JP3897565B2 - Resin sealing device and resin sealing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin encapsulating apparatus which is capable of making resin fed to cavity recesses, which are arranged in a matrix form for compression molding, uniform in amount so as not to waste encapsulating resin and improving the molding quality of a molded body. SOLUTION: The parting face of a molding die 1, where cavity recesses 4 are arranged in a matrix form is covered with a release film 5, a sheet resin 6 is fed to the cavity recesses 4 covered with the release film 5, a circuit board 8, where semiconductor chips 7 are arranged in the same matrix form as the cavity recesses 4, is placed on the sheet resin 6, and the circuit board 8 is clamped by the molding die 1 for compression molding.

Description

[0001]
BACKGROUND OF THE INVENTION
In the present invention, a parting surface of a mold mold in which cavity concave portions are formed in a matrix shape is covered with a release film, and a sheet-like resin is loaded in each cavity concave portion covered with the release film. The present invention relates to a resin sealing device and a resin sealing method in which a molded product mounted on a substrate is carried in, a mold is clamped, and compression molding is performed.
[0002]
[Prior art]
Various types of semiconductor packages have been developed and put into practical use. Among surface-mount type semiconductor packages, for example, a cavity-down type package called BGA (Ball / Grid / Array) is used. This is a package in which a resin-sealed portion (package portion) obtained by resin-sealing a semiconductor chip and external connection terminals (solder balls, metal bumps, etc.) are formed on the same surface.
Specifically, a cavity recess is formed on the terminal forming surface side of the substrate to accommodate the semiconductor chip, and the substrate side conductor pattern formed around the semiconductor chip and the cavity recess is electrically connected by wire bonding connection or the like. It is a connected package.
When manufacturing this cavity down type BGA package, there are generally the following methods for resin-sealing a semiconductor chip. First, a liquid resin is caused to flow down into the cavity recess by a potting method, and is sealed and thermally cured. Another method is a transfer molding method, in which the resin supplied to the pot is pressure-fed by a plunger to a cavity recess through a runner gate and sealed.
[0003]
[Problems to be solved by the invention]
However, in the case of the potting method, since it flows down into the cavity recess and seals, the manufacturing process takes time and the resin pressure cannot be applied, so air easily enters the sealing resin and voids are generated. Molding quality may be reduced.
Also, in the case of the transfer molding method, a resin path (runner gate cannot be formed on the terminal forming surface of the substrate, so it is necessary to provide a three-dimensional gate (providing a vertical gate) toward the cavity recess, In addition to the upper and lower molds, it was necessary to use an intermediate mold in which a resin path was formed, which complicates the resin sealing device and puts the intermediate mold in and out of the mold. Maintenance such as cleaning and cleaning becomes necessary, resulting in high manufacturing costs.
Also, in general, the transfer molding method fills and seals the resin path such as the mold cull, mold gate and runner from the pot to the cavity recess, and therefore unnecessary resin (scrap) is generated. Yield decreases. In particular, when the cavity recesses are arranged in a matrix, the sealing resin is wasted and it is difficult to maintain uniform molding quality.
[0004]
The object of the present invention is to solve the above-mentioned problems of the prior art, to make the amount of resin supplied to the cavity concave portion compression-molded in a matrix shape, and to eliminate the waste of sealing resin, and to improve the molding quality of the molded product. It is providing the resin sealing apparatus and the resin sealing method.
[0005]
[Means for Solving the Problems]
In order to solve the above problems, the present invention has the following configuration. That is, in the resin sealing device, the upper mold and the outer periphery are surrounded by the end block and partitioned by the partition block so that the cavity recess is formed in a matrix shape, and the cavity recess adjacent to the cavity recess formed in the matrix shape. A mold communication runner for connecting the molds is formed, a mold block having a lower mold in which a cavity block that forms the bottom of each cavity recess is supported on a support plate via an elastic body, and the support plate is moved up and down. A vertical movement mechanism that moves only the cavity block up and down, and a release film that is sucked and held so as to cover the mold parting surface of the mold, and the sheet-shaped resin that has been preliminarily weighed and cut into the release film It is supplied to each cavity recess of the covered lower mold in a lump and is arranged in the same manner as the cavity recess. Body tip is clamped to the mold is carried to the lower die downward the molded article which is a substrate implemented each semiconductor chip is compression-molded by operating the vertical movement mechanism is further moved upward only cavity block It is characterized by that.
[0006]
Further, in the resin sealing method, the cavity recess is formed in a matrix shape with the upper die and the outer periphery surrounded by the end block and partitioned by the partition block, and the cavity recess adjacent to the cavity recess formed in the matrix shape Mold runners that communicate with each other are formed, and the cavity block that forms the bottom of each cavity recess releases the parting surface of the mold mold that has a lower mold supported by elastic bodies on the support plate. A step of covering with a film, a step of collectively supplying sheet-shaped resin that has been preliminarily cut into a cavity recess covered with the release film, and a molded product on which a semiconductor chip having the same arrangement as the cavity recess is mounted on a substrate. A step of carrying each semiconductor chip downward into the lower mold, clamping the mold and compression molding; After clamping the de mold, characterized in that it comprises a step of residual air is removed only cavity block further moved upward by through mold communicating runner.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of a resin sealing device and a resin sealing method according to the present invention will be described in detail with reference to the accompanying drawings.
In this embodiment, as an example of a product to be molded, a resin sealing device and a resin sealing for manufacturing a semiconductor package in which a semiconductor chip is arranged in a matrix on a circuit board and there is no space for arranging a gate and a runner by a compression molding method A method will be described.
FIG. 1 is a schematic explanatory view showing a schematic configuration of a resin sealing device, FIGS. 2 (a) and 2 (b) are explanatory views showing a sheet-shaped resin carry-in operation, and FIG. 3 is an explanatory view showing a configuration of a mold. 4 to 8 are schematic explanatory views showing a resin sealing process.
[0008]
First, a schematic configuration of the resin sealing device will be described with reference to FIGS.
In FIG. 1, reference numeral 1 denotes a mold die, which has an upper die 2 and a lower die 3. The lower mold 3 has cavity recesses 4 formed in a matrix, and the upper mold 2 and the parting surfaces of the lower mold 3 are covered with a release film 5 (in FIG. 1, the release film 5 on the upper mold 2 side is covered). Omitted).
A sheet-like resin 6 is supplied to each cavity recess 4 of the lower mold 3, and a circuit board 8 on which semiconductor chips 7 are mounted in a matrix having the same arrangement as the cavity recess 4 faces the semiconductor chip 7 toward the cavity recess 4. And is clamped by the lower mold 3 and the upper mold 2 and compression molded. In the present embodiment, the case where the chip electrode portion of the semiconductor chip 7 is connected to the chip pad of the circuit board 8 by wire bonding in four directions and there is no space for arranging the gate / runner is illustrated. The semiconductor chip 7 may be flip-chip connected to the circuit board 8 by solder bumps or the like and arranged in a matrix.
[0009]
The sheet-like resin 6 is stacked and accommodated in the tray 9 in a state where the sheet-like resin 6 is optimally cut in accordance with, for example, a package. The sheet-like resin 6 is collectively sucked and held from the uppermost one by the resin loader 10 and is carried into each cavity recess 4 of the lower mold 3 as shown by an arrow A in FIG. The circuit board 8 is carried into the lower mold 3 with the semiconductor chip 7 facing downward. In this embodiment, the circuit board 8 is carried into the lower mold 3 by a substrate transport mechanism (not shown). However, when the release film 5 on the upper mold 2 side is omitted, as shown by an arrow B in FIG. Alternatively, the circuit board 8 transported by the substrate transport mechanism may be sucked and held on the parting surface of the upper mold 2.
[0010]
2 (a) and 2 (b), the lower mold 3 is formed with a mold communication runner 11 that connects adjacent cavity recesses 4, and a dummy cavity is formed at a position where the mold communication runners 11 intersect each other. 12 is formed. The mold communication runner 11 is used as an air vent for air remaining in the cavity recess 4 when clamping the mold 1. Since the sheet-like resin 6 can be quantitatively supplied to each cavity recess 4, the dummy cavity 12 can be omitted if an air vent is secured.
[0011]
In FIG. 3, the lower mold 3 has a cavity plate in which cavity recesses 4 are formed in a matrix. The cavity plate is provided with a partition block 13 and an end block 14 that form the cavity recess 4. A cavity block 15 whose upper end constitutes the bottom of each cavity recess 4 is provided so as to be fitted into the cavity plate.
The lower end side of each cavity block 15 is supported by a support plate 16 via a spring 17 which is an example of an elastic body. The support plate 16 is connected to a screw shaft 19 that is rotationally driven by an electric motor 18, and the cavity block 15 is provided so as to move up and down by starting the electric motor 18 in a predetermined direction.
[0012]
After clamping the mold 1, the electric motor 18 is activated to move only the cavity block 15 further upward, and the sealing resin 6 filled in the cavity recess 4 is pressed to drive out residual air and compression molding is performed. The It should be noted that the weighing of the sheet-like resin 6 may be set slightly larger than that of the package, and the overflowing resin may flow into the dummy cavity 12.
[0013]
As shown in FIG. 4, the release film 5 sucked and held on the parting surface of the upper mold 2 covers the back side of the circuit board 8 when the mold 1 is clamped. Further, the release film 5 sucked and held on the parting surface including the cavity recess 4 of the lower mold 3 covers the substrate surface other than the package portion. The release film 5 is sucked and adsorbed by vacuum from air suction paths (the upper die is 2a, the lower die is not shown) communicating with the parting surfaces of the upper die 2 and the lower die 3, respectively.
[0014]
The release film 5 has heat resistance capable of withstanding the heating temperature of the mold 1 and is easily peeled off from the mold surface. The release film 5 is a film material having flexibility and extensibility, such as PTFE, ETFE. PET, FEP, fluorine-impregnated glass cloth, polypropylene, polyvinyl chloride, etc. are preferably used. The release film 5 is sucked and held by sucking air from a suction hole (not shown) formed on the parting surface of the upper mold 2. For example, as shown in FIG. 1, the release film 5 is continuously supplied to the mold 1 and wound up by a long film wound between the supply reel 5a and the take-up reel 5b. However, it may be cut in a strip shape in advance.
[0015]
The resin sealing device is equipped with a known mold opening / closing mechanism that opens and closes the mold 1 by, for example, moving the lower mold 3 up and down with an electric motor using a toggle mechanism.
[0016]
Next, the resin sealing process will be described with reference to FIGS.
In FIG. 5, the release films 5 are held by suction on the parting surfaces of the upper mold 2 and the lower mold 3 of the mold mold 1 that has been opened. The release film 5 of the lower mold 3 is sucked by the suction path 3 a formed around the cavity block 15 and is adsorbed along with the cavity recess 4.
[0017]
Next, the sheet-shaped resin 6 that has been optimally weighed and cut in advance according to the package is adsorbed from the tray 9 by the resin loader 10 shown in FIGS. Carry in. Next, the circuit board 8 on which the semiconductor chip 7 is mounted and connected by wire bonding is set on the lower mold 3 of the mold 1 with the chip surface facing downward. At this time, as shown in FIG. 6, the semiconductor chip 7 is immersed in the sheet-like resin 6 supplied to the cavity recess 4 and heated and melted.
[0018]
Next, as shown in FIG. 7, a mold opening / closing mechanism (not shown) is operated to move the lower mold 3 upward to clamp the mold 1.
Next, as shown in FIG. 8, the electric motor 18 is operated to move the cavity block 15 upward by a predetermined amount. At this time, the residual air in the cavity recess 4 passes through the mold communication runner 11 in the peripheral portion to the dummy cavity 12. It is extruded and compression molding is performed. Since the sheet-like resin 6 is accurately measured, the sealing resin is not wasted without overflowing from the cavity recess 4.
[0019]
After compression molding, the mold 1 is opened and the circuit board 8 is separated from the release film 5 and taken out.
Thereafter, the semiconductor package formed in a matrix is carried into a dicing apparatus while being connected to the circuit board 8, and the semiconductor package is separated into individual pieces.
[0020]
According to the resin sealing device and the resin sealing method, the sheet-like resin 6 is supplied to the cavity recesses 4 covered with the release film 5, and the semiconductor chips 7 are mounted in the same matrix as the cavity recesses 4. Since the circuit board 8 is carried in and the mold 1 is clamped and compression-molded, the measurement accuracy of the sealing resin is higher than in the case of using a liquid resin, and a plurality of sheet-like resins 6 that have been cut by measurement are measured. Can be carried into the cavity recess 4 in a lump, so that even when molding a plurality of molded products at once, there is no waste of the sealing resin and it can be mass-produced quickly and inexpensively, and the molding quality of the molded product can be improved. Can do.
Further, in the mold 1, when a mold communication runner 11 that connects adjacent cavity recesses 4 of the lower mold 3 and a dummy cavity 12 is formed at a portion where the mold communication runners 11 intersect each other. Can accommodate residual air and rare but overflowing sealing resin, and remove the residual air by further moving the cavity block 15 that forms the bottom of the cavity recess 4 after the mold 1 is clamped The generation of voids can be prevented, and the resin is finally compressed after the viscosity of the resin is lowered. Therefore, even when the semiconductor chip 7 is connected by wire bonding, the wire is not crushed or cut.
[0021]
Various preferred embodiments of the present invention have been described above, but the resin sealing device and the resin sealing method are not limited to the above-described embodiments. For example, the release film 5 omits the upper mold 2 side. The circuit board 8 may be sucked. Further, the semiconductor chip is not limited to the case where it is wire-bonded to the circuit board 8, and may be flip-chip connected, and the molded product is a space for arranging a cavity down type BGA type semiconductor package and a gate / runner. Of course, other semiconductor packages such as QFN (Quad / Flat / Non-Leaded) type arranged in a matrix without a gap may be applied without departing from the spirit of the invention. .
[0022]
【The invention's effect】
According to the resin sealing device and the resin sealing method according to the present invention, the sheet-shaped resin is supplied to the cavity recesses covered with the release film, and the semiconductor chips are mounted in a matrix having the same arrangement as the cavity recesses. Since the product is carried in, and the mold is clamped and compression-molded, the sealing resin has a higher measurement accuracy than when using a liquid resin, and a plurality of sheet-shaped resins that have been measured are cut together. Since it can be carried into the cavity recess, even when a plurality of molded products are resin-sealed at one time, the sealing resin is not wasted and can be mass-produced quickly and inexpensively, and the molding quality of the molded product can be improved.
In addition, when a mold cavity is formed in a mold die that connects adjacent cavity recesses in the lower die, or a dummy cavity is formed at a location where the die die runners intersect, residual air or rare However, overflowing sealing resin can be accommodated, and after the mold mold is clamped, the cavity block constituting the bottom of the cavity recess can be further moved upward to remove residual air and prevent the generation of voids. Since the resin is finally compressed after the viscosity of the resin is lowered, even when the semiconductor chip is connected by wire bonding, the wire is not crushed or cut.
[Brief description of the drawings]
FIG. 1 is a schematic explanatory view showing a schematic configuration of a resin sealing device.
FIG. 2 is an explanatory view showing a sheet-like resin carry-in operation.
FIG. 3 is an explanatory view showing a configuration of a mold die.
FIG. 4 is a schematic explanatory view showing a resin sealing process.
FIG. 5 is a schematic explanatory view showing a resin sealing process.
FIG. 6 is a schematic explanatory view showing a resin sealing process.
FIG. 7 is a schematic explanatory view showing a resin sealing process.
FIG. 8 is a schematic explanatory view showing a resin sealing process.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Mold die 2 Upper die 3 Lower die 4 Cavity recessed part 5 Release film 6 Sheet-like resin 7 Semiconductor chip 8 Circuit board 9 Tray 10 Resin loader 11 Die communication runner 12 Dummy cavity 13 Partition block 14 End block 15 Cavity block 16 Support plate 17 Spring 18 Electric motor 19 Screw shaft

Claims (2)

Upper mold,
A cavity recess is formed in a matrix by being surrounded by an end block and partitioned by a partition block, and a mold communication runner for connecting adjacent cavity recesses of the cavity recess formed in the matrix is formed. A mold mold having a lower mold in which cavity blocks forming the bottom of the cavity recess are each supported on a support plate via an elastic body;
A vertical movement mechanism that moves the support plate up and down to move only the cavity block up and down;
A release film that is sucked and held so as to cover the mold parting surface of the mold mold,
Sheet-shaped resin that has been pre-metered and cut is supplied to the respective cavity recesses of the lower mold that are covered with the release film, and the molded product on which the semiconductor chip of the same arrangement as the cavity recesses is mounted on the substrate is replaced with each semiconductor chip. A resin sealing device, wherein the resin sealing device is carried into a lower mold downward and clamped to a mold, and is compressed by moving a cavity block further by operating a vertical movement mechanism . A mold communication runner that connects the cavity recesses adjacent to the cavity recesses formed in the matrix shape, the cavity recesses being formed in a matrix shape with the outer periphery surrounded by the end block and partitioned by the partition block. A step of covering a parting surface of a mold with a lower mold, each of which is formed and a cavity block forming a bottom of each cavity recess is supported on a support plate via an elastic body;
Supplying the sheet-shaped resin that has been preliminarily measured and cut into the cavity recesses covered with the release film;
A step in which a molded product on which a semiconductor chip having the same arrangement as the cavity recess is mounted on the substrate is carried into the lower mold with each semiconductor chip facing downward, and the mold is clamped and compression molded;
A resin sealing method comprising a step of further moving only a cavity block and removing residual air through a mold communication runner after clamping a mold.

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