JP4011781B2 - Resin coating method for semiconductor wafer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an improvement in a resin coating method for a semiconductor wafer in which, for example, a bump mounting surface of a semiconductor wafer on which solder bumps (projection electrodes) are mounted is coated with a resin.
[0002]
[Prior art]
Conventionally, for example, a bump mounting surface of a semiconductor chip in a chip size package ( CSP ) or the like is covered with a resin to protect and reinforce a soft and easily damaged bump. Is performed at the semiconductor wafer stage (wafer level).
For example, by using the resin coating mold shown in FIGS. 5 (1) and 5 (2), first, the bump mounting surface of the semiconductor wafer is resin-coated to form a resin-coated wafer, A number of resin-coated chips are formed by cutting and separating a resin-coated wafer.
[0003]
That is, the mold shown in FIGS. 5 (1) and 5 (2) is provided with an upper mold 81 and a lower mold 82 arranged opposite to each other, and the mold surface of the upper mold 81 is used for bump exposure. A resin-coated cavity 85 for supplying and setting the semiconductor wafer 84 on which the bumps 88 are mounted and a fitting hole including the cavity 85 are formed. 86 and a bottom surface member 87 including the bottom surface of the cavity 85 that slides up and down in the fitting hole 86 are provided.
Therefore, as shown in FIG. 5A, first, the film 83 is stretched on the mold surface of the upper mold 81, and the bump mounting surface of the semiconductor wafer 84 is placed on the upper surface side in the cavity 85. The resin material 89 is supplied and set in a state and a required amount of resin material 89 is supplied onto the bump mounting surface, the upper and lower molds 81 and 82 are clamped, and the resin material 89 in the cavity 85 is heated and melted.
Next, as shown in FIG. 5 (2), in the cavity, the bottom member 87 is moved upward with the semiconductor wafer 84 placed on the bottom member 87, whereby the bumps 88 are formed on the film 83. The tip part of is brought into contact.
At this time, since the bump mounting surface of at least the wafer 84 is particularly made is coated with a resin, the resin-coated surface of the resin-coated wafer 90 which is formed within the cavity 85 in (bump mounting surface), the film in the bump 88 The portion in contact with 83 (bump tip) is exposed on the resin surface.
[0004]
[Problems to be solved by the invention]
However, when the molten resin material enters and cures in the gap (sliding portion) between the fitting hole and the bottom member, a resin flash (cured product) is generated in the gap and slides on the bottom member. Defects are likely to occur.
Therefore, the resin burrs generated in the gaps must be frequently removed, and there is an adverse effect that the productivity of the resin-coated wafer is lowered.
In addition, due to the occurrence of the sliding failure, the bottom member cannot apply sufficient resin pressure to the resin in the cavity, so that the bump cannot be brought into contact with the film, and the bump is in the resin. There is an adverse effect that a high-quality and high-reliability resin-coated wafer (resin-coated chip) cannot be obtained, for example, because the bumps are completely buried and the bumps do not function as external connections.
[0005]
Then, this invention aims at providing the resin coating method of the semiconductor wafer which can improve the productivity of a resin coated wafer.
Another object of the present invention is to provide a resin coating method for a semiconductor wafer that can provide a resin-coated wafer with high quality and high reliability.
[0006]
[Means for Solving the Problems]
The resin coating method for a semiconductor wafer according to the present invention for solving the technical problem is a resin provided on one mold surface of a resin coating mold for coating a bump mounting surface of a semiconductor wafer on which a bump is mounted with a resin. A step of supplying a semiconductor wafer in a predetermined position on the bottom surface of the mold cavity for coating, and placing and supplying the semiconductor wafer in a state where the bump mounting surface is opposite to the bottom surface of the mold cavity; A film stretching process for stretching a bump exposure film on the other mold surface, and a semiconductor wafer adsorption / fixing process for adsorbing / fixing the wafer to the mold cavity bottom surface during the semiconductor wafer supply process; A film adsorbing / fixing step for adsorbing / fixing the film to the other mold surface of the mold during the film stretching process, and a resin material in the mold cavity A step of supplying the required amount supplied resin material, and the mold clamping step of the mold for clamping the mold, when the mold clamping step of the mold, a predetermined vacuum state by evacuating at least the mold cavity And an annular protrusion provided in one mold of the mold, an annular recess provided in the other mold of the mold, and a suction / discharge mechanism provided in the annular recess during the mold clamping process of the mold In the fixing member, the annular convex portion and the annular concave portion are fitted, and air or the like is forcibly sucked and discharged from the annular concave portion by the suction / discharge mechanism, and the film is drawn into the concave portion and extended. A step of heating and melting the resin material in the mold cavity, and a pressing member provided on the other mold surface of the mold in the mold cavity direction. Pressing process by pressing member In the pressing step by the pressing member, in the mold cavity, the film abutting step in which the film abuts on the tip of the bump in the mold cavity, and in the mold cavity through the film in the pressing step by the pressing member. A resin-covering molding process of the semiconductor wafer for covering the bump mounting surface of the semiconductor wafer with the resin by pressurizing the resin, and opening the mold to open the bump mounting surface from the mold cavity with the resin. And a resin-coated wafer releasing step for releasing the coated resin-coated semiconductor wafer.
[0007]
Moreover, the resin coating method of the semiconductor wafer according to the present invention for solving the technical problem described above is provided with a plurality of fixing members in the resin coating mold, and at the time of the mold clamping process of the mold, A step of forcibly sucking and discharging air or the like from the annular recesses of the plurality of fixing members is arbitrarily and appropriately performed by the suction and discharge mechanism.
[0008]
In addition, the semiconductor wafer resin coating method according to the present invention for solving the technical problem described above is applied to the locking member provided on the mold surface in the outer periphery of the mold cavity during the mold clamping process. And a step of locking the film.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
That is, by using a resin coating mold (upper and lower molds) of a semiconductor wafer, first, the semiconductor wafer is supplied to a predetermined position in the lower mold cavity with the bump mounting surface as an upper surface, and the bump While supplying the required amount of resin material on the mounting surface, and clamping the two molds, evacuating from the outside air blocking range including at least the cavity to at least a predetermined vacuum state in the cavity, The resin material is melted by heating, and then the upper mold surface extending film 7 is brought into contact with the tip of the bump, and the bump mounting surface of the semiconductor wafer is coated with resin in the cavity to form a resin-coated wafer. Form.
[0010]
【Example】
Hereinafter, the present invention will be described in detail with reference to the drawings.
[0011]
In other words, the mold shown in the drawing is composed of a fixed upper mold 1 and a movable lower mold 2 disposed opposite to the fixed upper mold 1.
The mold surface of the lower mold 2 is provided with a resin coating cavity 5 for supplying and setting the semiconductor wafer 4 on which the bump protruding electrodes 3 are mounted with the bump mounting surface on the upper surface (the mold surface side). In addition, a required amount of, for example, a powder or granular resin material 6 can be supplied onto the bump mounting surface of the wafer 4 placed and supplied at a predetermined position on the bottom surface of the cavity 5. Has been.
A bump exposing film 7 (release film) is stretched on the mold surface of the upper mold 1, and the upper mold 1 is pressed against the lower mold surface shape of the lower mold cavity 5. A pressing member 8 having a surface (upper mold surface) and a vertical movement mechanism 9 for moving the pressing member 8 up and down are provided.
Therefore, the pressing member 8 is moved downward by the vertical movement mechanism 9 so that the film 7 can be brought into contact with the tip of the bump 3 and the resin in the cavity 5 It can be pressurized with a predetermined resin pressure through the film 7.
In addition, a locking member 10 (annular protrusion) for locking and fixing the film 7 to the mold surface is provided on the outer periphery (lower mold surface) of the cavity 5, and at the time of mold clamping of both the molds 1. 2 is configured such that the film 7 can be sandwiched and fixed between the two mold surfaces and stretched on the lower mold cavity surface.
Although not shown, the mold is provided with heating means for heating to the resin molding temperature, and the resin material 6 supplied into the cavity 5 can be heated and melted. It is configured to be able to.
[0012]
Also, as shown in the figure, a semiconductor wafer suction fixing means (for example, a required number of suction holes) 31 for sucking and fixing the semiconductor wafer 4 to the bottom surface of the mold cavity 5 is provided on the bottom surface of the mold cavity 5. It is provided and configured.
Accordingly, when the semiconductor wafer 4 is placed and fed into the mold cavity 5, the semiconductor wafer 4 is placed on the bottom surface of the mold cavity 5 by evacuating the suction hole 31 on the bottom surface of the mold cavity 5. It can be sucked and fixed at a predetermined position.
[0013]
Further, as shown in the figure, the two molds 1 and 2 are located at predetermined positions on the upper and lower mold surfaces corresponding to the outer periphery of the locking member 10 provided on the outer periphery of the cavity 5 on the lower mold surface. The film fixing member is provided to clamp the film 7 and fix between the two mold surfaces when the mold is clamped, and the fixing member includes an annular protrusion 32 provided on the lower mold surface, An annular recess 33 (circumferential groove) corresponding to the lower mold annular protrusion 32 provided on the mold surface and a suction / discharge mechanism 35 provided in the recess 33 are configured.
Therefore, the film 7 can be adsorbed and fixed to the upper mold surface by forcibly sucking and discharging air or the like from the upper mold annular recess 33 by the suction / discharge mechanism 35.
Further, when the both molds 1 and 2 are clamped, the annular convex portion 32 and the annular concave portion 33 of the fixing member described above are fitted, and the suction and discharge mechanism 35 forcibly removes air or the like from the upper mold annular concave portion 33. By sucking and discharging the film 7 and drawing the film 7 into the recess 33 and extending it, the wrinkles of the film 7 can be extended and removed.
Moreover, the structure which provides the fixing member (a combination of the above-mentioned recessed part 33 and the convex part 32) of an above described film can be employ | adopted.
[0014]
Further, the above-described mold has a vacuuming mechanism (not shown) for evacuating from the outside air blocking range 34 including at least the molding part, which is configured by setting the molding part including at least the mold cavity 5 to the outside air blocking state. In addition to being provided, it is configured such that the molded part including at least the cavity 5 can be brought into a predetermined vacuum state by evacuating from the outside air blocking range 35 by the evacuation mechanism.
[0015]
That is, first, while stretched the film 7 on the mold surface of the upper mold 1, forcibly by suction and discharge the air or the like in the suction and discharge mechanism 35 from the annular recess 33 of the upper mold 1, the The film 7 can be efficiently adsorbed and fixed to the upper mold surface.
Next, the semiconductor wafer 4 is supplied and set at a predetermined position on the bottom surface in the lower mold cavity 5 with the mounting surface of the bump 3 facing up, and the resin material 6 is required on the bump mounting surface. Supply quantity.
At this time, the semiconductor wafer 4 can be efficiently suctioned and fixed to the bottom surface of the cavity 5 by the suction fixing means 31.
Next, the lower mold 2 is moved upward to perform intermediate mold clamping to hold the two mold surfaces at a required interval, and at least the molded portion including the cavity 5 is shut off from the outside air to set the outside air blocking range 34. By forming and evacuating from the outside air blocking range 34 with the evacuation mechanism, at least the inside of the cavity 5 (the outside air blocking range 34) is brought into a predetermined vacuum state.
Next, the lower mold 2 is moved upward to perform complete clamping of the mold that joins both mold surfaces, and the convex part and concave part of the fixing member are fitted together.
At this time, the film 7 is locked between the two mold surfaces by the locking member 10, and the film 7 is drawn into the recess 33 and the film 7 expands. 7 wrinkles can be extended and removed efficiently.
Next, the resin material 6 supplied into the cavity 5 is heated and melted.
Next, the pressing member 8 (the pressing surface thereof) is moved down (in the direction of the lower position of the lower mold surface in the cavity 5) by the vertical movement mechanism 9 to move the film 7 into the cavity 5. By pressing and extending, the film 7 is brought into contact with the tip of the bump 3 and the resin in the cavity 5 is pressed by the pressing member 8 through the film 7 with a predetermined resin pressure.
At this time, the film 7 can be configured such that at least the tip of the bump 3 is not in contact with the resin.
At this time, wrinkles of the film generated in the film 7 can be stretched and removed, and the resin can be sealed in the cavity 5 by sealing the cavity 5 with the film 7. .
After the time required for curing has elapsed, the molds 1 and 2 can be opened, and the resin-coated wafer 12 can be released with the film 7 attached between the molds.
That is, since the resin-coated wafer 12 can be formed in a state where the front ends of the bumps 3 mounted on the wafer 4 are exposed on the surface of the resin 11, there is no adverse effect as shown in the conventional example, and the resin coating is eliminated. Wafer productivity can be improved, and a high-quality and highly reliable resin-coated wafer can be obtained.
In addition, since at least the molding portion including the cavity 5 can be coated with a resin in a predetermined vacuum state, bubbles and voids generated in the resin 11 covering the bump 3 mounting surface of the semiconductor wafer 4 can be obtained. Can be efficiently prevented.
[0016]
Further, in the above-described embodiment, in the case of a configuration in which a plurality of the fixing members (the concave portion 33, the convex portion 32, and the suction / discharge mechanism 35 described above) are provided, from the inside of the concave portion 32 at the time of clamping the above-described molds, At approximately the same time, separately or sequentially from the outer concave portion 32, or arbitrarily and appropriately, forcibly sucking and discharging, the film 7 is drawn into the concave portion 32, and then stretched. It is possible to employ a configuration in which the wrinkle of 7 is extended.
[0017]
In addition, it is possible to employ a configuration in which the lower mold 2 is continuously moved upward during the intermediate mold clamping in the above-described embodiment.
[0018]
The resin-coated wafer 12 shown in FIGS. 4 (1) and 4 (2) is cut and separated for each chip 13 shown in FIG. 4 (2) to form the resin-coated chip 14 shown in FIG. 4 (3). In addition, the tip of the bump 3 exposed on the surface of the resin 11 of the resin-coated chip 14 can be electrically connected to, for example, a substrate or the like.
[0019]
In the above-described embodiment, the configuration in which a single cavity is provided in the mold is illustrated, but a configuration in which a plurality of cavities are provided in the mold may be employed.
[0020]
Moreover, although the structure which uses a powdery or granular resin material was illustrated in the above-mentioned Example, resin materials of various shapes, such as a resin tablet, can be used, for example.
Further, in the above-described embodiment, the configuration using the thermosetting resin material is exemplified, but, for example, a thermoplastic resin material or the like can be adopted.
[0021]
The present invention is not limited to the above-described embodiments, and can be arbitrarily changed and selected as necessary within a range not departing from the gist of the present invention.
[0022]
【The invention's effect】
According to the present invention, it is possible to provide an excellent effect that a semiconductor wafer resin coating method capable of improving the productivity of a resin coated wafer can be provided.
[0023]
In addition, according to the present invention, there is an excellent effect that it is possible to provide a resin coating method for a semiconductor wafer that can provide a resin-coated wafer with high quality and high reliability.
[Brief description of the drawings]
FIG. 1 (1) and FIG. 1 (2) are schematic longitudinal sectional views schematically showing a resin-coated mold for a semiconductor wafer according to the present invention. FIG. 1 (1) shows a semiconductor wafer and a film. FIG. 1 (2) shows the above-described suction / fixed state of the semiconductor wafer.
2 (1) and FIG. 2 (2) are schematic longitudinal sectional views schematically showing a resin-coated mold of a semiconductor wafer according to the present invention. FIG. 2 (1) is a diagram of a resin material. The supply state is shown, and FIG. 2 (2) shows a state in which a vacuum is drawn from the outside air blocking range formed in the mold as described above .
FIGS. 3 (1) and 3 (2) are schematic longitudinal sectional views schematically showing a resin-coated mold of a semiconductor wafer according to the present invention, and FIG. 3 (1) is a bump of the semiconductor wafer. FIG. 3B shows a state in which the film is in contact with the tip, and FIG. 3B shows a state in which the mold is opened and the resin-coated wafer is released.
4 (1) is a partially cutaway schematic side view schematically showing a resin-coated wafer, and FIG. 4 (2) is a schematic bottom view of the resin-coated wafer shown in FIG. 4 (1); FIG. 4 (3) is a schematic longitudinal sectional view schematically showing a resin-coated chip formed by cutting and separating the resin-coated wafer.
5 (1) and FIG. 5 (2) are schematic longitudinal sectional views schematically showing a conventional resin-coated mold.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Fixed upper type | mold 2 Movable lower type | mold 3 Bump 4 Semiconductor wafer 5 Cavity 6 Resin material 7 Film 8 Pressing member 9 Vertical movement mechanism 10 Locking member 11 Resin 12 Resin coated wafer 13 Chip 14 Resin coated chip 31 Adsorption fixing means of semiconductor wafer 32 Annular convex part 33 Annular concave part 34 Outside air blocking range 35 Suction / discharge mechanism

Claims (3)

The semiconductor wafer is placed at a predetermined position on the bottom surface of the resin coating mold cavity provided on one mold surface of the resin coating mold for coating the bump mounting surface of the semiconductor wafer on which the bump is mounted with resin. In the state opposite to the mold cavity bottom surface, a semiconductor wafer supply step of mounting and supplying,
A film stretching step of stretching a bump exposure film on the other mold surface of the mold,
During the semiconductor wafer supply process, the semiconductor wafer adsorption / fixing process for adsorbing and fixing the wafer to the bottom of the mold cavity;
A film adsorption / fixing step for adsorbing / fixing the film to the other mold surface of the mold during the film stretching step;
A resin material supplying step for supplying a required amount of the resin material into the mold cavity;
A mold clamping process for clamping the mold;
A step of evacuating at least the inside of the mold cavity to a predetermined vacuum state during the mold clamping process;
A fixing member comprising an annular protrusion provided on one mold of the mold, an annular recess provided on the other mold of the mold, and a suction / discharge mechanism provided on the annular recess during the mold clamping process The step of fitting the annular convex portion and the annular concave portion and forcibly sucking and discharging air or the like from the annular concave portion by the suction / discharge mechanism, and drawing and extending the film into the concave portion;
A heat-melting step of a resin material for heat-melting the resin material in the mold cavity;
A pressing step by a pressing member that presses the film in the mold cavity direction with a pressing member provided on the other mold surface of the mold; and
At the time of the pressing step by the pressing member, a film abutting step of abutting the film against the bump tip in the mold cavity;
During the pressing step by the pressing member, the resin coating molding step of the semiconductor wafer for covering the bump mounting surface of the semiconductor wafer with the resin by pressurizing the resin in the mold cavity through the film;
Of a semiconductor wafer characterized by comprising a releasing step of the resin-coated wafer to be resin-coated semiconductor wafer the release of the bump mounting surface is coated with a resin from the mold cavity by opening the mold the mold Resin coating method. A plurality of fixing members are provided on the resin coating mold, and air or the like is forcibly and arbitrarily forced from the annular recesses of the plurality of fixing members by the suction / discharge mechanism arbitrarily and appropriately during the mold clamping process. 2. The semiconductor wafer resin coating method according to claim 1, wherein a step of sucking and discharging the substrate is performed. 2. The resin coating method for a semiconductor wafer according to claim 1, wherein a step of locking the film with a locking member provided on the mold surface in the outer periphery of the mold cavity is performed during the mold clamping process. .

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