Laser die light source module with low inductance

• US 8,882,310 B2
• Filed: 12/10/2012
• Issued: 11/11/2014
• Est. Priority Date: 12/10/2012
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Mandelboum, David, Yahav, Giora, Pellman, Asaf, Felzenshtein, Shlomo
• Primary Examiner(s): Patel, Nimeshkumar
• Assistant Examiner(s): HORIKOSHI, STEVEN Y
• Application Number:
  US13/709,121
• Publication Number:
  US 20140160745A1
• Time in Patent Office: 701 Days
• Field of Search: 257/E33.066, 257/E33.075, 348/46, 348/135, 362/294, 362/373, 362/362, 362/382, 372/34, 372/36, 372/38.08
• US Class Current: 362/373
• CPC Class Codes: F21V 13/02 Combinations of only two kinds of elements
• CPC Class Codes: F21V 21/00 Supporting, suspending, or attaching arrangements for lighting devices F21V17/00, F21V19/00 take precedence; arrangement of signalling or lighting devices, the mounting or supporting thereof or circuits therefor, for vehicles in general B60Q, stands for supporting apparatus or articles in general F16M11/00; Hand grips
• CPC Class Codes: G01S 17/894 3D imaging with simultaneous measurement of time-of-flight at a 2D array of receiver pixels, e.g. time-of-flight cameras or flash lidar
• CPC Class Codes: G02B 27/0938 Using specific optical elements
• CPC Class Codes: G02B 27/0944 Diffractive optical elements, e.g. gratings, holograms gratings per se G02B5/18; holograms used as optical elements per se G02B5/32
• CPC Class Codes: G02B 27/20 for imaging minute objects, e.g. light-pointer
• CPC Class Codes: H01S 5/022 Mountings; Housings
• CPC Class Codes: H01S 5/02208 characterised by the shape of the housings
• CPC Class Codes: H01S 5/02212 Can-type, e.g. TO-CAN housings with emission along or parallel to symmetry axis
• CPC Class Codes: H01S 5/02253 using lenses
• CPC Class Codes: H01S 5/02257 using windows, e.g. specially adapted for back-reflecting light to a detector inside the housing
• CPC Class Codes: H01S 5/023 Mount members, e.g. sub-mount members
• CPC Class Codes: H01S 5/0233 Mounting configuration of laser chips
• CPC Class Codes: H01S 5/02345 Wire-bonding
• CPC Class Codes: H01S 5/0235 Method for mounting laser chips
• CPC Class Codes: H01S 5/024 Arrangements for thermal management
• CPC Class Codes: H01S 5/02469 Passive cooling, e.g. where heat is removed by the housing as a whole or by a heat pipe without any active cooling element like a TEC
• CPC Class Codes: H01S 5/06209 in single-section lasers H01S5/0608 takes precedence
• CPC Class Codes: H01S 5/06216 Pulse modulation or generation
• CPC Class Codes: H01S 5/4031 Edge-emitting structures
• CPC Class Codes: H05K 1/0243 : Printed circuits associated with mounted high frequency components
• CPC Class Codes: H05K 1/0296 : Conductive pattern lay-out details not covered by sub groups H05K1/02 - H05K1/0295 H05K1/11 takes precedence; lay-out adapted to mounted component configuration H05K1/18
• CPC Class Codes: H05K 2201/09145 : Edge details
• CPC Class Codes: H05K 2201/10106 : Light emitting diode [LED]
• CPC Class Codes: H05K 3/0052 : Depaneling, i.e. dividing a panel into circuit boards; Working of the edges of circuit boards

Abstract

An embodiment of the invention provides a low inductance light source module, which may have a small footprint and comprise a printed circuit board (PCB) mount having first and second conducting traces formed on a side of the PCB mount and a semiconducting light source having a first electrical contacts for receiving power that is bonded to the first conducting trace with a conducting bonding material and a second electrical contact for receiving power that is connected by at least one bondwire to the second conducting trace.

Claims

1. A light source module comprising:

a printed circuit board (PCB) mount having first and second sides and first and second conducting traces formed on the first side;

a semiconducting light source having first and second electrical contacts for receiving power that excites the light source to emit light, wherein the first electrical contact is bonded to the first conducting trace with a conducting bonding material and the second electrical contact is connected by at least one bondwire to the second conducting trace;

wherein the first and second traces extend to a same edge of the PCB so that the PCB may be inserted into a socket to connect the traces to a power supply that provides power to the semiconducting light source and are formed having at least one recess for aligning a preformed protective cover that protects the semiconducting light source to the module.

2. A light source module according to claim 1 wherein the first conducting trace is formed having a recess and the second conducting trace has a portion that extends into the recess.

3. A light source module according to claim 2 and comprising at least one heat conducting trace formed on the second side of the PCB mount.

4. A light source module according to claim 3 wherein the at least one heat conducting trace is thermally connected by at least one via to the first trace, the second trace, or both traces.

5. A light source module according to claim 4 wherein the at least one heat conducting trace comprises at least one electrically conducting trace.

6. A light source module according to claim 5 wherein the at least one electrically conducting trace comprises third and fourth electrically conducting traces.

7. A light source module according to claim 6 wherein the third and fourth conducting traces are minor images of the first and second conducting traces respectively.

8. A light source module according to claim 7 wherein the third and fourth conducting traces are connected respectively to the first and second conducting traces by vias.

9. A light source module according to claim 1 wherein current provided by a power supply that powers the semiconductor light source flows into and out from the semiconductor light source along the second and first conducting traces respectively and wherein the first and second conducting traces have lengths substantially parallel to current flow that is less than or equal to about 5 mm.

10. A light source module according to claim 9 wherein the first conducting trace has width in directions substantially perpendicular to current flow in the first conducting trace less than or equal to about 4 mm.

11. A light source module according to claim 9 wherein the second conducting trace has width in directions substantially perpendicular to current flow in the second conducting trace less than or equal to about 0.75 mm.

12. A light source module according to claim 9 wherein the first and second conducting traces have thickness greater than or equal to about 0.15 mm.

13. A light source module according to claim 1 wherein the at least one bondwire has a length less than or equal to about 0.5 mm.

14. A light source module according to claim 1 wherein the PCB mount is characterized by an inductance that is less than or equal to about 3 nH (nanoHenrys).

15. A light source module according to claim 1 wherein the PCB mount is characterized by an inductance that is less than or equal to about 1.5 nH.

16. A light source module according to claim 1 and comprising a protective cover that covers the semiconductor light source and the at least one bondwire.

17. A light source module according to claim 1 wherein the semiconductor light source comprises an edge emitting laser diode.

18. An illumination system comprising:

at least one light source module according to claim 1;

a tube having a recess in which the at least one light source module is seated;

a lens seated in the tube that receives light from the at least one light source module and collimates the received light; and

a diffuser seated in the tube that receives collimated light from the lens and diffuses the received light.

19. An illumination system according to claim 18 and comprising a circuit that controls the at least one light source to transmit a train of light pulses having pulse widths less than or equal to about 20 nanoseconds.

20. An illumination system according to claim 19 wherein the light pulses have a repetition frequency greater than or equal to about 0.8 MHz.