JP2008282853A - Semiconductor device and its manufacturing process - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor device which decreases the number of members used for packaging a semiconductor chip, and to provide its manufacturing process. <P>SOLUTION: The semiconductor device comprises a semiconductor chip 10, a resin 20 for sealing the semiconductor chip 10 having a recess 22 in the lower surface, a solder ball 30 provided in the recess 22, and a wire 40 for connecting the semiconductor chip 10 and the solder ball 30. Since the number of members used for packaging the semiconductor chip can be decreased, manufacturing cost of the semiconductor device is reduced sharply and a low profile semiconductor device can be obtained. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a surface-mount type semiconductor device such as BGA (Ball Grid Array) or LGA (Land Grid Array) and a method for manufacturing the same.

  Surface packaging technologies such as BGA and LGA are known as semiconductor chip packaging technologies for increasing the density of integrated circuits.

FIG. 1 is a cross-sectional view of a conventional semiconductor device. The semiconductor chip 10 is mounted on the relay substrate 90 in a face-up state using an adhesive (not shown). An electrode 92 is provided on the upper surface of the relay substrate 90 and is electrically connected to an electrode (not shown) on the semiconductor chip 10 by a wire 40. The semiconductor chip 10 and the wire 40 are sealed with the resin 20. An electrode 94 for electrically connecting to the outside of the semiconductor device is provided on the lower surface of the relay substrate 90. The electrode 92 and the electrode 94 are electrically connected by a connection portion 96. A solder ball 30 is formed on the lower surface of the electrode 94.

Patent Document 1 and Patent Document 2 disclose a technique for forming a plurality of solder balls in a batch using the surface tension of solder melted by heating.
JP 2004-214474 A JP 2001-203230 A

  In semiconductor chip packaging technology, cost reduction and profile reduction have always been issues. On the other hand, as shown in the conventional example, in many semiconductor devices, a relay substrate is used as a member for fixing components such as a semiconductor chip. Since the relay substrate is the most expensive member used for packaging semiconductor chips and has a predetermined thickness, there is a limit to reducing the cost and height of the semiconductor device.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a semiconductor device in which the number of members used for packaging a semiconductor chip is reduced and a method for manufacturing the semiconductor device.

  The present invention comprises a semiconductor chip, a resin having a recess on a lower surface, sealing the semiconductor chip, solder provided in the recess, and a wire connecting the semiconductor chip and the solder. A semiconductor device is characterized. According to the present invention, since the number of members used for packaging of a semiconductor chip can be reduced, the manufacturing cost of the semiconductor device can be greatly reduced. In addition, the height of the semiconductor device can be reduced.

  The said structure WHEREIN: The volume of the said recessed part can be set as the structure equal to the volume of the said solder.

  The said structure WHEREIN: The lower surface of the said semiconductor chip can be set as the structure exposed from the lower surface of the said resin.

  The said structure WHEREIN: The upper surface of the said solder can be set as the structure covered with the metal layer. According to this configuration, it is possible to improve the adhesion between the solder and the resin and to form the solder in accordance with the shape of the metal layer.

  In the above configuration, the solder may be a solder ball.

  In the above configuration, the solder may be a solder pad.

  The said structure WHEREIN: The said recessed part can be set as the structure spaced apart from the side surface of the said resin. According to this configuration, damage to the solder can be suppressed.

  The said structure WHEREIN: The said recessed part can be set as the structure which is in contact with the side surface of the said resin.

  The said structure WHEREIN: The said solder can be set as the structure arrange | positioned along the at least 1 piece of the said semiconductor chip.

  In the above configuration, the solder may be arranged in a grid pattern. According to this configuration, more solder can be provided.

  The present invention includes a step of mounting a semiconductor chip on a support portion, a step of mounting a solder piece on the support portion, a step of connecting the semiconductor chip and the solder piece on the support portion with a wire, A method of manufacturing a semiconductor device, comprising: a step of sealing the semiconductor chip, the solder piece, and the wire with a resin on the support portion; and a step of removing the support portion. According to the present invention, since the number of members used for packaging of a semiconductor chip can be reduced, the manufacturing cost of the semiconductor device can be greatly reduced. In addition, the height of the semiconductor device can be reduced.

  The said structure WHEREIN: After removing the said support part, it can be set as the structure which has the process of forming a solder ball from the said solder piece. According to this configuration, the external connection portion can be a solder ball.

  The said structure WHEREIN: It can be set as the structure which has the process of cut | disconnecting the said resin.

  The said structure WHEREIN: The process of mounting the said solder piece on the said support part can be comprised in the process of mounting the solder piece by which the upper surface was covered with the metal layer. According to this configuration, it is possible to improve the adhesion between the solder and the resin and to form the solder in accordance with the shape of the metal layer.

  The said structure WHEREIN: The said solder piece can be set as the structure which is circular when it sees from the top.

  According to the present invention, since the number of members used for packaging of a semiconductor chip can be reduced, the manufacturing cost of the semiconductor device can be greatly reduced. In addition, the height of the semiconductor device can be reduced.

  Embodiments according to the present invention will be described below with reference to the drawings.

  FIG. 2A to FIG. 2C are diagrams illustrating a method for manufacturing a semiconductor device according to the first embodiment. In the semiconductor chip packaging process, a plurality of semiconductor chips are collectively processed in a state of being arranged in a planar shape. Here, a diagram of one semiconductor chip is shown. 2A is a top view of the resin portion seen through, and FIGS. 2B and 2C are cross-sectional views taken along the line AA1 of FIG. 2A. 2A and 2B, a semiconductor chip 10 made of silicon is mounted on a support portion 50 made of polyimide resin using an adhesive (not shown). Next, a square plate-like solder piece 32 made of tin and silver is mounted on the support portion 50 by using an adhesive (not shown) along two opposite sides of the semiconductor chip 10. The semiconductor chip 10 and the solder piece 32 are mounted on the support unit 50 by a die bonder. Next, on the support portion 50, the semiconductor chip 10 and the solder piece 32 are electrically connected by a wire 40 made of gold. Next, on the support portion 50, the semiconductor chip 10, the solder piece 32, and the wire 40 are sealed with a resin 20 made of an epoxy resin. Resin sealing is performed by a transfer mold method using a mold. After the resin sealing is completed, the support part 50 is removed.

  Referring to FIG. 2C, after removing the support portion 50, the solder pieces 32 are heat treated. The solder pieces 32 are rounded by the surface tension accompanying heat melting, and the solder balls 30 are formed. The region where the solder pieces 32 originally existed is the recess 22. The side surfaces of the solder balls 30 are separated from the resin 20. Thereafter, the resin 20 is cut by a dicing method at a predetermined position. The semiconductor device according to Example 1 is completed through the above steps.

  FIG. 3 is a cross-sectional view of the semiconductor device according to the first embodiment. The semiconductor chip 10 is sealed with the resin 20 with its lower surface exposed to the outside from the lower surface of the resin 20. A recess 22 is formed in the lower surface of the resin 20, and a solder ball 30 is formed in the recess 22 for electrical connection to the outside of the semiconductor device. The concave portion 22 is formed by forming a region where the solder piece 32 originally exists as a depression on the lower surface of the resin 20 by melting the solder piece 32. Therefore, the volume of the recess 22 is substantially equal to the solder piece 32 or the solder ball 30. The recess 22 is in contact with the side surface of the resin 20. The solder ball 30 is rounded by surface tension when the solder piece 32 is heated and melted, and has a substantially hemispherical shape. The semiconductor chip 10 and the solder ball 30 are electrically connected by a wire 40.

  The semiconductor device according to the first embodiment is configured without using the relay substrate 90 which is the most expensive member among the members used for semiconductor packaging when compared with the conventional example (FIG. 1). Thereby, the material cost of the semiconductor device can be significantly reduced. Further, the height of the semiconductor device can be reduced by the thickness of the relay substrate 90. Further, since the solder ball 30 is formed in the recess 22 of the resin 20, the semiconductor device can be further reduced in height. For example, when the height of the semiconductor chip 10 is 100 μm and the clearance (the thickness of the resin 20 existing above the semiconductor chip 10) is 150 μm, the height of the entire semiconductor device can be about 250 μm. Further, by using the solder ball 30, the semiconductor device can be configured as a BGA type.

  According to the method for manufacturing a semiconductor device according to the first embodiment, the plurality of semiconductor chips 10 and the solder pieces 32 are both mounted on the support portion 50 with a die bonder, and the solder balls 30 are collectively formed by heat treatment. For this reason, the number of manufacturing steps can be reduced and the number of devices used for manufacturing can be reduced as compared with the case of individually forming solder balls. In addition, since a plurality of semiconductor chips are collectively encapsulated with resin, it is easier to develop a mold used for encapsulating resin than when individually encapsulating resin. As described above, the manufacturing process of the semiconductor device can be simplified and the assembly cost can be reduced.

  As shown in FIGS. 2A and 2B, the square plate-like solder piece 32 is used in the first embodiment, but a circular plate-like solder piece 32a may be used as shown in FIG. . Since the solder ball 30 has a substantially spherical shape, it is easier to form the solder ball 30 from a circular solder piece 32a.

  As shown in FIG. 2A, in the first embodiment, the solder pieces 32 are mounted on the support portion 50 along two opposite sides of the semiconductor chip 10, but the solder pieces 32 are at least of the semiconductor chip 10. What is necessary is just to be mounted on the support part 50 along one edge | side. For example, the solder pieces 32 may be mounted along the four sides of the semiconductor chip 10 as shown in FIG. Alternatively, the solder pieces 32 may be mounted on the support portion 50 in two or more rows. For example, the solder pieces 32 may be mounted on the support portion 50 in a grid pattern as shown in FIG. With these configurations, more solder balls can be provided. In FIG. 5B, a part of the wire 40 is omitted.

  As shown in FIG. 2C, in Example 1, cutting was performed at a position where the concave portion 22 was in contact with the side surface of the resin 20, but cutting was performed at a position where the concave portion 22 was separated from the side surface of the resin 20 as shown in FIG. May be performed. Thereby, since the solder ball 30 is protected by the resin 20, damage to the solder ball 30 can be suppressed. In the first embodiment, the solder ball 30 is formed by heat treatment and then cut. However, the heat treatment may be performed after first cutting. Or you may cut | disconnect before removing the support part 50 after resin sealing. In the case of the first embodiment, there is an advantage that the formation of the solder balls 30 can be performed collectively.

  In the first embodiment, the polyimide resin is used for the support portion 50. However, as long as it can support mounting components such as the semiconductor chip 10 and can withstand the temperature (for example, 170 ° C.) at the time of resin sealing. Other members may be used. Moreover, since the support part 50 is removed after resin sealing, what is easy to peel off is preferable. For example, it is conceivable to use a material with low resin affinity for the support part 50 or to cover the upper surface of the support part 50 with a material with low resin affinity. It is also conceivable to use a tape-like one rather than a plate-like one. Moreover, it is preferable that the support part 50 is a thing (for example, dicing tape) by which the adhesive agent was beforehand coated on one side. Thereby, since a die attach material becomes unnecessary, manufacturing cost can be further reduced.

  In Example 1, the solder balls 30 and the solder pieces 32 made of tin and silver were used, but melted at a predetermined temperature (a temperature that does not damage the mounted components including the semiconductor chip 10; for example, 235 ° C. or less). Other members may be used as long as they are alloys capable of joining metals together. For example, in addition to the example shown in Embodiment 1, tin, silver and copper, tin and lead, tin and zinc, and the like can be used.

  Example 2 is an example in which the upper surface of a solder ball is plated. FIG. 7 is a cross-sectional view of the semiconductor device according to the second embodiment. The upper surface of the solder ball 30 is covered with a metal layer 60 made of nickel and bonded to the recess 22 of the resin 20. The semiconductor chip 10 and the metal layer 60 are electrically connected by a wire 40. Other configurations are the same as those of the first embodiment.

  In the manufacturing process of the semiconductor device according to the second embodiment, the solder piece 32 whose upper surface is covered with the metal layer 60 in FIG. Other manufacturing steps are the same as those in the first embodiment.

According to the configuration of the second embodiment, the upper surface of the solder ball 30 is covered with the metal layer 60. The solder ball 30 has a high affinity for the metal layer 60 and covers the entire surface of the metal layer 60 as shown in FIG. Thereby, it is possible to make it difficult for the solder ball 30 to come off the resin 20. Also, the solder ball 30 can be formed in accordance with the shape of the metal layer 60. Furthermore, the electrical connectivity between the solder ball 30 and the wire 40 can be improved.

  The metal layer 60 may be made of other materials as long as it has high resin affinity and high connectivity with the wire 40. For example, gold, silver, palladium and the like can be considered. In addition, the solder piece 32 whose upper surface is previously covered with the metal layer 60 may be purchased and used. However, in the step before the solder piece 32 is mounted on the support portion 50, the metal layer is formed on the upper surface of the solder piece 32. 60 may be formed.

  Example 3 is an example in which solder pads are used instead of solder balls. FIG. 8 is a cross-sectional view of the semiconductor device according to the third embodiment. A solder pad 34 is provided in the recess 22 of the resin 20. The upper surface of the solder pad 34 is covered with a metal layer 60, and the semiconductor chip 10 and the metal layer 60 are electrically connected by a wire 40. Other configurations are the same as those of the first embodiment.

  In the manufacturing process of the semiconductor device according to the third embodiment, since the solder piece 32 which is the solder pad 34 in FIG. 2A is used and it is not necessary to form a solder ball, the support portion in FIG. No heat treatment is performed after 50 is removed. Other manufacturing steps are the same as those in the first embodiment.

  According to the configuration of the third embodiment, since the solder pads 34 are used instead of the solder balls 30, the semiconductor device can be configured as an LGA type.

  The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to the specific embodiments, and various modifications can be made within the scope of the gist of the present invention described in the claims.・ Change is possible.

FIG. 1 is a cross-sectional view of a conventional semiconductor device. FIG. 2A is a top view illustrating the method for manufacturing the semiconductor device according to the first embodiment, and FIGS. 2B and 2C are cross-sectional views illustrating the method for manufacturing the semiconductor device according to the first embodiment. is there. FIG. 3 is a cross-sectional view of the semiconductor device according to the first embodiment. 4A and 4B are top views showing the method for manufacturing the semiconductor device according to the first embodiment. FIG. 5 is a top view illustrating the method for manufacturing the semiconductor device according to the first embodiment. FIG. 6 is a cross-sectional view illustrating the method of manufacturing the semiconductor device according to the first embodiment. FIG. 7 is a cross-sectional view of the semiconductor device according to the second embodiment. FIG. 8 is a cross-sectional view of the semiconductor device according to the third embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Semiconductor chip 20 Resin part 30 Solder ball 40 Wire 50 Support part 60 Metal layer 90 Relay substrate

Claims (15)

A semiconductor chip;
A resin having a recess on the lower surface and sealing the semiconductor chip;
Solder provided in the recess,
A wire connecting the semiconductor chip and the solder;
A semiconductor device comprising:   The semiconductor device according to claim 1, wherein a volume of the recess is equal to a volume of the solder.   The semiconductor device according to claim 1, wherein a lower surface of the semiconductor chip is exposed from a lower surface of the resin.   4. The semiconductor device according to claim 1, wherein an upper surface of the solder is covered with a metal layer.   5. The semiconductor device according to claim 1, wherein the solder is a solder ball.   5. The semiconductor device according to claim 1, wherein the solder is a solder pad.   The semiconductor device according to claim 1, wherein the concave portion is separated from a side surface of the resin.   The semiconductor device according to claim 1, wherein the concave portion is in contact with a side surface of the resin.   The semiconductor device according to claim 1, wherein the solder is arranged along at least one side of the semiconductor chip.   10. The semiconductor device according to claim 1, wherein the solder is provided in a grid pattern. 10. Mounting a semiconductor chip on the support;
Mounting a solder piece on the support;
On the support portion, connecting the semiconductor chip and the solder piece with a wire;
On the support portion, sealing the semiconductor chip, the solder piece, and the wire with resin;
Removing the support;
A method for manufacturing a semiconductor device, comprising:   12. The method of manufacturing a semiconductor device according to claim 11, further comprising a step of forming a solder ball from the solder piece after removing the support portion.   13. The method of manufacturing a semiconductor device according to claim 11, further comprising a step of cutting the resin.   14. The method of manufacturing a semiconductor device according to claim 11, wherein the step of mounting the solder piece on the support portion is a step of mounting a solder piece whose upper surface is covered with a metal layer. Method.   The method of manufacturing a semiconductor device according to claim 10, wherein the solder piece is circular when viewed from above.

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