Integrated electronic protection device and photoelectric sensor adopting same

Abstract

The utility model provides an integrated electronic protection device and a photoelectric sensor employing the same, the integrated electronic protection device comprises a housing, a Schottky diode and an array TVS tube are arranged in the housing, the array TVS tube comprises an N-type semiconductor substrate located in the housing and four first P-type base regions arranged on the surface of the N-type semiconductor substrate, and the four first P-type base regions are arranged on the surface of the N-type semiconductor substrate. First anode electrodes are arranged on the surfaces of the four first P-type base regions, and first metal layers capable of leading out pins are arranged on the surfaces of the first anode electrodes; compared with the prior art, the integrated electronic protection device has the following beneficial effects that the integrated electronic protection device is high in integration level and very small in size, so that the integrated electronic protection device can be applied to a miniature photoelectric sensor, the space is greatly saved, and surge voltage protection and power supply polarity protection are taken into consideration; in addition, the integrated electronic protection device in the utility model carries out surge voltage protection between lines, the residual voltage is relatively low, and the requirement on the withstand voltage of a post-stage circuit is not very high.

Description

Technical Field

[0001] This utility model relates to the field of protection device technology, and in particular to an integrated electronic protection device and a photoelectric sensor using the protection device. Background Technology

[0002] With the development of industrial automation, equipment integration is increasing, and sensors are becoming smaller, requiring more compact designs. There is not enough space for electronic components, and the power of protection devices is directly proportional to their size. This results in a greater number of discrete components and higher costs.

[0003] Photoelectric sensors typically operate at voltages between 10 and 30V DC. To save space, high-voltage power lines (such as 220V and 380V) and motor drive lines are often placed in the same cable tray as the sensor's low-voltage wiring. This surge voltage, especially during motor startup and shutdown, can easily damage the sensor without proper surge protection. Sensors may have one (3-wire) or two (4-wire) switch outputs. The power supply positive and negative terminals and the output lines share the same cable. Incorrect cable connections, without polarity protection, can easily damage the sensor. Surge protection devices are added to the power supply positive and negative terminals, and a power polarity protection device is added between the output line and the power line. These surge protection devices are typically TVS diodes.

[0004] Existing technical solutions such as Figure 1 As shown above Figure 1 The diagram on the left shows a two-way output interface for an NPN type. Figure 1 The diagram on the right shows a PNP type two-output interface. It can be seen that it requires three TVS diodes and one polarized diode. Even so, Figure 1 As can be seen from the left, the surge protection circuits between A1 and B1, and between A1 and C1, through two bidirectional TVS diodes, will double the clamping voltage, thus placing higher demands on the withstand voltage of subsequent circuits; similarly, Figure 1 As can be seen on the right, the surge protection circuits between B2 and D2, and between C2 and D2, are through two bidirectional TVS diodes, and the devices are discrete components with relatively large size. Utility Model Content

[0005] In view of the shortcomings of the prior art described above, the purpose of this utility model is to provide an integrated electronic protection device and a photoelectric sensor using the protection device, in order to solve the problems that the protection device of the existing photoelectric sensor is composed of multiple protection devices, which makes the size relatively large and cannot be applied to micro sensors, and that the protection device of the existing photoelectric sensor will double the clamping pressure, which requires higher voltage withstand capability of the subsequent circuit.

[0006] To achieve the above and other related objectives, this utility model provides the following technical solution:

[0007] An integrated electronic protection device includes a housing containing a Schottky diode and an array TVS diode. The array TVS diode includes an N-type semiconductor substrate located within the housing and four first P-type base regions disposed on the surface of the N-type semiconductor substrate. An isolation structure is also provided on the surface of the N-type semiconductor substrate, and the four first P-type base regions are isolated from each other by the isolation structure. A first anode electrode is provided on the surface of each of the four first P-type base regions, and a first metal layer with lead-out pins is provided on the surface of the first anode electrode.

[0008] In one embodiment of the present invention, the housing is further filled with epoxy resin, and the Schottky diode and the array TVS diode are isolated by the epoxy resin.

[0009] In one embodiment of the present invention, the Schottky diode includes an N-type base region and a second P-type base region located within the housing and interconnected therewith. A cathode electrode is provided on the surface of the N-type base region, and a second metal layer with lead-out pins is provided on the surface of the cathode electrode. A second anode electrode is provided on the surface of the second P-type base region, and a third metal layer with lead-out pins is provided on the surface of the second anode electrode.

[0010] In one embodiment of the present invention, the Schottky diode is disposed on a first wafer, the array TVS diode is disposed on a second wafer, and the first wafer and the second wafer are packaged together to form an integrated electronic protection device.

[0011] A photoelectric sensor employing the aforementioned integrated electronic protection device includes a three-wire photoelectric sensor and a four-wire photoelectric sensor. The three-wire photoelectric sensor includes a photoelectric sensor body and a positive power supply line, a negative power supply line, and an output line connected to the photoelectric sensor body. When the photoelectric sensor body is NPN type, the Schottky diode is connected in series on the negative power supply line, and the array TVS diode is connected in parallel with the positive power supply line, the negative power supply line, and the output line, respectively. When the photoelectric sensor body is PNP type, the Schottky diode is connected in series on the positive power supply line, and the array TVS diode is connected in parallel with the positive power supply line, the negative power supply line, and the output line, respectively.

[0012] In one embodiment of this utility model, the four-wire photoelectric sensor includes a photoelectric sensor body and a positive power supply line, a negative power supply line, a first output line, and a second output line connected to the photoelectric sensor body. When the photoelectric sensor body is NPN type, the Schottky diode is connected in series on the negative power supply line, and the array TVS diode is connected in parallel with the positive power supply line, the negative power supply line, the first output line, and the second output line, respectively. When the photoelectric sensor body is PNP type, the Schottky diode is connected in series on the positive power supply line, and the array TVS diode is connected in parallel with the positive power supply line, the negative power supply line, the first output line, and the second output line, respectively.

[0013] As described above, the integrated electronic protection device and the photoelectric sensor using the present invention have the following beneficial effects: The integrated electronic protection device of the present invention integrates a Schottky diode and four single TVS diodes. The Schottky diode is used for power supply polarity protection. The four TVS diodes share an N-type semiconductor substrate, resulting in a larger heat dissipation area and thus higher power of the TVS diodes. The positive terminals of the four unidirectional TVS diodes are connected together to form an array TVS diode, which is used for surge voltage protection. Due to its high integration, the integrated electronic protection device of the present invention is very small in size, with a size of 1. With dimensions of 0.6*0.8*0.5mm, it can be applied to miniature photoelectric sensors, greatly saving space while also providing surge voltage protection and power polarity protection. The integrated electronic protection device in this invention can be applied to three-wire and four-wire photoelectric sensors. When applied to three-wire or four-wire photoelectric sensors, when a surge voltage occurs between the four pins of the array TVS diode, one TVS diode breaks down in reverse while the other conducts in the forward direction. This ensures that the clamping voltage between the pins of the array TVS diode is the same, providing good protection and reducing the need for high voltage withstand requirements in subsequent circuits. Attached Figure Description

[0014] Figure 1 The diagram shows an existing interface protection circuit.

[0015] Figure 2 The diagram shown is a front cross-sectional view of the integrated electronic protection device in the first embodiment of this utility model.

[0016] Figure 3 The diagram shown is a top cross-sectional view of the integrated electronic protection device in the first embodiment of this utility model.

[0017] Figure 4 The diagram shown is a top view of the integrated electronic protection device in the first embodiment of this utility model.

[0018] Figure 5 The diagram shown is an electrical schematic of the integrated electronic protection device in this utility model;

[0019] Figure 6 The diagram shows the wiring schematic of the integrated electronic protection device for a three-wire photoelectric sensor in this utility model.

[0020] Figure 7 The diagram shows the wiring schematic of the integrated electronic protection device for a four-wire photoelectric sensor in this utility model.

[0021] Figure 8 The diagram shown is a schematic of the NPN four-wire interface protection of the photoelectric sensor using the protection device in the second embodiment of this utility model.

[0022] Figure 9 The diagram shows a PNP-type four-wire interface protection for a photoelectric sensor using the protection device in the second embodiment of this utility model.

[0023] Component designation explanation

[0024] 1. Housing; 2. Schottky diode; 201. Second P-type base region; 202. Second anode electrode; 203. Third metal layer; 204. N-type base region; 205. Second metal layer; 3. TVS array; 301. N-type semiconductor substrate; 302. First P-type base region; 303. First anode electrode; 304. First metal layer; 305. Isolation structure; 4. Epoxy resin. Detailed Implementation

[0025] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. It should be noted that, unless otherwise specified, the following embodiments and features described herein can be combined with each other.

[0026] Please see Figures 2 to 4 The first embodiment of this utility model relates to an integrated electronic protection device, including a housing 1. A Schottky diode 2 and an array TVS diode 3 are disposed within the housing 1. The housing 1 is also filled with epoxy resin 4, and the Schottky diode 2 and the array TVS diode 3 are isolated by the epoxy resin 4. The Schottky diode 2 includes an N-type base region 204 and a second P-type base region 201 located within the housing 1 and interconnected. A cathode electrode is disposed on the surface of the N-type base region 204, and a second metal layer 205 with lead-out pins is disposed on the surface of the cathode electrode. A second anode electrode 202 is disposed on the surface of the second P-type base region 201, and a third metal layer 203 with lead-out pins is disposed on the surface of the second anode electrode 202. It should be noted that the Schottky diode 2 is used for power supply polarity protection.

[0027] The array TVS diode 3 includes an N-type semiconductor substrate 301 located within a housing 1 and four first P-type base regions 302 disposed on the surface of the N-type semiconductor substrate 301. Each of the four first P-type base regions 302 has a first anode electrode 303 disposed on its surface, and a first metal layer 304 disposed on the surface of the first anode electrode 303. An isolation structure 305 is also disposed on the surface of the N-type semiconductor substrate 301 between the four first P-type base regions 302, and the four first P-type base regions 302 are isolated from each other by the isolation structure 305. A Schottky diode 2 is disposed on a first wafer, and the array TVS diode 3 is disposed on a second wafer. The first wafer and the second wafer are packaged together to form an integrated electronic protection device. It should be noted that the array TVS diode 3 is integrated from four TVS diodes and is used for surge voltage protection.

[0028] Specifically, the integrated electronic protection device in this utility model integrates a Schottky diode 2 (P4 and N3) and four single TVS diodes. The Schottky diode 2 is used for polarity protection, and the four unidirectional TVS positive terminals (P1, P2, P5, P6) are connected together to form an array TVS diode 3, which has four surge protection ports and can be used for three-wire and four-wire photoelectric sensors.

[0029] Four TVS diodes share an N-type semiconductor substrate 301, which provides a larger heat dissipation area, thus enabling higher power output. The Schottky diode 2 and the array TVS diode 3 are packaged together in one package, with the array TVS diode 3 and the Schottky diode 2 isolated by epoxy resin 4. Due to the high integration density, the integrated electronic protection device is very small, measuring 1.6*0.8*0.5mm, and can be used in miniature photoelectric sensors, greatly saving space. It also provides surge voltage protection and power polarity protection, combining several protection devices into one, resulting in lower packaging costs.

[0030] More specifically, this integrated electronic protection device has six pins. The four positive pins 1, 2, 5, and 6 of the array TVS diode 3 are led out from the first P-type base region 302 (P1, P2, P5, P6), the first anode electrode 303, and the first metal layer 304 inside the wafer, allowing connection to external circuits. The negative terminals of the four TVS diodes are internally connected, sharing a single N-type semiconductor substrate 301. The positive terminal P4 and the negative terminal N3 of the Schottky diode 2 are led out from the electrode and the metal layer, respectively. The Schottky diode 2 has a lower voltage drop, thereby reducing the voltage difference of the proximity switch. Since the four TVS diodes and the Schottky diode 2 have different wafer characteristics and use different wafers, packaging the two wafers together reduces the device size and provides instantaneous overvoltage and polarity protection. For details, please refer to [link to relevant documentation]. Figure 5 .

[0031] Please see Figures 6 to 8The second embodiment of this utility model relates to a photoelectric sensor using the protection device, including a three-wire photoelectric sensor and a four-wire photoelectric sensor. The three-wire photoelectric sensor includes a photoelectric sensor body and a positive power supply line, a negative power supply line, and an output line connected to the photoelectric sensor body. When the photoelectric sensor body is NPN type, a Schottky diode 2 is connected in series on the negative power supply line, and an array TVS diode 3 is connected in parallel with the positive power supply line, the negative power supply line, and the output line, respectively. When the photoelectric sensor body is PNP type, a Schottky diode 2 is connected in series on the positive power supply line, and an array TVS diode 3 is connected in parallel with the positive power supply line, the negative power supply line, and the output line, respectively.

[0032] The four-wire photoelectric sensor includes a photoelectric sensor body and a positive power supply line, a negative power supply line, a first output line, and a second output line connected to the photoelectric sensor body. When the photoelectric sensor body is NPN type, a Schottky diode 2 is connected in series on the negative power supply line, and an array TVS diode 3 is connected in parallel with the positive power supply line, the negative power supply line, the first output line, and the second output line, respectively. When the photoelectric sensor body is PNP type, a Schottky diode 2 is connected in series on the positive power supply line, and an array TVS diode 3 is connected in parallel with the positive power supply line, the negative power supply line, the first output line, and the second output line, respectively.

[0033] Specifically, this integrated electronic protection device can be used in three-wire and four-wire photoelectric sensors. The main difference lies in the output line. The array TVS diode 3 and Schottky diode 2 are packaged from two wafers and are electrically independent within the device's operating range. When a surge voltage occurs between pins 1, 2, 5, and 6 of the TVS diode, one TVS diode will break down in reverse while the other will conduct in the forward direction. Thus, the clamping voltage between each pin of the TVS diode is the same, providing better protection.

[0034] More specifically, this integrated electronic protection device can be used for three-wire and four-wire interface protection. Two of the TVS diode pins can be connected together to the negative power supply line of the photoelectric sensor. Please refer to [link to details]. Figure 6 and Figure 7 Since three-wire and four-wire products are similar, the following explanation will mainly focus on four-wire products. Please refer to [link / reference needed] for details. Figure 8 and Figure 9 ,exist Figure 8 and Figure 9 As can be seen, there are TVS diodes and power polarity protection between the lines. The four unidirectional TVS diodes and polarized diodes in the dashed box are a single device.

[0035] exist Figure 8In the TVS diode surge protection mechanism, when a positive surge voltage occurs between N+ and N- and exceeds the clamping voltage of the TVS diode, the TVS diode exhibits an avalanche effect. The current discharge path is from A1 through T1, and the diode conducts in the forward direction. If it breaks down in the reverse direction through T2, the diode is in an avalanche effect, reaching point D1 and returning to N-, thus achieving a clamping effect. Similarly, when a reverse surge voltage occurs between N+ and N- and exceeds the clamping voltage of the TVS diode, the TVS diode exhibits an avalanche effect, and the current discharge path is from D1 through T2, and the diode conducts in the forward direction. If it breaks down in the reverse direction through T1, the diode is in an avalanche effect, reaching point A1 and returning to N+, thus achieving a clamping effect. Likewise, surge protection between other lines is similar, i.e., one TVS diode conducts in the forward direction, and the other TVS diode breaks down in the reverse direction, thus achieving a clamping effect.

[0036] Furthermore, there are other alternative solutions to this utility model that can also achieve the purpose of the utility model. The alternative solutions are: 1. Using a similar architecture, but with slight adjustments to the size of the device; 2. Using a similar architecture, but with a change in the diode material; 3. Using a similar architecture, but with adjustments to the positive and negative polarity of the TVS diode; 4. Using a similar architecture, but with a change in the pin order.

[0037] In summary, 1. This utility model has high integration and smaller size, and can be used for interface surge voltage and power polarity protection in miniature photoelectric sensors or photoelectric proximity switches; 2. It also provides surge protection between lines, with relatively low residual voltage; 3. This utility model saves the packaging cost of each discrete component by encapsulating it into a single material, resulting in lower overall cost.

[0038] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit this utility model. All equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

Claims

1. An integrated electronic protection device, comprising a housing (1), characterized in that: The housing (1) contains a Schottky diode (2) and an array TVS diode (3). The array TVS diode (3) includes an N-type semiconductor substrate (301) located inside the housing (1) and four first P-type base regions (302) disposed on the surface of the N-type semiconductor substrate (301). An isolation structure (305) is also disposed on the surface of the N-type semiconductor substrate (301). The four first P-type base regions (302) are isolated from each other by the isolation structure (305). A first anode electrode (303) is disposed on the surface of each of the four first P-type base regions (302). A first metal layer (304) with lead-out pins is disposed on the surface of the first anode electrode (303).

2. The integrated electronic protection device according to claim 1, characterized in that: The housing (1) is also filled with epoxy resin (4), and the Schottky diode (2) and the array TVS tube (3) are isolated by the epoxy resin (4).

3. The integrated electronic protection device according to claim 1, characterized in that: The Schottky diode (2) includes an N-type base region (204) and a second P-type base region (201) located within the housing (1) and interconnected. The surface of the N-type base region (204) is provided with a cathode electrode, and the surface of the cathode electrode is provided with a second metal layer (205) with lead-out pins. The surface of the second P-type base region (201) is provided with a second anode electrode (202), and the surface of the second anode electrode (202) is provided with a third metal layer (203) with lead-out pins.

4. The integrated electronic protection device according to claim 1, characterized in that: The Schottky diode (2) is disposed on the first wafer, and the array TVS diode (3) is disposed on the second wafer. The first wafer and the second wafer are packaged together to form an integrated electronic protection device.

5. A photoelectric sensor employing the integrated electronic protection device as described in any one of claims 1-4, comprising a three-wire photoelectric sensor and a four-wire photoelectric sensor, characterized in that: The three-wire photoelectric sensor includes a photoelectric sensor body and a positive power line, a negative power line, and an output line connected to the photoelectric sensor body; When the photoelectric sensor body is NPN type, the Schottky diode (2) is connected in series on the negative power line, and the array TVS diode (3) is connected in parallel with the positive power line, the negative power line and the output line respectively; when the photoelectric sensor body is PNP type, the Schottky diode (2) is connected in series on the positive power line, and the array TVS diode (3) is connected in parallel with the positive power line, the negative power line and the output line respectively.

6. The photoelectric sensor according to claim 5, characterized in that: The four-wire photoelectric sensor includes a photoelectric sensor body and a positive power line, a negative power line, a first output line, and a second output line connected to the photoelectric sensor body. When the photoelectric sensor body is NPN type, the Schottky diode (2) is connected in series on the negative power line, and the array TVS diode (3) is connected in parallel with the positive power line, the negative power line, the first output line and the second output line respectively; when the photoelectric sensor body is PNP type, the Schottky diode (2) is connected in series on the positive power line, and the array TVS diode (3) is connected in parallel with the positive power line, the negative power line, the first output line and the second output line respectively.

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