1. Field of the Invention
The present invention relates to a semiconductor package, and more particularly to a semiconductor package which can avoid solder bridge.
2. Description of the Related Art
As shown in
The conventional semiconductor package 1 has the following disadvantages. First, the solder mask 116 contacts the Ni/Au plating layer 115 directly, however the solder mask 116 and the Ni/Au plating layer 115 has low bonding strength, therefore delamination between the solder mask 116 and the Ni/Au plating layer 115 occurs easily. Moreover, the Ni/Au plating layer 115 disposed on the first solder balls 14 is encapsulated by the molding compound 15, and when the second solder balls 16 are reflowed, the first solder balls 14 expand because of high temperature. Meanwhile, the first solder balls 14 extrude to adjacent elements and protrude to the interface between the solder mask 116 and the Ni/Au plating layer 115 which has low bonding strength. As a result, it leads to the bridge between the first solder balls 14, as shown in area A of
Therefore, it is necessary to provide a semiconductor package to solve the above problems.
The present invention is directed to a semiconductor package. The semiconductor package comprises a substrate, at least one chip, a plurality of conductive elements, a plurality of first conductors and a molding compound. The substrate has a first surface, a second surface, a plurality of first pads and a solder mask. The first pads are exposed to the first surface, and the material of the first pads is copper. The solder mask directly contacts the first pads, and has at least one opening so as to expose part of the first pads. The chip is mounted on the substrate. The conductive elements electrically connect the chip and the substrate. The first conductors are disposed on the first pads. The molding compound is disposed on the first surface of the substrate, and encapsulates the chip, the conductive elements and the first conductors. The molding compound has a first top surface and a second top surface. The horizontal level of the first top surface is different from that of the second top surface, and one end of the first conductors is exposed. A top surface of the exposed first conductors is level with the second top surface of the molding compound.
The present invention is further directed to a semiconductor package. The semiconductor package comprises a substrate, at least one chip, a plurality of conductive elements, a plurality of first conductors and a molding compound. The substrate has a first surface, a second surface, a plurality of first pads and a solder mask. The first pads are exposed to the first surface, and the material of the first pads is copper. The solder mask directly contacts the first pads, and has at least one opening so as to expose part of the first pads. The chip is mounted on the substrate. The conductive elements electrically connect the chip and the substrate. The first conductors are disposed on the first pads. The molding compound is disposed on the first surface of the substrate, and encapsulates the chip, the conductive elements and part of the first conductors. The molding compound has a first surface and a plurality of blind holes. The blind holes open at the first surface of the molding compound, and expose part of the first conductors.
Whereby, the solder mask contacts the first pads directly, and thus results in higher bonding strength, so as to avoid the bridge between the first conductors caused by the first conductors permeating into the interface between the solder mask and the first pads.
The first pads 213 are exposed to the first surface 211, and the material of the first pads 213 is copper. The second pads 214 are exposed to the second surface 212. The solder mask 216 contacts the first pads 213 directly, and has at least one opening so as to expose part of the first pads 213. The anti-oxidation layer 217 is disposed on the first pads 213 exposed to the opening of the solder mask 216. That is, the anti-oxidation layer 217 does not completely cover the entire upper surface of the first pad 213. In the embodiment, the anti-oxidation layer 217 is a Ni/Au plating layer. However, in other applications, the anti-oxidation layer 217 can be an organic solderability preservative (OSP), and the anti-oxidation layer 217 does not exist in the final structure. Therefore, the present invention can avoid the first pads 213 from oxidizing after being exposed in the air, and thus the yield rate of the semiconductor package is increased.
The chip 22 is mounted on the substrate 21. In the embodiment, the chip 22 is adhered to the solder mask 216. In the present invention, the form of the chip 22 has no limitation. The wires 23 electrically connect the chip 22 and the substrate 21. The first solder balls 24 are disposed on the first pads 213, preferably, the first solder balls 24 are hemispheres. The second solder balls 26 are disposed on the second pads 214.
The molding compound 25 is disposed on the first surface 211 of the substrate 21, and encapsulates the chip 22, the wires 23 and the first solder balls 24. The molding compound 25 has a first top surface 251 and a second top surface 252, the horizontal level of the first top surface 251 is different from that of the second top surface 252, and one end of the first solder balls 24 is exposed. A top surface of the exposed first solder balls 24 is level with the second top surface 252 of the molding compound 25.
The molding compound 25 has a first height H1 and a second height H2, the first height H1 is the height from the first top surface 251 to the solder mask 216, the second height H2 is the height from the second top surface 252 to the solder mask 216, and the first height H1 is greater than the second height H2.
The first pads 313 are exposed to the first surface 311, and the material of the first pads 313 is copper. The second pads 314 are exposed to the second surface 312. The solder mask 316 contacts the first pads 313 directly, and has at least one opening so as to expose part of the first pads 313. The anti-oxidation layer 317 is disposed on the first pads 313 exposed to the opening of the solder mask 316, preferably, the anti-oxidation layer 317 is an organic solderability preservative (OSP) or a Ni/Au plating layer. Therefore, the present invention can avoid the first pads 313 from oxidizing after being exposed in the air, and thus the yield rate of the semiconductor package is is increased.
The chip 32 is mounted on the substrate 31. In the embodiment, the chip 32 is adhered to the solder mask 316. In the present invention, the form of the chip 32 has no limitation. The wires 33 electrically connect the chip 32 and the substrate 31. The first solder balls 34 are disposed on the first pads 313. The second solder balls 36 are disposed on the second pads 314. The molding compound 35 is disposed on the first surface 311 of the substrate 31, and encapsulates the chip 32, the wires 33 and part of the first solder balls 34. The molding compound 35 has a first surface 351 and a plurality of blind holes 352. The blind holes 352 open at the first surface 351 of the molding compound 35, and expose part of the first solder balls 34.
Therefore, the solder masks 216, 316 contact the first pads 213, 313 directly, and thus results in higher bonding strength, so as to avoid the bridge between the first conductors (the first solder balls 24, 34) caused by the first conductors (the first solder balls 24, 34) permeating into the interface between the solder masks 216, 316 and the first pads 213, 313.
While several embodiments of the present invention have been illustrated and described, various modifications and improvements can be made by those skilled in the art. The embodiments of the present invention are therefore described in an illustrative but not restrictive sense. It is intended that the present invention should not be limited to the particular forms as illustrated, and that all modifications which maintain the spirit and scope of the present invention are within the scope defined by the appended claims.
Number | Date | Country | Kind |
---|---|---|---|
98146112 A | Dec 2009 | TW | national |
Number | Name | Date | Kind |
---|---|---|---|
5072289 | Sugimoto et al. | Dec 1991 | A |
5128831 | Fox, III et al. | Jul 1992 | A |
5139610 | Dunaway et al. | Aug 1992 | A |
5207585 | Byrnes et al. | May 1993 | A |
5222014 | Lin | Jun 1993 | A |
5355580 | Tsukada | Oct 1994 | A |
5397997 | Tuckerman et al. | Mar 1995 | A |
5400948 | Sajja et al. | Mar 1995 | A |
5468681 | Pasch | Nov 1995 | A |
5579207 | Hayden et al. | Nov 1996 | A |
5594275 | Kwon et al. | Jan 1997 | A |
5608265 | Kitano et al. | Mar 1997 | A |
5714800 | Thompson | Feb 1998 | A |
5726493 | Yamashita et al. | Mar 1998 | A |
5748452 | Londa | May 1998 | A |
5763939 | Yamashita | Jun 1998 | A |
5844315 | Melton et al. | Dec 1998 | A |
5861666 | Bellaar | Jan 1999 | A |
5883426 | Tokuno et al. | Mar 1999 | A |
5889327 | Washida | Mar 1999 | A |
5889655 | Barrow | Mar 1999 | A |
5892290 | Chakravorty et al. | Apr 1999 | A |
5929521 | Wark et al. | Jul 1999 | A |
5973393 | Chia et al. | Oct 1999 | A |
5985695 | Freyman et al. | Nov 1999 | A |
6072236 | Akram et al. | Jun 2000 | A |
6177724 | Sawai | Jan 2001 | B1 |
6194250 | Melton et al. | Feb 2001 | B1 |
6195268 | Eide | Feb 2001 | B1 |
6303997 | Lee | Oct 2001 | B1 |
6448665 | Nakazawa et al. | Sep 2002 | B1 |
6451624 | Farnworth et al. | Sep 2002 | B1 |
6461881 | Farnworth et al. | Oct 2002 | B1 |
6489676 | Taniguchi et al. | Dec 2002 | B2 |
6501165 | Farnworth et al. | Dec 2002 | B1 |
6513236 | Tsukamoto | Feb 2003 | B2 |
6521995 | Akram et al. | Feb 2003 | B1 |
6525413 | Cloud et al. | Feb 2003 | B1 |
6614104 | Farnworth et al. | Sep 2003 | B2 |
6617687 | Akram et al. | Sep 2003 | B2 |
6740546 | Corisis et al. | May 2004 | B2 |
6740964 | Sasaki | May 2004 | B2 |
6762503 | Lee | Jul 2004 | B2 |
6780746 | Kinsman et al. | Aug 2004 | B2 |
6787392 | Quah | Sep 2004 | B2 |
6798057 | Bolkin et al. | Sep 2004 | B2 |
6812066 | Taniguchi et al. | Nov 2004 | B2 |
6815254 | Mistry et al. | Nov 2004 | B2 |
6828665 | Pu et al. | Dec 2004 | B2 |
6847109 | Shim | Jan 2005 | B2 |
6861288 | Shim et al. | Mar 2005 | B2 |
6888255 | Murtuza et al. | May 2005 | B2 |
6924550 | Corisis et al. | Aug 2005 | B2 |
6936930 | Wang | Aug 2005 | B2 |
6974334 | Hung | Dec 2005 | B2 |
7002805 | Lee et al. | Feb 2006 | B2 |
7015571 | Chang et al. | Mar 2006 | B2 |
7026709 | Tsai et al. | Apr 2006 | B2 |
7029953 | Sasaki | Apr 2006 | B2 |
7034386 | Kurita | Apr 2006 | B2 |
7049692 | Nishimura et al. | May 2006 | B2 |
7061079 | Weng et al. | Jun 2006 | B2 |
7071028 | Koike et al. | Jul 2006 | B2 |
7129576 | Humpston | Oct 2006 | B2 |
7185426 | Hiner et al. | Mar 2007 | B1 |
7187068 | Suh et al. | Mar 2007 | B2 |
7221045 | Park et al. | May 2007 | B2 |
7242081 | Lee | Jul 2007 | B1 |
7262080 | Go et al. | Aug 2007 | B2 |
7279784 | Liu | Oct 2007 | B2 |
7279789 | Cheng | Oct 2007 | B2 |
7288835 | Yim et al. | Oct 2007 | B2 |
7309913 | Shim et al. | Dec 2007 | B2 |
7345361 | Mallik et al. | Mar 2008 | B2 |
7354800 | Carson | Apr 2008 | B2 |
7364945 | Shim et al. | Apr 2008 | B2 |
7364948 | Lai et al. | Apr 2008 | B2 |
7365427 | Lu et al. | Apr 2008 | B2 |
7372141 | Karnezos et al. | May 2008 | B2 |
7372151 | Fan et al. | May 2008 | B1 |
7394663 | Yamashita et al. | Jul 2008 | B2 |
7408244 | Lee et al. | Aug 2008 | B2 |
7417329 | Chuang et al. | Aug 2008 | B2 |
7429786 | Karnezos et al. | Sep 2008 | B2 |
7429787 | Karnezos et al. | Sep 2008 | B2 |
7436055 | Hu | Oct 2008 | B2 |
7436074 | Pan et al. | Oct 2008 | B2 |
7473629 | Tai et al. | Jan 2009 | B2 |
7485970 | Hsu et al. | Feb 2009 | B2 |
7550832 | Weng et al. | Jun 2009 | B2 |
7550836 | Chou et al. | Jun 2009 | B2 |
7560818 | Tsai | Jul 2009 | B2 |
7586184 | Hung et al. | Sep 2009 | B2 |
7589408 | Weng et al. | Sep 2009 | B2 |
7633765 | Scanlon et al. | Dec 2009 | B1 |
7642133 | Wu et al. | Jan 2010 | B2 |
7671457 | Hiner et al. | Mar 2010 | B1 |
7719094 | Wu et al. | May 2010 | B2 |
7723839 | Yano et al. | May 2010 | B2 |
7728431 | Harada et al. | Jun 2010 | B2 |
7737539 | Kwon et al. | Jun 2010 | B2 |
7737565 | Coffy | Jun 2010 | B2 |
7777351 | Berry et al. | Aug 2010 | B1 |
7807512 | Lee et al. | Oct 2010 | B2 |
7834464 | Meyer et al. | Nov 2010 | B2 |
7838334 | Yu et al. | Nov 2010 | B2 |
8039303 | Shim et al. | Oct 2011 | B2 |
20030090883 | Asahi et al. | May 2003 | A1 |
20030129272 | Shen et al. | Jul 2003 | A1 |
20040106232 | Sakuyama et al. | Jun 2004 | A1 |
20040124515 | Tao et al. | Jul 2004 | A1 |
20040126927 | Lin et al. | Jul 2004 | A1 |
20040191955 | Joshi et al. | Sep 2004 | A1 |
20050054187 | Ding et al. | Mar 2005 | A1 |
20050117835 | Nguyen et al. | Jun 2005 | A1 |
20050121764 | Mallik | Jun 2005 | A1 |
20060035409 | Suh et al. | Feb 2006 | A1 |
20060170112 | Tanaka et al. | Aug 2006 | A1 |
20060220210 | Karnezos et al. | Oct 2006 | A1 |
20060240595 | Lee | Oct 2006 | A1 |
20060244117 | Karnezos et al. | Nov 2006 | A1 |
20070029668 | Lin et al. | Feb 2007 | A1 |
20070090508 | Lin et al. | Apr 2007 | A1 |
20070108583 | Shim et al. | May 2007 | A1 |
20070241453 | Ha et al. | Oct 2007 | A1 |
20070273049 | Khan et al. | Nov 2007 | A1 |
20070290376 | Zhao et al. | Dec 2007 | A1 |
20080017968 | Choi et al. | Jan 2008 | A1 |
20080073769 | Wu et al. | Mar 2008 | A1 |
20080116574 | Fan | May 2008 | A1 |
20080230887 | Sun et al. | Sep 2008 | A1 |
20090101400 | Yamakoshi | Apr 2009 | A1 |
20090127686 | Yang et al. | May 2009 | A1 |
20100000775 | Shen et al. | Jan 2010 | A1 |
20100032821 | Pagaila et al. | Feb 2010 | A1 |
20100171205 | Chen et al. | Jul 2010 | A1 |
20100171206 | Chu et al. | Jul 2010 | A1 |
20100171207 | Shen et al. | Jul 2010 | A1 |
20100214780 | Villard | Aug 2010 | A1 |
20100244208 | Pagaila et al. | Sep 2010 | A1 |
20100320585 | Jiang et al. | Dec 2010 | A1 |
20110049704 | Sun et al. | Mar 2011 | A1 |
20110068453 | Cho et al. | Mar 2011 | A1 |
20110117700 | Weng et al. | May 2011 | A1 |
20110140364 | Head | Jun 2011 | A1 |
20110241193 | Ding et al. | Oct 2011 | A1 |
20110278741 | Chua et al. | Nov 2011 | A1 |
Number | Date | Country |
---|---|---|
07335783 | Dec 1995 | JP |
2000294720 | Oct 2000 | JP |
2001298115 | Oct 2001 | JP |
2002158312 | May 2002 | JP |
2002170906 | Jun 2002 | JP |
2004327855 | Nov 2004 | JP |
2009054686 | Mar 2009 | JP |
20020043435 | Jun 2002 | KR |
20030001963 | Jan 2003 | KR |
529155 | Apr 2003 | TW |
229927 | Mar 2005 | TW |
200611305 | Apr 2006 | TW |
Entry |
---|
Wang et al., “Coupled power and thermal cycling reliability of board-level package-on-package stacking assembly.” IEEE Trans. Elec. Pkg. Mfg. 32(1): 14-21 (2009). |
Lai, et al. “Optimization of thermomechanical reliability of board-level package-on-package stacking assembly.” IEEE Tarns. Compon. Pkg. Techn. 29(4): 864-868 (Dec. 2006). |
Yoshida et al., A Study on Package Stacking Process for Package-on-Package (PoP) Electronic Components and Tech. Conf. (ECTC), May 2006, San Diego, CA. |
Dreiza et al., “High Density PoP (Package-on-Package) and Package Stacking Development” Electronic Components and Technology Conf. (May 2007). |
Number | Date | Country | |
---|---|---|---|
20110156251 A1 | Jun 2011 | US |