Packaging structure and manufacturing method of stacked MEMS photoelectric sensor

Abstract

The invention provides a packaging structure of a stacked MEMS photoelectric sensor and a manufacturing method, and belongs to the technical field of semiconductor manufacturing. Comprising a first substrate and a second substrate, the second substrate is inversely arranged at the top end of the first substrate, a logic chip and an MEMS light receiving chip are sequentially arranged on the first substrate, a first chip light sensing area is installed at the top of the MEMS light receiving chip, an MEMS light emitting chip is arranged on the second substrate, a second chip light sensing area is installed at the top of the MEMS light emitting chip, and the first substrate and the second substrate are in signal conduction connection. And the MEMS light receiving chip and the MEMS light emitting chip are arranged in a surface-mounted manner face to face. The first substrate and the second substrate are in signal conduction connection, and the MEMS light receiving chip and the MEMS light emitting chip are arranged in a surface-to-surface mounting manner, so that optical signals can be accurately transmitted.

Description

Technical Field

[0001] The present invention belongs to the technical field of semiconductor manufacturing, and in particular relates to a packaging structure and a manufacturing method of a stacked MEMS photoelectric sensor. Background Art

[0002] At present, MEMS (micro-electromechanical system) photoelectric sensor technology has been increasingly widely used in small household appliances, smart wearable devices and many other high-tech fields due to its miniaturization, high precision and high performance. In this broad application scenario, the most widely used MEMS photoelectric sensor products mainly include single-sealed light-receiving chip products, single-sealed light-emitting chip products, and packaging structures that integrate light-receiving and light-emitting functions. This structure can receive light signals from the outside while emitting light internally, thereby realizing more complex and sophisticated photoelectric control functions.

[0003] However, with the continuous changes in market demand and the continuous advancement of technology, more and more product applications have begun to put forward new demands in recent years, namely, requiring the transmission of optical signals between chips inside the product to achieve safer and more efficient optoelectronic application requirements. This demand poses new challenges to the packaging structure of MEMS photoelectric sensors, requiring the packaging structure to not only have a high degree of reliability and airtightness, but also to be able to achieve optical signal transmission between internal chips. In response to this market demand and technical challenge, the present invention aims to provide a new type of high-reliability stacked airtight internal light-emitting MEMS safety photoelectric sensor packaging structure and its manufacturing method. Summary of the invention

[0004] The purpose of the present invention is to overcome the problem that the existing photoelectric sensor cannot realize the optical signal transmission between internal chips and the airtightness of the existing packaging structure is poor, and to provide a packaging structure and a manufacturing method of a stacked MEMS photoelectric sensor.

[0005] In order to achieve the above object, the present invention adopts the following technical solution: A packaging structure of a stacked MEMS photoelectric sensor includes a first substrate and a second substrate, the second substrate is inverted on top of the first substrate, a logic chip and a MEMS light receiving chip are arranged in sequence on the first substrate, a first chip light sensing area is installed on the top of the MEMS light receiving chip, a MEMS light emitting chip is arranged on the second substrate, a second chip light sensing area is installed on the top of the MEMS light emitting chip, the first substrate and the second substrate are connected by signal conduction, and the MEMS light receiving chip and the MEMS light emitting chip are arranged face to face.

[0006] The first substrate and the logic chip, the logic chip and the MEMS light receiving chip, and the second substrate and the MEMS light emitting chip are all bonded by chip bonding adhesive.

[0007] Chip pads are installed on the first substrate, logic chip and MEMS light receiving chip, and circuit connection and signal transmission are achieved by connecting chip pads of adjacent layers through welding wires.

[0008] Chip pads are installed at both ends of the second substrate and the MEMS light-emitting chip, and the chip pads at the same end of the second substrate and the MEMS light-emitting chip are connected by welding wires to achieve circuit connection and signal transmission.

[0009] The welding wire adopts gold wire bonding to realize the connection between chip pads.

[0010] Glue is dispensed around the MEMS light-collecting chip to form a DAM retaining wall protective glue.

[0011] Insulating glue is poured between the DAM retaining wall protective glue and the first substrate.

[0012] The chip pads at both ends of the second substrate and the MEMS light-emitting chip are coated with coating glue.

[0013] A conductive material is disposed between the first substrate and the second substrate.

[0014] A method for manufacturing a stacked MEMS photoelectric sensor comprises the following steps: Using chip adhesive to stick the logic chip on the bottom of the first substrate; using chip adhesive to stick the MEMS light receiving chip on the logic chip; connecting the MEMS light receiving chip to the logic chip and the logic chip to the first substrate respectively through gold wire bonding; forming a DAM retaining wall protective glue around the MEMS light receiving chip; and filling the insulating glue between the DAM retaining wall protective glue and the first substrate; The MEMS light-emitting chip is attached to the second substrate using chip bonding glue; the MEMS light-emitting chip is connected to the second substrate by gold wire bonding; the chip pads on the MEMS light-emitting chip and the chip pads on the second substrate are sealed with glue; solder paste or silver paste is applied to the chip pads on the top of the first substrate, and a circle of substrate bonding glue is drawn on the top edge of the first substrate; The first substrate and the second substrate are laminated together; the front of the product is printed and cut into single finished products.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a packaging structure and manufacturing method of a stacked MEMS photoelectric sensor, including a first substrate and a second substrate, the second substrate is inverted on the top of the first substrate, a logic chip and a MEMS light-receiving chip are sequentially arranged on the first substrate, a first chip light-sensing area is installed on the top of the MEMS light-receiving chip, a MEMS light-emitting chip is arranged on the second substrate, a second chip light-sensing area is installed on the top of the MEMS light-emitting chip, the first substrate and the second substrate are connected by signal conduction, and the MEMS light-receiving chip and the MEMS light-emitting chip are arranged face to face. The first substrate and the second substrate are connected by signal conduction, and the MEMS light-receiving chip and the MEMS light-emitting chip are arranged face to face, so that the optical signal can be accurately transmitted, and the optical signal transmission inside the chip can be realized.

[0016] Furthermore, the invention also adds sealing and potting processes, through which a circle of retaining wall is formed at the edge of the MEMS light-collecting chip to enclose the potting glue and prevent the potting glue from overflowing and contaminating the chip sensing area; the sealing glue and potting glue are used to encapsulate the chip and the welding wire area to improve the reliability and airtightness of the product.

[0017] Furthermore, the use of gold wire bonding to achieve connection between chip pads can achieve micron-level connection accuracy to meet the needs of high-precision electronic equipment. In addition, gold wire bonding technology can adapt to different types of chips and packaging substrates to meet diverse connection needs.

[0018] Furthermore, this packaging structure not only has high reliability and airtightness, can effectively protect the internal chip from interference and damage from the external environment, but also cleverly realizes the optical signal transmission between internal chips. Through the stacked design, the packaging structure can compactly integrate multiple functional chips and realize the optical signal interconnection between chips through precise optical channels. This design not only improves the integration and stability of the system, but also significantly improves the efficiency and safety of photoelectric signal transmission, providing a more reliable and efficient photoelectric sensing solution for future high-tech products. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0020] Figure 1 It is a schematic diagram of the structure of the present invention; Figure 2 This is a schematic diagram of the structure of the first substrate and the logic chip of the present invention; Figure 3This is a schematic diagram of the structure of the logic chip and the MEMS light receiving chip of the present invention; Figure 4 It is a schematic diagram of the chip pad and bonding wire structure of the present invention; Figure 5 This is a schematic diagram of the DAM retaining wall protective adhesive structure of the present invention; Figure 6 It is a schematic diagram of the insulating glue potting between the DAM retaining wall protective glue and the first substrate of the present invention; Figure 7 This is a schematic diagram of the structure of the second substrate and the MEMS light-emitting chip of the present invention; Figure 8 It is a schematic diagram of chip pads and bonding wires on the second substrate of the present invention; Fig. 9 This is a schematic diagram of dispensing glue on the chip pad on the second substrate of the present invention; Fig.10 This is a schematic diagram of the glue bonding the top substrate of the first substrate of the present invention; Fig.11 It is a schematic diagram of the bonding structure of the first substrate and the second substrate of the present invention.

[0021] Explanation of the reference numerals in the figure: 1. first substrate; 2. pins; 3. chip bonding glue; 4. logic chip; 5. MEMS light-receiving chip; 6. photosensitive area of ​​the first chip; 7. chip pad; 8. welding wire; 9. DAM retaining wall protection glue; 10. insulating glue; 11. TSV; 12. signal interface; 13. second substrate; 14. MEMS light-emitting chip; 15. photosensitive area of ​​the second chip; 16. coating glue; 17. conductive material; 18. substrate bonding glue. DETAILED DESCRIPTION

[0022] In the following, only some exemplary embodiments are briefly described. As those skilled in the art will appreciate, the described embodiments may be modified in various ways without departing from the spirit or scope of the present invention. Therefore, the drawings and descriptions are considered to be exemplary and non-restrictive in nature.

[0023] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0024] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0025] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0026] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0027] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0028] It should also be understood that the terms used in the present specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0029] It should be further understood that the term "and / or" used in the present description and the appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0030] Various structural schematic diagrams of the embodiments disclosed in the present invention are shown in the accompanying drawings. These figures are not drawn to scale, and some details are magnified and some details may be omitted for the purpose of clear expression. The shapes of various regions and layers shown in the figures and the relative sizes and positional relationships therebetween are only exemplary, and may deviate in practice due to manufacturing tolerances or technical limitations, and those skilled in the art may additionally design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0031] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0032] A packaging structure of a stacked MEMS photoelectric sensor, the structure of which is as follows: like Figure 1 As shown, a packaging structure of a stacked MEMS photoelectric sensor includes a first substrate 1, the top of the first substrate 1 is bonded to a second substrate 13 by substrate bonding glue 18, the second substrate 13 is bonded to the top of the first substrate 1 invertedly, TSV 11 is vertically arranged inside the two ends of the first substrate 1, a signal interface 12 is arranged at the connection between the top of TSV 11 and the second substrate 13, and a conductive material 17 is coated at the signal interface 12 to achieve circuit connection and signal transmission between the first substrate 1 and the second substrate 13; TSV technology realizes vertical interconnection between substrates, and since the vertical interconnection line has the shortest distance and higher strength, it is easier to realize miniaturization, high density, high performance, and multifunctional heterogeneous structure packaging; at the same time, it can also interconnect chips of different materials. TSV mainly completes the vertical electrical interconnection of silicon vias by filling conductive materials such as copper, thereby reducing signal delay, reducing capacitance and inductance, realizing low power consumption and high-speed communication of chips, increasing bandwidth, and meeting the miniaturization requirements of device integration.

[0033] A logic chip 4 and a MEMS light receiving chip 5 are sequentially attached to the first substrate 1 through a chip adhesive 3, a first chip light sensing area 6 is provided on the top of the MEMS light receiving chip 5, a MEMS light emitting chip 14 is attached to the bottom of the second substrate 13 through a chip adhesive 3, a second chip light sensing area 15 is provided on the bottom of the MEMS light emitting chip 14, and the MEMS light receiving chip 5 and the MEMS light emitting chip 14 are face-to-face mounted and arranged; Furthermore, chip pads 7 are installed at both ends of the first substrate 1, the logic chip 4 and the MEMS light receiving chip 5, and the chip pads 7 of adjacent layers are connected by welding wires 8 to realize circuit connection and signal transmission. Specifically, a chip pad 7 is installed at the left end of the logic chip 4 and the left end of the MEMS light receiving chip 5, and the two chip pads 7 are connected by welding wires 8. A chip pad 7 is set at the right end of the logic chip 4, and two chip pads 7 are set at the right end of the MEMS light receiving chip 5. A chip pad 7 is set on the right end surface of the first substrate 1, and the chip pad 7 at the right end of the logic chip 4 is connected to a chip pad 7 at the right end of the MEMS light receiving chip 5 by welding wires 8, and the other chip pad 7 at the right end of the MEMS light receiving chip 5 is connected to the chip pad 7 on the right end surface of the first substrate 1 by welding wires 8, so as to realize circuit connection and signal transmission; similarly, chip pads 7 are set at both ends of the MEMS light emitting chip 14 and the second substrate 13, and the chip pads 7 of the MEMS light emitting chip 14 and the second substrate 13 are respectively connected by welding wires 8; Furthermore, a DAM retaining wall protective glue 9 is formed around the MEMS light receiving chip 5 through a dispensing device, while protecting the welding wire 8 and the chip pad 7, thereby enhancing the product reliability; an insulating glue 10 is potted between the DAM retaining wall protective glue 9 and the first substrate 1 through a potting process to protect the chip and further enhance the product reliability; through these two key packaging processes, a highly reliable and airtight MEMS safety photoelectric sensor packaging structure is successfully constructed. This structure can not only effectively resist interference and damage from the external environment, but also ensure the efficiency and stability of optical signal transmission between internal chips. In addition, this packaging structure also has excellent electrical insulation performance and mechanical strength, providing a solid guarantee for the long-term stable operation of the product.

[0034] Furthermore, coating glue 16 is applied on the chip pads 7 at both ends of the second substrate 13 and the MEMS light-emitting chip 14 to protect the chip pads 7; Furthermore, pins 2 are provided at the bottom of the first substrate 1, and are connected to external components such as an external PCB board through the pins 2 to achieve transmission of electrical signals.

[0035] Preferably, the viscosity of the DAM retaining wall protective glue 9 is higher than the viscosity of the coating glue 16 .

[0036] Preferably, the welding wire 8 is connected between the chip pads 7 by gold wire bonding. Through the gold wire bonding technology, the chip substrate can be electrically connected, so as to achieve a stable and reliable connection between the chip and the external circuit. The gold wire bonding technology can achieve micron-level connection accuracy to meet the needs of high-precision electronic equipment; the gold wire bonding connection has excellent stability and reliability and can withstand the test of various harsh environmental conditions. The gold wire bonding technology can adapt to different types of chips and packaging substrates to achieve diversified connection requirements. The gold wire bonding process has good repeatability and can ensure the consistency of connection quality in mass production.

[0037] Preferably, the conductive material 17 can be conductive glue, solder paste or silver paste. In practical applications, a suitable conductive material should be selected according to specific needs and working environment.

[0038] Embodiment 2: like Figures 2~11 As shown, a method for manufacturing a stacked MEMS photoelectric sensor is as follows: S1: Figure 2 , using chip adhesive 3 to stick the logic chip 4 on the bottom of the first substrate 1 using a core loading device; S2: Figure 3 , use chip adhesive 3 to stick the MEMS light receiving chip 5 on the top of the logic chip 4 using a chip mounting device; S3: Figure 4 , the MEMS light receiving chip 5 is connected to the logic chip 4, and the logic chip 4 is connected to the first substrate 1 respectively through gold wire bonding; S4: Figure 5 , a dispensing device is used to form a DAM retaining wall protective glue 9 around the MEMS light receiving chip 5 to protect the welding wire 8 and the chip pad 7, thereby enhancing product reliability and leaving space for potting; S5: Figure 6 , through the glue filling process, the insulating glue 10 is filled between the DAM retaining wall protection glue 9 and the first substrate 1 to protect the chip and the welding wire 8 and enhance the product reliability; S6: Figure 7 , using chip adhesive 3 to stick the MEMS light emitting chip 14 on the second substrate 13 using a chip mounting device; S7: Figure 8 , connecting the MEMS light emitting chip 14 to the second substrate 13 through gold wire bonding; S8: Fig. 9 , using coating glue 16 to seal the chip pad 7 on the MEMS light-emitting chip 14 and the chip pad 7 on the second substrate 13 to enhance product reliability; S9: Fig.10, by using the glue dispensing + glue drawing process, apply solder paste or silver paste on the signal interface 12 on the top of the first substrate 1, and draw a circle of substrate bonding glue 18 on the top edge of the first substrate 1; S10: Fig.11 , the first substrate 1 and the second substrate 13 are pressed together; S11: Printing on the front of the product; S12: Cutting into single finished products.

[0039] Finally, it should be noted that the above embodiments only describe the basic principles and main features of the present invention and the advantages of the present invention. For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the attached claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention. Any figure mark in the claims should not be regarded as limiting the claims involved.

[0040] In addition, it should be understood that although this specification is described in accordance with the implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation modes that can be understood by those skilled in the art. The above content is only to illustrate the technical idea of ​​the present invention, and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution according to the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A packaging structure of a stacked MEMS photoelectric sensor, characterized in that: The invention comprises a first substrate (1) and a second substrate (13), wherein the second substrate (13) is inverted on the top of the first substrate (1), a logic chip (4) and a MEMS light receiving chip (5) are arranged in sequence on the first substrate (1), a first chip light sensing area (6) is mounted on the top of the MEMS light receiving chip (5), a MEMS light emitting chip (14) is arranged on the second substrate (13), a second chip light sensing area (15) is mounted on the top of the MEMS light emitting chip (14), the first substrate (1) and the second substrate (13) are connected by signal conduction, and the MEMS light receiving chip (5) and the MEMS light emitting chip (14) are arranged face to face in mounting.

2. The packaging structure of a stacked MEMS photoelectric sensor according to claim 1, characterized in that: The first substrate (1) and the logic chip (4), the logic chip (4) and the MEMS light receiving chip (5), and the second substrate (13) and the MEMS light emitting chip (14) are all bonded together by means of chip bonding adhesive (3).

3. The packaging structure of a stacked MEMS photoelectric sensor according to claim 1, characterized in that: Chip pads (7) are installed on the first substrate (1), the logic chip (4) and the MEMS light receiving chip (5), and chip pads (7) at adjacent levels are connected by welding wires (8) to achieve circuit connection and signal transmission.

4. The packaging structure of a stacked MEMS photoelectric sensor according to claim 1, characterized in that: Chip pads (7) are installed at both ends of the second substrate (13) and the MEMS light-emitting chip (14), and the chip pads (7) at the same end of the second substrate (13) and the MEMS light-emitting chip (14) are connected by welding wires (8) to achieve circuit connection and signal transmission.

5. The packaging structure of a stacked MEMS photoelectric sensor according to claim 3 or 4, characterized in that: The welding wire (8) uses gold wire bonding to achieve connection between chip pads (7).

6. The packaging structure of a stacked MEMS photoelectric sensor according to claim 3, characterized in that: Glue is dispensed around the MEMS light-collecting chip (5) to form a DAM retaining wall protective glue (9).

7. The packaging structure of a stacked MEMS photoelectric sensor according to claim 6, characterized in that: An insulating glue (10) is poured between the DAM retaining wall protective glue (9) and the first substrate (1).

8. The packaging structure of a stacked MEMS photoelectric sensor according to claim 4, characterized in that: The chip pads (7) at both ends of the second substrate (13) and the MEMS light-emitting chip (14) are coated with coating glue (16).

9. The packaging structure of a stacked MEMS photoelectric sensor according to claim 8, characterized in that: A conductive material (17) is provided between the first substrate (1) and the second substrate (13).

10. The method for manufacturing a stacked MEMS photoelectric sensor according to claims 1 to 9, characterized in that: The steps include: Using chip adhesive (3) to adhere the logic chip (4) to the top of the bottom of the first substrate (1); using chip adhesive (3) to adhere the MEMS light receiving chip (5) to the top of the logic chip (4); connecting the MEMS light receiving chip (5) to the logic chip (4), and connecting the logic chip (4) to the first substrate (1) respectively by gold wire bonding; forming a DAM retaining wall protective glue (9) around the MEMS light receiving chip (5); and filling the insulating glue (10) between the DAM retaining wall protective glue (9) and the first substrate (1); The MEMS light-emitting chip (14) is adhered to the second substrate (13) using a chip adhesive (3); the MEMS light-emitting chip (14) is connected to the second substrate (13) by gold wire bonding; the chip pad (7) on the MEMS light-emitting chip (14) and the chip pad (7) on the second substrate (13) are sealed by applying adhesive; solder paste or silver paste is applied to the chip pad (7) on the top of the first substrate (1), and a circle of substrate bonding glue (18) is drawn on the top edge of the first substrate (1); The first substrate (1) and the second substrate (13) are pressed together as a whole; the front side of the product is printed and cut into single finished products.

Images