METHODS OF MANUFACTURING MICRODEVICES IN LAMINATES, LEAD FRAMES, PACKAGES, AND PRINTED CIRCUIT BOARDS

• US 20080283180A1
• Filed: 04/30/2008
• Published: 11/20/2008
• Est. Priority Date: 12/15/2006
• Status: Active Grant

• Current Assignee: Regents of the University of California (University of California)
• Original Assignee: Regents of the University of California (University of California)
• Inventors: Bachman, Mark, Li, Guann-Pyng
• Granted Patent: US 8,877,074 B2
• Time in Patent Office: Days
• US Class Current: 156/221
• CPC Class Codes: B32B 37/02 characterised by a sequence of laminating steps, e.g. by adding new layers at consecutive laminating stations
• CPC Class Codes: B81B 2203/0109 Bridges
• CPC Class Codes: B81B 2203/0118 Cantilevers
• CPC Class Codes: B81C 1/00182 Arrangements of deformable or non-deformable structures, e.g. membrane and cavity for use in a transducer
• CPC Class Codes: B81C 1/00253 Processes for integrating an electronic processing unit with a micromechanical structure not provided for in B81C1/0023 - B81C1/00246
• CPC Class Codes: Y10T 156/10 Methods of surface bonding and/or assembly therefor
• CPC Class Codes: Y10T 156/1043 Subsequent to assembly

Abstract

Systems and methods for producing micromachined devices, including sensors, actuators, optics, fluidics, and mechanical assemblies, using manufacturing techniques of lead frames, substrates, microelectronic packages, printed circuit boards, flex circuits, and rigid-flex materials. Preferred embodiments comprise using methods from post-semiconductor manufacturing to produce three-dimensional and free-standing structures in non-semiconductor materials. The resulting devices may remain part of the substrate, board or lead frame which can then used as a substrate for further packaging electronic assembly operations. Alternatively, the devices may be used as final components that can be assembled within other devices.

Claims

1. A method of manufacturing a free standing structure using a thin sheet carrier comprising the steps of

(a) preparing a thin sheet carrier,

(b) depositing a photosensitive material (photoresist) on the surface of the thin sheet carrier and lithographically patterning the photoresist,

(c) depositing a second material on the thin sheet carrier surface through the openings in the photoresist, and

(d) stripping the photoresist and leaving a patterned second material (patterned microstructure) on the thin sheet carrier.

2. The method of claim 1 wherein the thin sheet carrier is copper foil.

3. The method of claim 1 wherein the second material is electroplated on the thin sheet carrier.

4. The method of claim 1 wherein the second material is deposited prior to lithography, then etched through the openings in the photoresist.

5. The method of claim 1 further comprising repeating steps (b) through (d) to produce further microstructures on the thin sheet carrier.

6. The method of claim 1 wherein the thin sheet carrier is bonded against a third material by lamination, molding, deposition, or electroplating.

7. The method of claim 6 wherein the third material includes openings and structures.

8. The method of claim 1 further comprising the step of etching away at least a portion of the thin sheet carrier to reveal a freestanding structure.

9. The method of claim 1 wherein the thin sheet carrier is a laminate comprising more than one sheet.

10. The method of claim 1 wherein the patterned microstructure is made from multiple layers of material.

11. The method of claim 1 wherein the patterned microstructure is made from multiple layers of material, each patterned differently.

12. The method of claim 1 wherein the patterned microstructure is made from photosensitive material formed by lithography.

13. The method of claim 1 wherein the patterned microstructure is made from a material formed by depositing through a stencil.

14. The method of claim 1 wherein the patterned microstructure is made from a material formed by deposition and subsequent cutting or etching by other means, such as laser, sandblasting, edm, waterjet, milling, and the like.

15. The method of claim 1 wherein the patterned microstructure is made from a material formed by selective deposition such as by nozzle-based dispensing or by printing (ink-jet or offset).

16. The method of claim 1 further comprising the steps of mechanical shaping or pre-etching the thin sheet carrier.

17. The method of claim 1 further comprising the steps of micropatterning structures on both sides of the carrier sheet.

18. A method of manufacturing a free standing structure using a thin sheet carrier comprising the steps of

(a) preparing a thin sheet carrier,

(b) patterning a microstructure and transferring the microstructure to and assembling the microstructure on the thin sheet carrier surface,

(c) depositing a second material on the thin sheet carrier surface through the openings in the photoresist, and

(d) stripping the photoresist and leaving a patterned second material (patterned microstructure) on the thin sheet carrier.

19. A method of manufacturing a free standing structure comprising the steps of

creating a microstructure on a carrier material,

encapsulating the microstructure with a second material,

releasing the encapsulated microstructure from the carrier surface,

moving the encapsulated microstructure to a second carrier using precision pick and place machinery,

bonding the encapsulated microstructure to the second carrier, and

removing the encapsulant from the microstructure,

20. A method of manufacturing a free standing structure comprising the steps of

creating a first microstructure on a carrier material,

encapsulating the microstructure with a sacrificial material,

mechanically placing a second microstructure on the first microstructure and bonding the second microstructure to the first microstructure,

releasing the encapsulated microstructure from the carrier surface,

removing the encapsulant from the first microstructure,

21. A method of manufacturing a free standing structure comprising the steps of

preparing layers of laminate sheets on a carrier material,

cutting openings in the laminate sheets,

laminating the laminate sheets together to produce a layered structure, wherein openings in the sheets overlap to form a cavity,

flowing material into the cavity, and

etching away portions of the laminate structure adjacent to the cavities to reveal a freestanding structure.