Optoelectronic modules and submount for same and a method for manufacturing an array of optical devices
View Patent ↗An array of optical devices includes singlets diced or separated from a first diced surface and a second diced surface of a semiconductor wafer. Each singlet includes a single optical emitter or a single photosensitive semiconductor device. The singlets are identified as operationally fit before being arranged in corresponding features in a receiving region of a submount. The corresponding features of the submount are arranged to align and precisely control the pitch or separation distance between optical portions of a desired number of singlets. The use of operationally fit singlets dramatically increases production efficiency as it is no longer necessary to identify N contiguous operational optical devices in a semiconductor wafer to produce a precisely aligned array of N operational optical devices.
1. An optoelectronic module, comprising:
a heat sink having a first surface and a mounting surface opposed to the first surface;
a sub-assembly comprising a submount having a plurality of respective first and second surfaces that separately form a plurality of respective receiving regions for receiving optical devices comprising singlets, the first surface of the submount abutting and overlapping a portion of a first surface of a singlet over the entirety of the first surface of the submount, the second surface of the submount abutting and overlapping a respective portion of a second surface of the singlet over the entirety of the second surface of the submount, the first and second surfaces of the singlet extending beyond the first and second surfaces of the submount in a direction orthogonal to the mounting surface of the heatsink, such that for adjacent singlets arranged in the respective receiving regions a third surface of a first singlet abuts a portion of a first surface of a second singlet and such that the third surface of the first singlet lies entirely beyond the respective receiving region of the submount in a direction parallel to the mounting surface of the heat sink, the submount aligning and maintaining a consistent separation distance between adjacent optical elements in the respective singlets; and
at least one integrated circuit electrically coupled to the singlets.
2. The optoelectronic module of claim 1 , wherein the plurality of first and second surfaces of the submount define an angle of approximately 90 degrees in the receiving region.
3. The optoelectronic module of claim 2 , wherein the first and second surfaces of the submount define an angle having a tolerance range of about 0.3 degrees.
4. The optoelectronic module of claim 1 , wherein the submount comprises a material selected from the group consisting of quartz, silicon, and optical glass.
5. The optoelectronic module of claim 1 , wherein the submount has a thickness that is less than a height of the singlets, such that the submount does not interfere with a wirebond that electrically couples a contact on an exposed surface of the singlets to a corresponding contact on the at least one integrated circuit.
6. The optoelectronic module of claim 1 , wherein the singlets are physically coupled to the submount by an epoxy applied along an exposed portion of the first surface of the singlets, an exposed portion of the second surface of the singlets and a fourth surface of the submount opposed to the third surface of the submount.
7. The optoelectronic module of claim 6 , wherein as the epoxy is cured an unexposed portion of the first surface of the singlet closely contacts the first surface of the submount, an unexposed portion of the second surface of the singlet closely contacts the second surface of the submount.
8. The optoelectronic module of claim 1 , further comprising:
an epoxy layer adjacent to the third surface of the submount, the non-active surface of the singlets and the mounting surface of the heat sink for stabilizing the subassembly to form a linear array of optical devices.
9. The optoelectronic module of claim 1 , wherein at least one singlet comprises a VCSEL.
10. The optoelectronic module of claim 1 , wherein at least one singlet comprises a photosensitive semiconductor device.
11. A method for manufacturing an array of optical devices, the method comprising:
separating a desired number of operational singlets from a semiconductor wafer by forming a respective first diced surface, a respective second diced surface and a respective third diced surface for each of the desired number of operational singlets from the semiconductor wafer, the first diced surface being approximately orthogonal to the second diced surface, the first diced surface being approximately parallel to the third diced surface;
arranging the respective first diced surface and the second diced surface of each of the operational singlets in close proximity to corresponding first and second surfaces in a respective receiving region of a submount, the receiving regions arranging the operational singlets by contacting a portion of a length of the first diced surface and an entire length of the second diced surface such that optical portions are aligned with a consistent separation distance between optical portions of adjacent operational singlets such that for adjacent operational singlets arranged in the submount, the third diced surface of a first singlet abuts a portion of the first diced surface of a second singlet and such that the third surface of the first singlet extends in a direction parallel to a mounting surface of the submount entirely beyond the respective receiving region of the submount and such that the first and second diced surfaces of respective operational singlets extend beyond a third surface of the submount in a direction orthogonal to a mounting surface of a heatsink opposed to the mounting surface of the submount;
applying an epoxy at an intersection of respective exposed surfaces of the operational singlets and the submount; and
curing the epoxy.
12. The method of claim 11 , wherein the step of separating a desired number of operational singlets from a semiconductor wafer includes cutting along first and second axes.
13. The method of claim 12 , wherein the cutting along the first and second axes is performed with respect to the optical portion within the operational singlet.
14. The method of claim 11 , wherein the third surface of the submount is substantially orthogonal to the first and to the second surfaces of the submount, with a fourth surface of the submount opposed to the third surface of the submount.
15. The method of claim 11 , wherein the step of separating a desired number of operational singlets from a semiconductor wafer includes forming a first diced surface that is longer in a first direction than a second diced surface is in a second direction orthogonal to the first direction.
16. The method of claim 11 , further comprising:
exposing the epoxy to ultraviolet light to bond the operational singlets to the submount;
arranging a non-active surface of the operational singlets and the third surface of the submount on a mounting surface of a module; and
electrically coupling the operational singlets to the module.
17. The method of claim 16 , wherein the step of arranging a non-active surface of the operational singlets and the third surface of the submount on a surface of the module comprises introducing an adhesive layer between the mounting surface of the module and the non-active surface of the operational singlets.
18. The method of claim 11 , wherein at least one of the operational singlets comprises an emitter.
19. The method of claim 11 , wherein at least one of the operational singlets comprises a photosensitive semiconductor device.
20. The method of claim 11 , wherein the submount comprises a material selected from the group consisting of quartz, silicon, and optical glass.