Optical device

Abstract

An optical device includes a carrier, a light source, a die, a light guiding structure, and a reflective structure. The carrier has a surface. The light source is disposed on the surface and is configured to emit a light beam. The die is disposed on the surface and is configured to sense the light beam. The light guiding structure is disposed on the surface and is configured to guide the light beam. The light guiding structure includes a light receiving surface facing the light source and a light exit surface. The reflective structure is disposed above the die. The reflective structure includes a light reflecting surface facing the light exit surface of the light guiding structure and is configured to reflect the light beam exiting from the light exit surface to the die. The light reflecting surface and the light exit surface are separated from each other and define an exhaust aperture.

Description

Technical Field

[0001] This disclosure relates to an optical device. More specifically, this disclosure relates to an optical device having a small package size. Background Technology

[0002] Conventional optical devices used for gas sensing typically employ reflective structures. They do not require long beam paths or large package thicknesses. However, it is difficult to form small package sizes for these optical devices. Summary of the Invention

[0003] In one aspect, an optical device includes a carrier, a light source, a die, a light guiding structure, and a reflective structure. The carrier has a surface. The light source is disposed on the surface and configured to emit a light beam. The die is disposed on the surface and configured to sense the light beam. The light guiding structure is disposed on the surface and configured to guide the light beam. The light guiding structure includes a light-receiving surface facing the light source and a light-emitting surface. The reflective structure is disposed above the die. The reflective structure includes a light-reflecting surface facing the light-emitting surface of the light guiding structure and is configured to reflect the light beam emitted from the light-emitting surface to the die. The light-reflecting surface and the light-emitting surface are separated from each other and define an vent hole.

[0004] In one aspect, an optical device includes a carrier, a light source, a reflective structure, a light guiding structure, and a die. The carrier has a surface. The light source is disposed on the surface. The light guiding structure, the carrier, and the reflective structure define a chamber having vent holes. The die is disposed within the chamber. Attached Figure Description

[0005] Figure 1A This is a cross-sectional view of an optical device according to an embodiment of the present disclosure.

[0006] Figure 1B This is a cross-sectional view of an optical device according to an embodiment of the present disclosure.

[0007] Figure 2 This is a cross-sectional view of an optical device illustrating a beam path according to an embodiment of the present disclosure.

[0008] Figure 3 A top view illustrating an optical device according to an embodiment of the present disclosure.

[0009] Figure 4 This is a cross-sectional view of an optical device according to an embodiment of the present disclosure.

[0010] Figure 5 This is a cross-sectional view of an optical device according to an embodiment of the present disclosure.

[0011] Common reference numerals are used throughout the drawings and detailed embodiments to indicate the same or similar elements. Embodiments of this disclosure will become more apparent from the following detailed description in conjunction with the accompanying drawings. Detailed Implementation

[0012] Unless otherwise specified, spatial descriptions such as “above,” “below,” “upward,” “left,” “right,” “downward,” “top,” “bottom,” “vertical,” “horizontal,” “side,” “higher,” “lower,” “upper,” “above,” and “below” indicate the orientation shown in the figures. It should be understood that the spatial descriptions used herein are for illustrative purposes only, and actual embodiments of the structures described herein can be arranged in space in any orientation or manner, provided that the advantages of the embodiments of this disclosure are not deviated from by such arrangement.

[0013] Figure 1A This is a cross-sectional view of an optical device 1 according to an embodiment of the present disclosure. The optical device 1 includes a carrier 10, a light source 30, a die 20, a die 80, a light guiding structure 40, and a reflective structure 42. In some embodiments, the light source 30 and the light guiding structure 40 are disposed above the carrier 10. The carrier 10 may include a substrate, such as a semiconductor substrate, a circuit board, etc. The carrier 10 has a surface 101. In one or more embodiments, the surface 101 may be a top surface. In one or more embodiments, conductive wiring (not shown) is disposed above or embedded in the carrier 10. In some embodiments, the package height (size) of the optical device 1 may range from, but is not limited to, about 1.9 mm to about 2.1 mm.

[0014] A light source 30 is disposed on a surface 101 of a carrier 10. The light source 30 is configured to emit a light beam toward a light-receiving surface 407. A die 20 is disposed on a surface 101 of the carrier 10. The die 20 is configured to sense the light beam from the light source 30. In one or more embodiments, the die 20 includes an optical sensor chip. In some embodiments, the die 20 includes, but is not limited to, a gas sensing chip. In some embodiments, the die 20 may be formed with a complementary metal-oxide-semiconductor (CMOS) sensor, a charge-coupled device (CCD) sensor, or other suitable sensor to sense light. In some embodiments, the die 80 includes, but is not limited to, a thermopile chip. The light source 30 may include a light-emitting diode (LED) or other suitable light source capable of emitting light. In some embodiments, the light source 30 may emit infrared rays.

[0015] A light guiding structure 40 is disposed on the surface 101 of the carrier 10. The light guiding structure 40 is configured to guide a light beam. The light guiding structure 40 includes a light receiving surface 407 and a light emitting surface 405. The light receiving surface 407 faces the light source 30. In some embodiments, the light receiving surface 407 includes a curved surface configured for receiving a lens structure 90. The lens structure 90 faces the light source 30. The light guiding structure 40 includes a light receiving surface 407 spaced apart from the light source 30 by a gap. The light emitting surface 405 is exposed from an exhaust port 70. In some embodiments, the light emitting surface 405 may have a selectively electroplated metal layer. In some embodiments, the light emitting surface 405 may be ground to remove the metal layer. The light guiding structure 40 with the light emitting surface 405 and the reflective structure 42 for reflecting the light beam can be used to shorten the beam path and reduce the thickness of the package of the optical device 1.

[0016] In some embodiments, the light guiding structure 40 comprises a non-air medium or a transparent material. In some embodiments, the light guiding structure 40 comprises, but is not limited to, molding material or glass. The light guiding structure 40 and the carrier 10 together define a chamber A having one or more vent holes 70. Diesel wafers 20 and 80 are disposed within the chamber A.

[0017] In some embodiments, the light-emitting surface 405 may include a light-transmitting facet. The light-guiding structure 40 includes a light-permeable body 44 and a reflective layer 401 disposed on the outer surface 402 of the light-permeable body 44. The light beam is reflected by the reflective layer 401 outside the light-permeable body 44. The light-permeable body 44 and the reflective layer 401 form a total internal reflection structure. The light beam is transmitted through the light-permeable body 44 via total internal reflection. The light-guiding structure 40, formed of a non-air medium, can guide the light beam through the reflective layer 401 disposed on the outer surface 402 of the light-permeable body 44.

[0018] A reflective structure 42 is disposed above the die 20. The reflective structure 42 includes a light-reflecting surface 421. In some embodiments, a reflective layer 401 is disposed on the light-reflecting surface 421. The light-reflecting surface 421 of the reflective structure 42 is inclined relative to the surface 101. The light-reflecting surface 421 in the reflective structure 42, inclined towards the surface 101, can reflect a light beam to the die 20 and shorten the beam path. The light-reflecting surface 421 faces the light-emission surface 405 of the light-guiding structure 40. The light-reflecting surface 421 is configured to reflect the light beam emitted from the light-emission surface 405 to the die 20. Depending on the position of the die 20 relative to the reflective structure 42, the angle of the light-reflecting surface 421 can range, for example, from about 10 degrees to about 80 degrees, or from about 30 degrees to about 60 degrees. The light-reflecting surface 421 and the light-emission surface 405 are separated from each other.

[0019] The reflective layer 401 on the light-reflecting surface 421 may be or may contain a polished metallic material, a plastic material with a metallic coating, or other suitable reflective material. Examples of polished metallic materials or metallic coatings include aluminum (Al), copper (Cu), gold (Au), or silver (Ag), or alloys thereof, or other suitable metals or alloys. The reflective layer 401 increases the reflectivity of the light-reflecting surface 421.

[0020] The light-reflecting surface 421 and the light-emitting surface 405 together define the vent 70. In some embodiments, the number of vent 70 is at least one or more. In some embodiments, the light-guiding structure 40 and the carrier 10 together define space B. The light source 30 is located within space B. In some embodiments, the gas to be determined flows into chamber A via the vent 70. The gas will interact with a light beam emitted from the light-emitting surface 405 at a gas-light interaction region 701. This region may cover the path of the light beam emitted from the light-emitting surface 405 to the light-reflecting surface 421. A light beam of a specific wavelength may be absorbed by the gas to be determined. In some embodiments, the die 20 may determine the type and concentration of the gas by sensing the light beam after the interaction.

[0021] The optical devices or structures depicted in the following figures are similar in some respects to Figure 1A The optical device 1, and some components with the same numbers are not described again with reference to the following figures.

[0022] Figure 1B This is a cross-sectional view of an optical device 2 according to an embodiment of the present disclosure. Figure 1B The structure of optical device 2 is similar to Figure 1A The optical device 1 is described. The optical device 2 includes a carrier 10, a light source 30, a die 20, a die 80, a light guiding structure 40, and a reflecting structure 42. In some embodiments, the light emitting surface 405 includes a light diffusing structure. The light diffusing structure is configured to diffuse or scatter the light beam, allowing the beam to interact with the gas more efficiently. By way of example, the light diffusing structure may include a roughened surface of the light emitting surface 405. The roughened surface of the light emitting surface 405 may be formed by molding, such as chemical and / or mechanical processing or other suitable techniques.

[0023] Figure 2This is a cross-sectional view of an optical device 1 illustrating a beam path according to an embodiment of the present disclosure. In some embodiments, the beam path is illustrated as an arrow. The beam path extends from a light source 30 to a die 20. The beam emitted from the light source 30 is converged by a lens structure 90. The lens structure 90 reduces the loss of light energy in the beam. A reflective layer 401 reflects and converges the beam from the light source 30. In some embodiments, the beam may be transmitted through total internal reflection in a light-permeable body 44. The beam is transmitted and passed through an exhaust port 70 via a light-emitting surface 405. The beam is then reflected by the reflective layer 401, and the reflected beam may be emitted toward the die 20. In some embodiments, the beam may be reflected by a light-reflecting surface 421.

[0024] Figure 3 A top view illustrating the optical device 1 according to an embodiment of the present disclosure. Figure 2 a and 2b. Top view Figure 2 A shows two separate exhaust ports 70. The optical device 1 includes a connection structure 408 for connecting the reflective structure 42 to the light guiding structure 40. In some embodiments, the light guiding structure 40 and the reflective structure 42 are integrated. (Top view) Figure 2 b shows two interconnected exhaust ports 70.

[0025] Figure 4 This is a cross-sectional view of an optical device 3 according to an embodiment of the present disclosure. The optical device 3 includes a carrier 10, a light source 30, a die 20, a die 80, a cover structure 50, and a reflective structure 501. The carrier 10 may include a substrate, such as a semiconductor substrate, a circuit board, etc. In one or more embodiments, conductive wiring (not shown) is disposed above or embedded in the carrier 10.

[0026] A die 20 is disposed above a carrier 10. The die 20 is configured to sense a light beam from a light source 30. In one or more embodiments, the die 20 includes an optical sensor chip. In some embodiments, the die 20 includes, but is not limited to, a gas sensing chip. In some embodiments, the die 20 may be formed with a CMOS sensor, a CCD sensor, or other suitable sensor to sense light. In some embodiments, the die 80 includes, but is not limited to, a thermopile chip.

[0027] The light beam, path 60, is emitted from the light source 30 to the die 20. The beam is reflected by the reflective structure 501. The light source 30 may include an LED or other suitable light source capable of emitting light. In some embodiments, the light source 30 may emit infrared rays. In some embodiments, the gas to be determined flows into the chamber via an exhaust port 70. The gas interacts with the light beam emitted from the light source 30. A specific wavelength of the beam may be absorbed by the gas to be determined. In some embodiments, the die 20 may determine the type and concentration of the gas by sensing the light beam after the interaction. In some embodiments, the package height (size) of the optical device 3 is in the range of approximately 3.9 mm to approximately 4.1 mm. Compared to the optical device 3, the package height of the optical device 1 is reduced due to total internal reflection of the light beam transmitted in the light guiding structure 40.

[0028] Figure 5 This is a cross-sectional view of an optical device 4 according to an embodiment of the present disclosure. The optical device 4 includes a carrier 10, a light source 30, a die 20, a die 80, a light guiding structure 40, and a cover structure 48. In some embodiments, the light source 30 and the light guiding structure 40 are disposed above the carrier 10. The carrier 10 may include a substrate, such as a semiconductor substrate, a circuit board, etc. In one or more embodiments, conductive wiring (not shown) is disposed above or embedded in the carrier 10. Dies 20 and 80 are disposed on the carrier 10. Die 20 is configured to sense a light beam from the light source 30. In one or more embodiments, die 20 includes an optical sensor chip. In some embodiments, die 20 includes, but is not limited to, a gas sensing chip. In some embodiments, die 80 includes, but is not limited to, a thermopile chip. In some embodiments, the light source 30 may emit infrared rays.

[0029] The light guiding structure 40 is configured to guide a light beam. In some embodiments, the light guiding structure 40 comprises a non-air medium or a transparent material. In some embodiments, the light guiding structure 40 comprises, but is not limited to, a molding material or glass. The light guiding structure 40 comprises a light-transmitting body 44 and a reflective layer 401 disposed on the outer surface 402 of the light-transmitting body 44. The light guiding structure 40, formed of a non-air medium, can guide a light beam through the reflective layer 401 disposed on the outer surface 402 of the light-transmitting body 44.

[0030] The light source 30 is configured to emit a light beam. The light beam is reflected by the reflective layer 401. A cover structure 48 is disposed above the die 20. In one or more embodiments, the cover structure 48 is disposed above the light guiding structure 40. A reflective structure 42 protrudes from the cover structure 48 toward the die 20.

[0031] In some embodiments, the reflective layer 401 is disposed on the reflective structure 42 of the cover structure 48. The protruding portion of the cover structure 48, which is inclined toward the carrier 10, can reflect the light beam to the bare die 20 and shorten the beam path.

[0032] In some embodiments, the gas to be identified flows into the exhaust port 70. The gas interacts with a light beam emitted from the light-emitting surface 405 at the gas-light interaction region 701. The light beam of a specific wavelength can be absorbed by the gas to be identified. In some embodiments, the die 20 can determine the type and concentration of the gas by sensing the light beam after the interaction.

[0033] In some embodiments of this disclosure, a light-guiding structure with a light-emitting surface and a reflective structure for reflecting the light beam can be used to shorten the beam path and reduce the thickness of the optical device package. The light-emitting surface includes a light-diffusing (roughness) structure that functions as a light diffuser. A permeable body and a reflective layer form a total internal reflection structure. A light-guiding structure formed of a non-air medium can guide the light beam through a reflective layer disposed on the outer surface of the light-permeable body. A light-reflecting surface of a reflective structure tilted towards the surface can reflect the light beam to the die and shorten the beam path. The reflective layer reflects and converges the light beam from the light source.

[0034] As used herein, the terms “approximately” and “about” are used to describe and explain minor variations. When used in conjunction with an event or situation, the terms may refer to a situation where the event or situation clearly occurred or a situation where the event or situation is very close to occurring. For example, when used in conjunction with numerical values, the terms may cover a range of variation less than or equal to ±10% of the stated value, such as less than or equal to ±5%, less than or equal to ±4%, less than or equal to ±3%, less than or equal to ±2%, less than or equal to ±1%, less than or equal to ±0.5%, less than or equal to ±0.1%, or less than or equal to ±0.05%. For another instance, if the difference between a first angle and a second angle is less than or equal to ±10°, such as ±5°, ±4°, ±3°, ±2°, ±1°, ±0.5°, ±0.1°, or ±0.05°, then the first angle may be approximately the same as the second angle.

[0035] Additionally, quantities, ratios, and other values ​​are sometimes presented in range format in this document. It should be understood that such range format is used for convenience and brevity, and should be flexibly interpreted to include not only values ​​explicitly specified as range limits, but also all individual values ​​or subranges covered within the range, as if each value and subrange were explicitly specified.

[0036] Although this disclosure has been described and illustrated with reference to specific embodiments thereof, such descriptions and illustrations are not limiting of this disclosure. Those skilled in the art will understand that various changes and alternatives may be made without departing from the true spirit and scope of this disclosure as defined by the appended claims. Illustrations need not be drawn to scale. Differences may exist between artistic representations in this disclosure and actual equipment due to manufacturing processes and limitations. Other embodiments of this disclosure may exist that are not specifically described. This specification and drawings should be considered illustrative rather than restrictive. Modifications may be made to adapt particular circumstances, materials, compositions, methods, or processes to the objectives, spirit, and scope of this disclosure. All such modifications are intended to be within the scope of the appended claims. Although the methods disclosed herein have been described with reference to specific operations performed in a particular order, it should be understood that these operations may be combined, subdivided, or reordered to form equivalent methods without departing from the teachings of this disclosure. Therefore, the order and grouping of operations are not a limitation of this disclosure unless specifically indicated herein.

Claims

1. An optical device comprising: a carrier having a surface; a light source disposed on the surface and configured to emit a light beam; a die disposed on the surface and configured to sense the light beam; a light guiding structure disposed on the surface and configured to guide the light beam, the light guiding structure comprising a light receiving surface facing the light source, and a light exit surface; a reflective structure disposed above the die, the reflective structure comprising a light reflecting surface facing the light exit surface of the light guiding structure, and configured to reflect the light beam exiting from the light exit surface to the die, wherein the light reflecting surface and the light exit surface are separated from each other and define an exhaust aperture, wherein the light source is separated from the die in a horizontal direction by the light guiding structure.

2. The optical device of claim 1, wherein the light guiding structure comprises a light- penetrable body having a first surface facing the die and a second surface opposite to the first surface, and wherein the first reflective layer is disposed on the first surface, the second reflective layer is disposed on the second surface, the first reflective layer and the second reflective layer are configured to totally reflect the light beam to exit from the light exit surface.

3. The optical device of claim 2, wherein the light exit surface of the light guiding structure is free of the light-penetrable body from the reflective structure.

4. The optical device of claim 1, wherein the light exit surface has a light diffusing structure.

5. The optical device of claim 1, wherein the light guiding structure and the carrier define a space, and the light source is located within the space.

6. The optical device of claim 1, wherein the light receiving surface comprises a curved surface configured as a lens for receiving the light beam.

7. The optical device of claim 1, wherein the light reflecting surface of the reflective structure is tilted with respect to the surface.

8. The optical device of claim 1, wherein the die comprises a gas sensing chip.

9. The optical device of claim 8, wherein the die comprises a thermopile chip.

10. The optical device of claim 2, wherein the light exit surface extends between the first reflective layer and the second reflective layer.

11. The optical device of claim 1, further comprising a connecting structure connecting the reflective structure to the light guiding structure.

12. The optical device of claim 1, further comprising a cover disposed above the light guiding structure, wherein the reflective structure protrudes from the cover toward the die.

13. An optical device comprising: a carrier having a surface; a light source disposed on the surface; a reflective structure; a light guiding structure disposed on the surface, wherein the light guiding structure, the carrier and the reflective structure define a chamber having an exhaust aperture; and a die disposed within the chamber, wherein the light source is separated from the die in a horizontal direction by the light guiding structure.

14. The optical device of claim 13, wherein the light guiding structure comprises a light- permeable body having a first surface facing the die and a second surface opposite the first surface, a first reflective layer disposed on the first surface, and a second reflective layer disposed on the second surface, the first and second reflective layers configured to totally reflect a light beam out.

15. The optical device of claim 13, wherein the light guiding structure further comprises a light receiving surface spaced apart from the light source by a gap.

16. The optical device of claim 13, wherein the light guiding structure further comprises a lens facing the light source.

17. The optical device of claim 15, wherein the light guiding structure further comprises a light exit surface exposed from the vent hole.

18. The optical device of claim 17, wherein the light exit surface has a light diffusing structure.

19. The optical device of claim 14, wherein the light guiding structure comprises a light exit surface extending between the first reflective layer and the second reflective layer.

20. The optical device of claim 13, wherein the reflective structure has a light reflecting surface tilted with respect to the surface.

21. An optical device, comprising: a carrier having a surface; a light source disposed on the surface and configured to emit a light beam; a die disposed on the surface; a light guiding structure disposed on the surface and configured to guide the light beam, the light guiding structure comprising a light receiving surface facing the light source and a light exit surface; and a reflective structure disposed above the die, the reflective structure comprising a light reflecting surface, wherein the light source is separated from the die in a horizontal direction by the light guiding structure.

22. The optical device of claim 21, wherein the die comprises a sensing chip.

23. The optical device of claim 21, wherein the light guiding structure comprises a light- permeable body having a first surface facing the die and a second surface opposite the first surface, a first reflective layer disposed on the first surface, and a second reflective layer disposed on the second surface, the first and second reflective layers configured to totally reflect the light beam out from the light exit surface.

24. The optical device of claim 23, wherein the light guiding structure and the reflective structure comprise a same non-air medium.

25. The optical device of claim 21, further comprising a connecting structure connecting the reflective structure to the light guiding structure.

26. The optical device of claim 25, wherein the light guiding structure, the reflective structure, and the connecting structure collectively define a vent hole.

27. The optical device of claim 21, wherein the light guiding structure and the carrier define a space, and the light source is located within the space.

28. The optical device of claim 21, wherein the light-reflecting surface is tilted with respect to the surface.

29. The optical device of claim 23, wherein the light-emitting surface extends between the first reflective layer and the second reflective layer.

30. An optical device, comprising: a carrier having a surface; a light source disposed on the surface and configured to emit a light beam; a die disposed on the surface; a light-guiding structure disposed on the surface and configured to guide the light beam, the light-guiding structure comprising a light-receiving surface facing the light source and a light-emitting surface, wherein the light-guiding structure comprises a non-air medium; and a reflecting structure disposed above the die, wherein the light source is horizontally separated from the die by the light-guiding structure.

31. The optical device of claim 30, wherein the light-guiding structure comprises a light- transparent body having a first surface facing the die and a second surface opposite the first surface, and wherein the first reflective layer is disposed on the first surface and the second reflective layer is disposed on the second surface, the first and second reflective layers being configured to totally reflect the light beam to emit from the light-emitting surface.

32. The optical device of claim 30, wherein the light-guiding structure and the reflecting structure comprise the same non-air medium.

33. The optical device of claim 30, further comprising a connecting structure connecting the reflecting structure to the light-guiding structure.

34. The optical device of claim 33, wherein the light-guiding structure, the reflecting structure, and the connecting structure collectively define an air vent.

35. The optical device of claim 31, wherein the light-emitting surface extends between the first reflective layer and the second reflective layer.

36. An optical device, comprising: a carrier having a surface; a light source disposed on the surface and configured to emit a light beam; a die disposed on the surface and configured to sense a wavelength of the light beam; and a light-guiding structure disposed on the surface and configured to guide the light beam, the light-guiding structure comprising a light-receiving surface facing the light source and a light-emitting surface, wherein the light source is horizontally separated from the die by the light-guiding structure.

37. The optical device of claim 36, wherein the light-guiding structure comprises a light- transparent body having a first surface facing the die and a second surface opposite the first surface, and wherein the first reflective layer is disposed on the first surface and the second reflective layer is disposed on the second surface, the first and second reflective layers being configured to totally reflect the light beam to emit from the light-emitting surface.

38. The optical device of claim 36, wherein the light-guiding structure and the carrier define a space, and the light source is located within the space. ​ 39. The optical device of claim 36, further comprising a reflective structure disposed above the die and configured to reflect the light beam from the light directing structure to the die.

40. The optical device of claim 37, wherein the light exit surface extends between the first reflective layer and the second reflective layer.

41. An optical device, comprising: a carrier having a surface; a light source disposed on the surface and configured to emit a light beam; a die disposed on the surface and configured to sense the light beam; a light directing structure disposed on the surface and configured to direct the light beam, the light directing structure comprising a light receiving surface facing the light source and a light exit surface, wherein the light directing structure comprises a non-air medium; and a reflective structure disposed above the die, wherein the reflective structure and the light directing structure collectively define an air vent, wherein the light source is horizontally separated from the die by the light directing structure.

42. The optical device of claim 41, wherein the light directing structure comprises a light transparent body having a first surface facing the die and a second surface opposite the first surface, and wherein the first reflective layer is disposed on the first surface and the second reflective layer is disposed on the second surface, the first reflective layer and the second reflective layer being configured to totally reflect the light beam to exit from the light exit surface.

43. The optical device of claim 41, wherein the light directing structure and the carrier define a space, and the light source is located within the space.

44. The optical device of claim 41, wherein the die comprises a gas sensing chip.

45. The optical device of claim 44, wherein the die comprises a thermopile chip.

46. The optical device of claim 42, wherein the light exit surface extends between the first reflective layer and the second reflective layer.

47. The optical device of claim 41, further comprising a connecting structure connecting the reflective structure to the light directing structure.

48. The optical device of claim 41, further comprising a cover disposed above the light directing structure, wherein the reflective structure protrudes from the cover toward the die. ​

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