Patent Publication Number: US-2013252374-A1

Title: Semiconductor packaging method and structure thereof

Description:
FIELD OF THE INVENTION 
     The present invention is generally related to a semiconductor packaging method, which particularly relates to the semiconductor packaging method that prevents copper ions from dissociation. 
     BACKGROUND OF THE INVENTION 
     Modern electronic products gradually lead a direction of light, thin, short, and small. Accordingly, the circuit layout for electronic products destines to develop technique such as “micro space between two electronic connection devices”. However, a short phenomenon is easily occurred in mentioned circuit layout via an insufficient gap between two adjacent electronic connection devices. 
     SUMMARY 
     The primary object of the present invention is to provide a semiconductor packaging method includes providing a substrate having an upper surface and a plurality of pads disposed at the upper surface, and each of the pads comprises a first coupling surface having a plurality of first conductive contact areas and a plurality of first non-conductive contact areas; forming a conductible gel with anti-dissociation function on the upper surface and the pads of the substrate, wherein the conductible gel with anti-dissociation function includes a plurality of conductive particles and a plurality of anti-dissociation substances; mounting a chip on the substrate, the chip comprises an active surface facing toward the upper surface of the substrate and a plurality of copper-containing bumps disposed at the active surface, wherein the conductible gel with anti-dissociation function covers the copper-containing bumps, each of the copper-containing bumps comprises a second coupling surface and a ring surface, said second coupling surface comprises a plurality of second conductive contact areas and a plurality of second non-conductive contact areas, said copper-containing bumps are electrically connected with the pads via the conductive particles located between the first coupling surfaces and the second coupling surfaces, said conductive particles are electrically connected with the first conductive contact areas of the first coupling surfaces and the second conductive contact areas of the second coupling surfaces, wherein the anti-dissociation substances are located between adjacent conductive particles, each of the first coupling surfaces and each of the second coupling surfaces, said anti-dissociation substances are in contact with the second non-conductive contact areas of the second coupling surfaces, and the ring surfaces of the copper-containing bumps are covered with the anti-dissociation substances. As a result of the ring surfaces of the copper-containing bumps being covered by the anti-dissociation substances of the conductible gel with anti-dissociation function, when a dissociation phenomenon via copper ions from the copper-containing bumps is occurred, the anti-dissociation substances may capture those dissociated copper ions to avoid short phenomenon from happening. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
         FIGS. 1A to 1C  are section schematic diagrams illustrating a semiconductor packaging method in accordance with a preferred embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     With reference to  FIGS. 1A to 1C , a semiconductor packaging method in accordance with a preferred embodiment of the present invention includes the steps as followed. First, referring to  FIG. 1A , providing a substrate  110  having an upper surface  111  and a plurality of pads  112  disposed at the upper surface  111 , in this embodiment, the pad  112  can be a pin of the substrate  110  or a bump pad of trace lines. Each of the pads  112  comprises a first coupling surface  113  and a lateral surface  114 , wherein the first coupling surface  113  comprises a plurality of first conductive contact areas  113   a  and a plurality of first non-conductive contact areas  113   b.  Next, referring to  FIG. 1B ,  FIG. 1B  indicates forming a conductible gel with anti-dissociation function  120  on the upper surface  111  and the pads  112  of the substrate  110 , wherein the conductible gel with anti-dissociation function  120  includes a plurality of conductive particles  121  and a plurality of anti-dissociation substances  122 . In this embodiment, the anti-dissociation substance  122  can be an organic solderability preservative, wherein the material of the organic solderability preservative can be chosen from one of benzimidazole or imidazole derivative. Furthermore, the imidazole derivative can be one of Brenzotriazole, Phenylimidazole, Substituted Benzimidazole, Aryl Phonylimidazole or a mixture thereof, and the benzimidazole can be one of Brenzotriazole, Phenylimidazole, Substituted Benzimidazole, Aryl Phonylimidazole or a mixture thereof. 
     Finally, referring to  FIG. 1C , mounting a chip  130  on the substrate  110 , said chip  130  comprises an active surface  131  facing toward the upper surface  111  of the substrate  110  and a plurality of copper-containing bumps  132  disposed at the active surface  131 . In this embodiment, the material of the copper-containing bumps  132  can be chosen from one of copper/nickel or copper/nickel/gold. The conductible gel with anti-dissociation function  120  covers the copper-containing bumps  132 , each of the copper-containing bumps  132  comprises a second coupling surface  133  and a ring surface  134 , wherein the second coupling surface  133  comprises a plurality of second conductive contact areas  133   a  and a plurality of second non-conductive contact areas  133   b.  The copper-containing bumps  132  are electrically connected with the pads  112  via the conductive particles  121  located between the first coupling surfaces  113  and the second coupling surfaces  133 . The conductive particles  121  are electrically connected with the first conductive contact areas  113   a  of the first coupling surfaces  113  and the second conductive contact areas  133   a  of the second coupling surfaces  133 . The anti-dissociation substances  122  are located between adjacent conductive particles  121 , each of the first coupling surfaces  113  and each of the second coupling surfaces  133 . The anti-dissociation substances  122  are in contact with the second non-conductive contact areas  133   b  of the second coupling surfaces  133 , and the ring surfaces  134  of the copper-containing bumps  132  are covered with the anti-dissociation substances  122  therefore forming a semiconductor packaging structure  100 . Besides, the anti-dissociation substances  122  are in contact with the first non-conductive contact areas  113   b  of the first coupling surfaces  113  as well. As a result of the ring surfaces  134  of the copper-containing bumps  132  being covered by the anti-dissociation substances  122  of the conductible gel with anti-dissociation function  120 , when a dissociation phenomenon via copper ions from the copper-containing bumps  132  is occurred, the anti-dissociation substances  122  may capture those dissociated copper ions in time to avoid short phenomenon from happening and to improve manufacturing yield of the semiconductor packaging structure  100 . 
     With reference to  FIG. 1C  again, a semiconductor packaging structure  100  in accordance with a preferred embodiment of this invention includes a substrate  110 , a conductible gel with anti-dissociation function  120  and a chip  130 . The substrate  110  comprises an upper surface  111  and a plurality of pads  112  disposed at the upper surface  111 , wherein each of the pads  112  comprises a first coupling surface  113  and a lateral surface  114 . The first coupling surface  113  comprises a plurality of first conductive contact areas  113   a  and a plurality of first non-conductive contact areas  113   b.  The conductible gel with anti-dissociation function  120  is formed on the upper surface  111  and the pads  112  of the substrate  110 , and said conductible gel with anti-dissociation function  120  includes a plurality of conductive particles  121  and a plurality of anti-dissociation substances  122 . The chip  130  is mounted on the substrate  110  and comprises an active surface  131  facing toward the upper surface  111  of the substrate  110  and a plurality of copper-containing bumps  132  disposed at the active surface  131 . Each of the copper-containing bumps  132  is covered with the conductible gel with anti-dissociation function  120  and comprises a second coupling surface  133  and a ring surface  134 , wherein the second coupling surface  133  comprises a plurality of second conductive contact areas  133   a  and a plurality of second non-conductive contact areas  133   b.  The copper-containing bumps  132  are electrically connected with the pads  112  via the conductive particles  121  located between the first coupling surfaces  113  and the second coupling surfaces  133 . Besides, the conductive particles  121  are electrically connected with the first conductive contact areas  113   a  of the first coupling surfaces  113  and the second conductive contact areas  133   a  of the second coupling surfaces  133 , wherein the anti-dissociation substances  122  are located between adjacent conductive particles  121 , each of the first coupling surfaces  113  and each of the second coupling surfaces  133 . The anti-dissociation substances  122  are in contact with the second non-conductive contact areas  133   b  of the second coupling surfaces  133  and the first non-conductive contact areas  113   b  of the first coupling surfaces  113 . The anti-dissociation substances  122  cover the ring surfaces  134  of the copper-containing bumps  132  and the lateral surfaces  114  of the pads  112 . 
     While this invention has been particularly illustrated and described in detail with respect to the preferred embodiments thereof, it will be clearly understood by those skilled in the art that it is not limited to the specific features and describes and various modifications and changes in form and details may be made without departing from the spirit and scope of this invention.