A sandwich module integrated structure of a pressure sensitive resistor for lightning protection

Abstract

The application provides a lightning protection varistor sandwich module integrated structure, comprising a substrate, a stacking structure and a package shell; the stacking structure comprises two TVS devices and a metal oxide varistor sandwiched between the two TVS devices; the two TVS devices and the metal oxide varistor are connected together through conductive adhesive, forming a sandwich structure. When lightning or surge voltage is applied, the metal oxide varistor is turned on under high voltage and bears the main voltage, and when the TVS device fails, the module integrated structure does not immediately enter a short circuit state and bears the voltage by the metal oxide varistor; the traditional TVS short circuit failure problem is effectively solved, the area performance efficiency and the voltage resistance are improved, and the package cost is reduced.

Description

Technical Field

[0001] This invention belongs to the field of microelectronic packaging and circuit protection technology, and in particular, it is an integrated structure of a varistor sandwich module for lightning protection. Background Technology

[0002] Electrical surges / transient voltages refer to sudden, random, and excessively high voltages or currents that occur in a circuit, characterized by their short duration and extremely high instantaneous energy. Electrical surges are highly destructive to electronic components and integrated circuits. At best, they can induce malfunctions in logic circuits; at worst, they can cause secondary breakdowns in transistors, latch-up effects in complementary metal-oxide-semiconductor (CMOS) circuits, and other severe thermal effects leading to device or integrated circuit failure. Electrical surges typically originate from two random sources: first, instability in the power grid, such as sudden switching on / off, sudden starting of capacitive or inductive loads, hot-plugging of equipment, and unstable power supply operation; second, sudden external interference, such as lightning strikes and electrostatic discharge.

[0003] Lightning protection technology refers to the protection technology that prevents damage to equipment or its internal critical components caused by direct lightning strikes or electromagnetic pulses from lightning by forming an integrated system of interception, bypassing, and grounding. Surge protection devices (SPDs) are widely used in electronic equipment to prevent damage to circuits from transient overvoltages (such as lightning strikes and electrostatic discharges). Traditional surge protection devices typically use a single type of protective element, such as a TVS (Transient Voltage Suppressor) or a ZnO varistor. These devices each have their advantages and disadvantages: TVS devices have a fast response speed but limited voltage withstand and directly short-circuit upon failure; ZnO varistors have strong current carrying capacity and high voltage withstand, but are not semiconductor technology. To balance voltage withstand, current carrying capacity, and short-circuit failure, existing technologies often use a combination of components; however, this results in low integration, large circuit area, and poor reliability. Summary of the Invention

[0004] To address at least one technical problem in the prior art, embodiments of the present invention provide an integrated structure for a varistor sandwich module for lightning protection. By adding a metal oxide varistor layer between two TVS devices, a sandwich-like sandwich structure is formed, effectively solving the problems of low integration density, high packaging cost, low area performance efficiency, and limited withstand voltage capability of traditional stacked packaging, while improving the reliability and stability of the device. To achieve the above technical objectives, the technical solution adopted by embodiments of the present invention is as follows:

[0005] This invention provides an integrated structure for a varistor sandwich module for lightning protection, comprising:

[0006] A substrate, wherein a substrate anode and a substrate cathode are provided on the substrate;

[0007] A stacked structure is disposed on the substrate; the stacked structure includes a first adhesive layer, a first TVS device cathode, a first TVS device, a first TVS device anode, a second conductive adhesive layer, a metal oxide varistor, a third conductive adhesive layer, a second TVS device cathode, a second TVS device, and a second TVS device anode; the first adhesive layer is coated on the top of the substrate; directly above the first adhesive layer, from bottom to top, are the first TVS device cathode, the first TVS device, and the first TVS device anode; directly above the first TVS device anode, the second conductive adhesive layer is coated, fixing the metal oxide varistor directly above it; through the second conductive adhesive layer, an electrical connection is formed between the first TVS device anode and the metal oxide varistor; the third conductive adhesive layer is coated on the top of the metal oxide varistor, directly above the third conductive adhesive layer, from bottom to top, are the second TVS device cathode, the second TVS device, and the second TVS device anode; through the third conductive adhesive layer, an electrical connection is formed between the second TVS device cathode and the metal oxide varistor;

[0008] The anode wire connects the anode of the second TVS device to the anode of the substrate via the anode wire.

[0009] The cathode wire connects the cathode of the first TVS device to the cathode of the substrate via the cathode wire.

[0010] An encapsulation housing is disposed above the substrate, and encapsulates the stacked structure, anode wire, and cathode wire inside the encapsulation housing.

[0011] Furthermore, the metal oxide varistor is a ZnO varistor, a SnO2 varistor, or a TiO2 varistor.

[0012] Furthermore, the anode wire and the cathode wire are located on both sides of the stacked structure.

[0013] Furthermore, the second and third conductive adhesive layers are silver or copper paste.

[0014] Furthermore, the first TVS device and the second TVS device are transient voltage suppression diodes with a response time of less than 1 nanosecond.

[0015] The beneficial effects of the technical solution provided by the embodiments of the present invention are as follows:

[0016] 1) When lightning strikes or surge voltages are applied, the metal oxide varistor conducts under high voltage and bears the main withstand voltage. When the TVS device fails, the module integrated structure will not immediately enter a short circuit state, but the metal oxide varistor will bear the voltage; effectively solving the short circuit failure problem of traditional TVS.

[0017] 2) Reliable performance: By adding a layer of metal oxide varistor between two TVS devices to form a sandwich-like sandwich structure, the performance of the sandwich structure is superior to that of the traditional stacked packaging structure of the same area and volume in terms of voltage withstand capability and other performance aspects, and the performance is more reliable.

[0018] 3) High integration: Integrating the two devices into one package significantly improves integration and reduces external connections and wiring.

[0019] 4) High area performance efficiency: By optimizing the packaging structure, high area performance efficiency is achieved, making it suitable for space-constrained applications.

[0020] 5) Low packaging cost: Mature packaging technology can be used, which reduces packaging costs and is suitable for large-scale production. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the module integration structure in Embodiment 1 of the present invention.

[0022] Figure 2 This is a schematic diagram of the equivalent circuit in Embodiment 1 of the present invention. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0024] In the description of the embodiments of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0025] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can also refer to the internal connection of two components; and they can refer to a wireless connection or a wired connection. Those skilled in the art can understand the specific meaning of the above terms in the present invention based on the specific circumstances.

[0026] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0027] Example 1, as Figure 1 , Figure 2 As shown;

[0028] Example 1 proposes a varistor sandwich module integrated structure for lightning protection (hereinafter referred to as the module integrated structure), including:

[0029] A substrate 100 is provided with a substrate anode 101 and a substrate cathode 102.

[0030] A stacked structure a is disposed on the substrate 100; the stacked structure a includes a first adhesive layer 103, a first TVS device cathode 104, a first TVS device 105, a first TVS device anode 106, a second conductive adhesive layer 107, a metal oxide varistor 108, a third conductive adhesive layer 109, a second TVS device cathode 110, a second TVS device 111, and a second TVS device anode 112; the first adhesive layer 103 is coated on the top of the substrate 100; directly above the first adhesive layer 103, from bottom to top, are the first TVS device cathode 104, the first TVS device 105, and the first TVS device anode 106; the first TVS device anode 107... A second layer of conductive adhesive 107 is coated directly above the first TVS device 108, fixing the metal oxide varistor 108 to its top. Through the second layer of conductive adhesive 107, an electrical connection is formed between the anode 106 of the first TVS device and the metal oxide varistor 108. A third layer of conductive adhesive 109 is coated directly above the metal oxide varistor 108. Above the third layer of conductive adhesive 109, from bottom to top, are the cathode 110 of the second TVS device, the second TVS device 111, and the anode 112 of the second TVS device. Through the third layer of conductive adhesive 109, an electrical connection is formed between the cathode 110 of the second TVS device and the metal oxide varistor 108.

[0031] Anode wire 113, through which the anode 112 of the second TVS device forms an electrical connection with the substrate anode 101;

[0032] Cathode wire 114, the first TVS device cathode 104 is electrically connected to the substrate cathode 102 through cathode wire 114;

[0033] The encapsulation housing 115 is disposed above the substrate 100, and encapsulates the stacked structure a, the anode wire 113 and the cathode wire 114 inside the encapsulation housing 115.

[0034] The core of the module integration structure proposed in this application lies in using a metal oxide varistor as a sandwich layer in the stacked packaging structure, which effectively reduces the packaging area and cost, while improving the performance, reliability and stability of the device.

[0035] When lightning strikes or surge voltages are applied to the integrated module structure, the combination of TVS device / metal oxide varistor / TVS device exhibits extremely high withstand voltage due to the characteristics of the metal oxide varistor, making it highly suitable for high-voltage, high-power surge protection applications above 200V. Once the entire integrated module structure is turned on, the voltage drop is clamped to a safe value. If the surge energy exceeds the withstand capability of a single TVS device, a traditional structure will directly short-circuit and burn out, or trigger a trip protection. However, the integrated module structure in this application has a stronger overcurrent capability than the TVS due to the metal oxide varistor interlayer. Even if the TVS device breaks down and burns out, the metal oxide varistor interlayer can still maintain a certain withstand voltage, preventing direct short-circuit burnout and thus improving the overall device's resistance to burnout and short circuits.

[0036] Traditional stacked packaging structures require increased TVS device area to increase current capability, thus increasing package area. However, the module integration structure proposed in this application forms a sandwich-style packaging module by adding a metal oxide varistor between two TVS devices. The main withstand voltage is borne by the varistor material, effectively reducing package area and cost, while improving device reliability.

[0037] Furthermore, metal oxide varistors, due to their excellent nonlinear characteristics, can replace the middle multilayer stacking in traditional stacked packaging structures. Introducing metal oxide varistors as a sandwich layer reduces the number of stacking layers, thereby reducing packaging costs. Simultaneously, the excellent nonlinear characteristics and breakdown voltage properties of metal oxide varistors can improve the device's breakdown voltage and other performance characteristics.

[0038] Specifically, the metal oxide varistor 108 is a ZnO varistor.

[0039] More preferably, the anode wire 113 and the cathode wire 114 are located on both sides of the stacked structure a, which can prevent short circuits between them.

[0040] Specifically, the second conductive adhesive layer 107 and the third conductive adhesive layer 109 are silver paste or copper paste, possessing excellent conductivity and adhesion properties. The first adhesive layer 103 can be silver paste or copper paste, or other insulating adhesives.

[0041] Specifically, the first TVS device 105 and the second TVS device 111 are transient voltage suppression diodes with a response time of less than 1 nanosecond, which has the advantage of fast response speed.

[0042] Example 2;

[0043] In Example 2, the metal oxide varistor 108 is a SnO2 varistor; the rest is the same as in Example 1.

[0044] Example 3:

[0045] In Example 3, the metal oxide varistor 108 is a TiO2 varistor; the rest is the same as in Example 1.

[0046] Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A pressure sensitive resistance sandwich module integrated structure for lightning protection, characterized in that, It comprises: a substrate (100) provided with a substrate anode (101) and a substrate cathode (102); a stack structure (a) disposed on the substrate (100); the stack structure (a) comprises a first layer of adhesive (103), a first TVS device cathode (104), a first TVS device (105), a first TVS device anode (106), a second layer of conductive adhesive (107), a metal oxide varistor (108), a third layer of conductive adhesive (109), a second TVS device cathode (110), a second TVS device (111), and a second TVS device anode (112); the first layer of adhesive (103) is coated on the substrate (100); the first TVS device cathode (104), the first TVS device (105), and the first TVS device anode (106) are sequentially arranged from bottom to top on the first layer of adhesive (103); the second layer of conductive adhesive (107) is coated on the first TVS device anode (106), and the metal oxide varistor (108) is fixed on the second layer of conductive adhesive (107); the first TVS device anode (106) and the metal oxide varistor (108) are electrically connected through the second layer of conductive adhesive (107); the third layer of conductive adhesive (109) is coated on the metal oxide varistor (108), and the second TVS device cathode (110), the second TVS device (111), and the second TVS device anode (112) are sequentially arranged from bottom to top on the third layer of conductive adhesive (109); the second TVS device cathode (110) and the metal oxide varistor (108) are electrically connected through the third layer of conductive adhesive (109); an anode lead (113) electrically connects the second TVS device anode (112) and the substrate anode (101); a cathode lead (114) electrically connects the first TVS device cathode (104) and the substrate cathode (102); a packaging shell (115) is disposed on the substrate (100) to encapsulate the stack structure (a), the anode lead (113), and the cathode lead (114) in the packaging shell (115).

2. The metal oxide varistor sandwich module integrated structure for lightning protection according to claim 1, wherein the metal oxide varistor (108) is a ZnO varistor, a SnO2 varistor, or a TiO2 varistor.

3. The metal oxide varistor sandwich module integrated structure for lightning protection according to claim 1, wherein the anode lead (113) and the cathode lead (114) are located on both sides of the stack structure.

4. The metal oxide varistor sandwich module integrated structure for lightning protection according to claim 1, wherein the second layer of conductive adhesive (107) and the third layer of conductive adhesive (109) are silver adhesive or copper adhesive. ​ ​ ​ 5. The structure of claim 1, wherein the first TVS device (105) and the second TVS device (111) are transient voltage suppression diodes with response time less than 1 nanosecond. ​

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