Methods for making thick film elements

• US 7,234,214 B2
• Filed: 03/18/2005
• Issued: 06/26/2007
• Est. Priority Date: 02/25/2003
• Status: Expired due to Fees

• Current Assignee: Palo Alto Research Center, Inc. (Xerox Holdings Corp.)
• Original Assignee: Palo Alto Research Center, Inc. (Xerox Holdings Corp.)
• Inventors: Weisberg, Michael C., Buhler, Steven A., Fitch, John S., Wong, William S., Solberg, Scott E., Xu, Baomin, Littau, Karl A., Elrod, Scott A.
• Primary Examiner(s): TRINH, MINH N
• Application Number:
  US11/084,579
• Publication Number:
  US 20050162045A1
• Time in Patent Office: 830 Days
• Field of Search: 29 2535- 2542, 29830-834, 298/42, 298/46, 310328-332, 310/366, 310/358, 156/152, 156/247, 156/230, 438/455, 438/458, 438/107, 438/604, 428/202, 428/209
• US Class Current: 29/25.35
• CPC Class Codes: B41J 2/161 of film type, deformed by bending and disposed on a diaphragm
• CPC Class Codes: B41J 2/1623 bonding and adhesion
• CPC Class Codes: B41J 2/1632 machining
• CPC Class Codes: B41J 2/1634 laser machining
• CPC Class Codes: B41J 2/1637 molding
• CPC Class Codes: B41J 2/1646 thin film formation by sputtering
• CPC Class Codes: H01L 2221/68368 used in a transfer process involving at least two transfer steps, i.e. including an intermediate handle substrate
• CPC Class Codes: H10N 30/073 by fusion of metals or by adhesives
• CPC Class Codes: H10N 30/074 by depositing piezoelectric or electrostrictive layers, e.g. aerosol or screen printing
• CPC Class Codes: H10N 30/081 by coating or depositing using masks, e.g. lift-off
• CPC Class Codes: Y10T 29/42 Piezoelectric device making
• CPC Class Codes: Y10T 29/435 Solid dielectric type
• CPC Class Codes: Y10T 29/49128 Assembling formed circuit to base
• CPC Class Codes: Y10T 29/4913 Assembling to base an electrical component, e.g., capacitor, etc.
• CPC Class Codes: Y10T 29/49133 with component orienting
• CPC Class Codes: Y10T 29/49155 Manufacturing circuit on or in base
• CPC Class Codes: Y10T 29/4981 Utilizing transitory attached element or associated separate material

Abstract

A method of producing at least one thick film element, including depositing a material on a surface of at least one first substrate to form at least one thick film element structure having a thickness of approximately greater than 10 μm to 100 μm. Then, then the at least one thick film element structure is bonded to a second substrate, and the at least one first substrate is removed from the at least one thick film element structure using a lift-off process employing radiation energy. The lift-off process including emitting, from a radiation source, a radiation beam through the first substrate to an attachment interface formed between the first substrate and the at least one thick film element structure at the first surface of the first substrate. The first substrate being substantially transparent at the wavelength of the radiation beam, permitting the radiation beam to generate sufficient energy at the interface to break the attachment.

Claims

1. A method of producing at least one thick-film element comprising:

depositing a material onto a surface of at least one first substrate to form at least one thick-film element structure having a thickness of approximately greater than 10 μ

m to approximately 100 μ

m;

bonding the at least one thick-film element structure to a second substrate;

removing the at least one first substrate from the at least one thick-film element structure using a liftoff process using radiation energy including,

emitting, from a radiation source, a radiation beam through the first substrate to an attachment interface formed between the first substrate and the at least one thick-film element structure at the surface of the first substrate, wherein the first substrate is substantially transparent at the wavelength of the radiation beam, permitting the radiation beam to generate sufficient energy at the interface to break the attachment.

2. The method according to claim 1, wherein the radiation beam is a laser beam.

3. The method according to claim 1, wherein the step of removing the first substrate further includes heating the interface with a heater to break any remaining attachment.

4. The method of claim 3, wherein the heater generates a temperature of between 40°

C. to 50°

C.

5. The method according to claim 1, wherein the first substrate is reusable.

6. The method according to claim 1, wherein a step of depositing an electrode on a surface of the at least one thick-film element structure, is undertaken following the step of depositing a material onto a surface of the first substrate to form the at least one thick-film element structure.

7. The method according to claim 1, wherein the bonding step includes a step of providing at least one of:

(i) a nonconductive epoxy bonding containing conductive particles between the electrode and the second substrate, or (ii) a nonconductive epoxy bonding without conductive particles between the electrode and the second substrate, the second substrate being an electrically conductive substrate or having an electrically conductive portion, wherein the nonconductive epoxy bonding process provides for electrical contact between the electrode and the second substrate.

8. The method according to claim 1, wherein if more than one first substrate is used, the material on these substrates are the same.

9. The method according to claim 1, wherein the at least one thick-film element structure is a plurality of element structures, and if more than one substrate is used, the thickness and geometrical shape of the element structures on the substrates are the same.

10. The method according to claim 1, wherein the at least one thick-film element structure is a plurality of element structures, and if more than one substrate is used, the thickness and geometrical shape of the element structures on the substrates are different.

11. The method according to claim 1, wherein the depositing step includes patterning the at least one thick film element.

12. The method according to claim 1, wherein the depositing step implements a direct marking process.

13. The method according to claim 12, wherein the direct marking process is at least one of screen printing, ballistic aerosol marking, jet printing and acoustic ejection.

14. The method according to claim 1, wherein the depositing step includes sintering the at least one thick film element structure at a temperature of above 600°

C.

15. The method according to claim 1, wherein the depositing step includes sintering the at least one thick film element structure at a temperature in a range of approximately 1100°

C. to 1350°

C.

16. The method according to claim 1, further including polishing a surface of the at least one thick film element structure.

17. The method according to claim 16, wherein the polishing step is a dry tape polishing procedure.

18. The method according to claim 1, wherein the wavelength of the radiation beam is approximately 308 nm.

19. The method of claim 1, wherein the material deposited onto the first substrate is a polycrystalline and it was deposited by a screen printing process.

20. The method of claim 1, wherein the emitting from the radiation source results in damage to a surface of the at least one thick-film element structure, the damage being no more than to a thickness of about 0.1 μ

m.

21. The method according to claim 1, wherein if more than one first substrate is used, the material on these substrates are different from each other.