JP2010080698A - Semiconductor device mounting substrate and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor device mounting substrate having high contact reliability between bumps and connection terminals. <P>SOLUTION: On the underside of a semiconductor device 3 mounted on top of connection terminals 2, metal bumps 4 are disposed at the positions corresponding to the connection terminals 2, a resin 5 for maintaining the connecting state between the bumps 4 and connection terminals 2 is disposed at least between the semiconductor device 3 and the substrate 12, and a thermosetting resin 15 connecting between the side of the semiconductor device 3 and the substrate 12 is disposed at least in the proximity of the corner part of the semiconductor device 3. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a semiconductor element mounting substrate and a method for manufacturing the same.

  Hereinafter, a conventional semiconductor element mounting substrate will be described with reference to the drawings. FIG. 3 is a cross-sectional view of a conventional semiconductor element mounting substrate. In FIG. 3, connection terminals 2 are formed on the upper surface of the substrate 1. A semiconductor element 3 is mounted above the connection terminal 2. A bump 4 is formed on the lower surface side of the semiconductor element 3 so as to correspond to the connection terminal 2.

  Here, the bump 4 is brought into pressure contact with the connection terminal 2, thereby achieving electrical connection between the semiconductor element 3 and the substrate 1. Therefore, the resin 5 is provided between the semiconductor element 3 and the substrate 1, and the pressure contact state of the bumps 4 is maintained by the resin 5.

As prior art document information related to the invention of this application, for example, Patent Document 1 is known.
JP 2001-68508 A

  In recent years, there is a demand for reducing the height of such a semiconductor element mounting substrate, and the thickness of the substrate 1 is decreasing. Thereby, the bending strength of the board | substrate 1 becomes small, and the curvature of the board | substrate 1, the deformation | transformation by stress, etc. occur easily. In particular, the amount of warpage tends to increase at the peripheral edge of the semiconductor element 3.

  Further, the corners of the semiconductor element 3 are hardly filled with the resin 5, and the connection strength between the semiconductor element 3 and the substrate 1 in the vicinity of the corners is reduced. Therefore, due to such warpage or deformation of the substrate, the connection between the bumps 4 and the connection terminals 2 is disconnected in the vicinity of the periphery of the semiconductor element 3, particularly in the vicinity of the corners, and the connection is likely to be unstable.

  SUMMARY OF THE INVENTION The present invention solves this problem and aims to provide a semiconductor element mounting substrate having high contact reliability between bumps and connection terminals.

  In order to achieve this object, a semiconductor element mounting substrate of the present invention includes a substrate, a connection terminal formed on the upper surface of the substrate, a semiconductor element mounted above the connection terminal, and a lower surface side of the semiconductor element. The first resin is provided between the semiconductor element and the substrate and maintains the connection state between the bump and the connection terminal, at least between the metal bump provided at a position corresponding to the connection terminal And at least in the vicinity of the corner of the semiconductor element, a second resin for connecting the side surface of the semiconductor element and the substrate is provided. As a result, the intended purpose can be achieved.

  As described above, according to the present invention, the connection terminal formed on the upper surface of the substrate, the semiconductor element mounted above the connection terminal, and the connection terminal on the lower surface side of the semiconductor element are connected to the connection terminal. A metal bump provided at a corresponding position; and a first resin provided between at least the semiconductor element and the substrate and maintaining a connection state between the bump and the connection terminal; In the vicinity of the corner portion of the semiconductor element, a second resin for connecting the side surface of the semiconductor element and the substrate is provided, and the semiconductor element mounting with good connection reliability between the connection terminal and the semiconductor element There is an effect that a substrate can be obtained.

  As a result, the thickness of the substrate can be reduced, so that a semiconductor element mounting substrate having a low height can be realized.

(Embodiment 1)
Hereinafter, the present embodiment will be described in detail with reference to the drawings. FIG. 1A is a top view of the semiconductor element mounting substrate 11 in the present embodiment, and FIG. 1B is a cross-sectional view thereof. In FIGS. 1 (a) and 1 (b), the same reference numerals are used for the same components as in the prior art (FIG. 3), and the description thereof is simplified.

  In FIGS. 1A and 1B, an upper surface on which a connection terminal 2 for mounting the semiconductor element 3 and a frame body 13 (used as an example of an upper electronic component) are mounted on the upper surface of the substrate 12. A component land (not shown) is formed. On the other hand, a lower component land (not shown) on which the lower electronic component 14 is mounted is formed on the lower surface of the substrate 12. In the present embodiment, the frame 13 and the substrate 12 are connected by lead-free solder 17, while the lower electronic component 14 and the substrate 12 are also connected by lead-free solder (not shown). Yes.

  Then, the semiconductor element 3 is mounted above the connection terminal 2. Here, metal bumps 4 are formed on the lower surface side of the semiconductor element 3 so as to correspond to the connection terminals 2. The bumps 4 in the present embodiment use gold bumps, but for example, bumps made of other metals such as solder may be used.

  The important point here is that the bump 4 is pressed against the connection terminal 2 with the tip of the bump 4 deformed. For this purpose, the bump 4 is made of a soft and easily deformable material such as gold or solder. As a result, the bump 4 is easily deformed by the pressure contact. Therefore, the variation in the height of the bump 4 can be absorbed, and the bump 4 can be brought into contact with the connection terminal 2.

  In order to maintain this pressure contact state, in the present embodiment, a thermosetting resin 5 is provided between the semiconductor element 3 and the substrate 12. In this embodiment, the resin 5 is an epoxy resin.

  Here, according to the confirmation of the inventors, the bump 4 near the peripheral edge of the semiconductor element 3 is connected to the connection terminal 2 in comparison with the bump 4 in the central part of the semiconductor element 3 due to warpage or stress of the substrate 12. Contact pressure tends to be low.

  Further, in the vicinity of the central portion of the side surface of the semiconductor element 3, the resin 5 greatly protrudes from the semiconductor element 3 and crawls up to the side surface of the semiconductor element 3. Absent. Accordingly, the bump 4 near the corner of the semiconductor element 3 tends to have a lower contact pressure with the connection terminal 2. Therefore, the present invention connects the side surface of the semiconductor element 3 and the substrate 12 to the vicinity of the corner of the semiconductor element 3 with a heat-shrinkable thermosetting resin 15 different from the resin 5. The contact pressure between the bump 4 and the connection terminal 2 at the peripheral edge or corner of the semiconductor element 3 can be maintained. That is, the thermosetting resin 15 contracts by heating when the thermosetting resin 15 is cured, and the bumps 4 are pressed against the connection terminals 2 by the contraction. Therefore, the contact between the bump 4 and the connection terminal 2 can be maintained regardless of the warp of the substrate 12.

  In this embodiment, since the thermosetting resin 15 is applied to all four corners, good connection reliability between the bumps 4 and the connection terminals 2 on the substrate 12 regardless of the mounting position of the semiconductor element 3. Can maintain sex.

  Such a semiconductor element mounting substrate 11 is mounted on a mother substrate (not shown). Therefore, in the semiconductor element mounting substrate 11 in the present embodiment, a plurality of mounting terminals 16 are formed on the upper surface side of the frame body 13. The semiconductor element mounting substrate 11 is mounted on the mother substrate with the mounting terminal 16 side facing the mother substrate, and is reflow soldered. As described above, even when the semiconductor element mounting substrate 11 is mounted on the mother substrate, it has an effect of making it difficult to separate the connection between the bump 4 and the connection terminal 2.

  Further, after mounting the semiconductor element mounting board 11 on the mother board, a fixing resin (not shown) is provided between the mother board and the semiconductor element mounting board 11 for the connection strength between the semiconductor element mounting board 11 and the mother board. ) May be used to reinforce the strength. This is performed particularly when a drop impact resistance is required as in portable applications. In such a case, the fixing resin may adhere between the mother substrate and the top surface of the semiconductor element 3. In such a case, the semiconductor element 3 is pulled in a direction away from the substrate 12 (upward in the figure) by the shrinkage force of the fixing adhesive. Therefore, in the present embodiment, a fixing resin is hardly attached to the top surface of the semiconductor element 3 by providing a gap between the upper surface of the frame 13 and the top surface of the semiconductor element 3. Furthermore, since the connection strength between the semiconductor element 3 and the substrate 12 is reinforced by the thermosetting resin 15, even when the fixing resin adheres to the top surface of the semiconductor element 3, The connection with the connection terminal 2 can be stably maintained.

  Next, a method for manufacturing the semiconductor element mounting substrate 11 in the present embodiment will be described with reference to the drawings. FIG. 2 is a manufacturing flowchart of the semiconductor element mounting substrate 11 in the present embodiment. In FIG. 2, the same reference numerals are used for the same components as those in the prior art (FIG. 3) and FIG. 1, and the description thereof is simplified.

  In FIG. 2, first, in a resin film forming step 21, a paste-like resin 5 is applied by screen printing so as to cover the connection terminals 2. In this case, a non-conductive resin paste (NCP) is used as the resin 5, but an anisotropic conductive resin paste (ACP) may be applied instead. Further, although screen printing is used as this coating method, other methods (for example, dispenser coating, transfer coating, etc.) may be used as appropriate. Further, a non-conductive resin film (NCF), an anisotropic conductive film (ACF), or the like may be used for the resin 5. In this case, these films are affixed on the connection terminal 2.

  The mounting process 22 is a process in which the semiconductor element 3 is mounted on the substrate 12 after the resin film forming process 21. At this time, the bumps 4 of the semiconductor element 3 and the connection terminals 2 are mounted so as to correspond to each other.

  Next, the curing step 23 is a step of curing the paste-like resin 5. Here, since a thermosetting resin is used as the resin 5, the resin 5 is cured by heating the paste-like resin 5 in the curing step 23. At this time, until the resin 5 is completely cured, the semiconductor element 3 and the substrate 12 are pressurized from above and below. By this pressurization, the tip of the bump 4 is deformed, and the variation in the height of the bump 4 is absorbed. As a result, the bumps 4 have the same height, so that all the bumps 4 can securely contact the connection terminals 2.

  In the application step 24, after the curing step 23, the paste-like thermosetting resin 15 is applied in the vicinity of the four corners of the semiconductor element 3. In the present embodiment, the thermosetting resin 15 is applied to the corner portion of the semiconductor element 3 from above the corner portion by a dispenser. Thereby, the thermosetting resin 15 can be simultaneously applied to the top surface, the side surface, and the substrate 12 of the semiconductor element 3 at the same time, and the number of steps in the application process can be shortened.

  Next, in the curing step 25, the thermosetting resin 15 is cured by heating. The important point here is that the thermosetting resin 15 is a heat-shrinkable resin, and in the coating step 24, the thermosetting resin 15 is at least a side surface of the semiconductor element 3 and an upper surface of the substrate 12. It is applying so that it may adhere to both. By doing so, the thermosetting resin 15 contracts due to heat in the curing step 25, the semiconductor element 3 is firmly pressed to the substrate 12 side, and the semiconductor element 3 is fixed to the substrate 12 in a pressure contact state. The Rukoto. Thereby, the contact pressure between the bump 4 and the connection terminal 2 can be further increased.

  In this embodiment, the thermosetting resin 15 is applied from above the top surface in the vicinity of the corner of the semiconductor element 3 so that the paste-like thermosetting resin 15 is applied to the top surface and the side surface of the semiconductor element 3. And flows down to the top surface of the substrate. By doing in this way, since the thermosetting resin 15 will hold down the semiconductor element 3 also from the top | upper surface direction, connection reliability can be made still higher.

  Further, when the thermosetting resin 15 is cured in the curing step 25, it is important that the thermosetting resin 15 between the side surface of the semiconductor element 3 and the substrate 12 is not cut. Here, in the application step 24, the thermosetting resin 15 is applied with the semiconductor element 3 side facing upward, so that the applied thermosetting resin 15 flows to the substrate 12 side and is applied to the side surface of the semiconductor element 3. The remaining thermosetting resin 15 is reduced. Therefore, in order to increase the thickness of the thermosetting resin 15 on the side surface of the semiconductor element 3, in the curing step 25 in the present embodiment, the semiconductor element 3 side is heated in a direction facing downward. Thereby, the thermosetting resin 15 in a paste state once flowing down to the substrate 12 side and spreading on the substrate flows to the side surface side of the semiconductor element 3. Therefore, since the thickness of the thermosetting resin 15 on the side surface of the semiconductor element 3 can be increased, it is difficult for the thermosetting resin 15 to be cut by shrinkage in the curing step 25.

  Next, the lower mounting process 26 is a process of mounting the lower electronic component 14 on the lower surface side of the substrate 12. The lower mounting process 26 includes a printing process 27 in which cream-like lead-free solder 34 is screen-printed on a land on which the lower electronic component 14 is mounted on the lower surface side of the substrate 12, and then a predetermined process under the substrate 12. The mounting step 28 for mounting the lower electronic component 14 at the position, and the heating step 29 for melting the lead-free solder thereafter.

  After the lower mounting process 26, an upper mounting process 30 is performed. In the upper mounting process 30, in the printing process 31, creamy lead-free solder 17 is printed on the frame 13 in advance. Then, in the mounting step 32, mounting is performed on the lower surface side of the substrate 12 in such a direction that the solder application surface side of the frame 13 faces the substrate 12. And it heats by the subsequent reflow process 33, the frame 13 is connected and fixed to the board | substrate 12, and the semiconductor element mounting board | substrate 11 is completed.

  As described above, in the semiconductor element mounting substrate 11 according to the present embodiment, the semiconductor element 3 is pressed against the substrate 12 by the contraction force of the thermosetting resin 15, so that the lower mounting process 26 and the upper mounting process 30 are further performed. The connection between the bumps 4 and the connection terminals 2 can be maintained against warping of the substrate 12 caused by heat such as a soldering process to the mother substrate. Furthermore, the thickness of the substrate 12 can be reduced, and the height of the semiconductor element mounting substrate 11 can be reduced.

  The semiconductor element mounting substrate according to the present invention has an effect of obtaining good contact reliability between the bump and the connection terminal, and in particular, the semiconductor element mounting substrate on which components are mounted on both sides, and a module that passes through subsequent cutting and further heating processes. It is useful as a semiconductor element mounting substrate used for such as.

(A) Top view of a semiconductor element mounting substrate in an embodiment of the present invention, (b) Cross-sectional view from the side surface direction Same manufacturing flowchart Sectional view of a conventional semiconductor device mounting board

Explanation of symbols

2 Connection terminal 3 Semiconductor element 4 Bump 5 Resin 12 Substrate 15 Thermosetting resin

Claims (9)

A substrate, a connection terminal formed on the upper surface of the substrate, a semiconductor element mounted above the connection terminal, and a metal element provided at a position corresponding to the connection terminal on the lower surface side of the semiconductor element A bump and a first resin that is provided between at least the semiconductor element and the substrate and maintains a connection state between the bump and the connection terminal; and at least in the vicinity of a corner of the semiconductor element, the semiconductor A semiconductor element mounting substrate provided with a second resin for connecting a side surface of the element and the substrate. The semiconductor element mounting substrate according to claim 1, wherein the second resin is provided at all four corners of the semiconductor element. The semiconductor element mounting substrate according to claim 2, wherein the second resin is bonded to the upper surface and the side surface of the semiconductor element in the vicinity of the corner of the semiconductor element. 2. The method of manufacturing a semiconductor mounting substrate according to claim 1, wherein the connection terminal and the bump correspond after the step of supplying the first resin onto the connection terminal and the step of supplying the first resin. A step of mounting the semiconductor element on the substrate, a step of curing the first resin after the step of mounting the semiconductor element, and a vicinity of a corner of the semiconductor element after the step of curing the first resin. A semiconductor element mounting including a step of applying a paste-like second resin and a step of curing the resin after the step, and using a heat-shrinkable thermosetting resin as the second resin A method for manufacturing a substrate. The method for manufacturing a semiconductor element mounting substrate according to claim 4, further comprising a step of mounting a lower electronic component on the lower surface side of the substrate after the step of applying the second resin. 6. The method of manufacturing a semiconductor element mounting substrate according to claim 5, wherein in the step of applying the second resin, the second resin is applied to all four corners of the semiconductor element. The method of manufacturing a semiconductor element mounting substrate according to claim 6, wherein the second resin is dispenser-applied from above the peripheral edge of the upper surface of the semiconductor element on the upper surface of the semiconductor element. 8. The method of manufacturing a semiconductor element mounting substrate according to claim 7, further comprising a step of mounting an upper electronic component on the upper surface side of the substrate after the step of mounting the first electronic component on the lower surface side of the substrate. 9. The semiconductor element mounting substrate according to claim 8, wherein cream solder is supplied to the upper electronic component in advance, and in the step of mounting the upper electronic component, the upper electronic component supplied with the cream solder is mounted on the substrate. Method.

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