Film deposition to enhance sealing yield of microcap wafer-level package with vias

• US 6,777,263 B1
• Filed: 08/21/2003
• Issued: 08/17/2004
• Est. Priority Date: 08/21/2003
• Status: Expired due to Fees

• Current Assignee: Avago Technologies Wireless IP Singapore Pte Limited (Broadcom, Inc.)
• Original Assignee: Agilent Technologies, Inc.
• Inventors: Geefay, Frank S., Barfknecht, Andrew T., Ruby, Richard C., Gan, Qing
• Primary Examiner(s): Smith, Matthew
• Assistant Examiner(s): Yevsikov, Victor V
• Application Number:
  US10/647,040
• Time in Patent Office: 362 Days
• Field of Search: 438/106, 438/640, 438/455, 438/612, 438/107, 438/123, 257/704, 257/417, 257/457, 257/678
• US Class Current: 438/106
• CPC Class Codes: B81C 1/00269 Bonding of solid lids or wafers to the substrate
• CPC Class Codes: H01L 21/50 Assembly of semiconductor devices using processes or apparatus not provided for in a single one of the subgroups H01L21/06 - H01L21/326, e.g. sealing of a cap to a base of a container

Abstract

A method for forming a wafer package includes forming a die structure, wherein the die structure includes a first wafer, a device mounted on the first wafer, a second wafer mounted atop the first wafer with a first seal ring around the device and a second seal ring around a via contact. The method further includes forming a trench in the second wafer around the first seal ring, filling the trench and the via contact with a sealing agent, patterning a topside of the second wafer to removed the excessive sealing agent and to expose a contact pad of the via contact, and singulating a die around the first seal ring.

Claims

1. A method for forming a wafer package, comprising:

forming a die structure comprising;

a first wafer;

a device on the base wafer;

a second wafer mounted atop the first wafer with a first seal ring around the device and a second seal ring around a via contact, the via contact defining a via cavity;

forming a trench in the second wafer around the first seal ring;

filling the trench and the via cavity with a sealing agent;

patterning a topside of the second wafer to remove excessive sealing agent and to expose a contact pad of the via contact; and

singulating a die around the first seal ring.

2. The method of claim 1, wherein said forming a trench comprises performing a deep reactive ion etch to form the trench.

3. The method of claim 1, wherein said forming a trench comprises using a saw to form the trench.

4. The method of claim 1, wherein said patterning a topside of the second wafer comprises wet etching the sealing agent down to the contact pad.

5. The method of claim 1, wherein said patterning a topside of the second wafer comprises dry etching the sealing agent down to the contact pad.

6. The method of claim 1, wherein said singulating the die comprises sawing the die.

7. The method of claim 1, wherein the sealing agent is selected from the group consisting a photoresist, a polyimide, a B-staged bisbenzocyclobutene (BCB), a spin-on-glass, a glass, a pyrex, an oxide, and a nitride.

8. The method of claim 1, wherein the sealing agent is a polymer, the method further comprising depositing on the contact pad a thin film selected from the group consisting of a metal and a dielectric.