INTEGRATED SENSOR MODULES

• US 20160029911A1
• Filed: 03/18/2015
• Published: 02/04/2016
• Est. Priority Date: 07/31/2014
• Status: Active Grant

• Current Assignee: Salutron, Inc.
• Original Assignee: Salutron, Inc.
• Inventors: Lee, Yong Jin
• Granted Patent: US 10,165,954 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A61B 5/0205 Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition
• CPC Class Codes: A61B 5/02416 using photoplethysmograph signals, e.g. generated by infrared radiation A61B5/14552 takes precedence
• CPC Class Codes: A61B 5/02427 Details of sensor
• CPC Class Codes: A61B 5/0245 by using sensing means generating electric signals, i.e. ECG signals
• CPC Class Codes: A61B 5/0531 Measuring skin impedance
• CPC Class Codes: A61B 5/0537 Measuring body composition by impedance, e.g. tissue hydration or fat content
• CPC Class Codes: A61B 5/681 Wristwatch-type devices
• CPC Class Codes: H01L 2224/32245 the item being metallic
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 25/167 comprising optoelectronic devices, e.g. LED, photodiodes
• CPC Class Codes: H01L 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/181 Encapsulation

Abstract

An integrated sensor module includes one or more packaged light source semiconductor devices and one or more packaged light detector semiconductor devices mounted to a top surface of a substrate. A pre-molded cover structure includes a portion molded from an opaque molding compound and a further portion molded from a light transmissive molding compound. For each of the packaged light source and light detector semiconductor devices, the pre-molded cover structure includes a pre-molded cavity covered by a window formed of the light transmissive molding compound. The pre-molded cover structure is attached to the substrate such that each of the packaged light source and light detector semiconductor devices fits within a respective cavity, and such that a barrier formed of the opaque molding compound is positioned between each packaged light source semiconductor device and light detector semiconductor device. The module can also include additional sensors and/or electrodes for use by sensors.

Claims

1. A sensor module, comprising:

a substrate having a top surface and a bottom surface;

a packaged light source semiconductor device mounted to the top surface of the substrate, the packaged light source semiconductor device including

a light emitter die including one or more light emitting elements encapsulated by a light transmissive molding compound;

a top surface formed by a top surface of the light transmissive molding compound that encapsulates the one or more light emitting elements;

a bottom surface including electrical contacts for the one or more light emitting elements; and

a peripheral surface extending between the top and bottom surfaces;

a packaged light detector semiconductor device mounted to the top surface of the substrate such that there is a gap between the packaged light detector semiconductor device and the packaged light source semiconductor device, the packaged light detector semiconductor device including

a light detector die including one or more light detecting elements encapsulated by a light transmissive molding compound;

a top surface formed by a top surface of the light transmissive molding compound that encapsulates the one or more light detecting elements;

a bottom surface including electrical contacts for the one or more light detecting elements; and

a peripheral surface extending between the top and bottom surfaces;

a pre-molded cover structure including a portion of which is molded from an opaque molding compound and a further portion of which is molded from a light transmissive molding compound, the pre-molded cover structure including

a first pre-molded cavity covered by a first window formed of the light transmissive molding compound;

a second pre-molded cavity covered by a second window formed of the light transmissive molding compound;

a barrier formed of the opaque molding compound between the first pre-molded cavity and the second pre-molded cavity;

wherein the pre-molded cover structure is attached to the substrate such that the packaged light source semiconductor device is positioned within the first pre-molded cavity, the packaged light detector semiconductor device is positioned within the second pre-molded cavity, the barrier is positioned between the packaged light detector semiconductor device and the packaged light source semiconductor device, the first window covers the one or more light emitting elements of the light emitter die, and the second window covers the one or more light detecting elements of the light detector die.

2. The sensor module of claim 1, wherein:

the first pre-molded cavity has dimensions that are equal to dimensions of the packaged light source semiconductor device plus a tolerance so that the packaged light source semiconductor device completely fits within the first pre-molded cavity; and

the second pre-molded cavity has dimensions that are equal to dimensions as the packaged light detector semiconductor device plus a tolerance so that the packaged light detector semiconductor device fits within the second pre-molded cavity.

3. The sensor module of claim 1, further comprising:

a further die embedded within the substrate, between the top and bottom surfaces of the substrate, the further die including circuitry used to drive the one or more light emitting elements of the light emitter die and/or perform signal processing on a signal produced by the one or more light detecting elements of the light detector die.

4. The sensor module of claim 1, wherein:

the light transmissive molding compound that encapsulates the one or more light emitting elements of the light emitter die has an index of refraction that is substantially the same as an index of refraction of the light transmissive molding compound of which the first window is formed.

5. The sensor module of claim 4, wherein:

the light transmissive molding compound that encapsulates the one or more light detecting elements of the light detector die has an index of refraction that is substantially the same as an index of refraction of the light transmissive molding compound of which the second window is formed.

6. The sensor module of claim 4, further comprising:

a light transmissive adhesive between the top surface of the packaged light source semiconductor device and the first window, the light transmissive adhesive having an index of refraction that is substantially the same as the index of refraction of the light transmissive molding compound that encapsulates the one or more light emitting elements of the light emitter die and that is substantially the same as an index of refraction of the light transmissive molding compound of which the first window is formed.

7. The sensor module of claim 1, wherein the electrical contacts on the bottom surface of each of the dies are selected from the group consisting of:

electrically conductive lands;

electrically conductive pads;

electrically conductive balls;

electrically conductive pins; and

electrically conductive wires.

8. The sensor module of claim 1, further comprising:

one or more additional packaged light detector semiconductor devices mounted to the top surface of the substrate, such that there is a plurality of packaged light detector semiconductor devices mounted to the top surface of the substrate;

wherein the plurality of packaged light detector semiconductor devices and the packaged light source semiconductor device are mounted to the top surface of the substrate such that the packaged light source semiconductor device is positioned in a middle between the plurality of packaged light detector semiconductor devices and such that there is a respective gap between the light source semiconductor device and each of the plurality of packaged light detector semiconductor devices;

wherein the pre-molded cover structure includes one or more additional cavities, each of which is covered by a respective additional window formed of the light transmissive molding compound;

wherein with the pre-molded cover structure attached to the substrate, each of the one or more additional packaged light detector semiconductor devices is positioned within a respective one of the one or more additional cavities in the pre-molded cover structure, and the barrier formed of the opaque molding compound is also positioned between the packaged light detector semiconductor device and the one or more additional packaged light detector semiconductor devices.

9. The sensor module of claim 1, wherein a bottom surface of the substrate includes electrical contacts that enable the sensor module to be electrically connected to further circuitry.

10. The sensor module of claim 1, further comprising a lens that is integrally formed with or attached to one of the first and second windows.

11. The sensor module of claim 1, further comprising:

a packaged temperature sensor semiconductor device mounted to a top surface of the substrate;

a pre-molded temperature sensor cavity within the pre-molded cover structure having dimensions that are equal to dimensions of the packaged temperature sensor semiconductor device plus a tolerance so that the packaged temperature sensor semiconductor device completely fits within the pre-molded temperature sensor cavity; and

a metal structure within the pre-molded cover structure that extends between the top surface of the pre-molded cover structure and a top of the temperature sensor cavity;

wherein the metal structure is made of a thermally conductive metal and provides a thermal coupling between the packaged temperature sensor semiconductor device and a portion of the top surface of the pre-molded cover structure.

12. The sensor module of claim 11, further comprising:

a thermally conductive grease or a thermally conductive adhesive between a top surface of the temperature sensor semiconductor device and a bottom surface of the metal structure.

13. The sensor module of claim 11, further comprising:

one or more electrodes extending upward from a top surface of the substrate;

one or more electrode cavities with the pre-molded cover structure, wherein inner surfaces of the pre-molded cavities are coated with an electrically conductive metal;

one or more metal structures within the pre-molded cover structure each of which extends between the top surface of the pre-molded cover structure and a top of one of one or more the electrode cavities;

wherein each of the one or more metal structures is made of an electrically conductive metal and provides an electrical coupling between one of the one or more electrodes extending upward from the top surface of the substrate and a respective portion of the top surface of the pre-molded cover structure.

14. The sensor module of claim 13, further comprising:

an electrically conductive grease or an electrically conductive adhesive between a top surface of each of the one or more electrodes and a bottom surface of a respective said metal structure.

15. The sensor module of claim 1, further comprising:

one or more electrodes extending downward from a respective portion of a top surface of the pre-molded cover structure past a bottom surface of the pre-molded cover structure such that a portion of each of the one or more electrodes extend downward from the bottom surface of the pre-molded cover structure;

one or more openings or through holes in the substrate that are configured to receive the portion of the one or more electrodes that extend downward from the bottom surface of the pre-molded cover structure.

16. A method for manufacturing a sensor module, the method comprising:

mounting one or more packaged light source semiconductor device(s) and one or more packaged light detector semiconductor device(s) to a top surface of a substrate such that there is a gap between each of the packaged light detector semiconductor device(s) and each of the packaged light source semiconductor device(s); and

attaching a pre-molded cover structure to the top surface of the substrate such that the each of the packaged light source semiconductor device(s) and packaged light detector semiconductor device(s), which are mounted to the top surface of the substrate, fits within a respective cavity of the pre-molded cover structure.

17. The method of claim 16, further comprising, prior to the mounting step:

molding the pre-molded cover structure such that a portion thereof is molded from an opaque molding compound and a further portion thereof is molded from a light transmissive molding compound, such that each of the cavities is covered by a respective window formed of the light transmissive molding compound, and such that there is a barrier formed of the opaque molding between each of the cavities.

18. The method of claim 16, wherein that attaching includes at least one of the following:

dispensing a light transmissive adhesive within each of the cavities;

or

dispensing the light transmissive adhesive on a top surface of each of the packaged light source semiconductor device(s) and packaged light detector semiconductor device(s), wherein the light transmissive adhesive has an index of refraction that is substantially the same as an index of refraction of the light transmissive molding compound from with the windows are formed.

19. The method of claim 18, wherein that attaching also includes at least one of the following:

dispensing an opaque adhesive on a top surface of the substrate;

or

dispensing an opaque adhesive on a bottom surface of the pre-molded cover structure.

20. The method of claim 18, wherein:

the mounting includes mounting a packaged temperature sensor semiconductor device to the top surface of the substrate; and

the attaching includes attaching the pre-molded cover structure to the top surface of the substrate such that the packaged temperature sensor semiconductor device fits within a respective temperature sensor cavity of the pre-molded cover structure.

21. The method of claim 20, wherein that attaching includes at least one of the following:

dispensing a thermally conductive adhesive within the temperature sensor cavity;

or

dispensing a thermally conductive adhesive on a top surface of the packaged temperature sensor semiconductor device.

22. The method of claim 20, further comprising, between the mounting and the attaching:

dispensing a thermally conductive grease within the temperature sensor cavity;

or

dispensing a thermally conductive grease on a top surface of the packaged temperature sensor semiconductor device.

23. The method of claim 20, further comprising, prior to the mounting:

molding the pre-molded cover structure such that a portion thereof is molded from an opaque molding compound and a further portion thereof is molded from a light transmissive molding compound, such that each of the first and second cavities is covered by a respective window formed of the light transmissive molding compound, such that there is a barrier formed of the opaque molding between each of the cavities, and such that a metal structure extends between a portion of a top surface of the pre-molded cover structure and a top of the temperature sensor cavity.

24. The method of claim 16, further comprising, prior to the mounting:

molding the pre-molded cover structure such that a portion thereof is molded from an opaque molding compound and a further portion thereof is molded from a light transmissive molding compound, such that each of the first and second cavities is covered by a respective window formed of the light transmissive molding compound, such that there is a barrier formed of the opaque molding between each of the cavities, and such that one or more metal structures extend between a respective portion of a top surface of the pre-molded cover structure and a top of a respective electrode cavity of one or more electrode cavities in the pre-molded cover structure; and

wherein the attaching the pre-molded cover structure includes aligning one or more electrodes that extend from the top surface of the substrate with the one or more electrode cavities in the pre-molded cover structure.

25. The method of claim 16, further comprising, prior to the mounting:

molding the pre-molded cover structure such that a portion thereof is molded from an opaque molding compound and a further portion thereof is molded from a light transmissive molding compound, such that each of the first and second cavities is covered by a respective window formed of the light transmissive molding compound, such that there is a barrier formed of the opaque molding between each of the cavities, and such that one or more electrodes extend from a respective portion of a top surface of the pre-molded cover structure past a bottom surface of the pre-molded cover structure and thereby extend from the bottom surface of the pre-molded cover structure;

wherein the attaching the pre-molded cover structure includes aligning the one or more electrodes that extend from the bottom surface of the pre-molded cover structure with one or more respective openings or through-holes in the substrate.

26. A user-wearable device, comprising:

a housing having a front side and a back side;

a band that straps the housing to a person'"'"'s wrist;

a digital display on the front side of the housing; and

a sensor module on the back side of the housing;

wherein the sensor module comprises

a substrate having a top surface and a bottom surface;

a packaged light source semiconductor device mounted to the top surface of the substrate, the packaged light source semiconductor device including

a light emitter die including one or more light emitting elements encapsulated by a light transmissive molding compound;

a top surface formed by a top surface of the light transmissive molding compound that encapsulates the one or more light emitting elements;

a bottom surface including electrical contacts for the one or more light emitting elements; and

a peripheral surface extending between the top and bottom surfaces;

a packaged light detector semiconductor device mounted to the top surface of the substrate such that there is a gap between the packaged light detector semiconductor device and the packaged light source semiconductor device, the packaged light detector semiconductor device including

a light detector die including one or more light detecting elements encapsulated by a light transmissive molding compound;

a top surface formed by a top surface of the light transmissive molding compound that encapsulates the one or more light detecting elements;

a bottom surface including electrical contacts for the one or more light detecting elements; and

a peripheral surface extending between the top and bottom surfaces;

a pre-molded cover structure including a portion of which is molded from an opaque molding compound and a further portion of which is molded from a light transmissive molding compound, the pre-molded cover structure including

a first pre-molded cavity covered by a first window formed of the light transmissive molding compound;

a second pre-molded cavity covered by a second window formed of the light transmissive molding compound;

a barrier formed of the opaque molding compound between the first pre-molded cavity and the second pre-molded cavity;

wherein the pre-molded cover structure is attached to the substrate such that the packaged light source semiconductor device is positioned within the first pre-molded cavity, the packaged light detector semiconductor device is positioned within the second pre-molded cavity, the barrier is positioned between the packaged light detector semiconductor device and the packaged light source semiconductor device, the first window covers the one or more light emitting elements of the light emitter die, and the second window covers the one or more light detecting elements of the light detector die.

27. The user-wearable device of claim 26, wherein the sensor module also includes a further die embedded within the substrate, between the top and bottom surfaces of the substrate, the further die including circuitry used to drive the one or more light emitting elements of the light emitter die and/or perform signal processing on a signal produced by the one or more light detecting elements of the light detector die.

28. The user-wearable device of claim 27, wherein:

the light transmissive molding compound that encapsulates the one or more light emitting elements of the light emitter die has an index of refraction that is substantially the same as an index of refraction of the light transmissive molding compound of which the first window is formed; and

the light transmissive molding compound that encapsulates the one or more light detecting elements of the light detector die has an index of refraction that is substantially the same as an index of refraction of the light transmissive molding compound of which the second window is formed.

29. The user-wearable device of claim 28, further comprising:

a light transmissive adhesive between the top surface of the packaged light source semiconductor device and the first window, the light transmissive adhesive having an index of refraction that is substantially the same as the index of refraction of the light transmissive molding compound that encapsulates the one or more light emitting elements of the light emitter die and that is substantially the same as an index of refraction of the light transmissive molding compound of which the first window is formed; and

a light transmissive adhesive between the top surface of the packaged light detector semiconductor device and the second window, the light transmissive adhesive having an index of refraction that is substantially the same as the index of refraction of the light transmissive molding compound that encapsulates the one or more light detecting elements of the light detector die and that is substantially the same as an index of refraction of the light transmissive molding compound of which the second window is formed.

30. The user-wearable device of claim 26, wherein the sensor module also includes

a packaged temperature sensor semiconductor device mounted to a top surface of the substrate;

a metal structure within the pre-molded cover structure that extends between the top surface of the pre-molded cover structure and a top of the temperature sensor cavity;

wherein the metal structure is made of a thermally conductive metal and provides a thermal coupling between the packaged temperature sensor semiconductor device and a portion of the top surface of the pre-molded cover structure.

31. The user-wearable device of claim 26, wherein the sensor module also includes:

one or more electrodes extending upward from a top surface of the substrate;

one or more electrode cavities with the pre-molded cover structure, wherein inner surfaces of the electrode cavities are coated with an electrically conductive metal;

one or more metal structures within the pre-molded cover structure each of which extends between a top surface of the pre-molded cover structure and a top of one of one or more the electrode cavities;

wherein each of the one or more metal structures is made of an electrically conductive metal and provides an electrical coupling between one of the one or more electrodes extending upward from the top surface of the substrate and a respective portion of the top surface of the pre-molded cover structure.

32. The user-wearable device of claim 26, wherein the sensor module also includes:

one or more electrodes extending downward from a respective portion of a top surface of the pre-molded cover structure past a bottom surface of the pre-molded cover structure such that a portion of each of the one or more electrodes extend downward from the bottom surface of the pre-molded cover structure;

one or more openings or through holes in the substrate that are configured to receive the portion of the one or more electrodes that extend downward from the bottom surface of the pre-molded cover structure.