Optical sensing module structure and packaging method thereof
By employing a modular packaging method of substrate and plastic encapsulation in the optical sensing module, combined with epoxy encapsulation and bonding wire connection, the problems of large size, heavy weight and low integration of sensor packaging are solved, and efficient production and stable performance optical sensor packaging are achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- 山东满芯电子科技有限公司
- Filing Date
- 2024-11-22
- Publication Date
- 2026-05-22
AI Technical Summary
Existing optical sensor packaging methods suffer from problems such as large size, heavy weight, low production efficiency, low integration, and zero-point drift. Furthermore, the integration between the sensor chip and the control chip is low, resulting in poor performance.
The substrate is fixedly connected to a plastic encapsulated tube, which contains an epoxy encapsulation and a sensor chip. It is connected to an FPC flexible board via bonding wires. The control chip is bonded to the substrate with adhesive and connected to the plastic encapsulated tube with sealant. The filter can be optionally equipped to filter light waves. The modular packaging process is adopted.
It improves production efficiency, enhances adaptability, reduces size, improves integration and performance stability, and avoids the risk of sensor chip detaching from filter.
Smart Images
Figure CN122073879A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of optical sensor technology, specifically relating to an optical sensing module structure and its packaging method. Background Technology
[0002] The primary purpose of sensors is to detect changes in surrounding environmental events or physical quantities, and to collect, transform, and transmit this information to other electronic devices. Unlike traditional structural or solid-state sensors, integrated circuit-based sensor chips or modules are increasingly used in smartphones, computers, smart homes, industrial control, automotive electronics, medical electronics, financial security, and smart security. These diverse and rich applications have made sensor chips a pillar of modern information technology. Optical sensor chips or modules can be further subdivided into specialized sensors such as image sensors (CMOS), lidar modules, and infrared sensors.
[0003] Currently, common optical sensor packaging methods include metal packaging, ceramic packaging, or PCB + metal shell packaging. The sensing component is packaged as a separate unit, and then connected to a signal conversion and control chip via a PCB board to form a complete external signal sensing, conversion, and processing system. The metal package includes a base with leads for bonding the sensor chip and interconnecting leads. The metal shell protects the chip. The metal shell may have openings for attaching filters, such as in TO packages. The assembled metal sensor is then connected to the control chip via external wiring to form a complete sensor module.
[0004] Ceramic packaging uses a ceramic housing to bond and interconnect the sensor chip with leads. The control chip is then bonded inside the ceramic housing and interconnected with the sensor chip. A filter glass cover is placed on top. However, due to its high cost and low efficiency per chip, ceramic housings are not suitable for mass production.
[0005] The most common packaging method is a PCB board + metal casing. The sensor chip array is bonded to the PCB board, and the lead interconnection is completed. The metal casing is then soldered to the PCB board using solder paste.
[0006] However, metal packaging is bulky, heavy, and has low production efficiency. It also has a low pin count (density), limiting its ability to provide more functional outputs. Ceramic packaging is expensive and has low production efficiency. The PCB + metal shell packaging is heavy and has poor reliability. Since the integrated conversion control chip is also located within the metal shell cavity, some control chips requiring protection are easily affected, thus impacting their functionality. Because the PCB and metal shell have different bending strengths, structural yielding can easily occur with temperature changes, leading to sensor calibration errors such as zero-point drift.
[0007] Meanwhile, the current integration of optical sensing chips and control chips is mostly board-level integration, which results in low integration and poor performance. Summary of the Invention
[0008] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide an optical sensing module structure and its packaging method.
[0009] The technical solution adopted to solve the above-mentioned technical problems is: an optical sensing module structure, including a substrate, a plastic encapsulated shell fixedly connected to the upper part of the substrate, a control chip disposed on the upper surface of the substrate, the control chip being connected to the substrate through a second bonding line, an epoxy encapsulation disposed on the upper part of the inner part of the plastic encapsulated shell, a sensing chip disposed inside the epoxy encapsulation, a first bonding line disposed on the lower surface of the sensing chip, an FPC flexible board disposed on the lower surface of the sensing chip, the FPC flexible board surrounding the sensing chip, and the FPC flexible board being connected to the sensing chip through the first bonding line.
[0010] Through the above technical solution, the sensor chip transmits the received signal to the substrate through the first bonding wire and the FPC flexible board. The substrate then transmits the signal to the control chip through the second bonding wire, and the control chip performs control.
[0011] Furthermore, the epoxy encapsulation is placed inside the encapsulated tube shell, and the epoxy encapsulation and the encapsulated tube shell are connected by sealant.
[0012] With the above technical solution, the epoxy encapsulation and the encapsulated tube shell will not easily separate.
[0013] Furthermore, the control chip is bonded to the substrate using adhesive, and multiple control chips can be bonded to the upper surface of the substrate. Whether the adhesive is conductive can be selected according to the usage.
[0014] By employing the above technical solutions, conductive adhesive or insulating adhesive can be used depending on the actual application, thus enabling the invention to adapt to different application environments.
[0015] Furthermore, a light filter is disposed on the upper surface of the sensing chip. The light filter is bonded and cured to the sensing chip by light guide adhesive. The light filter is located inside the epoxy encapsulation. The outer surface of the light filter is coated with light guide adhesive. The sensing chip and the filter are sealed by epoxy encapsulation. The sensing chip and the filter adopt double-sided exposed encapsulation. Multiple sensing chips can be encapsulated inside the epoxy encapsulation.
[0016] Through the above technical solutions, the number of sensor chips can be increased or decreased according to actual needs, and the filter can be installed or not installed depending on the usage. In this way, different types of solutions can be used in different usage environments.
[0017] A packaging method for an optical sensing module structure:
[0018] Step 1: First, apply light guide adhesive to one side of the filter surface. Then, attach the sensor chip to the side with the light guide adhesive. Bake and cure the chip until it is completely bonded together. Next, perform double-sided exposed plastic sealing. The key feature of this process is that the upper and lower molds of the sealing equipment are covered with high-temperature release films. The sensor chip and filter are placed on the high-temperature release film in the lower mold. After the mold closes, the release film precisely presses down on the sensor chip and filter. The pressing height limit and the buffering effect of the release film ensure that the upper and lower surfaces are not covered by the molding compound. The molding compound wraps the side of the sensor chip, the side of the filter, and the bottom of the filter part. This means that the sensor chip and the filter are not only bonded and fixed by the light guide adhesive, but also fixed by the molding resin until an epoxy molding is formed. This avoids the risk of the sensor chip and the filter detaching due to the complex use environment later. Then, according to the shape of the molding shell, the epoxy molding is cut into a suitable shape.
[0019] Step 2: After the filter and sensor chip are cut into suitable shapes, the FPC flexible board can be glued to the surface of the sensor chip away from the filter. Then, the FPC flexible board can be rotated so that its pins are connected to the interface of the sensor chip through the first bonding wire. Finally, the exposed first bonding wire or pin surface is covered with glue using the gold wire protective glue process. In this way, a sensor component can be assembled.
[0020] Step 3: First, apply adhesive to the substrate surface, then attach the control chip to the substrate surface, and then bake and cure it to make the substrate and the control chip adhere tightly. Finally, connect the control chip to the substrate through the second bonding wire.
[0021] Step 4: After the control chip is connected to the substrate, it can be plastic encapsulated on both sides using a plastic encapsulation mold. The encapsulation process is the same as in Step 1. The control chip is wrapped in encapsulation resin, and a plastic encapsulation resin wall of a certain thickness is formed around it. This plastic encapsulation resin wall is the plastic encapsulation shell. Finally, it is cut into individual pieces according to the shape required for production, and then baked, dehumidified, and cured to form a control component.
[0022] Step 5: First, solder the FPC flexible board inside the sensing component to the corresponding solder points on the control component. This will connect the sensing component and the control component.
[0023] Step Six: Next, apply adhesive to the inside of the plastic-sealed tube and attach the sensor component to the inside of the plastic-sealed tube. Then, proceed with the subsequent baking and curing process. Finally, apply sealant between the sensor component and the control component to secure them together.
[0024] The beneficial effects of the present invention are as follows: (1) By setting up the filter, the present invention can filter different light waves through different filters to limit the light sensing detection range of the present invention; (2) The present invention modularizes the sensing component and the control component, so that they can be carried out independently in the production and packaging process, thereby improving the production efficiency of the present invention, and different modules can be produced according to different needs, thereby improving the adaptability of the present invention; (3) Finally, the present invention adopts a new packaging process, which reasonably reduces the size of the present invention, improves the performance of the present invention, increases the integration, and stabilizes the performance. Attached Figure Description
[0025] Figure 1 This is a side view of the overall structure of the present invention;
[0026] Figure 2 This is a side view of the structure of the plastic-encapsulated tube shell and substrate in this invention;
[0027] Figure 3 This is a three-dimensional view of the structure of the plastic-sealed tube shell of the present invention;
[0028] Figure 4 This is a side view of the structure of epoxy resin and sensor chip in this invention;
[0029] Figure 5 This is a bottom view of the structure of epoxy resin and FPC flexible board in this invention;
[0030] Figure 6 This is a flowchart of the optical sensing module structure packaging method in this invention.
[0031] Reference numerals: 100, epoxy encapsulation; 101, filter; 102, first bonding line; 103, sensor chip; 200, encapsulated casing; 201, second bonding line; 202, control chip; 203, FPC flexible board; 300, substrate; 400, sealant. Detailed Implementation
[0032] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.
[0033] like Figure 1 - Figure 6As shown, an optical sensing module structure of this embodiment includes a substrate 300. A plastic encapsulation shell 200 is fixedly connected to the upper part of the substrate 300. A control chip 202 is disposed on the upper surface of the substrate 300. The control chip 202 is connected to the substrate 300 through a second bonding line 201, so that the signal between the control chip 202 and the substrate 300 is exchanged through the second bonding line 201. An epoxy encapsulation 100 is disposed on the upper part of the inner part of the plastic encapsulation shell 200. A sensing chip 103 is disposed inside the epoxy encapsulation 100. A first bonding line 102 is disposed on the lower surface of the sensing chip 103. An FPC flexible board 203 is disposed on the lower surface of the sensing chip 103. The FPC flexible board 203 surrounds the sensing chip 103 and is connected to the sensing chip 103 through the first bonding line 102, so that the FPC flexible board 203 and the sensing chip 103 exchange signals through the first bonding line 102.
[0034] like Figure 1 As shown, the epoxy encapsulation 100 is placed inside the encapsulated tube shell 200, and the epoxy encapsulation 100 and the encapsulated tube shell 200 are connected by sealant 400. This makes the invention more stable and prevents it from easily separating.
[0035] like Figure 1 - Figure 2 As shown, the control chip 202 is bonded to the substrate 300 with adhesive. Multiple control chips 202 can be bonded to the upper surface of the substrate 300. This allows the number of control chips 202 to be increased or decreased according to different needs. Whether the adhesive is conductive or not can be selected according to the application. The use of conductive adhesive or insulating conductive adhesive can be selected according to the application requirements.
[0036] like Figure 1 , Figure 4 As shown, a light filter 101 is disposed on the upper surface of the sensor chip 103. The light filter 101 is optional and can filter unwanted light waves, thereby accurately determining the detection range of the present invention. The light filter 101 is bonded and cured to the sensor chip 103 by light guide adhesive. The light filter 101 is located inside the epoxy encapsulation 100. The outer surface of the light filter 101 is coated with light guide adhesive. The sensor chip 103 and the light filter 101 are sealed by the epoxy encapsulation 100. The sensor chip 103 and the light filter 101 are encapsulated on both sides, which makes it more convenient to receive light or transmit signals without any obstruction. Multiple sensor chips 103 can be encapsulated inside the epoxy encapsulation 100.
[0037] A packaging method for an optical sensing module structure:
[0038] Step 1: First, apply light guide adhesive to one side of the filter 101, then attach the sensor chip 103 to the side with the light guide adhesive. Bake and cure the adhesive. Once the filter 101 and sensor chip 103 are completely bonded together, perform double-sided exposed plastic sealing. The key feature of this double-sided exposed plastic sealing process is that a high-temperature release film covers the upper and lower molds of the sealing equipment. The sensor chip 103 and filter 101 are placed on the high-temperature release film of the lower mold. After the mold is closed, the release film precisely presses down on the sensor chip 103 and filter 101. The pressing height limit and the buffering effect of the release film ensure that the upper and lower surfaces are not covered by the molding compound. The molding compound wraps the side of the sensor chip 103, the side of the filter 101, and part of the bottom surface of the filter 101. This means that the sensor chip 103 and the filter 101 are not only bonded and fixed by the light guide adhesive, but also fixed by the molding resin until the epoxy molding 100 is formed. This avoids the risk of the sensor chip 103 and the filter 101 detaching due to the complex use environment later. Then, according to the shape of the molding shell 200, the epoxy molding 100 is cut into a suitable shape.
[0039] Step 2: After the filter 101 and the sensor chip 103 are cut into suitable shapes, the FPC flexible board 203 can be glued to the side of the sensor chip 103 away from the filter 101. Then, the FPC flexible board 203 can be rotated so that its pins are connected to the interface of the sensor chip 103 through the first bonding wire 102. Finally, the exposed first bonding wire 102 or pin surface is covered with glue using the gold wire protective glue process. In this way, a sensing component can be formed.
[0040] Step 3: First, apply adhesive to the surface of substrate 300, then attach the control chip 202 to the surface of substrate 300, and then bake and cure it to make the substrate 300 and the control chip 202 tightly bonded. Then, connect the control chip 202 and the substrate 300 through the second bonding wire 201.
[0041] Step 4: After the control chip 202 is connected to the substrate 300, it can be plastic encapsulated on both sides using a plastic encapsulation mold. The plastic encapsulation process is the same as in Step 1. The control chip 202 is partially wrapped with plastic encapsulation resin, and a plastic encapsulation resin wall of a certain thickness is formed around it. This plastic encapsulation resin wall is the plastic encapsulation shell 200. Finally, it is cut into individual pieces according to the shape required for production, and then baked, dehumidified, and cured to form a control component.
[0042] Step 5: First, solder the FPC flexible board 203 inside the sensing component to the corresponding solder points on the control component. This will connect the sensing component and the control component.
[0043] Step Six: Next, apply adhesive to the inside of the plastic-encapsulated tube shell 200 and attach the sensing component to the inside of the plastic-encapsulated tube shell 200. This allows for subsequent baking and curing. Finally, apply sealant 400 between the sensing component and the control component to seal them. Then, cure at room temperature to complete the encapsulation of the invention.
[0044] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention.
Claims
1. An optical sensing module structure, comprising a substrate (300), characterized in that: A plastic encapsulation shell (200) is fixedly connected to the upper part of the substrate (300). A control chip (202) is disposed on the upper surface of the substrate (300). The control chip (202) is connected to the substrate (300) through a second bonding line (201). An epoxy encapsulation shell (100) is disposed on the upper part of the inner side of the plastic encapsulation shell (200). A sensor chip (103) is disposed inside the epoxy encapsulation shell (100). A first bonding line (102) is disposed on the lower surface of the sensor chip (103). An FPC flexible board (203) is disposed on the lower surface of the sensor chip (103). The FPC flexible board (203) is surrounded by the sensor chip (103). The FPC flexible board (203) is connected to the sensor chip (103) through the first bonding line (102).
2. The optical sensing module structure according to claim 1, characterized in that, The epoxy sealant (100) is placed inside the sealant housing (200), and the epoxy sealant (100) and the sealant housing (200) are connected by sealant (400).
3. The optical sensing module structure according to claim 1, characterized in that, The control chip (202) is bonded to the substrate (300) with adhesive. Multiple control chips (202) can be bonded to the upper surface of the substrate (300), and whether the adhesive is conductive can be selected according to the usage.
4. The optical sensing module structure according to claim 1, characterized in that, A filter (101) is disposed on the upper surface of the sensor chip (103). The filter (101) is bonded and cured to the sensor chip (103) by light guide adhesive. The filter (101) is located inside the epoxy encapsulation (100). The outer surface of the filter (101) is coated with light guide adhesive. The sensor chip (103) and the filter (101) are sealed by the epoxy encapsulation (100). The sensor chip (103) and the filter (101) adopt double-sided exposed encapsulation. Multiple sensor chips (103) can be encapsulated inside the epoxy encapsulation (100).
5. The packaging method for an optical sensing module structure according to claim 1, characterized in that, The method includes the following steps; Step 1: First, apply light guide adhesive to one side of the filter (101), then attach the sensor chip (103) to the side where the light guide adhesive is located. Then, bake and cure the adhesive. Once the filter (101) and sensor chip (103) are completely bonded together, double-sided exposed plastic sealing can be performed. The characteristic of this double-sided exposed plastic sealing process is that a high-temperature release film covers the upper and lower molds of the sealing equipment. The sensor chip (103) and filter (101) are placed on the high-temperature release film of the lower mold. After the equipment closes the mold, the release film presses down on the sensor chip (103) and filter (101). The pressing height limit and the buffering effect of the release film ensure that the upper and lower surfaces are not covered by the molding compound. The molding compound wraps the side of the sensor chip (103), the side of the filter (101), and part of the bottom surface of the filter (101). This means that the sensor chip (103) and the filter (101) are not only bonded and fixed by the light guide adhesive, but also fixed by the molding resin until an epoxy molding compound (100) is formed. This avoids the risk of the sensor chip (103) and the filter (101) detaching due to the complex usage environment in the later stage. Then, according to the shape of the molding compound shell (200), the epoxy molding compound (100) is cut into a suitable shape. Step 2: After the filter (101) and the sensor chip (103) are cut into suitable shapes, the FPC flexible board (203) can be glued to the side of the sensor chip (103) away from the filter (101). Then, the FPC flexible board (203) can be rotated so that its pins are connected to the interface of the sensor chip (103) through the first bonding wire (102). Finally, the exposed first bonding wire (102) or pin surface is covered with glue by the gold wire protective glue process. In this way, a sensing component can be formed. Step 3: First, apply adhesive to the surface of the substrate (300), then attach the control chip (202) to the surface of the substrate (300), and then bake and cure it so that the substrate (300) and the control chip (202) are tightly bonded. Then, connect the control chip (202) and the substrate (300) through the second bonding wire (201). Step 4: After the control chip (202) is connected to the substrate (300), it can be plastic encapsulated on both sides using a plastic encapsulation mold. The encapsulation process is the same as in Step 1. The control chip (202) is partially wrapped with encapsulation resin, and a plastic encapsulation resin wall of a certain thickness is formed around it. This plastic encapsulation resin wall is the plastic encapsulation shell (200). Finally, it is cut into individual pieces according to the shape required for production, and then baked, dehumidified, and cured to form a control component. Step 5: First, solder the FPC flexible board (203) inside the sensing component to the corresponding solder points on the control component. This will connect the sensing component and the control component. Step Six: Next, apply adhesive to the inside of the plastic-encapsulated tube shell (200) and attach the sensing component to the inside of the plastic-encapsulated tube shell (200). This allows for subsequent baking and curing. Finally, apply sealant (400) between the sensing component and the control component to seal them. Then, cure at room temperature to complete the encapsulation of the invention.