An infrared proximity and ambient light brightness sensor with an optical reflective surface

Abstract

The invention discloses an infrared proximity and ambient light brightness sensor with an optical reflection surface, and relates to the technical field of sensors. The receiving sensing integrated chip of the sensor integrates infrared proximity and ambient light brightness sensing functions, a light emitting chip, an infrared baffle block and a receiving sensing integrated chip are sequentially mounted on a substrate, a transparent packaging colloid covers the light emitting chip, the infrared baffle block and the receiving sensing integrated chip and is combined with the substrate, an optical reflection structure is provided on the upper surface of the transparent packaging colloid, the optical reflection structure has an interval concave-convex structure to form a V-shaped optical reflection surface, the optical reflection structure is located between the light emitting chip and the receiving sensing integrated chip, and the optical reflection structure is provided on the transparent packaging colloid to reflect interference light emitted from the light emitting chip to the receiving sensing integrated chip, thereby reducing optical crosstalk and improving the performance of the proximity distance sensing sensor.

Description

Technical Field

[0001] The present invention relates to the field of sensor technology, and in particular to a structure having a proximity sensing sensor and an ambient light brightness sensing sensor. Background Art

[0002] At present, handheld electronic products (such as smart phones) are becoming more and more popular. These electronic products often use a lot of sensors to save energy and increase the convenience of human-computer interaction. The infrared proximity sensor is mainly used to realize the anti-touch function of answering the phone. When the user's head is close to the phone to answer the call, the touch function of the phone will be turned off. The ambient light brightness sensor is used to sense the changes in the ambient light source and adjust the brightness of the mobile phone panel according to the brightness of the environment. When the ambient brightness becomes darker, the brightness of the mobile phone panel will dim to avoid irritating the eyes. When the ambient brightness becomes brighter, the brightness of the mobile phone panel will become brighter to increase visibility. Infrared proximity sensors and ambient brightness sensors are both used to sense light and are often integrated in a packaging structure to save space and energy.

[0003] The existing optical sensor is equipped with a transmitting light chip and a receiving sensing integrated chip. When working normally, the transmitting light needs to pass through the glass screen of the mobile phone. If there is a target object above the glass screen of the mobile phone, the infrared transmitting light will encounter the target object and be reflected back to the receiving sensing integrated chip, thereby detecting the target object; if there is no target object, in order to prevent the light emitted from the side of the transmitting light chip from causing optical signal crosstalk to the receiving sensing integrated chip, various light-blocking materials will be encapsulated between the transmitting light chip and the receiving sensing integrated chip. However, the current optical sensor structure still has some light emitted from the transparent material to the receiving sensing integrated chip, which will affect the sensor's ability to detect the proximity distance. Summary of the invention

[0004] In view of the above problems and technical requirements, the inventors have proposed an infrared proximity and ambient light brightness sensor with an optical reflective surface. The technical solution of the present invention is as follows:

[0005] An infrared proximity and ambient light brightness sensor with an optical reflective surface comprises a substrate, a light emitting chip, a receiving sensing integrated chip, an infrared baffle block, and a transparent encapsulating colloid. The receiving sensing integrated chip has infrared proximity and ambient light brightness sensing functions. The light emitting chip, the infrared baffle block, and the receiving sensing integrated chip are sequentially mounted on the substrate. The light emitting chip and the receiving sensing integrated chip are both electrically connected to the substrate. The transparent encapsulating colloid covers the light emitting chip, the infrared baffle block, and the receiving sensing integrated chip and is combined with the substrate. The upper surface of the transparent encapsulating colloid has an optical reflective structure, the optical reflective structure has an interval concave-convex structure to form a V-shaped optical reflective surface, and the optical reflective structure is located between the light emitting chip and the receiving sensing integrated chip.

[0006] A further technical solution is that the optical reflective structure is concave relative to the remaining area of ​​the upper surface of the transparent encapsulating colloid.

[0007] A further technical solution is that the optical reflective structure is raised relative to the remaining area of ​​the upper surface of the transparent encapsulating colloid.

[0008] A further technical solution is that the transparent packaging colloid is provided with a transmitting end optical lens and a receiving end optical lens, the transmitting end optical lens is located above the transmitting light chip and the optical center of the transmitting end optical lens is in the same straight line with the center of the transmitting area of ​​the transmitting light chip, and the receiving end optical lens is located above the receiving sensing integrated chip and the optical center of the receiving end optical lens is in the same straight line with the center of the sensing area of ​​the receiving sensing integrated chip.

[0009] A further technical solution is that, for any one of the emitting light chip and the receiving sensing integrated chip, the chip is electrically connected to the substrate in the form of gold ball bonding wires.

[0010] A further technical solution is that, for any one of the emitting light chip and the receiving sensing integrated chip, the chip is electrically connected to the substrate in the form of solder balls.

[0011] A further technical solution is that an infrared isolation film is installed on the optical reflective structure, the upper surface of the infrared isolation film is flush, and the lower surface is in contact with the optical reflective structure.

[0012] Its further technical solution is that an infrared isolation cover is installed on the transparent packaging colloid, and the infrared isolation cover covers the transparent packaging colloid. The infrared isolation cover has a first through hole located above the emitting light chip and a second through hole located above the receiving sensing integrated chip. The opening center of the first through hole is in the same straight line with the center of the emitting area of ​​the emitting light chip, and the opening center of the second through hole is in the same straight line with the center of the sensing area of ​​the receiving sensing integrated chip. The upper surface of the infrared isolation cover is flush, and the lower surface has a joint portion that fits the optical reflection structure at a position facing the optical reflection structure, and is fixed to the upper surface of the transparent packaging colloid.

[0013] Its further technical solution is that the transmitting end optical lens is installed on the infrared isolation cover at the first through hole, and the optical center of the transmitting end optical lens, the opening center of the first through hole and the emission area center of the emitting light chip are on the same straight line; the receiving end optical lens is installed on the infrared isolation cover at the second through hole, and the optical center of the receiving end optical lens, the opening center of the second through hole and the sensing area center of the receiving sensing integrated chip are on the same straight line.

[0014] A further technical solution is that any one of the infrared isolation film and the infrared isolation cover plate is made of infrared isolation material, and the infrared isolation material includes any one of organic materials LCP, black glue, ceramic and metal.

[0015] The beneficial technical effect of the present invention is that the present invention reflects the interfering light emitted from the emitting light chip to the receiving sensing integrated chip by setting a reflective surface on the transparent packaging colloid, thereby reducing light crosstalk and improving the performance of the proximity distance sensing sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of the first embodiment of the sensor of the present application.

[0017] Figure 2 It is a schematic diagram of the principle of the first embodiment of the sensor of the present application.

[0018] Figure 3 It is another structural schematic diagram of the first embodiment of the sensor in the present application.

[0019] Figure 4 It is a schematic structural diagram of the second embodiment of the sensor of the present application.

[0020] Figure 5 It is a schematic structural diagram of the third embodiment of the sensor of the present application.

[0021] Figure 6It is a schematic structural diagram of the fourth embodiment of the sensor of the present application.

[0022] Figure 7 It is a structural schematic diagram of the fifth embodiment of the sensor of the present application.

[0023] Figure 8 It is another structural cross-sectional view of the fifth embodiment of the sensor of the present application.

[0024] Fig. 9 It is another structural cross-sectional view of the fifth embodiment of the sensor of the present application.

[0025] Fig.10 It is another structural cross-sectional view of the fifth embodiment of the sensor of the present application.

[0026] Fig.11 It is another structural cross-sectional view of the fifth embodiment of the sensor of the present application. DETAILED DESCRIPTION

[0027] The specific implementation of the present invention will be further described below in conjunction with the accompanying drawings.

[0028] like Figure 1 As shown, the embodiment of the present invention relates to an infrared proximity and ambient light brightness sensor with an optical reflective surface, the sensor includes a substrate 1, an emitting light chip 2, a receiving sensing integrated chip 3, an infrared baffle block 4, and a transparent encapsulating colloid 5, wherein the emitting light chip 2 has an infrared emitting function (the wavelength is generally between 800nm-1000nm), the receiving sensing integrated chip 3 integrates infrared proximity and ambient light brightness sensing functions, and the receiving sensing integrated chip 3 is used to amplify and convert analog photocurrent to output a digital signal. The emitting light chip 2 can be an infrared LED chip / VCSEL chip, etc., and the receiving sensing integrated chip 3 can use a commercially available chip such as a Si1141 chip, or a chip with the above functions designed and developed independently.

[0029] The substrate 1 is pre-installed with circuit wiring inside, and the substrate 1 is also reserved with circuit connection structures such as wires and pads for connecting with the emitting light chip 2 and the receiving sensing integrated chip 3. The emitting light chip 2 is mounted on the substrate 1 to form an emitting area, and the receiving sensing integrated chip 3 is also mounted on the substrate 1 to form a sensing area. The infrared baffle block 4 is located on the substrate 1, and the infrared baffle block 4 is located between the emitting light chip 2 and the receiving sensing integrated chip 3. The infrared baffle block 4 can isolate a part of the light emitted from the emitting light chip 2 to prevent light crosstalk. The transparent packaging colloid 5 encapsulates the emitting light chip 2, the receiving sensing integrated chip 3 and the infrared baffle block 4, and is combined with the substrate 1 to complete the entire packaging structure, thereby forming a complete sensor structure.

[0030] like Figure 2 As shown, the upper surface of the transparent encapsulation colloid 5 has an optical reflection structure 6, and the optical reflection structure 6 has an interval concave-convex structure to form a V-shaped optical reflection surface, and the optical reflection structure 6 is located between the emitting light chip 2 and the receiving sensing integrated chip 3; when the sensor is installed under the mobile phone glass screen 9, part of the light generated by the emitting light chip 2 is reflected on the optical reflection structure 6 through the inner surface of the mobile phone glass screen 9, and the optical reflection structure 6 effectively reflects the light reflected from the light emitting area to the light receiving area, thereby reducing optical crosstalk and improving the sensing performance of the infrared proximity sensor.

[0031] like Figure 1 and 3 As shown, the transmitting optical chip 2 and the receiving sensing integrated chip 3 are electrically connected to the substrate 1. For any one of the transmitting optical chip 2 and the receiving sensing integrated chip 3, the chip has the following two ways of connecting to the substrate 1. Different connection methods usually correspond to different structures of the substrate 1:

[0032] (1) The chip can be electrically connected to the substrate 1 by gold ball bonding wires. This connection method usually corresponds to the following: Figure 1 In the structure shown, the chip is connected to the circuit on the surface of the lead substrate 1 by bonding wires 10. The actual manufacturing method is usually: the chip is fixed on the substrate 1 by die bonding, and connected to the circuit on the substrate 1 by gold ball bonding wires.

[0033] (2) The chip can be electrically connected to the substrate 1 by soldering balls. This connection method usually corresponds to the following: Figure 3 In the structure shown, the bottom of the chip has a plurality of solder balls 11, and the chip is electrically connected to the circuit on the surface of the substrate 1 through the solder balls 11 at the bottom. The actual manufacturing method is usually: the solder balls 11 are generated at the bottom of the chip, and then fixed on the substrate 1 by solder ball reflow.

[0034] In actual implementation, the connection methods used by the two chips can be the same or different, but they are usually designed to use the same connection method, such as Figure 1 The structure in which the chip is electrically connected to the substrate 1 by means of gold ball bonding wires is shown. Figure 3 The structure in which the chip is electrically connected to the substrate 1 by means of solder balls is shown.

[0035] In such Figures 1 to 3 In the first embodiment, the optical reflective structure 6 is recessed relative to the remaining area of ​​the upper surface of the transparent encapsulant 5. Figure 4 In the second embodiment, the optical reflective structure 6 is protruding relative to the remaining area of ​​the upper surface of the transparent encapsulant 5 .

[0036] Based on the above first and second embodiments, no matter whether the optical reflective structure 6 is concave or convex relative to the rest of the upper surface of the transparent encapsulant 5, the method further includes a third embodiment: Figure 5 As shown, an infrared isolation film 7 is installed on the optical reflection structure 6. The upper surface of the infrared isolation film 7 is flush and the lower surface is in contact with the optical reflection structure 6, which is convenient for installation of the infrared isolation film 7. The infrared isolation film 7 can further prevent optical crosstalk.

[0037] Based on the above first and second embodiments, no matter whether the optical reflective structure 6 is concave or convex relative to the rest of the upper surface of the transparent encapsulant 5, the method further includes a fourth embodiment: Figure 6 As shown, an infrared isolation cover plate 8 is installed on the transparent packaging colloid 5, and the infrared isolation cover plate 8 covers the entire transparent packaging colloid 5. The upper surface of the infrared isolation cover plate 8 is flush, and the lower surface has a joint portion 16 that fits with the optical reflection structure 6 at a position directly opposite to the optical reflection structure 6. The infrared isolation cover plate 8 has a first through hole 12 located above the emitting light chip 2 and a second through hole 13 located above the receiving sensing integrated chip 3. The opening center of the first through hole 12 is in the same straight line with the center of the emitting area of ​​the emitting light chip 2, and the opening center of the second through hole 13 is in the same straight line with the center of the sensing area of ​​the receiving sensing integrated chip 3.

[0038] Furthermore, the method can also manufacture a transmitting end optical lens 14 above the transmitting optical chip 2 and a receiving end optical lens 15 on the receiving sensing integrated chip 3. There are two manufacturing methods:

[0039] (1) Figure 7 and 8 As shown, based on the above second embodiment, when the optical reflective structure 6 is raised relative to the remaining area of ​​the upper surface of the transparent encapsulating colloid 5, the method can also be expanded to form a fifth embodiment, that is, the upper surface of the transparent encapsulating colloid 5 also has a transmitting end optical lens 14 and a receiving end optical lens 15, the transmitting end optical lens 14 is located above the transmitting light chip 2 and the optical center of the transmitting end optical lens 14 is in the same straight line with the center of the transmitting area of ​​the transmitting light chip 2, and the receiving end optical lens 15 is located above the receiving sensing integrated chip 3 and the optical center of the receiving end optical lens 15 is in the same straight line with the center of the sensing area of ​​the receiving sensing integrated chip 3. In the present application, the transmitting end optical lens 14 and the receiving end optical lens 15 are injection molded by transparent materials, and the transparent material can be transparent glue, etc. The actual manufacturing method is usually: the optical reflective structure 6, the transmitting end optical lens 14 and the receiving end optical lens 15 are injection molded at one time with transparent glue on the surface of the substrate 1.

[0040] Furthermore, on this basis, Figures 9 to 11As shown, an infrared isolation cover plate 8 can also be installed on the transparent encapsulation colloid 5, and the infrared isolation cover plate 8 covers the entire transparent encapsulation colloid 5. At this time, the optical center of the transmitting end optical lens 14, the opening center of the first through hole 12 on the infrared isolation cover plate 8, and the center of the emission area of ​​the emitting light chip 2 are on the same straight line, and the optical center of the receiving end optical lens 15, the opening center of the second through hole 13 on the infrared isolation cover plate 8, and the center of the sensing area of ​​the receiving sensing integrated chip 3 are on the same straight line. The manufacturing method can be: firstly, injection molding the transparent encapsulation colloid 5 having the optical reflection structure 6 and the two optical lenses 14 and 15, and then fixing the infrared isolation cover plate 8 on the upper surface of the transparent encapsulation colloid 5.

[0041] (2) Based on the fourth embodiment, the method can also be expanded to form a sixth embodiment, that is, no matter whether the optical reflective structure 6 is concave or convex relative to the rest of the upper surface of the transparent encapsulating colloid 5, when the infrared isolation cover plate 8 is installed on the transparent encapsulating colloid 5, a transmitting end optical lens 14 is also installed on the infrared isolation cover plate 8 at the first through hole 12 of the infrared isolation cover plate 8, and a receiving end optical lens 15 is installed on the infrared isolation cover plate 8 at the second through hole 13 of the infrared isolation cover plate 8. At this time, similarly, the optical center of the transmitting end optical lens 14, the opening center of the first through hole 12 and the center of the emitting area of ​​the emitting optical chip 2 are on the same straight line, and the optical center of the receiving end optical lens 15, the opening center of the second through hole 13 and the center of the sensing area of ​​the receiving sensing integrated chip 4 are on the same straight line. The manufacturing method in this case is usually as follows: firstly process the transmitting end optical lens 14 and the receiving end optical lens 15, then fix the transmitting end optical lens 14 and the receiving end optical lens 15 correspondingly at the two through holes of the infrared isolation cover plate 8, and then fix the infrared isolation cover plate 8 with the two optical lenses fixed on the upper surface of the transparent packaging colloid 5.

[0042] Any one of the infrared isolation block 4, the infrared isolation sheet 7 and the infrared isolation cover plate 8 is made of infrared isolation material, including any one of organic materials LCP, vinyl, ceramics and metals and other possible materials, which are not limited in this application.

[0043] The above is only a preferred embodiment of the present application, and the present invention is not limited to the above embodiments. It is understood that other improvements and changes directly derived or associated by those skilled in the art without departing from the spirit and concept of the present invention should be considered to be included in the protection scope of the present invention.

Claims

1. An infrared proximity and ambient light brightness sensor having an optical reflective surface, characterized in that: The invention comprises a substrate, a light emitting chip, a receiving sensing integrated chip, an infrared baffle block, and a transparent encapsulating colloid. The receiving sensing integrated chip has infrared proximity and ambient light brightness sensing functions. The light emitting chip, the infrared baffle block, and the receiving sensing integrated chip are sequentially mounted on the substrate. The light emitting chip and the receiving sensing integrated chip are both electrically connected to the substrate. The transparent encapsulating colloid covers the light emitting chip, the infrared baffle block, and the receiving sensing integrated chip and is combined with the substrate. The upper surface of the transparent encapsulating colloid has an optical reflection structure. The optical reflection structure has an interval concave-convex structure to form a V-shaped optical reflection surface. The optical reflection structure is located between the light emitting chip and the receiving sensing integrated chip. An infrared isolation cover is installed on the transparent packaging colloid, and the infrared isolation cover covers the transparent packaging colloid. The infrared isolation cover has a first through hole located above the emitting light chip and a second through hole located above the receiving sensing integrated chip. The opening center of the first through hole is in the same straight line with the center of the emitting area of ​​the emitting light chip, and the opening center of the second through hole is in the same straight line with the center of the sensing area of ​​the receiving sensing integrated chip. The upper surface of the infrared isolation cover is flush, and the lower surface has a joint portion that fits the optical reflection structure at a position facing the optical reflection structure, and is fixed to the upper surface of the transparent packaging colloid.

2. The infrared proximity and ambient light brightness sensor with an optical reflective surface according to claim 1, characterized in that: The optical reflective structure is concave relative to the remaining area of ​​the upper surface of the transparent encapsulant.

3. The infrared proximity and ambient light brightness sensor with an optical reflective surface according to claim 1, characterized in that: The optical reflective structure is raised relative to the remaining area of ​​the upper surface of the transparent encapsulant.

4. The infrared proximity and ambient light brightness sensor with an optical reflective surface according to claim 3, characterized in that: The transparent packaging colloid is provided with a transmitting end optical lens and a receiving end optical lens. The transmitting end optical lens is located above the transmitting light chip and the optical center of the transmitting end optical lens is in the same straight line with the center of the transmitting area of ​​the transmitting light chip. The receiving end optical lens is located above the receiving sensing integrated chip and the optical center of the receiving end optical lens is in the same straight line with the center of the sensing area of ​​the receiving sensing integrated chip.

5. The infrared proximity and ambient light brightness sensor with an optical reflective surface according to claim 1, characterized in that: For any one of the emitting light chip and the receiving sensing integrated chip, the chip is electrically connected to the substrate in the form of gold ball bonding wires.

6. The infrared proximity and ambient light brightness sensor with an optical reflective surface according to claim 1, characterized in that: For any one chip among the emitting light chip and the receiving sensing integrated chip, the chip is electrically connected to the substrate in the form of solder balls.

7. The infrared proximity and ambient light brightness sensor with an optical reflective surface according to claim 1, characterized in that: An infrared isolation film is installed on the optical reflection structure, the upper surface of the infrared isolation film is flush, and the lower surface is in contact with the optical reflection structure.

8. The infrared proximity and ambient light brightness sensor with an optical reflective surface according to claim 1, characterized in that: The transmitting end optical lens is installed on the infrared isolation cover at the first through hole, and the optical center of the transmitting end optical lens, the opening center of the first through hole and the emission area center of the emitting light chip are on the same straight line. The receiving end optical lens is installed on the infrared isolation cover at the second through hole, and the optical center of the receiving end optical lens, the opening center of the second through hole and the sensing area center of the receiving sensing integrated chip are on the same straight line.

9. The infrared proximity and ambient light brightness sensor with an optical reflective surface according to claim 1, characterized in that: The infrared blocking block is made of infrared isolation material, and the infrared isolation material includes any one of organic materials LCP, black glue, ceramic and metal.

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