Reflowable opto-electronic module

• US 20130267273A1
• Filed: 03/14/2013
• Published: 10/10/2013
• Est. Priority Date: 04/05/2012
• Status: Active Grant

• Current Assignee: Ams Sensors Singapore Pte. Ltd. (Ams-Osram AG)
• Original Assignee: Heptagon Micro Optics Pte Ltd
• Inventors: Rudmann, Hartmut, Bietsch, Alexander
• Granted Patent: US 9,063,005 B2
• Time in Patent Office: Days
• US Class Current: 455/556.1
• CPC Class Codes: B29D 11/00307 Producing lens wafers
• CPC Class Codes: B29D 11/00375 by moulding lenses in holes through a substrate
• CPC Class Codes: B32B 38/0004 Cutting, tearing or severing, e.g. bursting; Cutter details cutting in general B26D; laminating combined with punching or perforating B32B38/04; removing all or part of the layers B32B38/10; cutting in combination with laying up and registration B32B38/185 takes precedence
• CPC Class Codes: G01J 1/0271 Housings; Attachments or accessories for photometers
• CPC Class Codes: G01J 1/0407 Optical elements not provided otherwise, e.g. manifolds, windows, holograms, gratings
• CPC Class Codes: G01S 17/04 Systems determining the presence of a target
• CPC Class Codes: G01S 7/4813 Housing arrangements
• CPC Class Codes: G01V 8/12 using one transmitter and one receiver
• CPC Class Codes: H01L 25/167 comprising optoelectronic devices, e.g. LED, photodiodes
• CPC Class Codes: H01L 25/50 Multistep manufacturing processes of assemblies consisting of devices, each device being of a type provided for in group H01L27/00 or H01L29/00 H01L21/50 takes precedence
• CPC Class Codes: H01L 27/14643 Photodiode arrays; MOS imagers
• CPC Class Codes: H01L 27/14649 Infrared imagers
• CPC Class Codes: H01L 27/14685 Process for coatings or optical elements
• CPC Class Codes: H01L 27/14687 Wafer level processing
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 31/12 structurally associated with, e.g. formed in or on a common substrate with, one or more electric light sources, e.g. electroluminescent light sources, and electrically or optically coupled thereto semiconductor devices with at least one potential barrier or surface barrier adapted for light emission H01L33/00; amplifiers using electroluminescent element and photocell H03F17/00; electroluminescent light sources per se H05B33/00
• CPC Class Codes: H03K 17/941 using an optical detector H03K17/968 takes precedence
• CPC Class Codes: H03K 2017/9455 constructional details of proximity switches using a magnetic detector H03K17/9505
• CPC Class Codes: H03K 2217/94108 making use of reflection
• CPC Class Codes: Y10T 156/1052 : with cutting, punching, tearing or severing

Abstract

An optical proximity sensor module includes a substrate, a light emitter mounted on a first surface of the substrate, the light emitter being operable to emit light at a first wavelength, and a light detector mounted on the first surface of the substrate, the light detector being operable to detect light at the first wavelength. The module includes an optics member disposed substantially parallel to the substrate, and a separation member, wherein the separation member is disposed between the substrate and the optics member. Multiple modules can be fabricated in a wafer-level process and can be composed of reflowable materials so that the modules can be incorporated more easily into devices whose manufacture occurs, at least in part, at elevated temperatures when the module is integrated into the device or during subsequent manufacturing processes.

Claims

1. An optical proximity sensor module comprising:

a substrate;

a light emitter mounted on a first surface of the substrate, the light emitter operable to emit light at a first wavelength;

a light detector mounted on the first surface of the substrate, the light detector operable to detect light at the first wavelength;

an optics member composed of a first polymer material and disposed substantially parallel to the substrate, wherein the optics member comprises first and second transparent portions that are transparent to light at the first wavelength, the optics member further comprising a blocking portion that substantially attenuates or blocks incident light at the first wavelength, and wherein the first transparent portion is disposed above the light emitter and the second transparent portion is disposed above the light detector; and

a separation member composed of a second polymer material, wherein the separation member is disposed between, and in contact with, the substrate and the optics member, and wherein the separation member surrounds the light emitter and the light detector,

wherein the first polymer material and the second polymer material are each thermally stable up to at least 260°

C.

2. The optical proximity sensor module of claim 1 wherein at least one of the first polymer material or the second polymer material comprises a thermosetting polymer.

3. The optical proximity sensor module of claim 1 wherein at least one of the first polymer material or the second polymer material comprises a thermoplastic polymer.

4. The optical proximity sensor module of claim 3 wherein a glass transition temperature of the thermoplastic polymer is above about 260°

C.

5. The optical proximity sensor module of claim 2 wherein at least one of the first polymer material or the second polymer material comprises a thermally-cured epoxy.

6. The optical proximity sensor module of claim 2 wherein at least one of the first polymer material or the second polymer material comprises an ultraviolet (UV)-cured epoxy.

7. The optical proximity sensor module of claim 1 wherein each of the first transparent portion and the second transparent portion comprises a lens.

8. The optical proximity sensor module of claim 7 wherein each lens is composed of a third polymer material that is thermally stable up to at least 260°

C.

9. The optical proximity sensor module of claim 8 wherein the third polymer material is a thermosetting polymer or a thermoplastic polymer.

10. The optical proximity sensor module of claim 8 wherein the third polymer material comprises a thermally-cured epoxy material.

11. The optical proximity sensor module of claim 8 wherein the third polymer material comprises a UV-cured epoxy.

12. The optical proximity sensor module of claim 8 wherein the third polymer material is transparent to light at the first wavelength.

13. A method of fabricating a plurality of optical proximity sensor modules, the method comprising:

providing a substrate wafer having a first surface on which a plurality of light emitters are mounted and a plurality of light detectors are mounted, wherein each light emitter is disposed adjacent a corresponding one of the light detectors, the light emitters and light detectors being mounted on the substrate wafer in an arrangement, and wherein the light emitters are operable to emit light at a first wavelength and the light detectors are operable to detect light at the first wavelength;

providing a spacer wafer composed of a first polymer material that is thermally stable up to at least 260°

C., wherein the spacer wafer has openings in an arrangement substantially corresponding to the arrangement of the light emitters and light detectors on the substrate wafer;

providing an optics wafer composed of a second polymer material that is thermally stable up to about 260°

C., the optics wafer comprising (1) a blocking portion that substantially attenuates or blocks incident light at the first wavelength, and (2) a plurality of first and second transparent portions that are transparent to light at the first wavelength, the first and second transparent portions being arranged in an arrangement substantially corresponding to the arrangement of the light emitters and light detectors on the substrate wafer;

bonding the substrate wafer, the spacer wafer, and the optics wafer together in a wafer stack, in which the spacer wafer is arranged between the substrate wafer and the optics wafer such that the light emitters and light detectors are disposed between the substrate wafer and the optics wafer; and

separating the wafer stack into a plurality of modules, each of which includes one of the light emitters and one of the light detectors.

14. The method of claim 13 wherein bonding comprises bonding the substrate wafer to the spacer wafer using a heat-curable epoxy.

15. The method of claim 14 wherein bonding the substrate wafer to the spacer wafer comprises heating the heat-curable epoxy to a temperature of at least 100°

C.

16. The method of claim 15 wherein bonding comprises bonding the spacer wafer to the optics wafer using a heat-curable epoxy.

17. The method of claim 16 wherein bonding the spacer wafer to the optics wafer comprises heating the heat-curable epoxy to a temperature of at least 100°

C.

18. The method of claim 13 wherein each of the first and second transparent portions comprises a lens composed of a third polymer material that is thermally stable up to at least 260°

C.

19. A mobile communication device comprising:

a processor,

memory,

a display,

a communication interface,

a transceiver, and

an optical proximity sensor module comprising;

a substrate;

a light emitter mounted on a first surface of the substrate, the light emitter operable to emit light at a first wavelength;

a light detector mounted on the first surface of the substrate, the light detector operable to detect light at the first wavelength;

an optics member composed of a first polymer material that is thermally stable up to at least 260°

C. and disposed substantially parallel to the substrate, wherein the optics member comprises first and second transparent portions that are transparent to light at the first wavelength, the optics member further comprising a blocking portion that substantially attenuates or blocks incident light at the first wavelength, and wherein the first transparent portion is disposed above the light emitter and the second transparent portion is disposed above the light detector; and

a separation member composed of a second polymer material that is thermally stable up to at least 260°

C., wherein the separation member is disposed between, and in contact with, the substrate and the optics member, and wherein the separation member surrounds the light emitter and the light detector.