Multi-point proximity sensor

Abstract

The present invention discloses a multi-point proximity sensor, which includes a multi-point proximity sensor module and a lens assembly. The multi-point proximity sensor module includes a PCB substrate provided with an optical design position of a sensor chip and a metal platform of a VCSEL chip, and further includes a VCSEL chip driver and a VCSEL chip. The VCSEL chip driver is signal-connected to the VCSEL chip, and the VCSEL chip is disposed on the metal platform of the VCSEL chip; the lens assembly includes a lens cover, and the lens cover is provided with a transmitting lens and a receiving lens; the lens cover is covered on the PCB substrate. The sensor chip includes a micro lens group and a microprocessor, the micro lens group is signal-connected to the microprocessor, and the micro lens group is disposed in the light receiving area. The present invention also provides an electronic device designed using the multi-point proximity sensor and a multi-point proximity detection method. The multi-point proximity sensor provided by the present invention can achieve detection at multiple position points, and realize the functions of multi-point focusing and face recognition.

Description

Technical Field

[0001] The present invention relates to the field of proximity sensor devices, and particularly to a multi-point proximity sensor and an electronic device designed by using the multi-point proximity sensor. Background Art

[0002] With the development of technology, especially the development of smart phones and digital camera technologies, the distance sensor plays an important role in assisting the focusing of mobile phones and cameras.

[0003] However, the existing distance sensors can only perform single-point detection and cannot perform multi-point detection. With the further development of smart phones and digital cameras, in order to cope with the applications of multi-point assisted focusing and face recognition, a multi-point proximity sensor is needed. The prior art does not provide a practical multi-point proximity sensor. Summary of the Invention

[0004] In view of the needs of existing electronic devices, the present invention provides a multi-point proximity sensor, a multi-point proximity detection method, and an electronic device designed by using the multi-point proximity sensor, such as a mobile phone, a digital camera, etc. The multi-point proximity sensor provided by the present invention can perform detection at multiple position points.

[0005] A multi-point proximity sensor provided by an embodiment of the present invention includes a multi-point proximity sensor module and a lens assembly. The multi-point proximity sensor module includes a PCB (Printed Circuit Board) substrate provided with an optical design position of a sensor chip and a metal platform of a VCSEL (Vertical Cavity Surface Emitting Laser) chip, and further includes a VCSEL chip driver and a VCSEL chip. The VCSEL chip driver is signal-connected to the VCSEL chip. The VCSEL chip is disposed on the metal platform of the VCSEL chip. Driver connection pads are provided on the PCB substrate, and the VCSEL chip driver is soldered on the driver connection pads. The multi-point proximity sensor module further includes a sensor chip disposed at the optical design position of the sensor chip. The PCB substrate, the sensor chip, and the VCSEL chip are integrally encapsulated. The lens assembly includes a lens cover. The lens cover is provided with a receiving cavity. The lens cover is provided with a transmitting lens area corresponding to the VCSEL chip area of the PCB substrate, and the lens cover is provided with a receiving lens area corresponding to the sensor chip area of the PCB substrate. A transmitting lens is provided in the transmitting lens area, and a receiving lens is provided in the receiving lens area. The lens cover is disposed on the PCB substrate such that a receiving cavity area between the PCB substrate and the lens cover forms a sealed space. The multi-point proximity sensor further includes a light shielding plate. The light shielding plate is connected to the PCB substrate and the inner side wall of the front end of the lens cover. The light shielding plate is configured to divide the sealed space between the PCB substrate and the lens cover into a laser emission area and a light receiving area. The laser emission area corresponds to the area from the VCSEL chip to the transmitting lens, and the light receiving area corresponds to the area from the receiving lens to the PCB substrate. The sensor chip includes a micro lens group and a microprocessor. The micro lens group is signal-connected to the microprocessor. The micro lens group is disposed in the light receiving area.

[0006] An embodiment of the present invention further provides a multi-point proximity detection method, including the following steps: A multi-point proximity detection method, characterized by including the following steps:

[0007] The VCSEL chip emits infrared laser photons in the 940-nanometer band. The 940-nanometer band infrared laser photons are filtered by the transmitting lens to filter out photons outside the 940-nanometer band, and after being diffracted by the transmitting lens, a group of 940-nanometer band infrared emission laser photons is formed.

[0008] The receiving lens receives the infrared laser photons, and after being filtered by the receiving lens, 940-nanometer band infrared received infrared laser photons are formed. After being further diffracted by the receiving lens, a group of 940-nanometer band infrared laser photons is formed.

[0009] The micro lens group senses the infrared laser photons in the 940-nanometer band, and sends the sensing result of the micro lens group to the microprocessor. The microprocessor calculates the distances of multiple position points of the object reflecting the infrared laser photons in the 940-nanometer band based on the sensing result.

[0010] In the multi-point proximity sensor and the multi-point proximity detection method provided by the embodiments of the present invention, a VCSEL chip emits infrared laser photons in the 940-nanometer band, and the infrared laser photons are emitted through the emitting lens. After the infrared laser photons encounter an obstacle, they will be reflected back, and then the infrared laser photons are received through the receiving lens. The micro lens group senses the infrared laser photons projected onto it. Among them, the inductions caused by the infrared laser photons transmitted through different transmission distances on the micro lenses of the micro lens group are different. The microprocessor can calculate the distances from different reflection points to the multi-point proximity sensor provided by the present invention based on this difference in induction, so as to realize the detection of multiple position points.

[0011] The VCSEL chip can be an infrared laser emitter in the 850-nanometer band or the 940-nanometer band. The embodiments of the present invention preferably use an infrared laser emitter in the 940-nanometer band, and the infrared laser emitted by it is more stable and the detection result is more accurate. 940-nanometer band infrared filter coatings are provided on both the emitting lens and the receiving lens. By setting the VCSEL chip as an infrared laser emitter in the 940-nanometer band, it mainly emits infrared laser photons with a 940-nanometer wavelength. At the same time, by providing 940-nanometer band infrared filter coatings on both the emitting lens and the receiving lens, only the infrared laser photons in the 940-nanometer band can pass through the emitting lens or the receiving lens, and the laser photons in other bands will be filtered out. The VCSEL chip of the multi-point proximity sensor provided by the present invention can be set as a laser emitter in other bands. Correspondingly, the emitting lens and the receiving lens need to be provided with filter coatings in the corresponding bands. However, due to the good propagation characteristics and detection characteristics of the infrared laser photons in the 940-nanometer band, the embodiments of the present invention preferably use an infrared laser emitter in the 940-nanometer band.

[0012] Preferably, both the emitting lens and the receiving lens are lenses with diffraction functions. Through diffraction, on the one hand, it can better emit the infrared laser photons in the 940-nanometer band emitted by the VCSEL chip, and on the other hand, it can also better receive the received infrared laser photons in the 940-nanometer band and be sensed by the micro lens group. Using lenses with diffraction functions can reduce the influence of ambient light on the sensor while realizing the emission and reception functions of the infrared laser photons in the 940-nanometer band, and obtain better detection effects.

[0013] Preferably, the micro lens group is a matrix micro lens group, and the matrix micro lens group includes 2,240 micro lenses.

[0014] Preferably, the transmitting lens is parallel to the VCSEL chip, and the receiving lens is parallel to the matrix micro lens.

[0015] Preferably, a two-dimensional code is fired on the back of the PCB substrate, and the two-dimensional code contains the wafer unit KGD (Known Good Die) for producing the sensor chip, the wafer unit KGD for producing the VCSEL chip, the wafer unit KGD for producing the transmitting lens and the receiving lens, and the production time information of the multi-point proximity sensor. KGD (Known Good Die) is a MAP file that indicates whether each chip is a good product or a defective product. An embodiment of the present invention further provides a camera with multi-point proximity recognition, including a camera lens assembly and the multi-point proximity sensor as described above, and the camera lens assembly is respectively signal-connected to the VCSEL chip and the sensor chip.

[0016] An embodiment of the present invention further provides an electronic device, including the camera with multi-point proximity recognition as described above. Specifically, the electronic device provided by the embodiment of the present invention is a mobile phone, a digital camera, or a digital video camera. Description of the Drawings

[0017] Figure 1 Schematic three-dimensional structure diagram of the multi-point proximity sensor in Embodiment 1 of the present invention;

[0018] Figure 2 Schematic module structure diagram of the multi-point proximity sensor in Embodiment 1 of the present invention;

[0019] Figure 3 Schematic structure diagram of the lens assembly in Embodiment 1 of the present invention;

[0020] Figure 4 Schematic structure diagram of the matrix micro lens group of 2,240 micro lenses in Embodiment 1 of the present invention;

[0021] Figure 5 Photon map presented by target objects at different distances in the test of 2,240 matrix micro lenses in Embodiment 1 of the present invention;

[0022] Figure 6 Schematic back pin structure diagram of the multi-point proximity sensor module in Embodiment 1 of the present invention;

[0023] Figure 7 Schematic wire bonding pin structure diagram of the PCB substrate in Embodiment 1 of the present invention;

[0024] Figure 8Schematic flow chart of the multi-point short-distance detection method in Embodiment 3 of the present invention;

[0025] Figure 9 Schematic flow chart of the packaging method of the multi-point short-distance sensor module in Embodiment 4 of the present invention;

[0026] Figure 10 Schematic flow chart of the packaging method of the multi-point short-distance sensor in Embodiment 5 of the present invention.

[0027] In the drawings: 310, PCB substrate; 311, sensor chip; 312, VCSEL chip; 313, driver connection pad; 314, matrix micro lens group; 320, lens cover; 321, transmitting lens; 322, receiving lens; 323, light shield. Detailed implementation manners

[0028] Next, in combination with the drawings and specific implementation manners, the present invention will be further described. It should be noted that, on the premise of no conflict, any combination of the following-described embodiments or technical features can form a new embodiment.

[0029] Embodiment 1:

[0030] As Figures 1 to 7As shown in the figure, the multi-point proximity sensor provided by the embodiment of the present invention includes a multi-point proximity sensor module and a lens assembly. The multi-point proximity sensor module includes a PCB substrate 310 provided with an optical design position of a sensor chip and a metal platform of a VCSEL chip, and further includes a driver connection pad 313 and a VCSEL chip 312. The driver connection pad 313 and the VCSEL chip 312 are signal-connected, and a VCSEL chip driver can be welded on the driver connection pad 313. The VCSEL chip 312 is disposed on the metal platform of the VCSEL chip, and further includes a sensor chip 311 disposed at the optical design position of the sensor chip. The PCB substrate 310, the sensor chip 311, and the VCSEL chip 312 are integrally encapsulated. The lens assembly includes a lens cover 320. The lens cover 320 is provided with a receiving cavity. The lens cover 320 is provided with a transmitting lens area corresponding to the VCSEL chip 312 area of the PCB substrate 310, and the lens cover is provided with a receiving lens area corresponding to the sensor chip 311 area of the PCB substrate 310. The transmitting lens area is provided with a transmitting lens 321, and the receiving lens area is provided with a receiving lens 322. The lens cover 320 is covered on the PCB substrate 310, so that a sealed space is formed in the receiving cavity area between the PCB substrate 310 and the lens cover 320. It further includes a light shielding plate 323. The light shielding plate 323 is connected to the inner side wall of the front end of the PCB substrate 310 and the lens cover 320. The light shielding plate is used to divide the sealed space between the PCB substrate 310 and the lens cover 320 into a laser emission area and a light receiving area. The laser emission area corresponds to the area from the VCSEL chip 312 to the transmitting lens 321, and the light receiving area corresponds to the area from the receiving lens 322 to the PCB substrate 310. The sensor chip 311 includes a micro lens group and a microprocessor. The micro lens group and the microprocessor are signal-connected, and the micro lens group is disposed in the light receiving area.

[0031] Pins are provided on the PCB substrate 310. The schematic diagram of the pins on the back of the PCB substrate 310 is as Figure 6 shown Figure 7 shows the wire bonding pins on the front of the PCB substrate 310. The contact connection between the PCB substrate 310 and the sensor chip 311 and the VCSEL chip 312 can be realized through gold wire and ultrasonic welding technology, so as to realize the circuit conduction of the sensor chip 311, the VCSEL chip 312, and the PCB substrate 310 and the transmission of signals. The numbers and functions of the pins on the PCB substrate 310 are as follows in the table: Among them, the parameters are as follows: FUNCTION: Brief explanation of the function; FBFPAD No.: Module pin number; BF: Substrate unit and chip pin number

[0032] FUNCTION PAD NO BF SPI_I2C_N A1 21 NCS A2 20 GPIO1 A3 19 IOVDD A4 14,15,22 XSHUT A5 13 SWD_IO A6 9 SWD_CLK A7 8 VDD B1, B7 1,7,26 GND B4, C1, C7 GPIO2 C2 17 MOSI C3 16 MCLK C4 12 MISO C5 11 ATEST1 C6 3 VSS 2,4,5,6,10,18,23,28,29 VCSEL ANODE 28,30,31 VCSEL CATHODE 27

[0033] Explanation of each function

[0034] SPI_I2C_N: SPI / I2C internal register selection pin;

[0035] NCS: SPI internal register selection pin;

[0036] GPIO1: Digital power supply pin;

[0037] IOVDD: Digital power supply pin;

[0038] XSHUT: Module operation enable pin;

[0039] SWD_IO: 150 MHz clock test pin;

[0040] SWD_CLK: 16 MHz clock scan pin;

[0041] VDD: Power supply pin;

[0042] GND: Ground pin;

[0043] GPIO2: 40 MHz clock scan pin;

[0044] MOSI: I2C clock / SPI data input pin;

[0045] MCLK: Scan clock input terminal;

[0046] MISO: SPI data output terminal;

[0047] ATEST1: Debug port pin;

[0048] VSS: Ground pin;

[0049] VCSEL ANODE: Vertical cavity surface emitting laser anode pin;

[0050] VCSEL CATHODE: Vertical cavity surface emitting laser cathode pin;

[0051] Among them, the VCSEL chip 312 is an infrared laser emitter in the 940-nanometer band, and infrared filter coatings in the 940-nanometer band are provided on both the emission lens 321 and the reception lens 322. By setting the VCSEL chip 312 as an infrared laser emitter in the 940-nanometer band, it mainly emits infrared laser photons in the 940-nanometer band. At the same time, by providing infrared filter coatings in the 940-nanometer band on both the emission lens 321 and the reception lens 322, only the infrared laser photons in the 940-nanometer band can pass through the emission lens 321 or the reception lens 322, and the laser photons in other bands will be filtered out. The VCSEL chip 312 of the multi-point proximity sensor provided by the present invention can be set as a laser emitter in other bands. Correspondingly, the emission lens 321 and the reception lens 322 need to be provided with filter coatings in the corresponding bands. However, due to the good propagation characteristics and detection characteristics of the infrared laser photons in the 940-nanometer band, the multi-point proximity sensor provided by the embodiments of the present invention preferably uses an infrared laser emitter in the 940-nanometer band.

[0052] At the same time, both the emission lens 321 and the reception lens 322 are lenses with diffraction functions. The specific structure of the diffraction lens can adopt any mature diffraction lens provided by the prior art. For a diffraction lens in one embodiment, its structure includes annular regions separated by multiple phase jumps to correct the wavefront aberration of the laser beam, and the diameter of the outermost phase jump of the diffraction lens structure is smaller than the second largest effective diameter among the effective diameters required to reproduce various types of information recording media. For a diffraction lens in another embodiment, there are two refractive / harmonic diffraction lenses and a spacer. Both of the two refractive / harmonic diffraction lenses have spherical surfaces and harmonic diffraction surfaces based on aspherical surfaces; the depths of the two harmonic diffraction surfaces satisfy 65 μm. The present invention places no limit on the specific structure of the diffraction lens of the multi-point proximity sensor. Through diffraction, on the one hand, it can achieve sending the infrared laser photons in the 940-nanometer band emitted by the VCSEL chip 312 to a larger range, and on the other hand, it can also receive the infrared laser photons in the 940-nanometer band over a larger range and be sensed by the micro lens group. By using a lens with a diffraction function, while realizing the emission and reception functions of the infrared laser photons in the 940-nanometer band, the influence of ambient light on the sensor can be reduced, and a better detection effect can be obtained.

[0053] Among them, the micro lens group can be set as a circularly arranged micro lens group. In the embodiments of the present invention, a matrix micro lens group 314 is preferably used, and this matrix micro lens group 314 includes 2,240 micro lenses.

[0054] Furthermore, the emission lens 321 can be set parallel to the VCSEL chip 312, and the receiving lens 322 can be set parallel to the matrix micro lens group 314. By setting the emission lens 321 parallel to the VCSEL chip 312 and the receiving lens 322 parallel to the matrix micro lens group 314, the infrared laser photons emitted by the VCSEL chip 312 can be emitted vertically through the emission lens 321, and the received infrared laser photons can be received vertically by the matrix micro lens group 314.

[0055] Preferably, a two-dimensional code is fired on the back of the PCB substrate 310, and the two-dimensional code contains the wafer unit KGD for manufacturing the sensor chip, the wafer unit KGD for manufacturing the VCSEL chip, the wafer unit KGD for manufacturing the emission lens and the receiving lens, and the production time information of the multi-point proximity sensor.

[0056] Embodiment 2:

[0057] This embodiment provides a camera with multi-point proximity recognition, including a camera lens assembly and the multi-point proximity sensor as in Embodiment 1. The camera lens assembly is respectively signal-connected to the VCSEL chip 312 and the sensor chip 311.

[0058] Furthermore, this embodiment also provides an electronic device, including a camera with multi-point proximity recognition. The electronic device includes a mobile phone, a camera or a video camera.

[0059] The electronic device such as a mobile phone gives a trigger signal to start the multi-point proximity sensor module. After the self-check of the multi-point proximity sensor module is completed, the VCSEL chip driver is first started to make the VCSEL chip 312 (vertical cavity surface emitting laser) emit laser photons in the 940-nanometer band. The laser photon beam passes through the emission lens 321 with diffraction function and the 940-nanometer coating infrared filter and then shoots towards the target object. After the laser beam contacts the target object, it is reflected to the receiving area of the receiving lens 322 with diffraction function and the 940-nanometer coating infrared filter, and then is sensed by the 2240 matrix micro lens groups in the sensor chip 311 and fed back to the microprocessor of the sensor chip. The microprocessor calculates the distances from the multi-point proximity sensor module to different positions of the target object and feeds them back to the electronic device, so that the camera / mobile phone can realize multi-point assisted focusing and face recognition pairing.

[0060] Embodiment 3:

[0061] As Figure 8 shown, this embodiment of the present invention provides a multi-point proximity detection method, which is realized by the multi-point proximity sensor in Embodiment 1 and includes the following steps:

[0062] S41: Emit infrared laser photons in the 940 - nanometer band through a VCSEL chip. The 940 - nanometer - band infrared laser photons are filtered by an emission lens to remove photons outside the 940 - nanometer band, and after being diffracted by the emission lens, a group of 940 - nanometer - band infrared emission laser photons is formed;

[0063] S42: Receive infrared laser photons through a receiving lens, and after being filtered by the receiving lens, 940 - nanometer - band infrared received infrared laser photons are formed. After further diffraction by the receiving lens, a group of 940 - nanometer - band infrared laser photons is formed;

[0064] S43: Sense the group of 940 - nanometer - band infrared laser photons through a micro - lens group, and send the sensing result of the micro - lens group to a micro - processor. The micro - processor calculates the distances of multiple position points of the object reflecting the group of 940 - nanometer - band infrared laser photons based on the sensing result.

[0065] The multi - point short - distance sensor and the multi - point short - distance detection method provided by the embodiments of the present invention emit 940 - nanometer - band infrared laser photons through a VCSEL chip and emit them through an emission lens. After the infrared laser photons encounter an obstacle, they will be reflected back. Then, the infrared laser photons are received through a receiving lens, and the micro - lens group senses the infrared laser photons projected onto it. Among them, the inductions caused by the infrared laser photons transmitted through different transmission distances on the micro - lenses of the micro - lens group are different, and its induction map is as Figure 5 shown. Based on this difference in induction, the micro - processor can calculate the distances from different reflection points to the multi - point short - distance sensor provided by the present invention, thereby realizing the detection of multiple position points.

[0066] Embodiment 4:

[0067] As Figure 9 shown, the present embodiment provides a method for packaging a multi - point short - distance sensor module for manufacturing a multi - point short - distance sensor module of a multi - point short - distance sensor, including the following steps:

[0068] S11: PCB substrate preparation step: Cut a PCB circuit board provided with multiple PCB substrate units into PCB substrates. The PCB substrates are provided with an optical design position for the sensor chip and a metal platform for the VCSEL chip;

[0069] S12: Sensor chip preparation step: Cut a wafer provided with multiple sensor chips into sensor chips; The sensor chip includes a micro - lens group and a micro - processor, and the micro - lens group is arranged on the surface of the micro - processor;

[0070] S13: Assembly step: Place the sensor chip at the optical design position of the sensor chip on the PCB substrate through chip mounting process, and place the pre-prepared VCSEL chip on the metal platform of the VCSEL chip on the PCB substrate through chip mounting process;

[0071] The chip mounting process mainly includes a dispensing machine and a chip mounter. Through the dispensing machine, conductive adhesive such as silver paste is dispensed at the optical design position of the sensor chip. The chip mounter has an automatic identification function and can identify whether the sensor chip, VCSEL chip or other chips are qualified. Then, the qualified sensor chip is ejected from the tape by the ejector pin of the chip mounter, so that it is detached from the adhesion of the tape. At the same time, vacuum is generated by the vacuum chuck. Under the action of the vacuum chuck, the sensor chip is grabbed, and the sensor chip is identified through the optical system on the chip mounter, and the sensor chip is placed at the optical design position of the sensor chip, thus realizing the positioning and installation of the sensor chip and the PCB substrate. Similarly, the VCSEL chip is installed on the VCSEL metal platform using the same chip mounting process.

[0072] S14: Curing step: Place the PCB substrate with the VCSEL chip and the sensor chip attached into an oven and bake it until the VCSEL chip and the sensor chip are firmly bonded to the PCB substrate; among them, the temperature of the oven is set to 160 degrees and baked for 2 hours, so that the VCSEL chip and the sensor chip can be firmly bonded to the PCB substrate.

[0073] S15: Wire bonding step: Between the VCSEL chip, the sensor chip and the PCB substrate, use gold wire and ultrasonic welding technology to connect the VCSEL chip and the PCB substrate, and the sensor chip and the PCB substrate, so that the circuits between the PCB substrate and the VCSEL chip, and the PCB substrate and the sensor chip are conducted, forming a multi-point short-distance sensor module.

[0074] The multi-point short-distance sensor module packaging method provided by the embodiment of the present invention forms an integrally packaged multi-point short-distance sensor module, thus providing components that are convenient for assembly and packaging for manufacturing multi-point short-distance sensors.

[0075] Among them, the PCB substrate preparation step specifically includes the following steps:

[0076] S111: Select a four-layer PCB circuit board with a thickness of 0.25 mm, and this PCB circuit board is provided with 572 PCB substrate units;

[0077] S112: Mount two currently smallest 01005 capacitors on the substrate of each PCB substrate unit through surface mounting technology;

[0078] S113: Use laser to burn the packaging information of the PCB substrate product on the back substrate area of each PCB substrate unit to facilitate customer traceability in subsequent processes;

[0079] S114: The back of the entire PCB is attached to the tape and a steel ring is attached to fix the PCB and facilitate the taking of the PCB at the back-end station;

[0080] S115: using a cutting blade to cut the PCB circuit board attached to the tape, and dividing the multiple PCB substrate units into independent PCB substrates, each PCB substrate corresponding to one PCB substrate unit;

[0081] S116: placing the divided PCB circuit board under ultraviolet light to release the adhesive force between the PCB substrate and the tape;

[0082] S117: Automatically identify qualified PCB substrates through a chip mounter and grab qualified PCB substrates, and attach the PCB substrates to a carrier with tape; the chip mounter includes a pin and a suction cup, and the suction cup generates a vacuum. The pin first pushes the PCB substrate out of the tape on the back of the PCB substrate to separate it from the tape, and the suction cup generates a vacuum, and uses the vacuum to adsorb the PCB substrate on the suction cup. The PCB substrate is moved to a stainless steel carrier with tape and fixed on the stainless steel carrier.

[0083] S118: The PCB substrate is placed in an oven via a stainless steel carrier and baked until dry.

[0084] The steps of preparing the sensor chip specifically include the following steps:

[0085] S121: Select a wafer that has passed the EWS test. The preferred embodiment of the present invention uses a 750 micron thick 12-inch wafer produced by STMicroelectronics. There are 10,000 sensor chips on the wafer;

[0086] S122: A protective tape is applied to the front side of the wafer by a film attaching machine;

[0087] S123: grinding the back side of the wafer by a wafer grinder to thin and polish the 750-micron-thick wafer to a 120-micron-thick wafer slice;

[0088] S124: A DAF (Die Attach Film) tape (die attach film) is attached to the back of the wafer sheet;

[0089] S125: removing the protective tape attached to the front side of the wafer sheet;

[0090] S126: To reduce the chipping of the wafer slice during cutting, a cutting groove is burned on the cutting path between the sensor chips on the surface of the wafer slice using a laser.

[0091] S127: Cut the wafer slice with a cutting blade so that multiple sensor chips become independent single sensor chips;

[0092] S128: Place the cut wafer slice under ultraviolet light irradiation to release the adhesive force between the tape and the wafer slice.

[0093] Embodiment 5:

[0094] As Figure 10 shown, this embodiment also provides a multi-point short-distance sensor packaging method for packaging and manufacturing the multi-point short-distance sensor in Embodiment 1 of the present invention. It includes the following steps:

[0095] S21: Obtain a multi-point short-distance sensor module through the multi-point short-distance sensor module packaging method as in Embodiment 1;

[0096] S22: Preparation of the lens assembly, including the following steps:

[0097] S221: Select a transmitting lens / receiving lens wafer. The transmitting lens / receiving lens wafer includes an infrared lens filter with a 940-nanometer band coating, and multiple 1.2-micron-high lenses are printed on the infrared lens filter; preferably, the infrared lens filter is a 6-inch infrared lens filter with 6000 1.2-micron-high lenses;

[0098] S222: Stick the back of the infrared lens filter on the tape and then stick it on the steel ring;

[0099] S223: Use a cutting blade to divide the entire infrared lens filter into independent lens units;

[0100] S224: Place the divided entire infrared lens filter under ultraviolet light irradiation to release the adhesive force between the lens units and the tape;

[0101] S225: Grab a lens cover from the reel. Generally, a plastic lens cover is selected, and the plastic lens cover is placed on the carrier with the tape; the lens cover is provided with a transmitting lens optical center position and a receiving lens optical center position, and the transmitting lens optical center position and the receiving lens optical center position are optically isolated by a light-shielding plate;

[0102] S226: Apply resin glue on the dispensing platform of the plastic lens cover, use a chip mounter to grab the lens unit, and use the optical system on the chip mounter to identify and place the lens unit at the accurate transmitting lens optical center position and receiving lens optical center position;

[0103] S227: Place the plastic lens cap with the lens unit installed in an oven and bake it until the lens unit is firmly bonded to the lens cap. Generally, set the oven at 150 degrees and bake for 1 hour to firmly bond the plastic lens cap to the lens unit. The plastic lens cap with the lens unit fixed can be picked up from the stainless steel carrier and placed in a coil tray for subsequent encapsulation.

[0104] S23: Apply resin glue on the lens cap mounting position of the PCB substrate, pick up the lens cap from the coil tray, and place it on the resin glue using an optical recognition system to bond the lens cap to the PCB substrate. The lens cap mounting position matching the shape of the plastic lens cap can be set on the PCB substrate according to the edge shape of the plastic lens cap. The resin glue can be applied on the lens cap mounting position by a dispenser.

[0105] S24: Place the PCB substrate with the lens cap adhered thereon in an oven and bake it until the lens cap is firmly bonded to the PCB substrate to encapsulate a multi-point proximity sensor. Setting the oven at 150 degrees and baking for 1 hour can meet the requirements.

[0106] The multi-point proximity sensor encapsulation method provided by the embodiments of the present invention can be used to manufacture a multi-point proximity sensor by adopting this method. The sensor can be applied to smart phones, digital cameras or other electronic devices, and can be applied to realize unlocking and payment for multi-point assisted focusing and face recognition technologies, and achieve accurate positioning of multi-point proximity with higher positioning accuracy.

[0107] In a preferred embodiment provided by the present invention, after placing the PCB substrate with the lens cap adhered thereon in an oven and baking it, the following steps are further included: firing a two-dimensional code on the back of the PCB substrate with a laser, and the two-dimensional code includes the wafer unit KGD for producing the sensor chip, the wafer unit KGD for producing the VCSEL chip, the wafer unit KGD for producing the transmitting lens and the receiving lens, and the production time information of the multi-point proximity sensor.

[0108] Preferably, the following steps are further included: pick out the manufactured multi-point proximity sensor from the carrier and place it in a tray.

[0109] The above embodiments are only the preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art on the basis of the present invention fall within the scope of protection required by the present invention.

Claims

1. A multi-point proximity sensor, characterized in that, It includes a multi-point proximity sensor module and a lens assembly. The multi-point proximity sensor module includes a PCB substrate provided with the optical design position of the sensor chip and the metal platform of the VCSEL chip, and further includes a VCSEL chip driver and a VCSEL chip. The VCSEL chip driver and the VCSEL chip are signal-connected. The VCSEL chip is disposed on the metal platform of the VCSEL chip. Driver connection pads are provided on the PCB substrate, and the VCSEL chip driver is soldered on the driver connection pads. It also includes a sensor chip disposed at the optical design position of the sensor chip. The PCB substrate, the sensor chip, and the VCSEL chip are integrally encapsulated. The lens assembly includes a lens cover. The lens cover is provided with an accommodation cavity. The lens cover is provided with a transmitting lens area corresponding to the VCSEL chip area of the PCB substrate, and a receiving lens area corresponding to the sensor chip area of the PCB substrate. A transmitting lens is provided in the transmitting lens area, and a receiving lens is provided in the receiving lens area. The lens cover is covered on the PCB substrate so that the accommodation cavity area between the PCB substrate and the lens cover forms a sealed space. It further includes a light shield. The light shield is connected to the PCB substrate and the inner side wall of the front end of the lens cover. The light shield is used to divide the sealed space between the PCB substrate and the lens cover into a laser emission area and a light reception area. The laser emission area corresponds to the area from the VCSEL chip to the transmitting lens, and the light reception area corresponds to the area from the receiving lens to the PCB substrate. The sensor chip includes a micro lens group and a microprocessor. The micro lens group and the microprocessor are signal-connected. The micro lens group is disposed in the light reception area. The micro lens group is a matrix micro lens group. The laser beam can be sensed by the matrix micro lens group and fed back to the microprocessor. The microprocessor calculates the distances from the multi-point proximity sensor to different positions of the target object. The receiving lens is a lens with diffraction function.

2. The multi-point proximity sensor according to claim 1, wherein The VCSEL chip is a 940-nanometer band infrared laser emitter, and 940-nanometer band infrared filter coatings are provided on both the transmitting lens and the receiving lens.

3. The multi-point proximity sensor according to claim 1 or 2, characterized in that, The transmitting lens is a lens with diffraction function.

4. The multi-point short-distance sensor according to claim 3, wherein The matrix micro lens group includes at least 2,240 micro lenses.

5. The multi-point proximity sensor according to claim 4, wherein The transmitting lens is parallel to the VCSEL chip, and the receiving lens is parallel to the matrix micro lens group.

6. The multi-point proximity sensor according to claim 3, wherein, A two-dimensional code is fired on the back of the PCB substrate. The two-dimensional code contains the wafer unit KGD for producing the sensor chip, the wafer unit KGD for producing the VCSEL chip, the wafer unit KGD for producing the transmitting lens and the receiving lens, and the production time information of the multi-point proximity sensor.

7. A camera with multi-point near-field recognition, characterized in that, It includes a camera lens assembly and the multi-point proximity sensor according to any one of claims 1 to 6. The camera lens assembly is respectively signal-connected to the VCSEL chip and the sensor chip.

8. An electronic device, characterized in that, It includes a camera with multi-point proximity recognition according to claim 7.

9. The electronic device according to claim 8, characterized in that, The electronic device is a mobile phone.

10. The electronic device according to claim 8, characterized in that, The electronic device is a camera or a video camera.

11. A multi-point short-distance detection method, characterized in that, Applied to the multi-point proximity sensor as described in any one of claims 1 to 6, the multi-point proximity detection method includes the following steps: Emitting infrared laser photons in the 940-nanometer band through a VCSEL chip. The infrared laser photons in the 940-nanometer band are filtered by an emission lens to filter out photons outside the 940-nanometer band, and after being diffracted by the emission lens, an infrared laser photon group in the 940-nanometer band is formed; Receiving infrared laser photons through a receiving lens, and filtering them through the receiving lens to form infrared received infrared laser photons in the 940-nanometer band. After further diffraction processing by the receiving lens, an infrared laser photon group in the 940-nanometer band is formed; Inducing the infrared laser photon group in the 940-nanometer band through a micro lens group, and sending the induction result of the micro lens group to a microprocessor. The microprocessor calculates the distances of multiple position points of the object reflecting the infrared laser photon group in the 940-nanometer band based on the induction result.

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