System-in-package structure and photoelectric smoke sensor
Through the system-level packaging structure, the bare chip and ASIC chip design is adopted to solve the problems of large size and low integration of traditional photoelectric smoke detector modules, and small and efficient photoelectric smoke sensors are realized, suitable for space-constrained environments and reduced production cost.
Patent Information
- Application Number
- CN202323378295.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-12
- Publication Date
- 2024-12-17
- Estimated Expiration
- 2033-12-12
AI Technical Summary
The electronic modules of traditional photoelectric smoke detection alarms are large in size, low in integration, high failure efficiency of a single device, cannot be used in environments with limited space size, and have low production efficiency.
Adopt a system-level packaging structure, including substrate, signal conditioning communication chip, infrared LED chip and photodiode, bonded to the substrate through silver paste and electrically connected through wire bonding, and is designed as a bare chip module to reduce the module size and eliminate part Protecting devices, using ASIC chips and small copper-clad substrates, integrated design and direct chip interconnection.
It achieves the reduction of module size, reduces device failure efficiency and production costs, is suitable for space-constrained environments, and improves the degree of integration and production efficiency.
Smart Images
Figure CN222190726U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of semiconductor technology, and in particular to a system-level packaging structure and a photoelectric smoke sensor. Background Art
[0002] Photoelectric smoke detectors are fire alarm devices that use the basic property that smoke produced when a fire breaks out can change the propagation characteristics of light. The working principle of photoelectric smoke detectors is based on the photoelectric effect, and fire prevention is achieved by monitoring the concentration of smoke.
[0003] In common photoelectric smoke detectors, independently packaged chips, optical devices and discrete devices are generally used. The size of the assembled electronic modules is mostly above 35mm×53mm, with low integration. The failure of a single device has a high probability of causing module function failure, and it cannot be used in an environment with limited space size. The electronic modules of traditional photoelectric smoke detectors are assembled using PCBA: chips, discrete devices, optical devices, etc. are mounted on the front and back of the PCB. This type of module needs to purchase chips and devices from different suppliers, and then assembly and testing can begin after PCB mounting. The finished product size is large and the production efficiency is relatively low. Summary of the invention
[0004] The present application provides a system-level packaging structure and a photoelectric smoke sensor to solve the above-mentioned technical problems.
[0005] A system-level packaging structure, the system-level packaging structure includes: a substrate, a signal conditioning communication chip, an infrared LED chip and a photodiode, the substrate is provided with a front side and a back side, the signal conditioning communication chip, the infrared LED chip and the photodiode are all bare chips and are bonded to the front side of the substrate through silver paste, and are electrically connected to the substrate through wire bonding, the infrared LED chip and the photodiode are respectively arranged on opposite sides of the signal conditioning communication chip, and an external solder pad is provided on the back side of the substrate.
[0006] Preferably, the size of the substrate is 7 mm×13 mm.
[0007] Preferably, the thickness of the substrate is 0.8 mm.
[0008] Preferably, the copper cladding layer of the substrate has a thickness of 1 oz.
[0009] Preferably, the signal conditioning communication chip is an ASIC chip.
[0010] Preferably, a chip mounting pad and a wire bonding pad are provided on the front side of the substrate, and the signal conditioning communication chip, the infrared LED chip, and the photodiode are respectively bonded to the chip mounting pad by silver paste.
[0011] Preferably, there are at least three wire bonding pads, each chip is provided with one wire bonding pad, and the three wire bonding pads are connected by wire bonding.
[0012] Preferably, there are multiple external solder pads, and the multiple external solder pads include a power interface and an SPI communication interface. The number of pins of the multiple external solder pad interfaces is 14, and the power interface and the SPI communication interface are both used to connect to a fire alarm system.
[0013] A photoelectric smoke sensor comprises a housing and any one of the above-mentioned system-level packaging structures, wherein the housing is connected to the substrate.
[0014] Preferably, the shell includes a shell, a first transparent cover plate and a second transparent cover plate, the shell and the substrate together enclose a first chamber, a second chamber and a third chamber, the infrared LED chip is located in the first chamber, the signal conditioning communication chip is located in the second chamber, the photodiode is located in the third chamber, the first transparent cover plate is covered on the cavity opening of the first chamber, and the second transparent cover plate is covered on the cavity opening of the third chamber.
[0015] The technical solution of the present application is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The accompanying drawings are used to provide a further understanding of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the present application and do not constitute a limitation of the present application. In the accompanying drawings:
[0017] Figure 1 This is a schematic diagram of the substrate structure of the system-level packaging structure of the present application.
[0018] Figure 2 This is a schematic diagram of the internal structure of the photoelectric smoke sensor of this application.
[0019] Figure 3 This is a schematic diagram of the structural layout of the front side of the substrate in this application.
[0020] Figure 4 This is a schematic diagram of the structural layout on the back side of the substrate in this application.
[0021] Figure 5 This is a schematic diagram of the circuit design of the system-level packaging structure in this application.
[0022] In the figure: 100, system-level packaging structure; 110, substrate; 111, front side; 112, back side; 113, external pad; 114, chip mounting pad; 115, wire bonding pad; 116, power interface; 117, SPI communication interface; 120, signal conditioning communication chip; 130, infrared LED chip; 140, photodiode; 200, housing; 210, first chamber; 211, first transparent cover; 220, second chamber; 230, third chamber; 231, second transparent cover. DETAILED DESCRIPTION
[0023] The preferred embodiments of the present application are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present application and are not used to limit the present application.
[0024] In addition, in the present application, the descriptions of "first", "second", etc. are only used for descriptive purposes, and do not specifically refer to the order or sequence, nor are they used to limit the present application. They are only used to distinguish components or operations described with the same technical terms, and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions and technical features between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present application.
[0025] See also Figure 1 and Figure 3 The embodiment of the present application provides a system-level package structure 100, including: a substrate 110, a signal conditioning communication chip 120, an infrared LED chip 130 and a photodiode 140. The substrate 110 has a front side 111 and a back side 112. The signal conditioning communication chip 120, the infrared LED chip 130 and the photodiode 140 are all bare chips and are bonded to the front side 111 of the substrate 110 through silver paste, and are electrically connected to the substrate 110 through wire bonding. The infrared LED chip 130 and the photodiode 140 are respectively arranged on opposite sides of the signal conditioning communication chip 120, and the back side 112 of the substrate 110 is provided with an external solder pad 113.
[0026] It should be noted that being electrically connected to the substrate 110 through wire bonding should be understood as the three chips being connected to the pads of the substrate 110 through the wire bonding process and forming electrical conduction.
[0027] The working principle and beneficial effects of the above technical solution are as follows: the system-level packaging structure 100 adopts the system-level packaging (System In a Package, SiP) method. Since the signal conditioning communication chip 120, the infrared LED chip 130 and the photodiode 140 are all bare chips, the bare chip size is much smaller than the packaged finished chip. Therefore, compared with the "chip + discrete device + PCBA" mode of the traditional smoke alarm, the electronic module is designed with an integrated approach, the module layout is designed from the bare chip level, and the substrate 110 and the chip interconnection routing on the substrate 110 are designed according to the bare chip size and layout, which greatly reduces the module size, reduces the probability of device failure, and saves the PCB patch production process. At the same time, the direct chip interconnection method can save some protection devices such as resistors and capacitors, so that the number of devices is reduced and the overall production cost of the module is reduced.
[0028] In addition, the module size of the system-level packaging structure 100 is relatively small, and the size of the accompanying photoelectric smoke detection alarm structure can also be reduced accordingly, so that it can be used in special environments with limited space size, which is conducive to further reducing production costs.
[0029] In one embodiment, see Figure 1 The size of the substrate 110 is 7 mm×13 mm.
[0030] The working principle and beneficial effects of the above technical solution are as follows: by using a small-sized substrate 110, the structure can be made compact, the overall structural size can be reduced, and thus the overall size of the photoelectric smoke sensor can be reduced.
[0031] In one embodiment, the thickness of the substrate 110 is 0.8 mm.
[0032] The working principle and beneficial effects of the above technical solution are: it can ensure that the substrate 110 is not deformed, and facilitate the subsequent installation of the outer shell 200. While ensuring the strength of the substrate 110, the overall size of the photoelectric smoke sensor can be further improved.
[0033] In one embodiment, the copper coating thickness of the substrate 110 is 1 oz. Specifically, the pads on the surface of the substrate 110 are gold-plated by chemical means.
[0034] The working principle and beneficial effects of the above technical solution are: it can ensure welding stability, avoid short circuits and short circuits, and at the same time ensure the stability of the bonding force between the copper layer and the substrate 110.
[0035] In one embodiment, see Figure 1 and Figure 2 , the signal conditioning communication chip 120 is an ASIC chip.
[0036] The working principle and beneficial effects of the above technical solution are as follows: ASIC chip is an integrated circuit (ASIC, Application Specific Integrated Circuit) chip technology used for special applications, with low energy consumption, small size, designed for specific purposes, and conducive to the realization of an integrated high-performance photoelectric smoke sensor.
[0037] In one embodiment, see Figure 3 and Figure 5 The front side 111 of the substrate 110 is provided with a chip mounting pad 114 and a wire bonding pad 115, and the signal conditioning communication chip 120, the infrared LED chip 130, and the photodiode 140 are respectively bonded to the chip mounting pad 114 by silver paste.
[0038] The working principle and beneficial effects of the above technical solution are: it is conducive to integrated design and reduces the overall volume. The direct chip interconnection method can save some protection devices such as resistors and capacitors, thereby reducing the number of devices and reducing the overall production cost of the module.
[0039] Specifically, see Figure 3 There are at least three wire bonding pads 115 , each chip is provided with one wire bonding pad 115 , and the three wire bonding pads 115 are connected by wire bonding.
[0040] The working principle and beneficial effects of the above technical solution are: the three chips are connected by wire bonding, which has high stability, low cost, simple operation, is conducive to reducing production costs, and reduces the overall volume of the structural module.
[0041] In one embodiment, see Figure 4 There are multiple external pads 113, and the multiple external pads 113 include a power interface 116 and an SPI communication interface 117. The number of pins of the multiple external pads 113 interfaces is 14. The power interface 116 and the SPI communication interface 117 are both used to connect to the fire alarm system. Specifically, the power interface 116 and the SPI communication interface 117 are spaced apart along the edge of the back side 112 of the substrate 110. The power interface 116 has three pins, and the three SPI communication interfaces 117 have 4, 4, and 3 pins, respectively.
[0042] The working principle and beneficial effects of the above technical solution are as follows: providing an external solder pad 113 on the back surface 112 facilitates wiring of the structural module without opening it, thereby facilitating improving the degree of integration.
[0043] In one embodiment, see Figure 2 , a photoelectric smoke sensor, the photoelectric smoke sensor includes a shell and any one of the above-mentioned system-level packaging structures 100, the shell is connected to a substrate 110.
[0044] The working principle and beneficial effects of the above technical solution are as follows: the photoelectric smoke sensor adopts the system in a package (SiP) method. Since the signal conditioning communication chip 120, the infrared LED chip 130 and the photodiode 140 are all bare chips, the bare chip size is much smaller than the packaged finished chip. Therefore, compared with the "chip + discrete device + PCBA" mode of the traditional smoke alarm, the electronic module is designed with an integrated approach, the module layout is designed from the bare chip level, and the substrate 110 and the chip interconnection routing on the substrate 110 are designed according to the bare chip size and layout, which greatly reduces the module size, reduces the device failure rate, and saves the PCB patch production process. At the same time, the direct chip interconnection method can save some protection devices such as resistors and capacitors, so that the number of devices is reduced and the overall production cost of the module is reduced.
[0045] In one embodiment, see Figure 2 The shell includes a shell 200, a first transparent cover plate 211 and a second transparent cover plate 231. The shell 200 and the substrate 110 together form a first chamber 210, a second chamber 220 and a third chamber 230. The infrared LED chip 130 is located in the first chamber 210, the signal conditioning communication chip 120 is located in the second chamber 220, and the photodiode 140 is located in the third chamber 230. The first transparent cover plate 211 is covered on the cavity opening of the first chamber 210, and the second transparent cover plate 231 is covered on the cavity opening of the third chamber 230.
[0046] The working principle and beneficial effects of the above technical solution are as follows: instead of using the commonly used plastic package, after the wire bonding is completed, the system package structure module is directly assembled with the housing 200 structure of the photoelectric smoke sensor to form a complete detector. Each chip is provided with a separate chamber, which is beneficial to protect the chip and the wire bonding gold wire. The transparent cover is used for the infrared LED chip 130 to emit light and the photodiode 140 to receive light, directly realizing the photoelectric sensing and alarm functions of the module.
[0047] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.
Claims
1. A system-level packaging structure (100), characterized in that: The system-level packaging structure (100) comprises: a substrate (110), a signal conditioning communication chip (120), an infrared LED chip (130) and a photodiode (140); the substrate (110) is provided with a front side (111) and a back side (112); the signal conditioning communication chip (120), the infrared LED chip (130) and the photodiode (140) are all bare chips and are bonded to the front side (111) of the substrate (110) by silver paste and are electrically connected to the substrate (110) by wire bonding; the infrared LED chip (130) and the photodiode (140) are respectively arranged on opposite sides of the signal conditioning communication chip (120); and the back side (112) of the substrate (110) is provided with an external solder pad (113).
2. The system-level packaging structure (100) according to claim 1, characterized in that: The size of the substrate (110) is 7 mm×13 mm.
3. The system-level packaging structure (100) according to claim 1, characterized in that: The thickness of the substrate (110) is 0.8 mm.
4. The system-level packaging structure (100) according to claim 1, characterized in that: The copper coating thickness of the substrate (110) is 1 oz.
5. The system-level packaging structure (100) according to claim 1, characterized in that: The signal conditioning communication chip (120) is an ASIC chip.
6. The system-level packaging structure (100) according to claim 1, characterized in that: The front side (111) of the substrate (110) is provided with a chip mounting pad (114) and a wire bonding pad (115); the signal conditioning communication chip (120), the infrared LED chip (130), and the photodiode (140) are respectively bonded to the chip mounting pad (114) by silver paste.
7. The system-level packaging structure (100) according to claim 6, characterized in that: There are at least three wire bonding pads (115), each chip is provided with one wire bonding pad (115), and the three wire bonding pads (115) are connected via wire bonding.
8. The system-level packaging structure (100) according to any one of claims 1 to 7, characterized in that: There are a plurality of external solder pads (113), the plurality of external solder pads (113) comprising a power supply interface (116) and an SPI communication interface (117), the number of pins of the plurality of external solder pads (113) interfaces is 14, and the power supply interface (116) and the SPI communication interface (117) are both used for connecting to a fire alarm system.
9. A photoelectric smoke sensor, characterized in that: The photoelectric smoke sensor comprises a housing and a system-level packaging structure (100) according to any one of claims 1 to 8, wherein the housing is connected to the substrate (110).
10. The photoelectric smoke sensor according to claim 9, characterized in that: The shell comprises a shell (200), a first transparent cover plate (211) and a second transparent cover plate (231); the shell (200) and the substrate (110) together enclose a first chamber (210), a second chamber (220) and a third chamber (230); the infrared LED chip (130) is located in the first chamber (210), the signal conditioning communication chip (120) is located in the second chamber (220), the photodiode (140) is located in the third chamber (230), the first transparent cover plate (211) is covered on the opening of the first chamber (210), and the second transparent cover plate (231) is covered on the opening of the third chamber (230).