Optoelectronic converters and electronic devices

Abstract

A photoelectric converter and electronic device are disclosed. The photoelectric converter includes: a receiving cavity, a light-emitting module, a light-receiving module, and a depletion-mode MOS chip located within the receiving cavity, wherein: the light-emitting module is adapted to emit light; the light-receiving module is coupled to the depletion-mode MOS chip and adapted to receive the light; the depletion-mode MOS chip has a light-shielding protective structure covering its photosensitive area, and the light-shielding protective structure has a light-shielding rate of not less than 99% for visible light and infrared light. This solution can prevent the depletion-mode MOS chip from being affected by light exposure, thereby improving the stability of the photoelectric converter.

Description

Technical Field

[0001] This utility model relates to the field of optoelectronic conversion device technology, and in particular to an optoelectronic converter and electronic device. Background Technology

[0002] Photoelectric converters, such as normally closed opto-relays, are commonly used switching devices. A normally closed opto-relay is a solid-state switching device based on opto-isolation technology. Its core characteristic is that it remains closed (conducting) when there is no control signal, and opens (turns off) when a control signal is applied. Compared with traditional mechanical relays or normally open opto-relays, it has advantages such as high reliability, long lifespan, and no contact wear, and is widely used in industrial automation, medical equipment, power systems, and other fields.

[0003] Currently, normally closed optocouplers typically use depletion-type MOS chips. However, depletion-type MOS chips are quite sensitive to light. When exposed to external light, photogenerated carriers are generated inside, further aggravating leakage current and severely interfering with the normal operation of the optocoupler. Utility Model Content

[0004] The purpose of this invention is at least to provide a photoelectric converter that can prevent depletion-type MOS chips from being affected by light, thereby improving the stability of the photoelectric converter.

[0005] In a first aspect, this utility model provides a photoelectric converter, comprising: a receiving cavity, a light-emitting module, a light-receiving module, and a depletion-type MOS chip located in the receiving cavity, wherein: the light-emitting module is adapted to emit light; the light-receiving module is coupled to the depletion-type MOS chip and adapted to receive the light; the depletion-type MOS chip has a light-shielding protective structure covering its photosensitive area, and the light-shielding protective structure has a light-shielding rate of not less than 99% for visible light and infrared light.

[0006] A light-shielding protection structure is provided on the photosensitive area of ​​the depletion-type MOS chip. This light-shielding protection structure can completely cover the photosensitive area of ​​the depletion-type MOS chip, thereby preventing the depletion-type MOS chip from being affected by light.

[0007] Optionally, the light-shielding protective structure is a black silicone layer coated on the photosensitive area.

[0008] Black silicone is applied to the photosensitive area of ​​a depletion-type MOS chip by dispensing adhesive, thus preventing the chip from being affected by light. This method is simple to operate, requires no complex equipment or processes, and can greatly reduce production costs and production cycle.

[0009] Optionally, the outer surface of the depletion-type MOS transistor is covered with the black silicone layer.

[0010] Optionally, the thickness of the black silicone layer is 0.2mm to 1mm.

[0011] Optionally, the black silicone layer may also be doped with at least one of the following: a thermally conductive material or an insulating material.

[0012] Optionally, the photosensitive area of ​​the depletion-type MOS chip is the region on the depletion-type MOS chip that generates photogenerated carriers when irradiated by the light.

[0013] Optionally, the photosensitive area of ​​the depletion-type MOS chip includes: the source region and the gate region of the depletion-type MOS chip.

[0014] Optionally, the photoelectric converter further includes a first bracket and a second bracket, wherein: the light-emitting module is disposed on the first bracket and includes a light-emitting diode and a transparent resin covering the surface of the light-emitting diode; the light-receiving module is disposed on the second bracket; the first bracket and the second bracket are disposed independently of each other.

[0015] Optionally, the light-shielding protection structure completely covers the outer surface of the depletion-type MOS chip.

[0016] This utility model embodiment also provides an electronic device, including: any of the above-described photoelectric converters. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of a photoelectric converter according to an embodiment of the present invention. Detailed Implementation

[0018] In the application of optocouplers, normally closed optocouplers are crucial for ensuring the stability and reliability of circuits under specific conditions. Currently, the depletion-mode MOS solution used in normally closed optocouplers has significant drawbacks, greatly limiting its performance improvement and widespread application.

[0019] I. Inherent defects of depletion-type MOS solutions

[0020] Leakage current is a serious problem: Due to their physical structure and operating principle, depletion-mode MOS chips exhibit a significant leakage current under normal conditions. Even under ideal operating conditions, a certain amount of current will flow through the MOS chip, resulting in wasted electrical energy and severely interfering with the performance of opto-relays. In circuits with extremely high current accuracy requirements, this leakage current may lead to circuit misjudgments and cause system-wide failures.

[0021] II. Insufficient ability to cope with environmental interference

[0022] Depletion-type MOS chips are highly sensitive to light. When exposed to external light, photogenerated carriers are generated internally, further exacerbating leakage current and severely interfering with the normal operation of the photorelay. However, the photorelay requires an LED for switching action, so the depletion-type MOS chip and the LED need to be isolated to avoid the LED's influence on the depletion-type MOS chip due to light exposure.

[0023] Furthermore, depletion-type MOS chips are sensitive to changes in environmental factors: variations in environmental factors such as temperature and humidity can significantly affect the optocouplers of depletion-type MOS chips. Temperature fluctuations can cause significant changes in the leakage current of depletion-type MOS chips, while increased humidity may reduce the insulation performance of the device, further increasing the leakage current.

[0024] In summary, existing normally closed opto-relay depletion-mode MOS chips have many shortcomings in terms of performance and environmental adaptability, which seriously restricts their application and development in various fields.

[0025] In this embodiment of the invention, a light-shielding protection structure is provided on the photosensitive area of ​​the depletion-type MOS chip. This light-shielding protection structure can completely cover the photosensitive area of ​​the depletion-type MOS chip, thereby preventing the depletion-type MOS chip from being affected by light.

[0026] To make the above-mentioned objectives, features and beneficial effects of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings.

[0027] This utility model embodiment provides a photoelectric converter, see reference Figure 1 The following will provide a detailed explanation through specific steps.

[0028] In this embodiment of the invention, the photoelectric converter may include a receiving cavity, a light-emitting module 1, a light-receiving module 4, and a depletion-type MOS chip 2 located within the receiving cavity, wherein:

[0029] Light-emitting module 1, suitable for emitting light;

[0030] The light receiving module 4 is coupled to the depletion-type MOS chip and is suitable for receiving the light emitted by the light emitting module 1;

[0031] The depletion-type MOS chip 2 has a light-shielding protection structure 3 covering its photosensitive area. The light-shielding protection structure 3 has a light-shielding rate of not less than 99% for visible light and infrared light.

[0032] In a specific implementation, the photoelectric converter may also include a first bracket 5 and a second bracket 6, wherein:

[0033] The light-emitting module can be set on the first bracket 5, and the light-receiving module can be set on the second bracket 6. The first bracket 5 and the second bracket 6 are set independently of each other.

[0034] In a specific implementation, the light-emitting module 1 may include a light-emitting diode, and a transparent resin may be covered on the light-emitting diode to protect it.

[0035] It is understandable that the light-emitting module 1 can also be other electronic devices capable of emitting visible light, and is not limited to light-emitting diodes.

[0036] In a specific implementation, a light-shielding protection structure 3 is provided on the photosensitive area of ​​the depletion-type MOS chip 2. This light-shielding protection structure 3 can completely cover the photosensitive area of ​​the depletion-type MOS chip 2, thereby preventing the depletion-type MOS chip 2 from being affected by light.

[0037] In practical implementation, a light-shielding protection structure 3 can also be provided over the entire area of ​​the depletion-type MOS chip 2 to create a closed, light-free environment. Placing the depletion-type MOS chip 2 within this light-shielding protection structure 3 prevents the depletion-type MOS chip 2 from being affected by light and the external environment.

[0038] In this embodiment of the invention, the light-shielding protection structure 3 can be a black silicone layer, and the black silicone layer can be completely coated on the photosensitive area of ​​the depletion-type MOS chip 2; or, the black silicone layer can completely cover the entire outer surface of the depletion-type MOS chip 2.

[0039] In practice, the thickness of the black silicone layer can be 0.2mm to 1mm. By selecting an appropriate thickness for the black silicone layer, visible light can be effectively blocked without affecting the heat dissipation of the depletion-type MOS chip 2.

[0040] In practical implementation, without affecting the light-blocking performance of the black silicone layer, thermally conductive materials can also be doped into the black silicone layer. These thermally conductive materials can effectively dissipate the heat generated by the depletion-type MOS chip 2 during operation, thus providing effective protection for the depletion-type MOS chip 2.

[0041] In practice, without affecting the light-blocking performance of the black silicone layer, insulating materials can also be incorporated into the black silicone layer. These insulating materials can be ceramic particles, etc.

[0042] In this embodiment of the present invention, the photosensitive area of ​​the depletion-type MOS chip 2 can be: the area on the depletion-type MOS chip 2 that generates photogenerated carriers due to the influence of light irradiation.

[0043] In a specific implementation, the photosensitive region of the depletion-type MOS chip 2 may include: the source region of the depletion-type MOS chip 2 and the gate region of the depletion-type MOS chip 2. The photosensitive region of the depletion-type MOS chip 2 may also include the region near the source region and the region near the gate region, etc.

[0044] In this embodiment of the invention, black silicone can be coated onto the photosensitive area of ​​a depletion-type MOS chip using a contact dispensing method.

[0045] In practice, black silicone can be selected in advance. Black silicone has good fluidity and curing properties to ensure that it can be extruded smoothly during the dispensing process and can be evenly distributed on the photosensitive area of ​​the depletion-type MOS chip.

[0046] In some embodiments, the viscosity of black silica gel at room temperature (e.g., 25°C) is 9000~15000 cps (centipoise).

[0047] In practical implementation, a flexible silicone pad can also be placed in the contact area between the black silicone and the depletion-type MOS chip to provide stress buffering.

[0048] In practice, when a black silicone layer is used to cover the outer surface of a depletion-type MOS chip, the black silicone can extend beyond the edge of the depletion-type MOS chip package by a certain distance to avoid delamination of the black silicone.

[0049] The following section uses black silicone as an example to explain the process of forming a light-shielding protective structure on the photosensitive area of ​​a depletion-type MOS chip.

[0050] Choose dispensing equipment, such as a high-precision dispensing machine. A high-precision dispensing machine can achieve a dispensing accuracy of ±0.05 mm to ensure accurate dispensing positioning.

[0051] During the dispensing process, the depletion-mode MOS chip to be dispensed is first fixed on the dispensing machine's worktable. The dispensing machine is controlled either by programming or manually, aligning the dispensing needle with the photosensitive area of ​​the depletion-mode MOS chip. Dispensing is performed according to the set dispensing path and parameters, with the dispensing speed controlled between 1mm and 5mm per second. The dispensing amount can be adjusted based on the size of the photosensitive area of ​​the depletion-mode MOS chip and the thickness of the black silicone layer, ensuring that the black silicone uniformly covers the photosensitive area of ​​the depletion-mode MOS chip.

[0052] In some embodiments, the thickness of the black silicone layer can be 0.2mm to 1mm to ensure good light-shielding performance without causing poor heat dissipation due to an excessively thick black silicone layer.

[0053] During the dispensing process, the working environment temperature of the dispensing machine can be maintained between 18℃ and 28℃, and the humidity between 30% and 60%, in order to avoid the influence of external environmental factors on the flowability and curing effect of black silicone.

[0054] After dispensing the photosensitive area of ​​the depletion-type MOS chip, the dispensed depletion-type MOS chip is placed in a curing oven for curing. The curing temperature is set to 150℃ and the curing time is set to 4 hours to fully cure the black silicone and form a stable light-shielding protective structure.

[0055] In practice, without affecting the light-blocking performance of the black silicone layer, magnetic particles of iron oxide can be doped into the black silicone layer. The flow direction of the black silicone can be controlled by a magnetic field to precisely control the coating area of ​​the black silicone.

[0056] After curing, the appearance of the depletion-type MOS chip can be inspected to ensure that the black silicone layer on its photosensitive area is free of bubbles and cracks, and that the photosensitive area is completely covered by the black silicone layer.

[0057] In some embodiments, optical detection methods can be used to detect whether there are bubbles or cracks in the coated black silicone layer.

[0058] For example, an infrared camera (wavelength 1500nm) can be used to detect whether there are bubbles or cracks in the black silicone layer.

[0059] In other embodiments, an electrical detection method can be used to detect whether there are bubbles or cracks in the coated black silicone layer.

[0060] For example, after coating the photosensitive area of ​​a depletion-type MOS chip with a black silicone layer, the presence of bubbles or cracks in the coated black silicone layer can be determined by detecting changes in the dark current of the depletion-type MOS chip.

[0061] By covering the photosensitive area of ​​the depletion-type MOS chip with a black silicone layer, the light emitted by the light-emitting module can be effectively blocked, thus preventing the depletion-type MOS chip from being affected by light. This ensures the normal conduction and cutoff of the depletion-type MOS chip and improves the stability and reliability of the circuit.

[0062] In summary, in this embodiment of the invention, black silicone is coated onto the photosensitive area of ​​the depletion-type MOS chip by dispensing adhesive, thus preventing the depletion-type MOS chip from being affected by light. The operation is simple, requires no complex equipment or processes, and can greatly reduce production costs and production cycle.

[0063] In this embodiment of the invention, the light-shielding protective structure described above can also be made of other opaque materials. For example, epoxy resin or silicone resin filled with carbon black or other black dyes, as long as its light-shielding rate for visible and infrared light is not less than 99%.

[0064] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the present invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. An opto-electric converter, characterized by, include: A receiving cavity, containing a light-emitting module, a light-receiving module, and a depletion-mode MOS chip, wherein: The light-emitting module is suitable for emitting light; The light-receiving module is coupled to the depletion-type MOS chip and is adapted to receive the light. The depletion-type MOS chip has a light-shielding protection structure covering its photosensitive area, and the light-shielding protection structure has a light-shielding rate of not less than 99% for visible light and infrared light.

2. The photoelectric converter of claim 1, wherein, The light-shielding protective structure is a black silicone layer, which is coated on the photosensitive area.

3. The photoelectric converter of claim 2, wherein, The outer surface of each depletion-type MOS transistor is covered with the black silicone layer.

4. The photoelectric converter as claimed in claim 2 or 3, characterized in that, The thickness of the black silicone layer is 0.2mm to 1mm.

5. The photoelectric converter of claim 2, wherein, The black silicone layer is also doped with at least one of the following: a thermally conductive material and an insulating material.

6. The photoelectric converter of claim 1, wherein, The photosensitive area of ​​the depletion-type MOS chip includes: the region on the depletion-type MOS chip that generates photogenerated carriers when irradiated by the light.

7. The photoelectric converter of claim 6, wherein The photosensitive area of ​​the depletion-type MOS chip includes: the source region of the depletion-type MOS chip and the gate region of the depletion-type MOS chip.

8. The photoelectric converter of claim 1, wherein, Also includes: The first support and the second support, wherein: The light-emitting module is mounted on the first bracket and includes a light-emitting diode and a transparent resin covering the surface of the light-emitting diode; The light-receiving module is mounted on the second bracket; the first bracket and the second bracket are set independently of each other.

9. The photoelectric converter as described in claim 1, characterized in that, The light-shielding protection structure completely covers the outer surface of the depletion-type MOS chip.

10. An electronic device, characterized in that, include: The photoelectric converter as described in any one of claims 1 to 9.

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