using a peelable mold made of fluororesin, it is very easy to release the molded product from the mold mold, and the durability of the mold mold can be improved. . In addition, since a mold insert basically does not require a pot insert or a plunger, it is possible to reduce the size of the mold.
In addition, since resin sealing can be performed simply by clamping with a mold while holding the substrate by the substrate transport means, the resin sealing can be performed while feeding the substrate at a constant distance. For resin sealing and T / F Can also be used as a pressing device, and the molded product after resin sealing can be continuously transferred to the T / F process to remove resin burrs and to separate the semiconductor device into pieces. Thus, compared with the case where the resin sealing process is performed with the dedicated machine and the T / F process is performed with the dedicated machine, the apparatus configuration can be reduced in size and rationalized, and the manufacturing cost can be remarkably reduced.
In addition, when a part of the insert block in which the molding recess of the mold is formed is equipped with a center block having higher thermal conductivity than the surrounding block, the curing rate of the sealing resin filled in the molding recess Can be uniformly cured without causing unevenness, and the molding quality of the molded product can be improved.
The molding resin of each insert block is filled with the sealing resin, and the semiconductor chip mounted on one surface of the substrate is buried in each molding concave and heated to cure the sealing resin at once. In the case of resin sealing, the productivity of the semiconductor device is improved, and mass production can be performed at low cost.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram viewed from the front of a resin sealing device according to a first embodiment and a top view of a mold.
FIG. 2 is an explanatory view of a multi-cavity type resin sealing device.
FIG. 3 is an explanatory view seen from the front showing another example of the resin sealing device of FIG. 1;
FIG. 4 is an explanatory view of a resin sealing device according to a second embodiment viewed from the front and a top view of a mold.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Handler 2 Semiconductor chip 3 Board | substrate 4 Hand 5 Auxiliary heater 6 Resin sealing part 7 Mold die 8 Base plate 9 Molding recessed part 10, 17 Insert block 11, 15 Chase block 12 Heater 13 Heater block 14 Liquid resin 15a Suction hole 16 Pilot pin 17a Center block 17b Surrounding block 18 Release film 19 Drive source

Claims (10)

A substrate holding means for transporting to a lower mold while holding a substrate on which a semiconductor chip is mounted;
An upper die that presses the heater block against the substrate and clamps it between the lower die and heats it;
A base plate having a peelable mold formed with a molding recess filled with a sealing resin for resin-sealing the semiconductor chip , and a heater that supports the peelable mold and heats the molding recess mainly. A resin sealing means having the lower mold ,
While the substrate is held by the substrate holding means, the semiconductor chip is embedded in a molding recess filled with a sealing resin and mounted on the lower mold, and the upper mold including the heater block moves down to lower the substrate. A resin sealing device characterized in that resin sealing is performed by curing the sealing resin by preferentially heating a molding recess with a heater block and a heater by clamping with a mold.   2. The resin sealing device according to claim 1, wherein a plurality of semiconductor chips are mounted on the substrate, and the resin sealing means includes a plurality of the mold dies.   The resin sealing device according to claim 1, wherein the substrate holding means is equipped with a heater.   4. The resin sealing device according to claim 1, wherein the peelable mold is an insert block made of fluororesin or surface-treated with fluororesin.   The resin sealing device according to claim 4, wherein PTFE (polytetrafluoroethylene) or ETFE (polytetrafluoroethylene polymer) is used as the fluororesin.   6. The resin sealing device according to claim 1, further comprising a drive source capable of pushing the peelable mold against the substrate from the side opposite to the molding recess. A substrate transport means for feeding a long substrate having a semiconductor chip mounted on one surface thereof to a lower mold ;
An upper mold provided with a heater block that clamps and heats the substrate with the lower mold;
A center block for forming a bottom surface of a molding recess filled with a sealing resin for sealing the semiconductor chip and a peripheral block for forming a side surface, and supporting the center block and the surrounding block, emphasizing the molding recess. A resin sealing means having the lower mold provided with a base plate having a heater for automatically heating ;
It is equipped with a release film conveying means for feeding and stretching a release film on a parting surface including a molding recess formed in the lower mold ,
Feeding by substrate Ri by said substrate conveying means, on the sealing resin through the release film is mounted on the lower mold by burying the semiconductor chip into the molding recess filled with a heater block types by curing the sealing resin by intensively heating the shaped recess by the heater block and the heater by clamping between the lower mold the substrate moves downward to the resin sealing is performed A resin sealing device.   The resin sealing apparatus according to claim 7, wherein a plurality of semiconductor chips are mounted on the substrate, and the resin sealing means includes a plurality of mold dies. 9. The resin sealing device according to claim 7, wherein a center block having higher thermal conductivity than a surrounding block is provided in an insert block forming a molding recess in the mold. 10. The center block is a copper block including a bottom of the molding recess, and a surrounding block is a steel block including a side surface of the molding recess . The resin sealing apparatus of any one of them .

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