Pulsed-mode direct-write laser metallization

Patent metadata

Field	Value
Publication number	US-10622244-B2
Application number	US-201515124036-A
Country	US
Kind code	B2
Filing date	Apr 5, 2015
Priority date	Feb 18, 2013
Publication date	Apr 14, 2020
Grant date	Apr 14, 2020

Abstract

A method for manufacturing includes coating a substrate ( 22 ) with a matrix ( 28 ) containing a material to be patterned on the substrate. A pattern is fixed in the matrix by directing a pulsed energy beam to impinge on a locus of the pattern so as to cause adhesion of the material to the substrate along the pattern without fully sintering the material in the pattern. The matrix remaining on the substrate outside the fixed pattern is removed, and after removing the matrix, the material in the pattern is sintered.

First claim

The invention claimed is:

1. A method for manufacturing, comprising:
coating a substrate with a matrix containing a material to be patterned on the substrate;
fixing a pattern in the matrix by directing a pulsed energy beam to impinge on a locus of the pattern so as to cause adhesion of the material to the substrate along the pattern without fully sintering the material in the pattern;
removing the matrix remaining on the substrate outside the fixed pattern; and
after removing the matrix, sintering the material in the pattern.

2. The method according to claim 1 , wherein the material to be patterned comprises nanoparticles.

3. The method according to claim 2 , wherein the material in the nanoparticles is electrically conductive, and wherein the pulsed energy beam comprises pulses of radiation having an energy fluence and repetition rate selected so that a resistivity of the trace after fixing the pattern remains at least ten times greater than a final resistivity that is to be achieved by full sintering of the material in the pattern after removing the matrix.

4. The method according to claim 1 , wherein directing the pulsed energy beam comprises directing a sequence of pulses of the energy beam to impinge on each location in the locus on the substrate.

5. The method according to claim 1 , wherein the pulsed energy beam has a pulse repetition rate of at least 1 MHz.

6. The method according to claim 5 , wherein the pulse repetition rate is at least 10 MHz.

7. The method according to claim 1 , wherein the matrix comprises an organic compound in addition to the material to be patterned, and wherein directing the pulsed energy beam comprises directing a sequence of pulses of the energy beam with a fluence per pulse selected to as to cause evaporation of the organic compound from the matrix without fully sintering the material in the pattern.

8. The method according to claim 7 , wherein the fluence per pulse that is applied in fixing the pattern is selected so that the material remains sufficiently porous to permit the organic compound to evaporate through pores in the material without ablation or delamination of the material due to the evaporation of the organic compound.

9. The method according to claim 1 , wherein sintering the material comprises applying a bulk sintering process to the pattern fixed on the substrate.

10. The method according to claim 1 , wherein sintering the material comprises directing further pulses of the pulsed energy beam to sinter the pattern fixed on the substrate.

11. The method according to claim 1 , wherein coating the substrate comprises drying the matrix on the substrate before irradiating the coated substrate.

12. The method according to claim 1 , wherein removing the matrix comprises applying a solvent to remove the matrix remaining on the substrate outside the fixed pattern.

13. A method for manufacturing, comprising:
coating a substrate with a matrix containing a material to be patterned on the substrate; and
directing a pulsed energy beam comprising pulses having a ramped temporal profile, in which an instantaneous power of each pulse increases gradually over a duration of the pulse, to impinge on a point on the coated substrate with a fluence sufficient to fix the material to the substrate and sinter the material at the point.

14. The method according to claim 13 , wherein the matrix comprises an organic compound in addition to the material that is to be fixed to the substrate, and wherein the ramped temporal profile and the fluence are selected to as to cause evaporation of the organic compound from the matrix before sintering the material without causing ablation or delamination of the material due to the evaporation of the organic compound.

15. The method according to claim 13 , wherein the material comprises nanoparticles, and wherein sintering the material causes fusion of the nanoparticles at the point.

16. The method according to claim 13 , wherein the pulses have a duration no greater than 20 ns.

17. The method according to claim 13 , wherein directing the pulsed energy beam comprises creating a pattern of the material on the substrate by directing the pulses to impinge on a sequence of points defining the pattern on the coated substrate.

18. The method according to claim 17 , wherein the points in the sequence are mutually non-overlapping.

19. The method according to claim 17 , and comprising, after creating the pattern, removing the matrix remaining on the substrate outside a locus of the pattern.

20. A system for manufacturing, comprising:
a coating machine, which is configured to coat a substrate with a matrix containing a material to be patterned on the substrate;
a writing machine, which is configured to fix a pattern in the matrix by directing a pulsed energy beam to impinge on a locus of the pattern so as to cause adhesion of the material to the substrate along the pattern without fully sintering the material in the pattern;
a matrix removal machine, which is configured to remove the matrix remaining on the substrate outside the fixed pattern; and
a sintering machine, which is configured to sinter the material in the pattern after removal of the matrix.

21. The system according to claim 20 , wherein the material to be patterned comprises nanoparticles.

22. The system according to claim 21 , wherein the material in the nanoparticles is electrically conductive, and wherein the pulsed energy beam comprises pulses of radiation having an energy fluence and repetition rate selected so that a resistivity of the trace after fixing the pattern remains at least ten times greater than a final resistivity that is to be achieved by full sintering of the material in the pattern after removing the matrix.

23. The system according to claim 20 , wherein the writing machine is configured to direct a sequence of pulses of the energy beam to impinge on each location in the locus on the substrate.

24. The system according to claim 20 , wherein the pulsed energy beam has a pulse repetition rate of at least 1 MHz.

25. The system according to claim 24 , wherein the pulse repetition rate is at least 10 MHz.

26. The system according to claim 20 , wherein the matrix comprises an organic compound in addition to the material to be patterned, and wherein the writing machine is configured to direct a sequence of pulses of the energy beam with a fluence per pulse selected to as to cause evaporation of the organic compound from the matrix without fully sintering the material in the pattern.

27. The system according to claim 26 , wherein the fluence per pulse that is applied in fixing the pattern is selected so that the material remains sufficiently porous to permit the organic compound to evaporate through pores in the material without ablation or delamination of the material due to the evaporation of the organic compound.

28. The method according to claim 20 , wherein the sintering machine is configured to apply a bulk sintering process to the pattern fixed on the substrate.

29. The method according to claim 20 , wherein the sintering machine is configured to apply further pulses of the pulsed energy beam to sinter the pattern fixed on the substrate.

30. The method according to claim 20 , and comprising a drying machine, which is configured to dry the matrix on the substrate before irradiating the

Assignees

• Orbotech Ltd

Inventors

• Zenou Michael
• Kotler Zvi
• Ankri Jonathan
• Rotnemer Abraham
• Ermak Oleg

Classifications

• H05K3/02 Primary

  in which the conductive material is applied to the surface of the insulating support and is thereafter removed from such areas of the surface which are not intended for current conducting or shielding · CPC title

• H05K3/105

  by conversion of non-conductive material on or in the support into conductive material, e.g. by using an energy beam · CPC title

• H05K1/097

  Inks comprising nanoparticles and specially adapted for being sintered at low temperature (H05K1/095 takes precedence) · CPC title

• H05K2203/107

  Using laser light · CPC title

• H05K2203/1492

  Periodical treatments, e.g. pulse plating of through-holes · CPC title