OPTICAL PROXIMITY SENSOR AND MANUFACTURING METHOD THEREOF

Abstract

A complex optical proximity sensor includes a substrate, a light emitter coupled to the substrate, an application-specific integrated circuit chip coupled to the substrate with a proximity sensor thereon, a barrier disposed between the application-specific integrated circuit chip and the light emitter, and an ambient light detection chip manufactured in advance and then coupled to the application-specific integrated circuit chip thereon with a pre-determined height. Also, with the manufacturing method of the complex optical proximity sensor, the detection angle of the ambient light is thereby maximized and the one of the proximity sensor is thereby minimized.

Claims

1. A complex optical proximity sensor, comprising: a substrate; a light emitter coupled to the substrate; an application-specific integrated circuit chip coupled to the substrate with a proximity sensor installed on the chip and a barrier disposed between the chip and the light emitter; and an ambient light detection chip separately manufactured and then coupled to the application-specific integrated circuit chip, the ambient light detection chip extending to a pre-determined height relative to a laterally extended surface of the application-specific integrated circuit chip; said ambient light detection chip being offset in position from the proximity sensor to be laterally spaced therefrom and to thereby form a complex optical proximity sensor; whereby a light is emitted from the light emitter and reflected to the proximity sensor for detection; the barrier is arranged at a pre-determined height to prevent interference from the emitted light to the proximity sensor and to minimize a detection angle of the proximity sensor; and the ambient light detection chip is manufactured separately with a height in accordance with the height of the barrier to maximize a detection angle of the ambient light detection chip.

2. The complex optical proximity sensor as claimed in claim 1, wherein the ambient light detection chip is a chip for ambient light detection, RGB color detection, or ultraviolet (UV) detection.

3. The complex optical proximity sensor as claimed in claim 1, wherein the light emitter is a LED, a laser diode (LD), or a vertical-cavity surface-emitting laser (VCSEL).

4. The complex optical proximity sensor as claimed in claim 1, wherein the substrate is either a ceramic substrate or a PCB, and the application-specific integrated circuit chip has a plurality of first connect points to be coupled to a plurality of second connect points on the ambient light detection chip.

5. The complex optical proximity sensor as claimed in claim 4, wherein the substrate has a plurality of bond pads arranged under a bottom thereof to be coupled to the application-specific integrated circuit chip and the light emitter, making the complex optical proximity sensor a surface-mount device.

6. The complex optical proximity sensor as claimed in claim 1, wherein the substrate has a plurality of transparent packages for the ambient light detection chip, the application-specific integrated circuit chip and the light emitter to be separately encapsulated therein.

7. The complex optical proximity sensor as claimed in claim 1, wherein the substrate further has a non-transparent package for the barrier to be encapsulated therein.

8. The complex optical proximity sensor as claimed in claim 6, wherein the material of transparent packages is made of lens.

9. A manufacturing method of the complex optical proximity sensor as claimed in claim 1, comprising: a) providing a substrate; b) providing a light emitter coupled to the substrate; c) providing an application-specific integrated circuit chip coupled to the substrate with a proximity sensor installed on the chip and a barrier disposed between the chip and the light emitter; and d) providing an ambient light detection chip coupled to the application-specific integrated circuit chip, the ambient light detection chip extending to a pre-determined height relative to a laterally extended surface of the application-specific integrated circuit chip; said ambient light detection chip being offset in position from the proximity sensor to be laterally spaced therefrom and to thereby form a complex optical proximity sensor; whereby a light is emitted from the light emitter and reflected to the proximity sensor for detection; the barrier is arranged at a pre-determined height to prevent interferences from the emitted light to the proximity sensor and to minimize a detection angle of the proximity sensor; and the ambient light detection chip is manufactured separately and has a height in accordance with the height of the barrier to maximize a detection angle of the ambient light detection chip.

10. The method as claimed in claim 9, wherein the substrate is either a ceramic substrate or a PCB to be coupled to the application-specific integrated circuit chip and the light emitter, and the application-specific integrated circuit chip has a plurality of first connect points to be coupled to a plurality of second connect points on the ambient light detector chip.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] FIG. 1A is a schematic diagram of a smartphone with an elongated hole in the prior art;

[0019] FIG. 1B is a schematic diagram of a smartphone with a circular hole in the prior art;

[0020] FIG. 2 is a schematic diagram illustrating a package structure of an optical proximity sensor in the prior art;

[0021] FIG. 3 is a schematic diagram illustrating a package-on-package structure of an optical proximity sensor in the prior art;

[0022] FIG. 4 is a schematic diagram illustrating a package structure of a photo sensor chip in the prior art;

[0023] FIG. 5 is a top plan view of the present invention;

[0024] FIG. 6 is a bottom plan view of the present invention;

[0025] FIG. 7A is a sectional view along ling 7A-7A in FIG. 5;

[0026] FIG. 7B is a schematic diagram of the present invention;

[0027] FIG. 8 is a practical application view of the present invention; and

[0028] FIG. 9 is a curve diagram of angular displacement comparison between the present invention and the prior art in ambient light detection.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0029] FIGS. 5-9 illustrated a preferred embodiment of the present invention—a complex optical proximity sensor 40 that has a minimum detection angle for proximity θ.sub.a4 and a maximum detection angle for ambient light θ.sub.b4.

[0030] In the embodiment, the complex optical proximity sensor 40 includes a substrate 41, a light emitter 42, an application-specific integrated circuit (ASIC) chip 43, and an ambient light detection chip 45.

[0031] The substrate 41 is a ceramic substrate or a PCB, but it is not limited to such application. The light emitter 42 is coupled to the substrate 41 thereon by an electric wire 48. In the embodiment, the light emitter 42 is a LED, a laser diode (LD), or a vertical-cavity surface-emitting laser (VCSEL), but it is not limited to such application.

[0032] The ASIC chip 43 is coupled to the substrate 41 thereon by an electric wire 48 and has a proximity sensor (PS) 431 installed on the ASIC chip 43. A barrier 44 is further disposed between the ASIC chip 43 and the light emitter 42. In the embodiment, the ASIC chip 43 has a plurality of first connect points 432 to be coupled to a plurality of second connect points 451 on the light emitter 42 ASIC chip 43 via an electric wire 48.

[0033] The ambient light detection chip 45 is separately manufactured and then coupled by an electric wire 48 to the ASIC chip 43 with a pre-determined height thereon to form the complex optical proximity sensor 40 without obstructing the proximity sensor 431 on the ASIC chip 43. In the embodiment, the ambient light detection chip 45 is a chip for ambient light detection, RGB color detection, or ultraviolet (UV) detection.

[0034] As shown in FIGS. 5 and 7A, the ambient light detection chip 45 is separately manufactured and then disposed on and coupled to the ASIC chip 43 to enable adjustment of a distance to the barrier 44 without changing or affecting the circuits on the ASIC chip 43. Further referring to FIG. 6, the substrate 41 has a plurality of bond pads 411 arranged under a bottom thereof to be coupled to the ASIC chip 43 and the light emitter 42, making the complex optical proximity sensor 40 a surface-mount device.

[0035] FIG. 7B shows a plurality of transparent packages 46 is disposed on the substrate 41 for the ambient light detection chip 45, the ASIC chip 43 and the light emitter 42 to be separately encapsulated therein, and a non-transparent package 47 is disposed on the substrate 41 for the barrier 44 to be encapsulated therein. In another embodiment, the material of the transparent packages 46 is made of lens.

[0036] As illustrated in FIG. 8, a light is emitted from the light emitter 42 and reflected by an object O to the proximity sensor 431 for detection with the barrier 44 at a pre-determined height h.sub.1 to prevent interferences from the emitted light to the proximity sensor 431. In addition, the ambient light detection chip 45 is manufactured separately with a height h.sub.2 in accordance with the height h.sub.1 of the barrier 44 to ensure the barrier 44 not to obstruct the ambient light detection chip 45 in ambient light L detection, thereby minimizing the detection angle θ.sub.a4 of the proximity sensor 431 and maximizing the detection angle θ.sub.b4 of the ambient light detection chip 45. With a circular opening as an aperture G.sub.2 on a front surface of a smartphone P, the ASIC chip 43 is able to receive the light emitted from the light emitter 42 and ambient light L to control the operation of the ambient light detection chip 45, the light emitter 42 and the proximity sensor 431.

[0037] To further explain the differences between the technologies in the prior art and the present invention in aperture sizes, detection angle θ.sub.a of the proximity sensor, and detection angle θ.sub.b of ambient light detection, a table chart is disclosed below.

TABLE-US-00001 An optical proximity A POP A photosensor The sensing optical chip package present package sensor structure invention Aperture of Large Large Small Small an opening Proximity Medium Medium Narrow Narrow detection angle θa Ambient light Medium Wide Narrow Wide detection angle θb

[0038] With reference to FIG. 9, further analysis and clarification of the differences are described as following.

[0039] 1. Curve A shows an angular displacement of ambient light detection in an optical proximity sensing package structure. A PS thereof is disposed close to the left of an ALS thereof so the proximity detection angle cannot be too narrow, and the ALS cannot reach a wide angle for ambient light detection either due to arrangement of a barrier; plus, such structure has the ALS and PS arranged laterally. Therefore, it requires an elongated hole to be arranged on a front surface of a smartphone with a large aperture.

[0040] 2. Curve B shows an angular displacement of ambient light detection in a POP optical sensor. The ambient light detection angle can be wide without a blocking element, but the proximity detection angle remains unchanged comparing to the structure in an optical proximity sensing package. Therefore, it still requires an elongated hole on a front surface of a smartphone with a large aperture.

[0041] 3. Curve C shows an angular displacement of ambient light detection in a photosensor chip package structure. The proximity detection angle and the ambient light detection angle become narrower with the PS and ALS thereof disposed in different basins. Thus an opening on a smartphone for its application is a circular hole with a small aperture, but the ambient light detection angle is not suitable for operation.

[0042] 4. Curve D shows an angular displacement of ambient light detection in the present invention. With the ambient light detection chip 45 isolated and disposed on the ASIC chip 43 with a pre-determined height thereon, the detection angle for ambient light is maximized, and with the proximity sensor 431 coupled to and installed on the ASIC chip 43, the detection angle for proximity is minimized. Moreover, such structure can operate by a circular hole as the opening with a small aperture on a smart mobile device without any compromise in detection angles.