Reflective sensing module having light chip and sensor chip mounted to bottom surface of transparent top cover, and wristband comprising said reflective sensing module

1. A reflective sensing module, comprising:

a top cover which is transparent;

a first bottom circuitry on a bottom surface of the top cover;

a light chip having first top electrodes on a top surface of the light chip, the first top electrodes being physically attached and electrically coupled to the first bottom circuitry; and

a sensor chip having second top electrodes on a top surface of the sensor chip, the second top electrodes being physically attached and electrically coupled to the first bottom circuitry; wherein

the light chip is configured to emit light beams upwards passing through the top cover to an object, and

the sensor chip is configured to detect light beams reflected downwards from the object and passing through the top cover for a further processing.

2. The reflective sensing module as claimed in claim 1 , further comprising:

a molding compound enclosing the light chip and the sensor chip;

a second bottom circuitry on a bottom surface of the molding compound; and

a plurality of via metals passing through the molding compound, and electrically coupling the first bottom circuitry with the second bottom circuitry.

3. The reflective sensing module as claimed in claim 2 , further comprising:

a redistribution circuitry on bottom of the second bottom circuitry;

a plurality of bottom pads on bottom of the redistribution circuitry; and

a plurality of solder balls, each on one corresponding bottom pad among the plurality of bottom pads.

4. The reflective sensing module as claimed in claim 1 , further comprising:

a molding compound enclosing side surfaces while exposing a bottom surface of each of the light chip and the sensor chip;

a plurality of bottom pads on a bottom surface of the molding compound; and

a plurality of solder balls, each on one corresponding bottom pad among the plurality of bottom pads.

5. The reflective sensing module as claimed in claim 1 , wherein the top cover comprises:

a first Fresnel lens on top of the light chip; and

a second Fresnel lens on top of the sensor chip.

6. A wristband, comprising:

a reflective sensing module, comprising:

a top cover;

a bottom circuitry configured on a bottom surface of the top cover;

a light chip electrically coupled to the bottom circuitry of the top cover;

a sensor chip electrically coupled to the bottom circuitry of the top cover;

a first Fresnel lens configured on top of the light chip; and

a second Fresnel lens configure on top of the sensor chip, wherein

the light chip is able to emit light beams upwards passing through the top cover to an object;

the sensor chip is able to detect reflective light beams downwards passing through the top cover for a further processing;

a flexible circuit board electrically coupled to the reflective sensing module;

a control chip electrically coupled to the flexible circuit board; and

a flexible molding compound enclosing the reflective sensing module and the control chip.

7. The wristband as claimed in claim 6 , wherein

the wristband has a shape of a closed loop.

8. The wristband as claimed in claim 7 , wherein

the closed loop of the wristband has a size adapted to be worn on a wrist of a user.

9. The wristband as claimed in claim 8 , wherein the closed loop of the wristband has

an outer side adapted to face away from the wrist when the wristband is worn on the wrist, and

an inner side adapted to face toward the wrist when the wristband is worn on the wrist, wherein the top cover of the reflective sensing module is on the inner side.

10. The reflective sensing module as claimed in claim 1 , further comprising:

a molding compound enclosing the light chip and the sensor chip, wherein the molding compound is in contact with side surfaces of the light chip and side surfaces of the sensor chip, and the molding compound has

a top surface in contact with the first bottom circuitry, and

a bottom surface; and

a plurality of via metals electrically coupled to the first bottom circuitry, and extending from the top surface of the molding compound through an entire thickness of the molding compound to the bottom surface of the molding compound.

11. The reflective sensing module as claimed in claim 10 , further comprising:

a second bottom circuitry on the bottom surface of the molding compound, wherein

the plurality of via metals electrically couple the first bottom circuitry with the second bottom circuitry.

12. The reflective sensing module as claimed in claim 11 , wherein

the bottom surface of the molding compound is below entireties of the light chip and the sensor chip, and

the molding compound is in contact with a bottom surface of the light chip and a bottom surface of the sensor chip.

13. The reflective sensing module as claimed in claim 12 , further comprising:

a redistribution circuitry on bottom of the second bottom circuitry, wherein the redistribution circuitry has a plurality of bottom pads; and

a plurality of solder balls, each on one corresponding bottom pad among the plurality of bottom pads.

14. The reflective sensing module as claimed in claim 13 , wherein

the plurality of solder balls is below an entirety of the molding compound.

15. The reflective sensing module as claimed in claim 14 , wherein, in a cross section view of the reflective sensing module,

the plurality of solder balls, the light chip and the sensor chip are arranged in a middle portion of the reflective sensing module, and

the plurality of via metals is arranged in a peripheral portion of the reflective sensing module, wherein the peripheral portion surrounds the middle portion.

16. The reflective sensing module as claimed in claim 10 , wherein

the molding compound exposes bottom surfaces of the light chip and the sensor chip,

the bottom surface of the molding compound is flush with the bottom surfaces of the light chip and the sensor chip,

the reflective sensing module further comprises a plurality of bottom pads on the bottom surface of the molding compound, and

the plurality of via metals electrically couple the first bottom circuitry with the plurality of bottom pads.

17. The reflective sensing module as claimed in claim 16 , further comprising:

a plurality of solder balls, each on one corresponding bottom pad among the plurality of bottom pads,

wherein the plurality of solder balls is below an entirety of the molding compound.

18. The reflective sensing module as claimed in claim 17 , wherein, in a cross section view of the reflective sensing module,

the light chip and the sensor chip are arranged in a middle portion of the reflective sensing module, and

the plurality of solder balls and the plurality of via metals are arranged in a peripheral portion of the reflective sensing module, wherein the peripheral portion surrounds the middle portion.

19. The reflective sensing module as claimed in claim 10 , further comprising:

underfill material filled in

a first gap between the bottom surface of the top cover and the top surface of the light chip, and

a second gap between the bottom surface of the top cover and the top surface of the sensor chip, wherein

the molding compound is in contact with the underfill material.

20. A wristband, comprising:

the reflective sensing module as claimed in claim 1 ;

a flexible circuit board electrically coupled to the reflective sensing module;

a control chip electrically coupled to the flexible circuit board; and

a flexible molding compound enclosing the reflective sensing module and the control chip, wherein

the wristband has a shape of a closed loop of a size adapted to be worn on a wrist of a user, and the closed loop of the wristband has

an outer side adapted to face away from the wrist when the wristband is worn on the wrist, and

an inner side adapted to face toward the wrist when the wristband is worn on the wrist, wherein the top cover of the reflective sensing module is on the inner side.