Abstract:
A resin sealing method of a semiconductor device, is provided with: providing a semiconductor device on which a dummy dump is formed; providing a support body including an adhesive layer provided on a surface of the support body; forming a recess in the adhesive layer; inserting the dummy bump of the semiconductor device into the recess of the adhesive layer; adhering the semiconductor device to the adhesive layer with the semiconductor device positioned on the support body; setting the supporting body having the semiconductor device in a resin sealing mold; supplying a resin into a cavity of the resin sealing mold; sealing the semiconductor device with the resin on the support body while using the dummy bump to inhibit displacement of the semiconductor device caused by a flow of the resin supplied into the cavity of the resin sealing mold; and removing the support body, the adhesive layer, and the dummy bump from the semiconductor device sealed with the resin.

Description:
This application claims priority from Japanese Patent Application No. 2008-328904, filed on Dec. 25, 2008, the entire contents of which are hereby incorporated by reference. 
     FIELD OF THE INVENTION 
     The present disclosure relates to a resin sealing method of a semiconductor device and more particularly to a resin sealing method of a semiconductor device for making it possible to prevent displacement of the semiconductor device at the resin sealing time when the semiconductor device disposed at a predetermined position of a support plate is sealed with a resin. 
     DESCRIPTION OF RELATED ART 
     There is a wafer level molding method of positioning and disposing electrode terminals formed on one side of a plurality of semiconductor devices with the electrode terminals aimed at an adhesive film applied onto a support body and then sealing an opposite side of the semiconductor devices with a resin in a collective manner. In the wafer level molding method, there are a transfer molding method of injecting a seal resin from a side face of semiconductor devices positioned and disposed on a support body and sealing the semiconductor devices with the seal resin and a compression molding method of supplying a seal resin from an upper face of semiconductor devices positioned and disposed on a support body and compressing the seal resin and the semiconductor devices up and down, thereby sealing the semiconductor devices with the seal resin. 
     As a related art of the wafer level molding method of semiconductor devices, Japanese Patent Application Publication No. JP-A-1992-283987 discloses a method of applying an epoxy-based adhesive layer onto a support substrate of a metal substrate and positioning and disposing external electrode terminals of semiconductor devices on the uncured adhesive layer with the external electrode terminals aimed at the adhesive layer and then sealing the semiconductor devices disposed on the support body with an insulating resin and peeling off the support substrate from the insulating resin and then removing the adhesive layer and exposing the external electrode terminals before connecting a wiring circuit and external connection bumps to the external electrode terminals. 
     As disclosed in JP-A-1992-283987, since a wiring circuit is formed in the external electrode terminals of the semiconductor devices sealed with resin, often the adhesive layer does not have a so strong adhesive force so as to facilitate peeling off the external electrode terminals of the semiconductor devices and the adhesive layer. In recent years, one support substrate has been formed large and the number of semiconductor devices mounted on the support substrate has increased; there is a problem of displacement of the semiconductor devices caused by a resin flow at the resin sealing time of the semiconductor devices regardless of the compression molding method or the transfer molding method. Such displacement of the semiconductor devices makes it impossible to form micro wiring after resin seal and results in defectives of most or all of the semiconductor devices on the support substrate; it leads to reduction in yield and poor economy. 
     SUMMARY OF INVENTION 
     Illustrative aspects of the present invention provide a resin sealing method of a semiconductor device for sealing a semiconductor device with a resin at an accurate position without causing displacement of the semiconductor device on a support plate from the initial adhesion position by the fluid power of the seal resin when the semiconductor device disposed at a predetermined position of the support plate is sealed with the resin. 
     According to a first aspect of the invention, a resin sealing method of a semiconductor device, is provided with: providing a semiconductor device on which a dummy dump is formed; providing a support body including an adhesive layer provided on a surface of the support body; forming a recess in the adhesive layer; inserting the dummy bump of the semiconductor device into the recess of the adhesive layer; adhering the semiconductor device to the adhesive layer with the semiconductor device positioned on the support body; setting the supporting body having the semiconductor device in a resin sealing mold; supplying a resin into a cavity of the resin sealing mold; sealing the semiconductor device with the resin on the support body while using the dummy bump to inhibit displacement of the semiconductor device caused by a flow of the resin supplied into the cavity of the resin sealing mold; and removing the support body, the adhesive layer, and the dummy bump from the semiconductor device sealed with the resin. 
     Other aspects and advantages of the invention will be apparent from the following description, the drawings and the claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is a front view to show a semiconductor device according to a first exemplary embodiment of the invention, and  FIG. 1B  is a bottom plan view the semiconductor device shown in  FIG. 1A ; 
         FIG. 2A  is a plan view to show a state in which an adhesive layer is formed on a support body, and  FIG. 2B  is a sectional view taken on line A-A of  FIG. 2A ; 
         FIG. 3A  is a plan view to show a state in which semiconductor devices are disposed after the adhesive layer is formed, and  FIG. 3B  is a sectional view taken on line B-B of  FIG. 3A ; 
         FIGS. 4A to 4C  are sectional views taken on line C-C of  FIG. 3A  to show a state in which semiconductor devices are sealed with resin by compression mold; 
         FIGS. 5A and 5B  are enlarged views in the range of an arrow Z in FIG.  4 C; 
         FIG. 6A  is a front view to show the work state of a semiconductor device according to a second exemplary embodiment of the invention, and  FIG. 6B  is a bottom plan view the semiconductor device shown in  FIG. 6A ; 
         FIG. 7A  is a plan view to show a state in which an adhesive layer is formed on a support body, and  FIG. 7B  is a sectional view taken on line D-D of  FIG. 7A ; 
         FIGS. 8A to 8D  are sectional views taken on line D-D of  FIG. 7A  to show a state in which semiconductor devices are sealed with resin by compression mold; 
         FIG. 9A  is a front view of a semiconductor device to show another exemplary embodiment of dummy pads and dummy bumps, and  FIG. 9B  is a bottom plan view the semiconductor device shown in  FIG. 9A ; 
         FIG. 9C  is a front view of a semiconductor device to show more another exemplary embodiment of dummy pads and dummy bumps, and  FIG. 9D  is a bottom plan view the semiconductor device shown in  FIG. 9C ; and 
         FIGS. 10A and 10B  are sectional views to show further another exemplary embodiment of a semiconductor device and a semiconductor package. 
     
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     First Exemplary Embodiment 
     A resin sealing method of a semiconductor device according to a first exemplary embodiment of the invention will be discussed.  FIG. 1A  is a front view to show a semiconductor device according to the first exemplary embodiment of the invention, and  FIG. 1B  is a bottom plan view the semiconductor device shown in  FIG. 1A . 
     First, a treatment method (working method) for a semiconductor device  10  will be discussed. The semiconductor device  10  is formed with dummy bumps  22  at periphery positions of a face where electrode terminals  12  of the semiconductor device  10  are formed, as shown in  FIGS. 1A and 1B . Each of the electrode terminals  12  in the first exemplary embodiment is formed so as to project from a bottom face of the semiconductor device  10 . Each of the dummy bumps  22  is stacked on a dummy pad  20  provided on the face side where the electrode terminals  12  of the semiconductor device  10  are formed to prevent damage to the semiconductor device  10  by etching because the dummy bumps  22  are removed by etching after the semiconductor device  10  is sealed with resin. In the first exemplary embodiment, a gold film is used as the dummy pad  20  and a copper bump is used as the dummy bump  22 . The dummy pad  20  and the dummy bump  22  are provided at every corner of the semiconductor device  10  having a planar shape formed as a rectangle, but may be disposed at least two points for the semiconductor device  10 . In this case, preferably, the dummy bumps are disposed at two points on a diagonal line connecting the corners of the semiconductor device  10 . The dummy pad  20  is formed having the same thickness dimension as the projection height of the electrode terminal  12 , and the total of the height dimensions of the dummy pad  20  and the dummy bump  22  is formed equal to the lay thickness dimension of an adhesive layer  40  as shown  FIG. 3B . Although  FIGS. 1A and 1B  show the semiconductor device  10  separated as one piece, the dummy pads  20  and the dummy bumps  22  can be formed in batch by using photolithography, plating processing, etc., before the semiconductor devices  10  are separated. 
     Thus, the semiconductor device  10  formed with the dummy bumps  22  on the face side where the electrode terminals  12  are formed is positioned on the adhesive layer  40  applied to a support body  30  and is adhered to the adhesive layer  40 . The support body  30  and the adhesive layer  40  will be discussed below:  FIG. 2A  is a plan view to show a state in which an adhesive layer is formed on a support body, and  FIG. 2B  is a sectional view taken on line A-A of  FIG. 2A . The dashed line in  FIG. 2A  indicates the position where the semiconductor device  10  is disposed.  FIG. 3A  is a plan view to show a state in which semiconductor devices are disposed after the adhesive layer is formed, and  FIG. 3B  is a sectional view taken on line B-B of  FIG. 3A .  FIGS. 4A to 4C  are sectional views taken on line C-C of  FIG. 3A  to show a state in which semiconductor devices are sealed with resin by compression mold. 
     As shown in  FIG. 2A , the adhesive layer  40  is applied to an upper face side of the support body  30  formed like a thin disk using a metal plate. A thin copper plate is used as the support body  30  and an epoxy-based adhesive is used as the adhesive layer  40 . The layer thickness dimension of the adhesive layer  40  in the first exemplary embodiment is 30 μm. After the adhesive layer  40  is formed on the support body  30 , recesses  42  are formed in the adhesive layer  40  as shown in  FIG. 2B . The recesses  42  can be formed using a laser irradiation working method. If the adhesive layer  40  is photosensitive, the recesses  42  can also be formed using photolithography. The recesses  42  are formed at the positions corresponding to the positions of the dummy bumps  22  formed on the semiconductor device  10 . The recesses  42  in the first exemplary embodiment pierce the adhesive layer  40  in the thickness direction thereof, and the surface of the support body  30  is exposed on the bottom faces of the recesses  42 . 
     After the recesses  42  are formed in the adhesive layer  40 , the semiconductor devices  10  are disposed as shown in  FIGS. 3A and 3B . Each of the semiconductor devices  10  is disposed as the dummy bumps  22  are positioned in the recesses  42  formed in the adhesive layer  40  and the dummy bumps  22  and the dummy pads  20  are fitted into the recesses  42 . Since the total height dimension of each dummy bump  22  and each dummy pad  20  are formed equal to the depth dimension of the recess  42 , the semiconductor device  10  is pressed against the adhesive layer  40 , whereby the semiconductor device  10  can be disposed in a state in which the face of the semiconductor device  10  where the electrode terminals  12  are formed is intimately contacted with the surface of the adhesive layer  40 . Although the electrode terminals  12  project on the bottom face of the semiconductor device  10 , the projection height of the electrode terminal  12  is extremely small. Thus, if the semiconductor device  10  is pressed against the adhesive layer  40 , the adhesive layer  40  follows the faces of the electrode terminals  12 , whereby the bottom face of the semiconductor device  10  and the adhesive layer  40  can be intimately contacted with each other. Thus, the semiconductor devices  10  are adhered to the adhesive layer  40  applied to the support body  30  in the positioned state, and the dummy bumps  22  are fitted into the recess  42 , whereby the semiconductor devices  10  and the support body  30  can be put into one body. The semiconductor devices  10  and the support body  30  put into one body are set in a lower mold  80  of a resin molding mold, and a seal resin  50  is supplied to the top faces of the semiconductor devices  10 , as shown in  FIG. 4A . Although a liquid resin is shown as the seal resin  50  in  FIG. 4A , the seal resin  50  may be a granular resin. After the seal resin  50  is supplied, an upper mold  90  of the resin molding mold is abutted against the lower mold  80 , and the seal resin  50  is heated and pressurized together with the lower mold  80  and the upper mold  90  (undergoes compression molding), whereby the seal resin  50  is cured and the top face sides of the semiconductor devices  10  are sealed with the seal resin  50 , as shown in  FIG. 4B . 
     After the semiconductor devices  10  are resin-sealed, the resin-sealed semiconductor devices  10  are taken out from the female mold  80  together with the support body  30  as shown in  FIG. 4C . And then, the support body  30  is removed. The support body  30  is removed by etching. In the first exemplary embodiment, since the support body  30  and the dummy bumps  22  are formed of copper, an etchant (etching liquid) for etching copper can be used to selectively etch only the support body  30  and the dummy bumps  22 .  FIG. 5A  is a sectional view to show a state in which the support body  30  and the dummy bumps  22  are thus removed.  FIGS. 5A and 5B  are enlarged views in the range of an arrow Z in  FIG. 4C . When the support body  30  is removed, the adhesive layer  40  and the dummy pads  20  are exposed on the face of the semiconductor device  10  where the electrode terminals  12  are formed. 
     Next, the adhesive layer  40  is removed by etching or laser irradiation and a semiconductor package  60  shown in  FIG. 5B  can be provided. 
     According to the resin sealing method of a semiconductor device according to the first exemplary embodiment, the dummy pads  20  and the dummy bumps  22  of projections formed on one face side of the semiconductor device  10  are fitted into the recesses  42  of the adhesive layer  40  formed on the surface of the support body  30  and act as stoppers. Accordingly, when the semiconductor device  10  is sealed with resin while the opposite face side of the semiconductor device  10  is pressurized, the positioning state of the semiconductor device  10  is not displaced because of fluid power of the seal resin  50  and the semiconductor device  10  can be resin-sealed in a state in which an initial disposed position of the semiconductor device  10  is maintained. Therefore, in the process of re-wiring after the semiconductor device  10  is resin-sealed, there is no fear of displacement of the semiconductor device  10  in the semiconductor package  60  and the manufacturing yield of the semiconductor package  60  formed with a wiring circuit (re-wiring) at the required position can be improved, whereby the semiconductor package  60  is efficiently manufactured. After the semiconductor packages  60  are separated, an external connection bump (not shown) can be connected to the separated semiconductor package  60  for providing a semiconductor device. The semiconductor packages  60  may be stacked in the height direction thereof. 
     In the first exemplary embodiment, copper bumps are used as the dummy bumps  22 , but the dummy bumps  22  are not limited to those made of metal if the dummy bumps  22  have strength resisting the fluid power of the seal resin in a molten state when the semiconductor device  10  is resin-sealed; the dummy bumps  22  may be formed of any other material such as a synthetic resin. 
     Second Exemplary Embodiment 
     In a second exemplary embodiment of the invention, a resin sealing method of a semiconductor device  110  that can provide the advantages similar to those of the first exemplary embodiment by filling a paste into an adhesive layer  140  formed on a surface of a support body  130  and hardening the filled paste to form a hard body will be discussed.  FIG. 6A  is a front view to show the work state of a semiconductor device according to the second exemplary embodiment of the invention, and  FIG. 6B  is a bottom plan view the semiconductor device shown in  FIG. 6A .  FIG. 7A  is a plan view to show a state in which an adhesive layer is formed on a support body, and  FIG. 7B  is a sectional view taken on line D-D of  FIG. 7A .  FIGS. 8A to 8D  are sectional views taken on line D-D of  FIG. 7A  to show a state in which semiconductor devices are sealed with resin by compression mold. 
     The semiconductor device  110  according to the second exemplary embodiment is formed of dummy pads  120  by gold plating, etc., on the face where electrode terminals  112  are formed as with the first exemplary embodiment. The dummy pads  120  can be formed like the dummy pads  20  in the first exemplary embodiment. In the second exemplary embodiment, each dummy pad  120  is formed at two corners on the face of the semiconductor device  110  where the electrode terminals  112  are formed, as shown in  FIGS. 6A and 6B . 
     Next, as shown in  FIG. 7A , the adhesive layer  140  is applied to the support body  130  of a thin copper plate and each of recesses  142  is formed in each of the adhesive layer  140  by laser irradiation working method or photolithography in a similar manner to that of the first exemplary embodiment. The positions of the recesses  142  correspond to the positions of the dummy pads  120  formed on the semiconductor device  110 . A copper paste  144  is filled into each of the recesses  142 . In the second exemplary embodiment, the copper paste  144  is not densely filled into the recesses  142  (the copper paste  144  is not filled to the height position of an upper face opening part of the recess  142 ). A volume of the copper paste  144  filled into the recesses  142  is as much as the volume resulting from deducting the volume of the dummy pad  120  entering the recess  142 , as shown in  FIG. 7B . Accordingly, when the dummy pad  120  enters the recess  142 , the copper paste  144  does not overflow and the space in the recess  142  can be filled just enough with the copper paste  144  and the dummy pad  120 . 
     As shown in  FIG. 8A , the dummy pads  120  of the semiconductor device  110  are positioned in the positions of the copper paste  144  and are entered in the recesses  142  filled with the copper paste  144  And then, the dummy pads  120  are contacted with the copper paste  144 . After the semiconductor device  110  is adhered to the adhesive layer  140 , the copper paste  144  is heated to form copper bumps  145  of hard bodies. Since the copper bumps  145  are intimately contacted with the dummy pads  120  at the time of the copper paste  144 , each of the copper bumps  145  and each of the dummy pads  120  are reliably put into one body for strongly fixing the semiconductor device  110  at a required position of the adhesive layer  140 . 
     After the semiconductor devices  110  and the adhesive layer  140  are fixed to each other, in a similar manner to that of the first exemplary embodiment (see  FIGS. 4A to 4C ), the semiconductor devices  110  and the support body  130  (containing the adhesive layer  140 , etc.) are set in a lower mold  80  of a resin molding mold and a seal resin  150  is supplied to the top faces of the semiconductor devices  110 . And then, an upper mold  90  of the resin molding mold is abutted against the lower mold  80 , the seal resin  150  is heated and pressurized with the lower mold  80  and the upper mold  90 . The seal resin  150  is widened uniformly in a cavity formed by the lower mold  80  and the upper mold  90  and is thermally cured, whereby the semiconductor device  110  is resin-sealed, as shown in  FIG. 8B . In the second exemplary embodiment, the copper bumps  145  are fitted into the recesses  142  of the adhesive layer  140 , so that the semiconductor device  110  can resist the fluid power of the seal resin  150  when the semiconductor device  110  is resin-sealed, and the semiconductor device  110  can be resin-sealed in a state in which an initial disposed position of the semiconductor device  110  is maintained. 
     After completion of resin-sealing the semiconductor device  110 , the support body  130  is removed as shown in  FIG. 8C . An etchant of copper can be used to remove the support body  130  and the copper bumps  145  at once in a similar manner to that of the first exemplary embodiment. After this, processing (treatment) similar to that of the first exemplary embodiment is performed, whereby a semiconductor package  160  shown in  FIG. 8D  can be provided. 
     By the first and second exemplary embodiment of the invention is adopted, the positioning state of the adhesive layer applied onto the support body and the semiconductor device can be fixed reliably to the adhesive layer by the dummy bump and the hard body (cured paste). Thus, if a molten resin supplied to the inside of the resin sealing mold is pressed (or transferred) at a high pressure, the positioning state of the semiconductor device and the adhesive layer can be reliably maintained resisting the fluid power of the molten resin. Accordingly, the semiconductor device can be appropriately sealed with the resin. Further, it is made possible to precisely form a micro wiring circuit for every semiconductor device after the resin seal, yield is improved, and it is made possible to efficiently manufacture semiconductor packages and semiconductor products. 
     While the invention has been described in detail based on the first and second exemplary embodiments shown above, the invention is not limited to the first and second exemplary embodiments. For example, in the exemplary embodiments, copper is used as the dummy bumps  22  and the paste material filled into the recesses  142  of the adhesive layer  140 , but the dummy bumps  22  and the paste material filled into the recesses  142  are not limited to copper. Essentially, if the adhesive force with the dummy pads  20  provided on the face of the semiconductor device  10  where the electrode terminals  12  are formed can be made larger than the force acting in the plane direction caused by the flow of the seal resin  50  when the semiconductor device  10  is resin-sealed, and if a hard body which is selectively removable can be provided, any other material than copper (for example, a synthetic resin or a metal material other than copper) can also be used. 
     In the first exemplary embodiment described above, a mode in which the dummy pads  20  formed on the semiconductor device  10  are formed at the corners of the plane area of the semiconductor device  10  is described, but the invention is not limited to the mode. Essentially, when the semiconductor device  10  is resin-sealed, the positioning state of the semiconductor device  10  adhered to the adhesive layer  40  may be able to be maintained and the dummy pads  20  and the recesses  42  may be formed anywhere if the dummy pads  20  and the recesses  42  are in the plane area of the semiconductor device  10 . A mode in which the planar shape of each of the dummy pads  20 , the dummy bumps  22 , and the recesses  42  is formed as a circle is described in the first exemplary embodiment, but a planer shape of each of dummy pads and dummy bumps may be formed having projections in longitudinal and lateral directions (X axis direction and Y axis direction), such as a letter L or a cross as shown in  FIGS. 9A to 9D . Such a shape is adopted, whereby the disposition number of dummy bumps can be reduced. 
     Particularly, if cross planar shapes of the dummy pads  320 , the dummy bumps  322 , and the recesses  342  as shown in  FIGS. 9C and 9D  are adopted, it is extremely advantageous in that the disposition numbers of the dummy pads  320  and the dummy bumps  322  formed on the semiconductor device  310  and the recesses  342  formed in the adhesive layer  340  can be reduced to each one per one semiconductor device  310 . 
     The dummy pads  220  and  320 , the dummy bumps  222  and  322 , and the recesses  242  and  342  shown in  FIGS. 9A to 9D  can be easily formed by photolithography. 
     A semiconductor device  410  formed with electrode terminals  412  and dummy pads  420  contained within the thickness of the semiconductor device  410  as shown in  FIG. 10A  can also be used. In the semiconductor device  410  shown in  FIG. 10A , either of the exemplary embodiments described above is applied, whereby a semiconductor package  460  shown in  FIG. 10B  can also be provided. The semiconductor package  460  shown in  FIG. 10B  makes it possible to flat the face where the electrode terminals  412  are formed (the bottom face of the semiconductor device  410 ); it is also advantageous for slimming down the semiconductor package  460  and a semiconductor apparatus using the semiconductor package  460 . 
     It is also possible to previously form the dummy pads  20  and the dummy bumps  22  on the semiconductor device  10  in a discrete state. If the semiconductor device  10  previously formed with the dummy pads  20  and the dummy bumps  22  is fitted into the recesses  42  of the adhesive layer  40  deposited on the support body  30  in a state in which the semiconductor device  10  is housed in a jig (not shown), the later processing (treatment) can be performed in a similar manner to that of the first exemplary embodiment. The dummy bumps  22  and the copper bumps  145  (hard bodies) may be formed on signal pads provided on an active face of the semiconductor device  10  or  110 . 
     Further, in the exemplary embodiments, the compression molding mold is used as the molding mold for resin-sealing the semiconductor device, but the molding mold is not limited to that of the exemplary embodiments and the invention can also be applied when the semiconductor device is resin-sealed by a transfer molding mold. 
     While the present inventive concept has been shown and described with reference to certain exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.