Wafer-to-wafer transfer of microstructures using break-away tethers

• US 6,142,358 A
• Filed: 05/31/1997
• Issued: 11/07/2000
• Est. Priority Date: 05/31/1997
• Status: Expired due to Term

• Current Assignee: Regents of the University of California (University of California)
• Original Assignee: Regents of the University of California (University of California)
• Inventors: Howe, Roger T., Cohn, Michael B.
• Primary Examiner(s): Ryan, Patrick
• Assistant Examiner(s): STONER, KILEY SHAWN
• Application Number:
  US08/866,954
• Time in Patent Office: 1,256 Days
• Field of Search: 228/177, 228/110.1, 228/120, 228/138, 228/135, 228/191, 228/180.21, 228/44.7, 414/935, 414/936, 414/937, 414/938, 414/939, 414/940, 414/941, 257/737, 257/738, 438/613
• US Class Current: 228/44.7
• CPC Class Codes: B23K 1/0016 Brazing of electronic components
• CPC Class Codes: B23K 2101/40 Semiconductor devices
• CPC Class Codes: B81B 7/00 Microstructural systems; Auxiliary parts of microstructural devices or systems
• CPC Class Codes: H01L 21/6835 using temporarily an auxiliary support
• CPC Class Codes: H01L 2221/68359 used as a support during manufacture of interconnect decals or build up layers
• CPC Class Codes: H01L 2924/30105 Capacitance
• CPC Class Codes: Y10S 414/135 Associated with semiconductor wafer handling
• CPC Class Codes: Y10S 414/136 including wafer orienting means

Abstract

Break-away tethers to secure electronic, mechanical, optical, or other microstructures, during release from one substrate and transfer to another. Microstructures are fabricated with integrated tethers attaching them to a first substrate. The structures are undercut by etching and contacted and bonded to a second substrate. First and second substrates are separated, breaking the tethers.

Claims

1. An apparatus for transferring a microfabricated structure, comprising:

a handle substrate;

a set of anchors positioned on said handle substrate;

a platform supporting a microfabricated structure;

a set of tethers connected between said set of anchors and said platform, said set of tethers assuming a load bearing state to support said platform in the absence of a transfer load, said set of tethers assuming a detached tether state from said anchors in the presence of said transfer load; and

a transition mechanism attached to said platform, said transition mechanism adapted to engage a target structure in the presence of said transfer load, which causes said detached tether state, resulting in said transition mechanism and said platform being attached to said target structure.

2. The apparatus of claim 1 wherein said transition mechanism is a solder bump.

3. The apparatus of claim 1 wherein said transition mechanism is a mechanical fastener.

4. The apparatus of claim 1 wherein said transition mechanism is a deposited film.

5. The apparatus of claim 1 wherein said deposited film is selected from the group comprising a chemical vapor deposition film, a sputtered film, an evaporated film, and a spin-coated film.