Multi-group plastic package optical MOS relay

Abstract

The utility model discloses a multi-group plastic package optical MOS relay, which comprises an input part and an output part which are sealed in an epoxy resin shell through a compression molding process, and the input part is positioned above the output part; the input part comprises an upper-layer frame, and a plurality of groups of input leading-out ends, and first bonding pads and second bonding pads correspondingly connected with the input leading-out ends are arranged below the upper-layer frame; an infrared light-emitting diode chip is fixed on the lower end surface of the first bonding pad and is electrically connected with the second bonding pad; the output part comprises a lower-layer frame, the lower-layer frame is internally provided with a plurality of groups of output leading-out ends and third and fourth bonding pads connected with the output leading-out ends, and field-effect tube chips are fixed on the lower-layer frame; a fifth bonding pad is arranged between the third bonding pad and the fourth bonding pad, and a photovoltaic chip is fixed on the fifth bonding pad; the field effect transistor chip is electrically connected with the photovoltaic chip, and the photovoltaic chip is located under the infrared light emitting diode chip; the structure is beneficial for meeting the requirements of small size and low height of the relay.

Description

Technical Field

[0001] This utility model belongs to the field of manufacturing technology of optical MOS relays, specifically relating to a multi-group plastic-encapsulated optical MOS relay. Background Technology

[0002] With the rapid development of advanced electronic equipment, the demand for relays, which serve as circuit switching and isolation functions, has increased dramatically to meet the miniaturization and high-performance requirements of these devices. Furthermore, considering the rapid pace of technological advancements in advanced electronic equipment, there is a significant demand for optical MOS relays with characteristics such as low cost, small size, and high insulation performance. In recent years, with the continuous development of plastic-encapsulated optical MOS relay manufacturing technology, these relays have advantages such as good protection performance, low cost, and high reliability. They can also control the independent on / off states of multiple different circuits and perform logic judgments as needed. Currently, driven by the development of the advanced electronic equipment industry, the demand for small-sized, multi-group plastic-encapsulated optical MOS relays has increased dramatically. However, the current plastic-encapsulated optical MOS relays required are complex in structure and relatively expensive. Summary of the Invention

[0003] To address the aforementioned problems in the existing technology, this utility model provides a multi-group plastic-encapsulated optical MOS relay. The technical problem to be solved by this utility model is achieved through the following technical solution:

[0004] A multi-group encapsulated optical MOS relay includes an input portion and an output portion sealed in an epoxy resin housing by a compression molding process, wherein the input portion is located above the output portion;

[0005] The input section includes an upper frame, and below the upper frame are multiple sets of input leads and a first pad and a second pad connected to the multiple sets of input leads respectively; an infrared light-emitting diode chip is fixed on the lower surface of the first pad, and the infrared light-emitting diode chip is electrically connected to the second pad through bonding wires.

[0006] The output section includes a lower frame, above which are arranged multiple sets of output leads and a third and a fourth pad connected to the multiple sets of output leads; a field-effect transistor (FET) chip is fixed on the upper surface of each of the third and fourth pads; a fifth pad is arranged on the side of the third and fourth pads away from the output leads, and the fifth pad is located between the third and fourth pads, with a photovoltaic chip fixed on its upper surface; the FET chips are electrically connected to each other and to the photovoltaic chip via bonding wires.

[0007] The upper frame is positioned above the lower frame, and the photovoltaic chip is located directly below the infrared light-emitting diode chip; the multiple sets of input leads and multiple sets of output leads extend from both sides of the epoxy resin shell.

[0008] Furthermore, the first pad is connected to the negative terminal of the input lead, the second pad is connected to the positive terminal of the input lead, and the third and fourth pads are respectively connected to the output leads.

[0009] Furthermore, the infrared light-emitting diode chip is coated with photosensitive adhesive.

[0010] Furthermore, both the input and output leads are made of A194 copper alloy.

[0011] Furthermore, the infrared LED chip, field-effect transistor chip, and photovoltaic chip are all unpackaged, exposed chips.

[0012] The beneficial effects of this utility model are:

[0013] 1. This utility model adopts an upper and lower frame structure design. The input and output parts formed by the upper and lower frames are stacked to form the relay mechanism. This design can ensure the consistency of product parameters while meeting the requirements of multiple control functions. Compared with the ceramic tube shell optical MOS relay, the design of the lower frame structure of this utility model optimizes the arrangement of the field effect transistor chip and the photovoltaic chip, which is conducive to achieving the requirements of small size and low height of the relay. Moreover, the structure is simple and the cost is low.

[0014] 2. The relay of this utility model adopts a hybrid microcircuit process to achieve full chip assembly. It has four sets of inputs and four sets of normally open bidirectional outputs. The structure is compact and more suitable for use in electronic devices with limited space.

[0015] 3. This utility model adopts a plastic encapsulation structure. The epoxy resin used for encapsulation has good insulation properties. The plastic encapsulation structure can effectively isolate the internal circuit of the relay from the external environment, reduce the risk of leakage and short circuit, and improve electrical safety.

[0016] 4. This utility model has a photosensitive adhesive coated on the infrared light-emitting diode chip. The photosensitive adhesive can improve the dielectric withstand voltage characteristics, ensuring that the relay meets the dielectric withstand voltage index of 2500Vd.c., and at the same time has good infrared light transmission characteristics.

[0017] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the external structure of this utility model;

[0019] Figure 2 This is a schematic diagram of the relay mechanism;

[0020] Figure 3 for Figure 2 A schematic diagram of the front structure;

[0021] Figure 4 This is a structural diagram of the input section;

[0022] Figure 5 This is a schematic diagram of the output section;

[0023] Figure 6 This is the wiring diagram of the lead-out terminals of this utility model;

[0024] Figure 7 This is a schematic diagram of the circuit principle of this utility model.

[0025] Explanation of reference numerals in the attached figures:

[0026] 1-Epoxy resin shell; 2-Input section; 3-Output section; 4-Gold wire bonding; 2-1-Upper frame; 2-2-Input lead-out terminal; 2-3-First pad; 2-4-Second pad; 2-5-Infrared LED chip; 3-1-Lower frame; 3-2-Output lead-out terminal; 3-3-Third pad; 3-4-Fourth pad; 3-5-Field effect transistor chip; 3-6-Fifth pad; 3-7-Photovoltaic chip; 2-2-1-Positive input lead-out terminal; 2-2-2-Negative input lead-out terminal. Detailed Implementation

[0027] The present invention will be further described in detail below with reference to specific embodiments, but the implementation of the present invention is not limited thereto.

[0028] Please also see Figures 1-5 This utility model embodiment provides a molded optical MOS relay with four inputs and four normally open bidirectional outputs. Specifically, it includes an input portion 2 and an output portion 3 sealed within an epoxy resin housing 1 using a compression molding process, with the input portion 2 located above the output portion 3. The upper input portion 2 and the lower output portion 3 are stacked to form the relay mechanism. The epoxy resin housing 2 helps maintain the stability of the internal frame, preventing deformation and improving the product's insulation and withstand voltage performance.

[0029] The input section 2 includes an upper frame 2-1. Below the upper frame 2-1 are four sets of equally spaced input leads 2-2 and first pads 2-3 and second pads 2-4 connected to the four sets of input leads 2-2. Each input lead 2-2 includes a positive input lead 2-2-1 and a negative input lead 2-2-2, i.e., there are four positive input leads 2-2-1 and four negative input leads 2-2-2. The four sets of input leads 2-2 are vertically bent upwards and connected to the first pads 2-3 and the second pads 2-4, such that the first pads 2-3 and the second pads 2-4 are both located above the input leads 2-2. The first pad 2-3 is connected to the negative input lead 2-2-2, and the second pad 2-4 is connected to the positive input lead 2-2-1. An infrared light-emitting diode chip 2-5 is fixed on the lower end surface of the first pad 2-3 by a die bonding process. The infrared light-emitting diode chip 2-5 is electrically connected to the second pad 2-4 by a gold wire bonding wire 4.

[0030] The output section 3 includes a lower frame 3-1, which has four sets of eight equally spaced output leads 3-2, as well as a third pad 3-3 and a fourth pad 3-4 connected to the four sets of output leads 3-2. Each output lead 3-2 can be used as either a positive or negative output. Eight output leads 3-2 are bent vertically downwards and connected to the third pad 3-3 and the fourth pad 3-4, i.e., the third pad 3-3 and the fourth pad 3-4 are both located below the output leads 3-2; field-effect transistor chips 3-5 are fixed on the upper surfaces of the third pad 3-3 and the fourth pad 3-4 by a die bonding process; a fifth pad 3-6 is provided on the side of the third pad 3-3 and the fourth pad 3-4 away from the output leads 3-2, and the fifth pad 3-6 is located between the third pad 3-3 and the fourth pad 3-4, and a photovoltaic chip 3-7 is fixed on the upper surface of the fifth pad 3-6 by a die bonding process; the field-effect transistor chips 3-5 are electrically connected to each other and to the photovoltaic chip 3-7 by gold wire bonding wires 4 respectively.

[0031] The upper frame 2-1 is positioned above the lower frame 3-1, and the photovoltaic chip 3-7 is positioned directly below the infrared light-emitting diode chip 2-5. The two are connected by photoelectric isolation to form a vertical illumination structure, which maximizes the photoelectric conversion efficiency.

[0032] The four sets of input leads 2-2 and the four sets of output leads 3-2 extend from both sides of the epoxy resin housing 1. Preferably, the input leads 2-2 and the output leads 3-2 are both made of A194 copper alloy and are tin-plated, which facilitates soldering and improves their surface oxidation and corrosion resistance. These leads are all printed circuit board type, requiring only simple external wiring to achieve the function of four sets of inputs and four sets of normally open bidirectional outputs.

[0033] Furthermore, a photosensitive adhesive is coated on the infrared LED chip 2-5 and the gold wire bonding wire 4 connected to the infrared LED chip 2-5. This photosensitive adhesive contains a large amount of SiO2, exhibiting high dielectric strength characteristics, which improves the dielectric withstand voltage characteristics, ensuring the relay meets the 2500Vd.c. dielectric withstand voltage specification. Simultaneously, the photosensitive adhesive has very low absorption of infrared light in the near-infrared region (800nm~1000nm), with absorption less than 0.1 at approximately 940nm, thus increasing the light transmittance of the infrared LED chip 2-5. Preferably, in this embodiment of the invention, the photosensitive adhesive is a transparent silicone potting compound, model 1002AB.

[0034] The optical MOS relay in this invention adopts a 1.27mm narrow pin pitch SOP16 package with dimensions of 10.37×4.45mm×2.00mm. Internally, it features a vertical illumination structure, four inputs, four normally open outputs, and both bidirectional and DC output configurations. The output load is ±80Vd.c., 0.3A. It utilizes upper and lower frames and hybrid microcircuit technology. The infrared LED chip, photovoltaic chip, and MOSFET chip inside the epoxy resin housing are all assembled using exposed chips. This assembly method ensures high chip reliability. The relay is small in size, light in weight, highly reliable, and adaptable to various environments, meeting the requirements of output electrical performance and structural design. Furthermore, this invention employs a low-threshold power control circuit design, ensuring that when the input drive current reaches a minimum value, the output voltage of the photovoltaic chip reaches the turn-on voltage of the power MOSFET, enabling reliable conduction of the power MOSFET. Simultaneously, a fast discharge circuit is designed inside the photovoltaic chip to ensure rapid discharge of the power MOSFET's gate voltage, meeting the requirements of a relay turn-on time of less than 0.2ms and a turn-off time of less than 0.1ms.

[0035] Please see Figure 6 The wiring diagram of the lead-out terminals of this utility model is shown below:

[0036] This utility model's bidirectional output includes output mode A and output mode B. The first group of relay leads 1 and 2 are the IN1+ and IN1- terminals of the input control terminal, respectively. Wiring mode A: lead 16 is the OUT1+ terminal of the output, and lead 15 is the OUT1- terminal of the output; Wiring mode B: lead 15 is the OUT1+ terminal of the output, and lead 16 is the OUT1- terminal of the output. The second group of relay leads 3 and 4 are the IN2+ and IN2- terminals of the input control terminal, respectively. Wiring mode A: lead 14 is the OUT2+ terminal of the output, and lead 13 is the OUT2- terminal of the output; Wiring mode B: lead 13 is the OUT2+ terminal of the output, and lead 14 is the OUT2- terminal of the output. For the third group of relays, leads 5 and 6 are the IN3+ and IN3- terminals of the input control terminal, respectively. Wiring method A: lead 12 is the OUT3+ output terminal, and lead 11 is the OUT3- output terminal; Wiring method B: lead 11 is the OUT3+ output terminal, and lead 12 is the OUT3- output terminal. For the fourth group of relays, leads 7 and 8 are the IN4+ and IN4- terminals of the input control terminal, respectively. Wiring method A: lead 10 is the OUT4+ output terminal, and lead 9 is the OUT4- output terminal; Wiring method B: lead 9 is the OUT4+ output terminal, and lead 10 is the OUT4- output terminal.

[0037] The working principle of this utility model:

[0038] Please see Figure 7 This optical MOS solid-state relay uses an infrared LED chip as the input device, a photovoltaic chip as the photosensitive device, and a field-effect transistor (FET) chip as the output device. When the input current reaches the turn-on current of the infrared LED chip, the infrared LED chip emits a light signal, which shines directly on the photovoltaic chip in the output circuit. The photovoltaic chip generates a voltage at its output terminal. When the voltage reaches the turn-on threshold voltage of the FET chip, the FET chip conducts, and the relay is turned on. When the input is de-energized, the voltage generated by the photovoltaic chip is less than the turn-on threshold voltage of the FET chip, and the FET chip is turned off, thus turning off the relay. The gate voltage of the FET chip is rapidly discharged through the internal discharge circuit of the photovoltaic chip.

[0039] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the protection scope of the present invention.

Claims

1. A multi-group encapsulated optical MOS relay, characterized in that, It includes an input portion and an output portion sealed within an epoxy resin housing by a compression molding process, with the input portion located above the output portion; The input section includes an upper frame, and below the upper frame are multiple sets of input leads and a first pad and a second pad connected to the multiple sets of input leads respectively; an infrared light-emitting diode chip is fixed on the lower surface of the first pad, and the infrared light-emitting diode chip is electrically connected to the second pad through bonding wires. The output section includes a lower frame, above which are arranged multiple sets of output leads and a third and a fourth pad connected to the multiple sets of output leads; a field-effect transistor (FET) chip is fixed on the upper surface of each of the third and fourth pads; a fifth pad is arranged on the side of the third and fourth pads away from the output leads, and the fifth pad is located between the third and fourth pads, with a photovoltaic chip fixed on its upper surface; the FET chips are electrically connected to each other and to the photovoltaic chip via bonding wires. The upper frame is positioned above the lower frame, and the photovoltaic chip is located directly below the infrared light-emitting diode chip; the multiple sets of input leads and multiple sets of output leads extend from both sides of the epoxy resin shell.

2. The multi-group encapsulated optical MOS relay according to claim 1, characterized in that, The first pad is connected to the negative terminal of the input lead, and the second pad is connected to the positive terminal of the input lead; the third and fourth pads are respectively connected to the output leads.

3. The multi-group encapsulated optical MOS relay according to claim 1, characterized in that, The infrared light-emitting diode chip is coated with photosensitive adhesive.

4. The multi-group encapsulated optical MOS relay according to claim 1, characterized in that, Both the input and output leads are made of A194 copper alloy.

5. The multi-group encapsulated optical MOS relay according to claim 1, characterized in that, The infrared LED chip, field-effect transistor chip, and photovoltaic chip are all unpackaged, exposed chips.

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