Adjustable dual-step light sensor packaging structure

Abstract

This invention discloses an adjustable dual-step optical sensor packaging structure, including a stepped cover (1), a light-transmitting plate (2), an emitting chip (3), a receiving chip (4), and a substrate (5). The emitting chip is fixed on the substrate, and the receiving chip is stacked on the emitting chip and away from the beam emitting part (301). The stepped cover has a stepped structure with one side higher and the other side lower and is fixed on the substrate. The lower step section (101) covers the beam emitting part, and the higher step section (102) covers the receiving chip. Both the lower and higher step sections have hollowed-out portions (103). Two light-transmitting plates are installed at the two hollowed-out portions of the stepped cover and are located directly above the beam emitting part and the receiving chip. This invention can solve the problems in the prior art, such as epoxy resin not being able to completely block light, high cost of epoxy resin, epoxy resin overflow, pressure lines in the middle part of the cover, large size, and limited layout utilization.

Description

Technical Field

[0001] This invention relates to a chip packaging structure, and more particularly to an adjustable dual-step optical sensor packaging structure. Background Technology

[0002] The working principle of an optical sensor is as follows: an optical transmitter chip emits a light beam at a certain angle. After diffuse reflection by obstacles or obstructions, the beam is captured by an optical receiver chip. The varying depths of reflection images are used to achieve non-contact and non-destructive measurement. Currently, optical sensors are widely used in motion detection in industries such as manufacturing, automotive, electronics, and retail automation.

[0003] In the packaging of optical sensor chips for electronic products, the transmitting chip and the receiving chip of the optical sensor need to be packaged separately in two independent cavities to prevent the light emitted by the transmitting chip from directly affecting the receiving chip and causing a decrease in the optical measurement accuracy of the electronic product.

[0004] Chinese utility model patent CN206134714U discloses an optical sensor packaging structure, specifically disclosing: a first optical chip disposed in a first cavity, and a second optical chip disposed in a second cavity; a first optical window corresponding to the first cavity and a second optical window corresponding to the second cavity are disposed on the housing; a light-transmitting cover plate covering the first optical window and the second optical window is also attached to the housing; the light-transmitting cover plate has a first convex lens structure and a second convex lens structure respectively formed at the positions of the first optical window and the second optical window.

[0005] The existing optical sensor packaging structures and the aforementioned utility model patents both have the following shortcomings:

[0006] 1. Because the two cavities are separated by the middle part of the cover, the bottom of the middle part of the cover needs to be bonded to the substrate with epoxy resin to block light. However, epoxy resin cannot completely block light penetration, causing some light beams from the transmitter chip-side cavity to pass through the epoxy resin layer and enter the receiver chip-side cavity. The light beam from the transmitter chip is then directly received by the receiver chip, affecting the measurement accuracy of the optical sensor. Furthermore, using epoxy resin for light blocking is costly, and to ensure sufficient coating and light blocking, a large amount of epoxy resin is used, leading to frequent glue overflow issues.

[0007] 2. Since the cavities are separated by the middle part of the cover, if the transmitter chip and receiver chip need to be wired near the middle part of the cover, the middle part of the cover often has wire pressing problems during installation, which affects the normal use of the transmitter chip and receiver chip.

[0008] 3. Due to the horizontal arrangement of the two cavities, their size is relatively large, making the layout of the chip packaging structure inflexible and limiting space utilization.

[0009] Therefore, there is a need to provide an adjustable dual-step light sensor packaging structure to solve the problems in the existing technology, such as epoxy resin not being able to completely block light, high cost of epoxy resin, epoxy resin overflow, pressure lines in the middle of the cap, large size, and limited layout utilization. Summary of the Invention

[0010] The purpose of this invention is to provide an adjustable dual-step optical sensor packaging structure that can solve the problems in the prior art, such as epoxy resin not being able to completely block light, high cost of epoxy resin, epoxy resin overflow, pressure lines in the middle of the cover, large size, and limited layout utilization.

[0011] This invention is implemented as follows:

[0012] An adjustable dual-step optical sensor packaging structure includes a stepped cover, a light-transmitting plate, an emitting chip, a receiving chip, and a substrate. The emitting chip is fixed on the substrate, and the receiving chip is stacked and fixed on the emitting chip, with the receiving chip positioned away from the beam emission portion of the emitting chip. The stepped cover has a stepped structure with one side higher than the other. The stepped cover is fixed on the substrate and covers the emitting chip and the receiving chip, such that the lower step of the stepped cover covers the beam emission portion of the emitting chip, and the higher step of the stepped cover covers the receiving chip. Both the lower and higher step of the stepped cover have cutouts, and two light-transmitting plates are respectively installed at the two cutouts of the stepped cover and are located directly above the beam emission portion and the receiving chip.

[0013] The stepped cover has a light-blocking plate on the inner wall of the higher step section, which is located on the inner wall of the connecting facade between the higher and lower steps.

[0014] The light-blocking plate is provided as one or more, and the light-blocking plates are arranged horizontally at intervals from bottom to top, and the width of the light-blocking plates increases from bottom to top to form a stepped light-blocking structure.

[0015] The width of the light-blocking plate shall not exceed the horizontal distance between the connecting facade and the hollowed-out part on the higher step section.

[0016] The lower step extends to the side of the receiving chip, and the lower step is not higher than the receiving chip, so that the sidewalls of the higher step, the connecting facade and the stepped cover surround the receiving chip.

[0017] A first mounting groove is formed on the substrate, and the bottom of the transmitter chip is fitted onto the substrate through the first mounting groove, so that the transmitter chip is fixed on the substrate in a sink-down manner.

[0018] A second mounting groove is formed on the substrate, and the second mounting groove surrounds the outside of the first mounting groove. The bottom of the stepped cover is fitted onto the substrate through the second mounting groove, so that the stepped cover is fixed to the substrate in a recessed manner.

[0019] The depth of both the first and second mounting slots does not exceed half the thickness of the substrate.

[0020] The top of each light-transmitting plate is formed with a convex lens surface, and the light-transmitting plate is fixed on the inner wall of the stepped cover, so that all or part of the convex lens surface is located in the hollow part.

[0021] The top width of the hollowed-out portion is greater than the bottom width, so that the side wall of the hollowed-out portion forms a sloping structure.

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] 1. This invention features a stepped cover and a light-blocking plate, forming a stepped structure with low-step sections, high-step sections, and connecting facades. The low-step sections and the light-blocking plate effectively and completely shield the transmitting chip, ensuring that the light beam from the transmitting chip can only exit through the light-transmitting plate above it. The high-step sections effectively shield the receiving chip, ensuring that the receiving chip can only receive the light beam from the light-transmitting plate above it. This prevents the light beam from the transmitting chip from directly affecting the receiving chip, thus guaranteeing the optical measurement performance of the optical sensor. Simultaneously, the stepped cover divides the area into two regions through the connecting facade. The middle part of the stepped cover does not need to be fixed to the substrate with epoxy resin, avoiding the high processing cost and easy overflow of epoxy resin. The middle part of the stepped cover will not interfere with nearby wire bonding, which helps reduce production costs and manufacturing process difficulty.

[0024] 2. Because the present invention has a stepped cover, the height difference between the low step and the high step can be formed. The space between the low step and the connecting surface can accommodate more components, which has high layout flexibility and adjustment elasticity. This is conducive to reducing the size of the entire packaging structure, thereby reducing the volume of electronic products.

[0025] 3. Because the present invention has a first mounting slot and a second mounting slot, the first mounting slot enables the sinking installation of the transmitter chip, and the second mounting slot enables the sinking installation of the stepped cover, which can reduce the height of the entire packaging structure and thus further reduce the size of the entire packaging structure. Attached Figure Description

[0026] Figure 1 This is a cross-sectional view of the adjustable dual-step optical sensor packaging structure of the present invention.

[0027] In the figure, 1 is a stepped cover, 101 is a low step, 102 is a high step, 103 is a hollow part, 104 is a connecting surface, 2 is a light-transmitting plate, 201 is a convex lens surface, 3 is a transmitting chip, 301 is a beam emitting part, 4 is a receiving chip, 5 is a substrate, 501 is a first mounting slot, 502 is a second mounting slot, and 6 is a light-blocking plate. Detailed Implementation

[0028] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0029] Please see the appendix Figure 1 An adjustable dual-step optical sensor packaging structure includes a stepped cover 1, a light-transmitting plate 2, an emitting chip 3, a receiving chip 4, and a substrate 5. The emitting chip 3 is fixed on the substrate 5, and the receiving chip 4 is stacked and fixed on the emitting chip 3, with the receiving chip 4 positioned away from the beam emission portion 301 of the emitting chip 3. The stepped cover 1 has a stepped structure with one side higher than the other, and is fixed on the substrate 5 and covers the emitting chip 3. On the receiver chip 4, the lower step section 101 of the stepped cover 1 covers the beam emitting part 301 of the transmitter chip 3, and the higher step section 102 of the stepped cover 1 covers the receiver chip 4; both the lower step section 101 and the higher step section 102 of the stepped cover 1 have hollowed-out parts 103, and two light-transmitting plates 2 are respectively installed at the two hollowed-out parts 103 of the stepped cover 1 and are located directly above the beam emitting part 301 and the receiver chip 4.

[0030] The stepped cover 1 uses a low-step section 101 to shield the transmitter chip 3, covering most of its area. This ensures that the light beam from the transmitter chip 3's beam emission section 301 can only be emitted outwards from the light-transmitting plate 2 at the cutout 103 of the low-step section 101, preventing the beam from directly affecting the receiver chip 4. The stepped cover 1 also uses a high-step section 102 to shield the receiver chip 4, allowing it to receive diffusely reflected light beams only from the light-transmitting plate 2 at the cutout 103 of the high-step section 102. The stepped cover 1 does not require epoxy resin to fix it to the substrate 5 in the middle, thus ensuring the measurement accuracy of the optical sensor while avoiding problems in existing technologies such as epoxy resin not completely blocking light, high cost of epoxy resin, epoxy resin overflow, and pressure lines in the middle of the cover. At the same time, a height difference is formed between the low-step section 101 and the high-step section 102, and a layout space is formed between the low-step section 101 and the connecting facade 104, which can be used to arrange other chip components, improving the flexibility and adaptability of layout utilization and adjustment, and helping to reduce the size of the entire electronic product.

[0031] A light-blocking plate 6 is provided on the inner wall of the higher step section 102 of the stepped cover 1. The light-blocking plate 6 is located on the inner wall of the connecting facade 104 between the higher step section 102 and the lower step section 101.

[0032] The light-blocking plate 6 further prevents the beam from the transmitting chip 3 from spreading to the receiving chip 4, thus ensuring the performance of the optical sensor. The height of the light-blocking plate 6 can be determined according to the actual layout, as long as interference between the light-blocking plate 6 and the bonding wires of the receiving chip 4 is avoided.

[0033] The light-blocking plate 6 is provided in one or more pieces, and the light-blocking plates 6 are arranged horizontally at intervals from bottom to top, and the width of the light-blocking plates 6 increases from bottom to top to form a stepped light-blocking structure.

[0034] The number, spacing, and width of the light-blocking plates 6 can be adaptively adjusted according to actual light-blocking requirements. The stepped light-blocking structure not only ensures complete blocking of the beam from the transmitting chip 3, but also avoids interference with the wire bonding of the receiving chip 4.

[0035] The width of the light-blocking plate 6 does not exceed the horizontal distance between the connecting facade 104 and the hollowed-out portion 103 on the high-step section 102. This prevents the light-blocking plate 6 from affecting the receiving chip 4's reception of diffusely reflected light beams from the light-transmitting plate 2 of the hollowed-out portion 103 on the high-step section 102, thus ensuring the intensity of the optical signal.

[0036] The lower step section 101 extends to the side of the receiver chip 4, and the lower step section 101 is not higher than the receiver chip 4, so that the sidewalls of the higher step section 102, the connecting facade 104 and the stepped cover 1 surround the receiver chip 4.

[0037] The lower step 101 extends to the side of the receiver chip 4, ensuring complete light shielding of the transmitter chip 3. It also widens the step between the higher step 102 and the lower step 101, allowing for the placement of more components and further reducing the size of the electronic product. The higher step 102, the connecting facade 104, and the sidewalls of the stepped cover 1 surround the receiver chip 4, ensuring that the receiver chip 4 can only receive diffusely reflected light from the light-transmitting plate 2 of the cutout 103 on the higher step 102, avoiding direct interference from the transmitter chip 3 and thus ensuring the performance of the light sensor.

[0038] A first mounting groove 501 is formed on the substrate 5. The bottom of the transmitter chip 3 is fitted onto the substrate 5 through the first mounting groove 501, so that the transmitter chip 3 is fixed on the substrate 5 in a sinking manner.

[0039] By utilizing the recessed mounting of the transmitter chip 3, it is possible to further reduce the height of the entire packaging structure, thereby reducing the size of electronic products.

[0040] The depth of the first mounting groove 501 does not exceed half the thickness of the substrate 5, so as to avoid affecting the internal structure of the substrate 5.

[0041] A second mounting groove 502 is formed on the substrate 5. The second mounting groove 502 surrounds the outside of the first mounting groove 501. The bottom of the stepped cover 1 is fitted onto the substrate 5 through the second mounting groove 502, so that the stepped cover 1 is fixed to the substrate 5 in a recessed manner.

[0042] The recessed mounting of the stepped cover 1 helps to further reduce the height of the entire packaging structure, thereby reducing the size of electronic products.

[0043] The depth of the second mounting groove 502 does not exceed half the thickness of the substrate 5, so as to avoid affecting the internal structure of the substrate 5.

[0044] The top of each light-transmitting plate 2 is formed with a convex lens surface 201. The light-transmitting plate 2 is fixed on the inner wall of the stepped cover 1, so that all or part of the convex lens surface 201 is located in the hollow part 103.

[0045] The convex lens surface 201 can enhance the intensity of beam transmission and reception. By hiding all or part of the convex lens surface 201 within the cutout portion 103, the convex lens surface 201 can be avoided from occupying the packaging space, thereby further reducing the height of the entire packaging structure and thus reducing the size of electronic products.

[0046] The height of the convex lens surface 201 does not exceed the thickness of the stepped cover 1, so that the convex lens surface 201 is completely hidden in the hollow part 103, thereby reducing the impact on other components arranged on the stepped cover 1 while reducing the packaging height.

[0047] The top width of the hollowed-out portion 103 is greater than the bottom width, so that the side wall of the hollowed-out portion 103 forms a sloping structure, which can further ensure the transmission and reception strength of optical signals.

[0048] Please see the appendix Figure 1 The manufacturing process of this invention is as follows:

[0049] 1. A first mounting groove 501 is formed on the substrate 5 according to the size of the transmitter chip 3, and the transmitter chip 3 is fixed on the substrate 5 through the first mounting groove 501; the receiver chip 4 is stacked on the transmitter chip 3, and the receiver chip 4 is away from the beam emission part 301 of the transmitter chip 3. After stacking, baking is performed.

[0050] 2. Perform wire bonding on the transmitter chip 3 and the receiver chip 4, and apply plasma before wire bonding.

[0051] 3. A stepped cover 1 is fabricated according to the dimensions of the transmitter chip 3 and the receiver chip 4. Two light-blocking plates 6 are installed on the inner wall of the connecting surface 104 between the lower stepped section 101 and the upper stepped section 102 of the stepped cover 1. The width of the lower light-blocking plate 6 is smaller than the width of the upper light-blocking plate 6, forming a stepped light-blocking structure. The width of the upper light-blocking plate 6 is smaller than the horizontal distance between the connecting surface 104 and the hollowed-out portion 103 on the upper stepped section 102.

[0052] Both the stepped cover 1 and the light-blocking plate 6 are made of light-blocking material and are integrally injection molded.

[0053] Based on the position of the beam emitting part 301, a cutout 103 is formed on the lower step section 101, such that the cutout 103 is located directly above the beam emitting part 301. Based on the position of the receiving chip 4, a cutout 103 is formed on the higher step section 102, such that the cutout 103 is located directly above the receiving chip 4.

[0054] A light-transmitting panel 2 is made of a transparent glass or other light-transmitting material. Two light-transmitting panels 2 are fixed to the inner walls of the lower step section 101 and the higher step section 102 respectively with glass glue, and each is covered with a hollow part 103, with the convex lens surface 201 of the light-transmitting panel 2 embedded in the hollow part 103. The glass glue is then baked to ensure reliable installation on the stepped cover 1.

[0055] 4. According to the size of the stepped cover 1, a second mounting groove 502 is opened on the substrate 5. The stepped cover 1 is fixed on the substrate 5 through the second mounting groove 502, so that the lower step section 101 covers the top of the un-die transmitter chip 3, and the higher step section 102 covers the top of the die-die transmitter chip 3 and receiver chip 4.

[0056] The lower step 101 of the stepped cover 1 forms a shield above the transmitter chip 3. Because the lower step 101 is relatively low, it ensures light shielding of the transmitter chip 3 while increasing the usable space above it, thus increasing layout flexibility and adjustability. The beam emission portion 301 of the transmitter chip 3 emits the beam from the light-transmitting plate 2 of the cutout portion 103, and the beam emission intensity is increased by the convex lens surface 201.

[0057] The stepped section 102 of the stepped cover 1 and the two light-blocking plates 6 form an effective light block between the transmitting chip 3 and the receiving chip 4. The double-step structure of the stepped cover 1 and the two light-blocking plates 6 ensures that the receiving chip 4 can only receive the diffused light beam from the light-transmitting plate 2 on the hollow part 103 above it. At the same time, the light beam receiving intensity is improved under the action of the convex lens surface 201.

[0058] The above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the invention. Therefore, any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An adjustable dual-step optical sensor packaging structure, characterized in that: The device includes a stepped cover (1), a light-transmitting plate (2), a transmitter chip (3), a receiver chip (4), and a substrate (5). The transmitter chip (3) is fixed on the substrate (5), and the receiver chip (4) is stacked and fixed on the transmitter chip (3), with the receiver chip (4) positioned away from the beam emission part (301) of the transmitter chip (3). The stepped cover (1) has a stepped structure with one side higher and the other side lower. The stepped cover (1) is fixed on the substrate (5) and covers the transmitter chip (3) and the receiver chip (4). The lower step section (101) of the stepped cover (1) covers the beam emitting part (301) of the transmitting chip (3), and the higher step section (102) of the stepped cover (1) covers the receiving chip (4); both the lower step section (101) and the higher step section (102) of the stepped cover (1) have hollowed-out parts (103), and two light-transmitting plates (2) are respectively installed at the two hollowed-out parts (103) of the stepped cover (1) and located directly above the beam emitting part (301) and the receiving chip (4); The stepped cover (1) is provided with a light-blocking plate (6) on the inner wall of the high step section (102) and the low step section (101). The light-blocking plate (6) is located on the inner wall of the connecting facade (104) between the high step section (102) and the low step section (101). The light-blocking plate (6) is provided with one or more plates, and the multiple light-blocking plates (6) are arranged horizontally at intervals from bottom to top, and the width of the multiple light-blocking plates (6) increases from bottom to top to form a stepped light-blocking structure. The width of the light-blocking plate (6) shall not exceed the horizontal distance between the connecting facade (104) and the hollow part (103) on the high step section (102); The lower step section (101) extends to the side of the receiver chip (4), and the lower step section (101) is not higher than the receiver chip (4), so that the sidewalls of the higher step section (102), the connecting facade (104) and the stepped cover (1) surround the receiver chip (4). The lower step section acts as a light shield for the transmitting chip, covering most of its area. This ensures that the light beam from the transmitting chip's beam emission section can only be emitted outwards from the light-transmitting plate at the cutout of the lower step section. The higher step section acts as a light shield for the receiving chip.

2. The adjustable dual-step optical sensor packaging structure according to claim 1, characterized in that: A first mounting groove (501) is formed on the substrate (5). The bottom of the transmitter chip (3) is fitted onto the substrate (5) through the first mounting groove (501), so that the transmitter chip (3) is fixed on the substrate (5) in a sinking manner.

3. The adjustable dual-step optical sensor packaging structure according to claim 2, characterized in that: A second mounting groove (502) is formed on the substrate (5). The second mounting groove (502) surrounds the outside of the first mounting groove (501) in the circumferential direction. The bottom of the stepped cover (1) is fitted onto the substrate (5) through the second mounting groove (502), so that the stepped cover (1) is fixed to the substrate (5) in a sinking manner.

4. The adjustable dual-step optical sensor packaging structure according to claim 3, characterized in that: The depth of the first mounting groove (501) and the second mounting groove (502) does not exceed half the thickness of the substrate (5).

5. The adjustable dual-step optical sensor packaging structure according to claim 1, characterized in that: The top of each of the light-transmitting plates (2) is formed with a convex lens surface (201). The light-transmitting plates (2) are fixed on the inner wall of the stepped cover (1), so that the convex lens surface (201) is located entirely or partially within the hollow part (103).

6. The adjustable dual-step optical sensor packaging structure according to claim 1 or 5, characterized in that: The top width of the hollow part (103) is greater than the bottom width, so that the side wall of the hollow part (103) forms a sloping structure.

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