Plastic package patch type ceramic piezoresistor

Abstract

The utility model relates to the related technical field of piezoresistors, in particular to a plastic package patch type ceramic piezoresistor which comprises a substrate, an electrode plate is connected to the surface of the substrate, a heat-conducting glue layer is arranged on the surface of the electrode plate, a ceramic shell is arranged outside the substrate, a protective layer is arranged above the ceramic shell, and the protective layer is arranged on the surface of the substrate. The side edge of the ceramic shell is connected with a heat conduction pipe, a heat conduction piece is attached to the upper portion of the heat conduction pipe, fixing bolts penetrate through the surface of the protection layer and the surface of the heat conduction piece, a buffering assembly is arranged at the bottom of the ceramic shell, and a welding block is arranged at the bottom of the buffering assembly. According to the plastic package patch type ceramic varistor, through the arrangement of the guide groove and the damping block, accurate control over damping force is achieved, the damping block is made of a high-friction-coefficient material and is in interference fit with the guide groove to generate stable damping force, the reset speed of the buffer rod is reduced, vibration rebound is effectively restrained, impact energy is converted into heat energy to be dissipated, and the service life of the buffer rod is prolonged. The damping efficiency is improved.

Description

Technical Field

[0001] This utility model relates to the field of varistor technology, and in particular to a plastic-encapsulated chip ceramic varistor. Background Technology

[0002] A varistor is a non-linear resistive element that is sensitive to voltage. Its resistance value changes significantly with the voltage across its terminals. In the context of the rapid miniaturization and integration of modern electronic devices and the ever-increasing demands for overvoltage protection, there is a particular need for a molded surface-mount ceramic varistor. Its surface-mount packaging achieves a small size and standardized dimensions, meeting the needs of high-density circuit board layouts and automated production, thus saving significant space. Using zinc oxide ceramic as its core material, it possesses nanosecond-level ultra-fast response speed and excellent overvoltage suppression capabilities, effectively protecting sensitive chips. The added molding layer provides electrical insulation, mechanical protection, and environmental adaptability, enabling stable operation under harsh conditions such as humidity and vibration. Therefore, it has become a key component in consumer electronics, communication equipment, automotive electronics, and other fields to ensure circuit safety and reliable equipment operation. Hence, there is a particular need for a molded surface-mount ceramic varistor.

[0003] However, existing molded surface-mount ceramic varistors still have significant shortcomings in terms of shock resistance. Their ceramic body material has high hardness but poor toughness. Under high-frequency vibration or impact environments, stress concentration can easily cause internal ceramic body cracking or electrode detachment. There is a difference in the coefficient of thermal expansion between the molding layer and the ceramic body. Long-term vibration will aggravate interface delamination and cause electrical connection failure. Utility Model Content

[0004] The purpose of this invention is to provide a molded surface mount ceramic varistor with a buffer component at the bottom of the ceramic housing, which solves the problem that existing molded surface mount ceramic varistors are insufficient in shock resistance and affect the electrical connection effect.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a molded surface-mount ceramic varistor, comprising a substrate, an electrode plate connected to the surface of the substrate, a thermally conductive adhesive layer disposed on the surface of the electrode plate, a heat sink connected to the surface of the thermally conductive adhesive layer, heat dissipation grooves formed on the surface of the heat sink, a ceramic shell disposed outside the substrate, a protective layer disposed on top of the ceramic shell, a heat-conducting pipe connected to the side of the ceramic shell, a heat-conducting sheet attached above the heat-conducting pipe, fixing pins penetrating the surfaces of the protective layer and the heat-conducting sheet, a buffer assembly disposed at the bottom of the ceramic shell, and a solder block disposed at the bottom of the buffer assembly;

[0006] The buffer assembly includes a buffer seat that is slidably connected to a ceramic shell. A buffer groove is formed inside the buffer seat, and a buffer plate is slidably connected inside the buffer groove. The top of the buffer plate is fixedly connected to the bottom of the ceramic shell. A sliding groove is formed on the bottom side of the buffer groove, and a slider is slidably connected inside the sliding groove. Connectors are fixedly connected to the bottom of the buffer plate and the top of the slider. A supporting inclined rod is connected to the surface of the connecting member. A sleeve is connected to the bottom of the buffer plate, and a limit groove is formed inside the sleeve. A guide groove is formed on the inner side of the limit groove. A limit plate is slidably connected inside the limit groove. A damping block is connected to the side of the limit plate. A buffer spring is connected above the limit plate, and a buffer rod is connected to the bottom of the limit plate. A buffer pad is connected to the bottom of the buffer rod.

[0007] Preferably, the electrode plate has two identical sets on the surface of the substrate and is respectively connected to the upper and lower sides of the substrate.

[0008] Preferably, the heat dissipation grooves are formed in multiple sets on the surface of the heat dissipation plate, and the heat dissipation grooves in each set are distributed at equal intervals.

[0009] Preferably, the heat-conducting pipes are distributed in multiple groups at equal intervals on the surface of the ceramic shell, and the heat-conducting sheets are distributed in two groups symmetrically about the central axis of the protective layer.

[0010] Preferably, the heat-conducting sheet is fixedly connected to the protective layer by fixing bolts, and multiple sets of fixing bolts are provided on the surface of the heat-conducting sheet.

[0011] Preferably, the ceramic shell slides up and down inside the buffer seat via a buffer plate and a buffer groove, and the outer wall size of the slider matches the inner wall size of the groove.

[0012] Preferably, the limiting plate slides inside the limiting groove via a damping block and a guide groove, and the size of the damping block is adapted to the size of the guide groove.

[0013] Compared with the prior art, the beneficial effects of this utility model are:

[0014] 1. This type of molded surface mount ceramic varistor, through the arrangement of a buffer seat, buffer groove, buffer plate, slide groove, slider, connector, and support rod, forms a multi-level buffer structure through the coordinated action of these components when the molded surface mount ceramic varistor is subjected to external vibration or impact. The vertical sliding of the buffer plate in the buffer groove, combined with the horizontal displacement of the slider in the slide groove, decomposes the impact force into multi-directional components. The linkage mechanism formed by the support rod and connector further converts the linear impact force into rotational torque, dissipating energy through structural deformation. At the same time, the precise fit between the slider and the slide groove provides stable guidance, preventing lateral offset or jamming during the buffering process, ensuring the smoothness and reliability of the buffering action, and enabling the ceramic varistor to maintain stable electrical connection even in environments with high vibration acceleration. This significantly improves the applicability of the component in high vibration scenarios such as aerospace and automotive electronics.

[0015] 2. This type of molded surface-mount ceramic varistor achieves precise control of damping force through the setting of guide groove and damping block. The damping block is made of high friction coefficient material, and the interference fit with the guide groove generates stable damping force, which slows down the reset speed of the buffer rod, effectively suppresses vibration rebound, converts impact energy into heat energy dissipation, and improves vibration reduction efficiency. Attached Figure Description

[0016] Figure 1 This is a side view of the structure of the present utility model;

[0017] Figure 2 This is a schematic diagram of the structure of the electrode plate, thermally conductive adhesive layer and heat sink of this utility model.

[0018] Figure 3 This is a schematic diagram of the buffer component structure of this utility model;

[0019] Figure 4 This is a schematic diagram of the structure of the sleeve and buffer rod of this utility model.

[0020] In the diagram: 1. Substrate; 2. Electrode plate; 3. Thermally conductive adhesive layer; 4. Heat sink plate; 5. Heat dissipation groove; 6. Ceramic shell; 7. Protective layer; 8. Heat pipe; 9. Heat-conducting sheet; 10. Fixing bolt; 11. Buffer assembly; 1101. Buffer seat; 1102. Buffer groove; 1103. Buffer plate; 1104. Slide groove; 1105. Slider; 1106. Connector; 1107. Supporting diagonal rod; 1108. Sleeve; 1109. Limiting groove; 1110. Guide groove; 1111. Limiting plate; 1112. Damping block; 1113. Buffer spring; 1114. Buffer rod; 1115. Buffer pad; 12. Weld block. Detailed Implementation

[0021] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0022] Please see Figure 1-4 This utility model provides a technical solution: a plastic-encapsulated surface-mount ceramic varistor, including a substrate 1, an electrode plate 2 connected to the surface of the substrate 1, a thermally conductive adhesive layer 3 disposed on the surface of the electrode plate 2, a heat sink 4 connected to the surface of the thermally conductive adhesive layer 3, heat sink grooves 5 formed on the surface of the heat sink 4, a ceramic shell 6 disposed outside the substrate 1, a protective layer 7 disposed on the top of the ceramic shell 6, a heat-conducting pipe 8 connected to the side of the ceramic shell 6, a heat-conducting sheet 9 attached above the heat-conducting pipe 8, fixing bolts 10 penetrating the surfaces of the protective layer 7 and the heat-conducting sheet 9, a buffer assembly 11 disposed at the bottom of the ceramic shell 6, and a solder block 12 disposed at the bottom of the buffer assembly 11;

[0023] The buffer assembly 11 includes a buffer seat 1101, which is slidably connected to the ceramic shell 6. A buffer groove 1102 is formed inside the buffer seat 1101, and a buffer plate 1103 is slidably connected inside the buffer groove 1102. The top of the buffer plate 1103 is fixedly connected to the bottom of the ceramic shell 6. A sliding groove 1104 is formed on the bottom side of the buffer groove 1102, and a slider 1105 is slidably connected inside the sliding groove 1104. Connectors 1106 are fixedly connected to the bottom of the buffer plate 1103 and the top of the slider 1105. A support rod 1107 is connected to the surface of the connector 1106. A sleeve 1108 is connected to the bottom of plate 1103. A limiting groove 1109 is formed inside the sleeve 1108, and a guide groove 1110 is formed on the inner side of the limiting groove 1109. A limiting plate 1111 is slidably connected inside the limiting groove 1109. A damping block 1112 is connected to the side of the limiting plate 1111. A buffer spring 1113 is connected above the limiting plate 1111. A buffer rod 1114 is connected to the bottom of the limiting plate 1111, and a buffer pad 1115 is connected to the bottom of the buffer rod 1114. Through the setting of the buffer assembly 11, when the plastic-encapsulated surface-mount ceramic varistor is subjected to external vibration or impact, the buffer assembly... Component 11 achieves efficient vibration reduction through the synergistic effect of multiple structures. The impact force transmitted by the ceramic shell 6 first acts on the buffer plate 1103, causing it to slide downward in the buffer groove 1102, which in turn drives the slider 1105 to move horizontally in the slide groove 1104. At this time, the linkage mechanism formed by the connecting component 1106 and the supporting inclined rod 1107 converts the vertical impact force into horizontal and oblique components through angle changes, dispersing the impact force while consuming some vibration energy. The limiting plate 1111 in the sleeve 1108 is squeezed by the buffer plate 1103, compressing the buffer spring 1113. The spring absorbs vibration energy and converts it into elasticity through elastic deformation. Potential energy is generated by the damping blocks 1112 on both sides of the limiting plate 1111 closely fitting with the guide groove 1110, generating frictional damping during sliding, further dissipating vibration kinetic energy. The buffer pad 1115 at the lower end of the buffer rod 1114 is made of highly elastic rubber material, which buffers residual impact force through its own deformation to avoid rigid collision. When the vibration weakens, the buffer spring 1113 restores its deformation and pushes the limiting plate 1111 to reset, driving the buffer plate 1103 and the slider 1105 back to their initial positions, so that the entire buffer assembly is ready for the next impact, thereby ensuring the structural stability and reliable performance of the ceramic varistor in complex vibration environments.

[0024] Furthermore, two identical sets of electrode plates 2 are provided on the surface of the substrate 1 and are respectively connected to the upper and lower sides of the substrate 1. Through the setting of electrode plates 2, a stable electrical connection between the varistor and the external circuit is realized. The symmetrical distribution structure ensures uniform current conduction and avoids local overheating or poor contact caused by single-point connection. At the same time, it enhances mechanical stability and enables the component to maintain reliable electrical performance under high-frequency vibration environment.

[0025] Furthermore, multiple sets of heat sinks 5 are formed on the surface of the heat sink 4, and each set of heat sinks 5 is evenly distributed. Through the arrangement of the heat sink 4 and the heat sinks 5, the heat dissipation area is significantly expanded. The evenly distributed heat sinks form an efficient heat conduction channel, which allows the heat generated by the varistor during operation to be quickly diffused to the surrounding environment, effectively reducing the component temperature, extending the service life and improving the surge resistance.

[0026] Furthermore, multiple sets of heat pipes 8 are evenly distributed on the surface of the ceramic shell 6, and two sets of heat-conducting plates 9 are symmetrically distributed around the central axis of the protective layer 7. Through the arrangement of heat pipes 8 and heat-conducting plates 9, a three-dimensional heat dissipation network is constructed. The heat pipes 8 conduct heat from inside the ceramic shell vertically to the protective layer 7, while the symmetrically distributed heat-conducting plates 9 diffuse heat laterally, forming a heat dissipation system that combines "point-line-surface", reducing thermal resistance by 30%, greatly improving heat dissipation efficiency, and ensuring that the varistor works stably under high power conditions.

[0027] Furthermore, the heat-conducting sheet 9 is fixedly connected to the protective layer 7 by the fixing bolts 10, and multiple sets of fixing bolts 10 are provided on the surface of the heat-conducting sheet 9. Through the setting of fixing bolts 10, a rigid connection between the heat-conducting sheet 9 and the protective layer 7 is achieved. The multiple sets of fixing bolts are evenly distributed, ensuring the connection strength while eliminating the interface thermal resistance, making the heat conduction smoother, and effectively resisting the loosening caused by vibration, thus ensuring long-term reliability.

[0028] Furthermore, the ceramic shell 6 slides up and down inside the buffer seat 1101 via the buffer plate 1103 and the buffer groove 1102. The outer wall size of the slider 1105 matches the inner wall size of the groove 1104. Through the arrangement of the buffer groove 1102, the buffer plate 1103, the groove 1104 and the slider 1105, a precise guiding effect is formed, so that the vertical displacement accuracy of the ceramic shell 6 is controlled within a certain range, ensuring that there is no jamming during the buffering process. At the same time, the tight cooperation between the slider and the groove restricts lateral swaying and improves the shock resistance stability.

[0029] Furthermore, the limiting plate 1111 slides within the limiting groove 1109 via the damping block 1112 and the guide groove 1110. The size of the damping block 1112 is adapted to the size of the guide groove 1110. Through the arrangement of the guide groove 1110 and the damping block 1112, precise control of the damping force is achieved. The damping block 1112 is made of a high-friction coefficient material, and its interference fit with the guide groove 1110 generates a stable damping force, which slows down the reset speed of the buffer rod 1114, effectively suppresses vibration rebound, converts impact energy into heat energy dissipation, and improves vibration reduction efficiency.

[0030] Working principle: Two sets of electrode plates 2 on the substrate 1 are symmetrically distributed vertically and welded to the external circuit through solder blocks 12 to form a stable current path. When a surge voltage occurs in the circuit, the ceramic varistor material on the substrate 1 responds rapidly, and the resistance value drops sharply to discharge the current and suppress overvoltage. The thermally conductive adhesive layer 3 conducts the heat generated by the electrode plates 2 to the heat sink 4. The heat sink 5 with equal spacing on its surface expands the heat dissipation area. Together with the heat pipes 8 on the side of the ceramic shell 6 and the heat-conducting plate 9 on the top, a three-dimensional heat dissipation network is formed. The heat is conducted vertically to the protective layer 7 through the heat pipes 8 and diffused horizontally through the heat-conducting plate 9. The fixing bolts 10 ensure that the heat-conducting plate 9 and the protective layer 7 are tightly connected, reducing contact thermal resistance and rapidly reducing the component temperature. When the equipment is subjected to vibration or impact, the cushioning at the bottom of the ceramic shell 6... When the impact assembly 11 is activated, the buffer plate 1103 slides within the buffer groove 1102. The impact force is dispersed by the linkage mechanism between the connector 1106 and the supporting inclined rod 1107. The buffer spring 1113 in the sleeve 1108 absorbs energy through elastic deformation. The friction damping of the damping block 1112 and the guide groove 1110 dissipates kinetic energy. The buffer pad 1115 further buffers the residual impact. The precisely matched slide groove 1104 and slider 1105, and the guide groove 1110 and limit plate 1111 ensure a smooth and non-displaced buffering process. Ultimately, overvoltage protection, efficient heat dissipation, and structural reliability under complex vibration environments are achieved, ensuring stable operation of the component under high-frequency surge, high temperature, and strong vibration scenarios. This completes the application process of a plastic-encapsulated surface-mount ceramic varistor.

[0031] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A molded surface-mount ceramic varistor, comprising a substrate (1), characterized in that: An electrode plate (2) is connected to the surface of the substrate (1). A thermally conductive adhesive layer (3) is provided on the surface of the electrode plate (2). A heat sink (4) is connected to the surface of the thermally conductive adhesive layer (3). A heat sink groove (5) is opened on the surface of the heat sink (4). A ceramic shell (6) is provided on the outside of the substrate (1). A protective layer (7) is provided on the top of the ceramic shell (6). A heat pipe (8) is connected to the side of the ceramic shell (6). A heat-conducting sheet (9) is attached to the top of the heat pipe (8). Fixing bolts (10) penetrate the surfaces of the protective layer (7) and the heat-conducting sheet (9). A buffer assembly (11) is provided at the bottom of the ceramic shell (6). A solder block (12) is provided at the bottom of the buffer assembly (11). The buffer assembly (11) includes a buffer seat (1101), which is slidably connected to the ceramic shell (6). A buffer groove (1102) is provided inside the buffer seat (1101), and a buffer plate (1103) is slidably connected inside the buffer groove (1102). The top of the buffer plate (1103) is fixedly connected to the bottom of the ceramic shell (6). A sliding groove (1104) is provided on the bottom side of the buffer groove (1102), and a slider (1105) is slidably connected inside the sliding groove (1104). Connectors (1106) are fixedly connected to the bottom of the buffer plate (1103) and the top of the slider (1105). 106) is connected to a support diagonal rod (1107) on its surface. The bottom of the buffer plate (1103) is connected to a sleeve (1108). The sleeve (1108) has a limiting groove (1109) inside. The limiting groove (1109) has a guide groove (1110) on its inner side. The limiting groove (1109) has a limiting plate (1111) slidably connected inside. The limiting plate (1111) has a damping block (1112) connected to its side. The limiting plate (1111) has a buffer spring (1113) connected to its top. The limiting plate (1111) has a buffer rod (1114) connected to its bottom. The buffer rod (1114) has a buffer pad (1115) connected to its bottom.

2. The molded surface mount ceramic varistor according to claim 1, characterized in that: The electrode plate (2) has two identical sets on the surface of the substrate (1) and is respectively connected to the upper and lower sides of the substrate (1).

3. The molded surface mount ceramic varistor according to claim 1, characterized in that: The heat dissipation grooves (5) are formed on the surface of the heat dissipation plate (4) in multiple groups, and the heat dissipation grooves (5) are distributed at equal intervals between each group.

4. The molded surface mount ceramic varistor according to claim 1, characterized in that: The heat pipes (8) are distributed in multiple sets at equal intervals on the surface of the ceramic shell (6), and the heat-conducting sheets (9) are distributed in two sets symmetrically about the central axis of the protective layer (7).

5. A molded surface-mount ceramic varistor according to claim 1, characterized in that: The heat-conducting sheet (9) is fixedly connected to the protective layer (7) by a fixing bolt (10), and multiple sets of fixing bolts (10) are provided on the surface of the heat-conducting sheet (9).

6. A molded surface-mount ceramic varistor according to claim 1, characterized in that: The ceramic shell (6) slides up and down inside the buffer seat (1101) via the buffer plate (1103) and the buffer groove (1102). The outer wall size of the slider (1105) matches the inner wall size of the groove (1104).

7. A molded surface-mount ceramic varistor according to claim 1, characterized in that: The limiting plate (1111) slides inside the limiting groove (1109) via the damping block (1112) and the guide groove (1110), and the size of the damping block (1112) is adapted to the size of the guide groove (1110).

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