An electrostatic protection structure

Abstract

The present invention provides an electrostatic protection structure comprising an electrostatic protection module and an electrostatic absorption module. The electrostatic protection module comprises a resistor and a TVS diode connected in series, with the other end of the resistor connected to VCC or left floating. The electrostatic absorption module comprises a resistor and a capacitor connected in series. The resistor of the electrostatic absorption module and the resistor of the electrostatic protection module are connected between the resistor of the electrostatic protection module and the TVS diode. The capacitor of the electrostatic absorption module and the TVS diode of the electrostatic protection module are also grounded. The present invention adds an electrostatic absorption circuit to the semiconductor sensor being protected to absorb static electricity and achieve protection for the semiconductor sensor.

Description

Technical Field

[0001] The present invention belongs to the field of chip technology, and in particular relates to an electrostatic protection structure. Background Art

[0002] An IC chip is an integrated circuit formed by placing a large number of microelectronic components on a plastic substrate and then making it into a chip. Nowadays, almost all chips we see can be called IC chips. With the continuous development and progress of science and technology, IC chips have been widely used in various fields of our lives. However, the control module of the IC is easily affected by the static electricity of the incoming current, which in turn affects the performance of the IC chip.

[0003] For half a century, static electricity has caused countless fires, explosions, and other accidents in the electronics industry. In the US electronics industry alone, static electricity costs the industry tens of billions of dollars annually. Therefore, ESD protection plays a vital role in reducing losses, improving quality, and enhancing consumer efficiency.

[0004] With the rapid development and widespread application of conductor technology and the integrated circuit industry, small, highly integrated devices are becoming increasingly popular in the market. This demand has also led to increasingly smaller spacing between conductors and thinner internal oxide films. This has also made devices extremely sensitive to static electricity, so much so that even tiny voltages can break down these electronic devices. However, the static voltage generated by electronic products during production, transportation, storage, and shipping far exceeds their withstand voltage, which can cause device breakdown or failure, affecting product reliability. Therefore, it is imperative to prioritize static electricity protection to fundamentally address this issue.

[0005] In the electronics industry, the impact of electrostatic discharge (ESD) energy on traditional components is not easily perceived. However, for highly densely packed components, where short circuit spacing and small circuit areas result in reduced voltage and current capacity, ESD can often be a fatal threat.

[0006] ESD can also cause more serious problems. Component defects caused by ESD may not be discovered during component testing. If a component failure is discovered during subsequent assembly, rework or replacement costs will increase. Once a component fails in the field, the cost of repairing or replacing it can be over 100 times higher than if the problem had been discovered and resolved during manufacturing. Some electronic components, after ESD damage, only exhibit a degradation of certain performance parameters, but not complete failure, often going undetected without comprehensive testing. For example, an increase in current input levels after ESD damage to a digital integrated circuit is generally undetectable during functional circuit testing. Alternatively, ESD can cause self-healing breakdown or other non-fatal damage, but these effects can accumulate, creating a potential problem that could lead to fatal failure with continued use. These problems are difficult to predict and impossible to screen for in advance.

[0007] In actual use, because the surface of the semiconductor fingerprint sensor is exposed to air, the insulating protective layer used to isolate the human skin surface from the detection electrodes is only a thin protective film. The human body can typically carry static voltages of several thousand volts or even over ten thousand volts (this is particularly common in the dry environment of northern China). Therefore, during the fingerprint acquisition process, static voltage can also couple to the detection electrodes through the inter-plate capacitance, and then conduct through these detection electrodes to the sensor's internal operating circuitry, causing irreversible damage to the semiconductor fingerprint sensor. Therefore, enhancing electrostatic protection is a key consideration for semiconductor fingerprint sensors to enhance their market competitiveness. Summary of the Invention

[0008] In order to solve the problems existing in the prior art, the present invention provides an electrostatic protection structure, which adds an electrostatic absorption circuit to the protected semiconductor sensor to absorb static electricity and protect the semiconductor sensor.

[0009] The electrostatic protection structure provided by the present invention includes an electrostatic protection module and an electrostatic absorption module; the electrostatic protection module includes a resistor and a TVS tube connected in series, and the other end of the resistor is connected to VCC or is left floating; the electrostatic absorption module includes a resistor and a capacitor connected in series; the resistor of the electrostatic absorption module and the resistor of the electrostatic protection module are connected between the resistor of the electrostatic protection module and the TVS tube; the capacitor of the electrostatic absorption module and the TVS tube of the electrostatic protection module are also grounded.

[0010] The semiconductor sensor is connected between the resistor and capacitor of the electrostatic absorption module. The resistor + TVS diode combination functions as both a low-pass filter and a varistor, as well as a series resistor current limiter. The resistor + capacitor combination absorbs a significant amount of energy from the main electrostatic energy spectrum. In the multi-stage protection circuit diagram, when static electricity occurs, an induced overvoltage is introduced at both ends. The resistor + TVS diode combination provides protection, followed by the resistor + capacitor combination. This significantly reduces the induced overvoltage and absorbs a significant amount of energy from the main electrostatic energy spectrum, further reducing the voltage reaching the transceiver and thus protecting the receiver.

[0011] The present invention comprises at least two groups of electrostatic absorption modules, the resistors of adjacent electrostatic absorption modules are connected in series, and the semiconductor sensor is connected between the resistor and the capacitor of the adjacent electrostatic absorption module to increase the absorption of static electricity.

[0012] The present invention includes two sets of ESD protection modules. The ESD absorption module is located between the two sets of ESD protection modules. The resistor of the other ESD protection module is connected between the resistor and capacitor of the adjacent ESD absorption module. The semiconductor sensor is no longer connected in series with the resistor of the ESD absorption module, but is connected between the resistor of the other ESD protection module and the TVS diode, providing further protection for the ESD protection module.

[0013] The present invention also improves the success rate of tip-discharge-induced electrostatic discharge by providing a multi-channel tip discharge module with multiple discharge channels. The multi-channel tip discharge module includes a wire, a discharge tip, and a grounding ring or a grounding cylinder. The discharge tip is connected to the wire, which passes through the center of the grounding ring or the axis of the grounding cylinder. The discharge tip is located within the grounding ring or within a radial ring of the grounding cylinder, with the radial ring parallel to the bottom surface of the grounding cylinder. Multiple discharge channels are formed between the discharge tip and the grounding ring or the grounding cylinder within a 180-degree range of the front end of the discharge tip, significantly improving the success rate of discharge-induced electrostatic discharge.

[0014] The discharge tip of the present invention coincides or nearly coincides with the center of the grounding ring or the axis of the grounding cylinder. The discharge tip corresponds to a radial ring of the grounding ring or the grounding cylinder, and the discharge tip coincides or nearly coincides with the center of the grounding ring or the axis of the grounding cylinder. This ensures that within a 180-degree range in front of the discharge tip, the distance from the free end of the discharge tip to any point on the semicircular arc of the radial ring of the grounding ring or the grounding cylinder is equal or nearly equal. The lengths of the multiple discharge channels formed thereby are all equal or nearly equal, greatly improving the success rate of electrostatic discharge induced by the tip discharge. Since the lengths of the discharge channels are equal or nearly equal, the discharge channels are not empty.

[0015] In order to further increase the number of discharge channels, the radial ring of the grounding ring or the grounding cylinder has multiple discharge tips, and the multiple discharge tips are evenly distributed in the circumferential direction of the radial ring of the grounding ring or the grounding cylinder. The uniform distribution avoids mutual interference between adjacent discharge tips.

[0016] The grounding ring or cylinder of the present invention has multiple discharge tips within its radial ring, evenly distributed around the circumference of the ring or cylinder. This multi-channel tip discharge module, by arranging multiple discharge tips with the shortest distance between the free end of each tip and the radial ring of the grounding ring or cylinder being equal, provides at least multiple discharge channels with equal distances, thereby improving the success rate of tip-induced electrostatic discharge.

[0017] In order to avoid mutual interference between adjacent discharge tips, the discharge tips are evenly distributed in the circumferential direction of the radial ring of the grounding ring or the grounding cylinder.

[0018] The number of the discharge tips is 4-8. Setting 4-8 discharge tips can, on the one hand, ensure the number of discharge channels and improve the discharge success rate; on the other hand, the 4-8 discharge tips can be better distributed in the circumferential direction to avoid mutual interference between adjacent discharge tips.

[0019] The present invention also includes a discharge ring, which is concentric with the grounding ring or the grounding cylinder. The discharge ring is connected to the wire. The discharge tip is arranged on the discharge ring and connected to the wire through the discharge ring. The arrangement of the discharge tip is facilitated by the discharge ring.

[0020] In order to further improve the success rate of electrostatic discharge induced by tip discharge, multiple groups of discharge tips are arranged at intervals along the length direction of the wire.

[0021] To avoid mutual interference, multiple groups of discharge tips are evenly distributed along the length of the wire.

[0022] The present invention utilizes the method of absorbing static electricity and the principle of tip discharge. On the one hand, it adds an electrostatic absorption circuit to the protected semiconductor sensor. On the other hand, it designs a discharge tip on the protective electrode to discharge the electrostatic energy in advance, so as to reduce or prevent the electrostatic voltage from being transmitted to the internal detection circuit via the detection electrode; the semiconductor acquisition device thereby obtains enhanced electrostatic protection capabilities. The discharge tip of the present invention corresponds to the arc of the grounded ring or the grounded cylinder, and multiple discharge channels can be formed between the two, allowing the electrostatic current to discharge from any discharge channel, thereby improving the success rate of electrostatic discharge induced by the tip discharge. The present invention is also configured so that the lengths of the multiple discharge channels are equal or nearly equal, avoiding the virtual channels caused by the distance. The present invention can enhance the electrostatic protection function of the semiconductor fingerprint sensor device, and is easy to produce and implement, with low implementation cost. The present invention can play an electrostatic protection role at a lower cost and in a simpler implementation method. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic structural diagram of a multi-channel tip discharge module of the present invention;

[0024] Figure 2 The distance from the discharge tip to the grounded cylinder Figure 1 ;

[0025] Figure 3 The distance from the discharge tip to the grounded cylinder Figure 2 ;

[0026] Figure 4 This is a schematic diagram of the structure of the composite protection circuit of the present invention;

[0027] In the figure: 1- conductor; 2- insulating shell; 3- ring tip; 4- grounding cylinder; 5- discharge channel; 6- discharge ring. DETAILED DESCRIPTION

[0028] Example 1:

[0029] like Figure 1 As shown, the multi-channel tip discharge module of the present invention includes a conductor 1, to which a plurality of discharge tips are connected. A grounding cylinder 4 is disposed outside the conductor 1, and the conductor 1 passes through the axis of the grounding cylinder 4, with a gap between the discharge tips and the grounding cylinder. The grounding cylinder 4 is encapsulated by an insulating housing 2. The discharge tips overlap or nearly overlap with the axis of the grounding cylinder 4 (electronic components are relatively small, so the discharge tips approximately overlap with the axis of the grounding cylinder 4. The present invention achieves overlap as much as possible). Figure 3As shown, within the 180-degree range of the front end of the discharge tip, the distances from the discharge tip to each point on the arc of the radial ring of the grounding cylinder 4 (parallel to the bottom surface of the grounding cylinder) are equal or nearly equal. This arrangement allows each discharge tip to form a discharge channel 40 with the grounding cylinder 4 (the specific gap between the discharge tip and the grounding cylinder, the discharge channel 40 shown in the figure is not the "line" drawn in the figure), and the distance of each discharge channel is equal. By utilizing this arrangement of the discharge tip corresponding to the grounding cylinder, the discharge path of the electrostatic arc may be within 180° in front of the discharge tip. Due to the increase in discharge channels, the success rate of electrostatic induced discharge is further improved, making it easier for electrostatic current to dissipate through multiple discharge channels, and at the same time, the service life of the discharge tip and the grounding tip can be further improved. From Figure 1 It can be seen that multiple discharge tips are set in the radial ring of the grounded cylinder. Each discharge tip is located in the same radial ring of the grounded cylinder, and the distance between the discharge tip and the radial ring is equal. 4-8 discharge tips can be set, and the discharge tips are evenly distributed in the circumferential direction of the radial circle.

[0030] The present invention can also be configured as follows: multiple discharge tips are set in the same radial ring of the grounding cylinder, and the shortest distances from each discharge tip to the radial ring are equal. In this way, multiple discharge channels with equal distances can be formed, thereby improving the success rate of electrostatic discharge.

[0031] like Figure 1 As shown, several discharge tips can be arranged in the circumferential direction of the grounding cylinder 4, preferably evenly arranged to form a group. At the same time, multiple groups can be arranged along the length direction of the wire 1. The present invention can further improve the grounding cylinder 4. Figure 1 There are three sets of discharge tips, each forming a ring. A new grounding ring can be provided for each ring to replace the grounding cylinder 4. The grounding ring is concentric with the ring formed by the discharge tips. Thus, three new grounding rings are formed outside the three sets of discharge tips. These three new grounding rings replace the grounding cylinder. In other words, the grounding cylinder 4 is divided into several parts. The grounding rings or grounding cylinder 4 are grounded.

[0032] Example 2:

[0033] like Figure 1As shown, the multi-channel tip discharge module provided by the present invention includes a wire 1, and three groups of discharge rings 6 are coupled to the wire 1. The discharge rings 6 are spaced apart in the length direction of the wire 1, preferably evenly spaced. There are several ring tips 3 in the circumferential direction of the discharge ring 6, and the ring tips 3 are preferably evenly arranged on the discharge ring 6. Generally, 4 to 8 discharge tips can be set on the discharge ring 6, and the discharge effect is relatively good, while avoiding mutual interference. The outside of the discharge ring 6 is covered with a grounding cylinder 4, and the axis of the grounding cylinder 4 and the discharge ring 6 coincides with the wire 1. The grounding cylinder 4 is encapsulated with an insulating shell 2. A discharge channel 5 is formed between the ring tip 3 of the discharge ring 6 and the grounding cylinder 4 (the specific gap between the discharge tip and the grounding cylinder, the discharge channel 5 shown in the figure is not the "line" drawn in the figure). As shown Figure 3 As shown, the discharge tip is mounted on a discharge ring and connected to the conductor 1 via the discharge ring. Within a 180-degree radius from the front end of the discharge tip, the distances from the discharge tip to various points on the radial ring of the grounding cylinder 4 (parallel to the bottom surface of the grounding cylinder 4) are not completely equal, meaning that the discharge channels 5 are of varying lengths. By disposing multiple discharge tips on the discharge ring, the shortest distances between each discharge tip and the radial ring are equal, thus forming multiple, equidistant discharge channels and improving the success rate of electrostatic discharge.

[0034] Since electronic components are small in size, the discharge ring can be made as small as possible so that the discharge tip and the axis of the grounding cylinder 4 are nearly coincident. In this way, the distance from the discharge tip to each point of the radial ring is nearly equal, forming several nearly equal discharge channels.

[0035] The present invention can further improve the grounding cylinder 4. Figure 1 There are three sets of discharge rings 6. A new grounding ring can be provided for each discharge ring 6 to replace the grounding cylinder 4. Thus, three new sets of grounding rings are formed outside the three sets of discharge rings. The grounding rings are concentric with the discharge rings 6. These three new sets of grounding rings replace the grounding cylinder. In other words, the grounding cylinder 4 is divided into several parts. The grounding rings or grounding cylinder 4 are grounded.

[0036] Since the route of electrostatic discharge is not entirely straight, it is easy to cause the discharge channel formed by the discharge tip and the grounded part in front to fail, and it is impossible to smoothly guide the static electricity into the ground end to dissipate the static electricity. The discharge tip 3 of the present invention is covered with a grounding ring or a grounding cylinder, and the discharge tip 3 can form multiple discharge paths with the grounding ring or the grounding cylinder; because the discharge ring where the discharge tip 3 is located is concentric with the grounding ring or the grounding cylinder, the discharge channels formed between the discharge tip and the grounding ring within 180° of the front end of the discharge tip 3 are all equidistant, that is, the distance of each discharge path is the same, and the channel will not be virtual due to the distance. Due to the increase in discharge channels, the electrostatic current can be discharged from any discharge channel, thereby improving the success rate of electrostatic discharge induced by tip discharge.

[0037] In the multi-channel tip discharge module provided by the present invention, the discharge ring, discharge tip and grounding cylinder are all made of conductive metal. Figure 1 In the illustrated structure, the left and right ends of wire 1 can be designed as two pins. The left pin is connected to the chip's shielding electrode, and the right pin is grounded. This allows the multi-channel tip discharge module provided by the present invention to be installed as a component on any chip to achieve electrostatic protection. Static electricity is conducted through the wires and discharged from the discharge tips on the discharge ring through the discharge channels.

[0038] Example 3:

[0039] The electrostatic protection structure provided by the present invention includes a multi-channel tip discharge module and a composite protection circuit module.

[0040] The composite protection circuit module includes an electrostatic protection module and an electrostatic absorption module; the electrostatic protection module includes a resistor and a TVS tube connected in series, with the other end of the resistor connected to VCC or left floating; the electrostatic absorption module includes a resistor and a capacitor connected in series; the resistor of the electrostatic absorption module and the resistor of the electrostatic protection module are connected between the resistor of the electrostatic protection module and the TVS tube; the capacitor of the electrostatic absorption module and the TVS tube of the electrostatic protection module are also grounded. The composite protection circuit module of the present invention includes at least two groups of electrostatic absorption modules, with the resistors of adjacent electrostatic absorption modules connected in series. The composite protection circuit module of the present invention includes two groups of electrostatic protection modules, with the electrostatic absorption module located between the two groups of electrostatic protection modules, and the resistor of the other group of electrostatic protection modules connected between the resistor and capacitor of the adjacent electrostatic absorption module.

[0041] like Figure 4As shown, the composite protection circuit module includes two sets of electrostatic protection modules and two sets of electrostatic absorption modules. The electrostatic protection module on the left includes a resistor R1 and a TVS diode TVS1 connected in series. The other end of resistor R1 is left floating or connected to VCC, and TVS1 is also connected to ground. The electrostatic absorption module on the left includes a resistor R2 and a capacitor C1 connected in series. The other end of resistor R2 is connected between resistor R1 and TVS1, and the other end of capacitor C1 is connected to ground. The electrostatic absorption module on the right includes a resistor R3 and a capacitor R2 connected in series. The other end of resistor R3 is connected between resistor R2 and capacitor C1, and the other end of capacitor C2 is connected to ground. The electrostatic protection module on the right includes a resistor R4 and a TVS diode TVS2 connected in series. The other end of resistor R4 is connected between resistor R3 and capacitor C2, and TVS2 is also connected to ground. The semiconductor fingerprint sensor is connected between resistor R4 and TVS2.

[0042] The composite protection circuit module of the present invention includes a resistor + TVS diode combination and a resistor + capacitor combination. A transient voltage suppressor (TVS) is a solid-state diode specifically designed to protect sensitive semiconductor devices from ESD transient voltage damage. Compared to traditional voltage regulator diodes, TVS diodes have a larger P / N junction area. This structural improvement gives the TVS greater high-voltage withstand capability and reduces the voltage cutoff rate, thus providing better protection for low-voltage circuits. The resistor + TVS diode combination functions as both a low-pass filter and a varistor, as well as current limiting with a series resistor, making it a highly cost-effective protection method. The resistor + capacitor combination can significantly absorb energy from the main electrostatic energy spectrum. In the multi-stage protection circuit, when static electricity occurs, an induced overvoltage is introduced at both ends. R1 and TVS1 provide protection, followed by current limiting by resistors R2 and R3, and filtering by C1 and C2. This absorbs a significant amount of energy from the main electrostatic energy spectrum, further reducing the voltage reaching the transceiver. The voltage then passes through R4 and TVS2 for protection, significantly reducing the induced overvoltage, thereby protecting the transceiver.

Claims

1. An electrostatic protection structure, characterized in that: It includes two groups of electrostatic protection modules, two groups of electrostatic absorption modules and a multi-channel tip discharge module; the two groups of electrostatic absorption modules are located between the two groups of electrostatic protection modules; the electrostatic protection modules include resistors and TVS tubes connected in series, and the electrostatic absorption modules include resistors and capacitors connected in series; wherein the resistor input of the first group of electrostatic protection modules is connected to VCC, and the output is connected to the resistor input of the first group of electrostatic absorption modules, the resistor output of the first group of electrostatic absorption modules is connected to the resistor input of the second group of electrostatic absorption modules, and the resistor output of the second group of electrostatic absorption modules is connected to the resistor input of the second group of electrostatic protection modules; the capacitors of all the electrostatic absorption modules and the TVS tube outputs of the electrostatic protection modules are also grounded; The multi-channel tip discharge module includes a wire, a discharge tip, and a grounding ring or a grounding cylinder; the discharge tip is connected to the wire, and the wire passes through the center of the grounding ring or the axis of the grounding cylinder; the discharge tip is located within the grounding ring or within a radial ring of the grounding cylinder, and the radial ring is parallel to the bottom surface of the grounding cylinder; The discharge tip coincides with or nearly coincides with the center of the grounding ring or the axis of the grounding cylinder; or, the device comprises at least two discharge tips, the shortest distances between the free ends of the discharge tips and the radial rings of the grounding ring or the grounding cylinder being equal; and further comprises a discharge ring, the discharge ring being concentric with the grounding ring or the grounding cylinder, the discharge ring being connected to a wire, the discharge tip being disposed on the discharge ring, and the discharge tip being connected to the wire via the discharge ring; A plurality of discharge tips are arranged at intervals along the length direction of the wire; Multiple groups of discharge tips are evenly distributed along the length direction of the wire; The number of the discharge tips is 4-8.

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