WLCSP target and method for forming the same

• US 7,795,074 B2
• Filed: 01/13/2009
• Issued: 09/14/2010
• Est. Priority Date: 08/20/2008
• Status: Active Grant

• Current Assignee: China Wafer Level CSP Co., Ltd.
• Original Assignee: China Wafer Level CSP Co., Ltd.
• Inventors: Li, Hanyu, Wang, Wei, Huang, Xiaohua, Shao, Mingda, Yu, Guoqing
• Primary Examiner(s): Nhu; David
• Application Number:
  US12/352,858
• Publication Number:
  US 20100044857A1
• Time in Patent Office: 609 Days
• Field of Search: 438/106, 438/113, 438/311, 438/197, 438/199, 438/460, 438/463, 438/753, 257/E21.499, 257/505, 257/508, 257/509, 257/511, 257/517
• US Class Current: 438/106
• CPC Class Codes: H01L 21/561 Batch processing
• CPC Class Codes: H01L 21/568 Temporary substrate used as encapsulation process aid H01L21/4832 and H01L21/566 take precedence
• CPC Class Codes: H01L 23/3114 the device being a chip scale package, e.g. CSP
• CPC Class Codes: H01L 24/94 at wafer-level, i.e. with connecting carried out on a wafer comprising a plurality of undiced individual devices
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/01033 Arsenic [As]
• CPC Class Codes: H01L 2924/01082 Lead [Pb]
• CPC Class Codes: H01L 2924/14 Integrated circuits
• CPC Class Codes: H01L 2924/1461 MEMS

Abstract

The invention provides a Wafer Level Chip Size Packaging (WLCSP) target and a method for forming it. A WLCSP target is formed by recombining single chips, wafer parts each including two or more chips or half finished packaging targets which have been subjected to at least one previous step of packaging onto a first substrate, or bonding a wafer part which is formed by dicing a whole wafer and includes at least two chips to a second substrate for bonding. Thus, a wafer with a larger size can be packaged through the WLCSP on a WLCSP apparatus with a smaller size while benefiting from the advantages of the WLCSP, the WLCSP apparatus remains applicable within a longer period of time, the cost is lowered, and enterprises may keep up with the development of the market and the increase of the wafer size without having to update the WLCSP apparatus substantially.

Claims

1. A method for forming a Wafer Level Chip Size Packaging (WLCSP) target, comprising:

providing at least two discrete recombination units and a first substrate; and

bonding a side of each of the at least two discrete recombination units, which is opposite to a side including a circuit, to the first substrate to recombine the at least two discrete recombination units so as to form a WLCSP target.

2. The method for forming a WLCSP target according to claim 1, wherein, the at least two discrete recombination units are bonded to the first substrate in array.

3. The method for forming a WLCSP target according to claim 1, further comprising:

bonding the at least two discrete recombination units to a second substrate.

4. The method for forming a WLCSP target according to claim 3, further comprising:

forming cavity walls corresponding to chips respectively on the second substrate.

5. The method for forming a WLCSP target according to claim 3, further comprising:

removing the first substrate.

6. The method for forming a WLCSP target according to claim 5, further comprising:

thinning each of the at least two discrete recombination units from the side opposite to the side including the circuit.

7. The method for forming a WLCSP target according to claim 3, wherein, the second substrate is made of a material comprising glass or silicon.

8. The method for forming a WLCSP target according to claim 1, wherein, each of the at least two discrete recombination units comprises one of a single chip, a wafer part comprising at least two chips and a half finished packaging target.

9. The method for forming a WLCSP target according to claim 8, wherein the half finished packaging target is formed through the following steps:

bonding a wafer to the second substrate to form a two-layer structure; and

dicing the two-layer structure into half finished packaging targets.

10. The method for forming a WLCSP target according to claim 8, wherein, the wafer part is formed through wafer dicing or cracking.

11. The method for forming a WLCSP target according to claim 10, further comprising:

removing a portion of a wafer comprising a crack by dicing the wafer with reference to the crack so as to keep the wafer part formed through wafer dicing or cracking from the crack.

12. The method for forming a WLCSP target according to claim 8, wherein, a single chip or a wafer part comprising at least two chips is packaged in the half finished packaging target.

13. The method for forming a WLCSP target according to claim 8, wherein, the chip comprises an integrated circuit chip, a sensor chip or a micro electro-mechanical system.

14. The method for forming a WLCSP target according to claim 1, wherein, an adhesive for bonding the at least two discrete recombination units to the first substrate comprises a UV adhesive or a wax adhesive.

15. The method for forming a WLCSP target according to claim 1, wherein, a diameter of a circumcircle of the first substrate is larger than or equal to 100 mm.

16. A method for forming a Wafer Level Chip Size Packaging (WLCSP) target, comprising:

providing at least two discrete wafer parts which are formed through wafer dicing or cracking and each comprises at least two chips and a second substrate for bonding; and

bonding a side of each of the at least two discrete wafer parts on which a circuit is formed to the second substrate for bonding to recombine the at least two discrete wafer parts so as to form a WLCSP target.

17. The method for forming a WLCSP target according to claim 16, further comprising:

bonding a side of each of the at least two discrete wafer parts opposite to the side comprising the circuit to a first substrate.

18. The method for forming a WLCSP target according to claim 17, further comprising:

removing a portion of the at least two discrete wafer parts which extends beyond the first substrate.

19. The method for forming a WLCSP target according to claim 17, further comprising:

removing the first substrate.

20. The method for forming a WLCSP target according to claim 16, further comprising:

thinning the at least two discrete wafer parts from the side opposite to the side comprising the circuit.

21. The method for forming a WLCSP target according to claim 19, wherein, an adhesive for bonding the at least two discrete wafer parts to the first substrate comprises a UV adhesive or a wax adhesive.

22. The method for forming a WLCSP target according to claim 16, further comprising:

forming cavity walls corresponding to the chips respectively on the second substrate.

23. The method for forming a WLCSP target according to claim 16, wherein, the second substrate is made of a material comprising glass or silicon.

24. The method for forming a WLCSP target according to claim 16, wherein, a diameter of a circumcircle of the second substrate is larger than or equal to 100 mm.

25. The method for forming a WLCSP target according to claim 16, further comprising:

removing a portion of a wafer comprising a crack by dicing the wafer with reference to the crack so as to keep each of the at least two discrete wafer parts which are formed through dicing or cracking the wafer comprising the crack from the crack.

26. The method for forming a WLCSP target according to claim 17, wherein, the chips comprises an integrated circuit chip, a sensor chip or a micro electro-mechanical system.