OPTICAL SENSORS AND METHODS FOR PROVIDING OPTICAL SENSORS

• US 20100259766A1
• Filed: 07/08/2009
• Published: 10/14/2010
• Est. Priority Date: 04/14/2009
• Status: Abandoned Application

• Current Assignee: Intersil Americas LLC (Renesas Electronics Corporation)
• Original Assignee: Intersil Americas LLC (Renesas Electronics Corporation)
• Inventors: Patwardhan, Viraj, Wiese, Lynn K., Kelkar, Nikhil
• Application Number:
  US12/499,693
• Publication Number:
  US 20100259766A1
• Time in Patent Office: Days
• US Class Current: 356/614
• CPC Class Codes: H01L 2224/49171 Fan-out arrangements
• CPC Class Codes: H01L 25/167 comprising optoelectronic devices, e.g. LED, photodiodes
• CPC Class Codes: H01L 33/58 Optical field-shaping elements

Abstract

Provided herein are optical sensor devices, methods for making the same, and systems including the same. An optical sensor device, according to an embodiment, includes a light detector die and a light source die attached to the same or different die attachment substrates so that there is a space between the light source die and the light detector die. A light transmissive material covers the light detector die, the light source die and at least a portion of the space between the light detector die and the light source die. A groove is formed (e.g., saw, blade or laser cut, or cast) in the light transmissive material between the light detector die and the light source die, and an opaque material is put within the groove to provide a light barrier between the light detector die and the light source die.

Claims

1. An optical sensor device, comprising:

at least one die attachment substrate;

a light detector die attached to a said die attachment substrate;

a light source die attached to the same die attachment substrate to which the light detector die is attached, or to another said die attachment substrate, so that there is a space between the light source die and the light detector die;

a light transmissive material covering the light detector die, the light source die and at least a portion of the space between the light detector die and the light source die;

a groove formed in the light transmissive material between the light detector die and the light source die; and

an opaque material, within the groove, wherein the opaque material provides a light barrier between the light detector die and the light source die.

2. The device of claim 1, wherein the groove is saw cut, blade cut, or laser cut.

3. The device of claim 1, wherein:

the light transmissive material is formed over the light detector die, the light source die and the at least a portion of the space between the light detector die and the light source die using a mold; and

the groove is formed by a feature in the mold.

4. The device of claim 1, wherein the groove is formed in the light transmissive material such that the groove extends to the die attachment substrate.

5. The device of claim 1, wherein each said die attachment substrate comprises a die attachment leadframe substrate.

6. The device of claim 1, wherein each said die attachment substrate comprises a die attachment circuit board substrate.

7. The device of claim 1, wherein each said die attachment substrate comprises a die attachment ceramic substrate.

8. The device of claim 1, further comprising:

a strip of opaque material on a said die attachment substrate, between where the light detector die is attached and where the light source die is attached;

wherein the groove is formed into the light transmissive material such that the groove extends to or into the strip of opaque material.

9. The device of claim 1, wherein:

a further groove is formed in a said die attachment substrate below where the groove is formed in the light transmissive material.

10. The device of claim 9, wherein:

the same type of opaque material within the groove formed in the light transmissive material is also within the further groove formed in the die attachment substrate.

11. The device of claim 10, further comprising:

a strip of opaque material within the further groove and extending above a planar surface of the die attachment substrate to which the light detector die and/or the light source die is/are attached; and

wherein the groove formed in the light transmissive material extends to or into the strip of opaque material.

12. The device of claim 1, wherein the opaque material comprises a black epoxy.

13. The device of claim 1, wherein the light source die and the light detector die are attached to the same said die attachment substrate.

14. The device of claim 1, wherein:

the optical sensor device comprises a proximity sensor device;

the light source die includes one or more elements that emit light;

the light detector die includes one or more elements that detect light and can be used to produce signals indicative of a magnitude of detected light; and

the light barrier, formed by the opaque material within the groove, prevents light produced by the one or more elements that emit light from being transmitted directly to and detected by the one or more elements that detect light.

15. A method for providing an optical sensor device, comprising:

(a) attaching a light detector die to a die attachment substrate and attaching a light source die to the same die attachment substrate to which the light detector die is attached, or to another die attachment substrate, so that there is a space between the light detector die and the light source die;

(b) covering, with a light transmissive material, the light detector die, the light source die and at least a portion of the space between the light detector die and the light source die;

(c) forming a groove in the light transmissive material between the light detector die and the light source die; and

(d) putting an opaque material within the groove to form a light barrier between the light detector die and the light source die.

16. The method of claim 15, wherein step (c) comprises:

saw cutting the groove;

blade cutting the groove;

or

laser cutting the groove.

17. The method of claim 15, wherein steps (b) and (c) are performed simultaneously and comprise using a mold to form the light transmissive material over the light detector die, the light source die and the at least a portion of the space between the light detector die and the light source die, and using a feature in the mold to form the groove between the light detector die and the light source die.

18. The method of claim 15, wherein:

step (c) comprising forming the groove in the light transmissive material such that the groove extends to the die attachment substrate.

19. The method of claim 15, further comprising:

prior to steps (b), (c) and (d), forming a strip of opaque material on the die attachment substrate to which the light detector die and/or the light source die is/are attached, or is/are to be attached, so that the strip is between where the light detector die is or is to be attached and where the light source die is or is to be attached; and

wherein step (c) comprises forming the groove in the light transmissive material such that the groove extends to or into the strip of opaque material.

20. The method of claim 15, further comprising:

prior to steps (b), (c) and (d), forming a further groove in the die attachment substrate below where the groove in the light transmissive material is to be formed.

21. The method of claim 20, wherein:

step (d) comprises putting the opaque material into the further groove formed in the die attachment substrate while putting the opaque material into the groove in the light transmissive material.

22. The method of claim 20, further comprising:

prior to steps (b), (c) and (d), forming a strip of opaque material over the further groove such that the strip extends above a planar surface of the die attachment substrate within which the further groove is formed; and

step (c) comprises forming the groove in the light transmissive material such that the groove extends to or into the strip of opaque material.

23. The method of claim 15, wherein:

the opaque material comprises a black epoxy; and

step (d) comprises at least substantially filling the groove with the black epoxy to form the light barrier between the light detector die and the light source die.

24. A method for providing a plurality of optical sensor devices, comprising:

(a) attaching a plurality of light detector dies and a plurality of light source dies to one or more die attachment substrate such that there is a predetermined amount of space between each one of the light detector dies and a corresponding one of the light source dies;

(b) covering, with a light transmissive material, the light detector dies, the light source dies and at least a portion of the spaces therebetween;

(c) forming grooves in the light transmissive material so that a groove is formed between each one of the light detector dies and a corresponding one of the light source dies;

(d) putting an opaque material within the grooves so that each one of the light detector dies and a corresponding one of the light source dies are separated by the opaque material; and

(e) cutting through the light transmissive material and the one or more die attachment substrates, to which the light detector dies and the light source dies are attached, to thereby provide a plurality of separated optical sensor devices that each include one of the light detector dies and a corresponding one of the light source dies with a light barrier formed by the opaque material therebetween.

25. The method of claim 24, wherein step (c) comprises forming the grooves by cutting into the light transmissive material, wherein each one of the cuts forms a groove between a plurality of the light detector dies and corresponding ones of the light source dies.

26. The method of claim 24, wherein steps (b) and (c) are performed simultaneously and comprise using a mold to form the light transmissive material over the light detector dies, the light source dies and the at least a portion of the spaces therebetween, and using features in the mold to form the grooves, wherein each one of the features in the mold forms a groove between a plurality of the light detector dies and the corresponding ones of the light source dies.

28. A system, comprising:

an optical sensor;

a driver to selectively drive one or more light emitting elements of the optical sensor;

a processor and/or circuitry to detect proximity of an object, if any, relative to the optical sensor; and

a subsystem that is responsive to proximity of an object, if any, relative to the optical sensor, as detected by the processor and/or circuitry;

wherein the optical sensor includes

at least one die attachment substrate;

a light detector die attached to a said die attachment substrate;

a light source die attached to the same die attachment substrate to which the light detector die is attached, or to another said die attachment substrate, so that there is a space between the light source die and the light detector die;

a light transmissive material covering the light detector die, the light source die and at least a portion of the space between the light detector die and the light source die;

a groove formed in the light transmissive material between the light detector die and the light source die; and

an opaque material, within the groove, wherein the opaque material provides a light barrier between the light detector die and the light source die; and

wherein the light source die includes the light emitting elements driven by the driver.