Chip zinc oxide piezoresistor

Abstract

The utility model discloses a surface-mounted zinc oxide varistor, which relates to the technical field of varistors and comprises a pressure-sensitive ceramic chip, solder mask layers can be arranged on the periphery of the pressure-sensitive ceramic chip, and electrodes are arranged on two sides of the pressure-sensitive ceramic chip. According to the utility model, low-gradient zinc oxide powder is configured; preparing powder, mixing and grinding the prepared powder, mixing the ground mixture with ZnO, grinding, adding glue, and spray-drying to obtain zinc oxide pressure-sensitive ceramic powder; the preparation method comprises the following steps: preparing a pressure-sensitive ceramic chip, pressing a green body, pre-discharging glue from the green body, sintering to form the pressure-sensitive ceramic chip, and preparing electrodes: taking 80% of silver paste, and respectively printing the electrodes at two ends of the pressure-sensitive ceramic chip in the length direction; after drying, sintering silver in a silver sintering furnace; and finally, taking the yellow UV photocuring ink corresponding to the K, respectively printing on two sides in the height direction, and performing UV photocuring to obtain a sample, the device adopts a fixed length, is convenient for PCB welding spot layout, is free of lead wires, is accurate and controllable in size, and is convenient for low-cost large-scale production.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of patch zinc oxide varistors. BACKGROUND

[0002] At present, most of the lighting devices use LED lamp beads, which have relatively poor resistance to surge impact in the circuit and need surge protection. Due to the conductivity of the heat dissipation aluminum substrate, plug-in components are not suitable. The surge protection varistors currently in use all use patch packaging, which facilitates mass production of LED lamp heads.

[0003] However, in the prior art, Chinese patents CN202211338129.4, CN201610472205.9, CN201510955379.6, and CN201010580937.2 disclose multilayer varistors and their manufacturing methods, which use a multilayer ceramic capacitor process, use a casting machine to cast, print internal electrodes, isostatic pressing, layering cutting, pre-gluing, atmosphere sintering, electrode connection, and nickel and tin plating processes. On the one hand, the production equipment investment is large, and the equipment requirements are high. On the other hand, due to the thickness limitation between layers, it is suitable for voltage protection of 5V-100V rated voltage. When a surge impact occurs, the uneven heat of the multilayer structure can easily cause cracking failure. For example, Chinese patent CN202010966184.2 discloses a traditional plug-in assembly, coating flattening treatment, and horizontal mounting scheme. Chinese patent CN201820356800.0 discloses a matrix varistor patch packaging scheme, and Chinese patent CN201711165632.3 discloses an embedded varistor flat packaging scheme. Both use traditional varistor chips, which are welded through leads or frames, with the surface electrode parallel to the PCB board, flat packaging, and SMD patching. However, the structure is relatively complex, the lead processing size consistency is poor, the production control is difficult, and the chip flat packaging occupies more PCB board area. For example, Chinese patent CN201822145675.1 discloses a series structure varistor patch scheme, which uses two varistors in series. However, the distance between the two varistors is small, which can easily cause air breakdown, limiting the application of the product.

[0004] Therefore, it is urgent for those skilled in the art to provide a patch zinc oxide varistor. UTILITY MODEL CONTENT

[0005] The purpose of the utility model is to provide a chip zinc oxide varistor to solve the problems of large investment in production equipment, high equipment requirements, easy crack failure caused by heat imbalance, relatively complex structure, poor consistency of lead processing dimensions, difficult production control, flat chip packaging, superimposed leads and packaging layers, occupying a large area of ​​PCB board; small spacing between two pressure-sensitive electrodes, easy air breakdown, resulting in limited product application.

[0006] To achieve the above-mentioned purpose, the present invention specifically provides the following technical solutions: a chip zinc oxide varistor, comprising a varistor ceramic, wherein a solder resist layer can be provided on all four sides of the varistor ceramic, and electrodes are provided on both sides of the varistor ceramic, wherein the electrodes are made by printing and sputtering, and the solder resist layer is fixed to both sides of the varistor ceramic by coating, and the coating method includes electroplating, brush plating, chemical plating, physical vapor deposition, chemical vapor deposition, thermal spraying, surfacing, laser beam and electron beam surface cladding, and hot dip plating, and the solder resist layer is made of UV light-curing ink with different colorants, and the UV light-curing ink refers to an ink that uses ultraviolet light of different wavelengths and energies under ultraviolet irradiation to polymerize monomers in the ink binder into polymers until the ink forms a film and dries.

[0007] As a further solution of the present invention: the pressure-sensitive ceramic piece has a length of 2.5-5 mm, a width of 1.5-3.5 mm, and a height of 1-3 mm.

[0008] As a further solution of the present invention: the electrode is fully coated on the edge of the pressure-sensitive ceramic sheet.

[0009] Compared with the prior art, the beneficial effects of the present invention are:

[0010] 1. The rectangular pressure-sensitive ceramic piece is convenient for the nozzle of the placement machine to absorb and is not easy to roll;

[0011] 2. Electrodes without margins are provided at both ends of the length direction of the pressure-sensitive ceramic to facilitate contact between the electrodes and the solder paste to achieve reflow soldering;

[0012] 3. The setting of solder mask can effectively prevent solder paste from contaminating the lower side of the porcelain body, resulting in a drop in varistor voltage and side flashover during surge impact.

[0013] 4. Different colors of solder resist can effectively distinguish the varistor voltage specifications;

[0014] 5. No leads, no secondary processing leads, simple structure, and precise size control. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The main view of this utility model Figure 1 ;

[0016] Figure 2 is a side view of the utility model Figure 1 ;

[0017] Figure 3 is a side view of the utility model Figure 1 ;

[0018] Figure 4 is a side view of the utility model Figure 2 ;

[0019] Figure 5 is a side view of the utility model Figure 2 ;

[0020] Figure 6 is a side view of the utility model Figure 2 .

[0021] In the figure: 1, pressure-sensitive porcelain piece; 2, electrode; 3, solder resist layer. DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the utility model will be apparently and completely described below with reference to the drawings in the embodiments of the utility model. Apparently, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all the other embodiments obtained by the person skilled in the art without creative labor fall within the protection scope of the utility model.

[0023] In the description of the utility model, it should be explained that the orientation or position relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like is the orientation or position relationship based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the utility model. In addition, the terms "first", "second", "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance. In the description of the utility model, it should be explained that, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connecting", "setting" should be understood in a broad sense, for example, can be fixedly connected, or can be detachably connected, or integrally connected; can be mechanically connected, or can be electrically connected; can be directly connected, or can be indirectly connected through an intermediate medium, or can be the communication inside two elements. For the person skilled in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances. The embodiments will be described below according to the overall structure of the utility model.

[0024] Please refer to Figures 1-6The utility model discloses an embodiment of a kind of patch zinc oxide voltage-dependent resistor, including voltage-dependent porcelain piece 1, voltage-dependent porcelain piece 1 It can be equipped with solder resist layer 3 around, both sides of voltage-dependent porcelain piece 1 It is equipped with electrode 2, electrode 2 It is made by printing and sputtering method, solder resist layer 3 It is fixed with both sides of voltage-dependent porcelain piece 1 By coating, coating mainly includes electroplating, electrobrush plating, chemical plating, physical vapor deposition, chemical vapor deposition, thermal spraying, surfacing, laser beam or electron beam surface cladding, hot dip galvanizing, solder resist layer 3 It is made by different colorant UV light curing ink, UV ink refers to under ultraviolet irradiation, using different wavelength and energy ultraviolet light makes monomer in ink connecting material polymerize into polymer, makes the film and dry ink of ink.

[0025] Please refer to Figure 1 、 2 , 3, 4, 5 and 6, the length of voltage-dependent porcelain piece 1 It is 2.5-5mm, width 1.5-3.5mm, height 1-3mm, rectangular cuboid voltage-dependent porcelain piece, convenient suction nozzle of patch machine adsorption, and not easy to roll.

[0026] Please refer to Figure 1 、 2 , 3, 4, 5 and 6, electrode 2 It is full of coating on the edge of voltage-dependent porcelain piece 1, it is convenient for electrode to contact with tin paste to realize reflow soldering.

[0027] The utility model discloses a manufacturing principle is: configuration low gradient zinc oxide powder;Preparation gradient G=140V / mm powder;Take ZnO, Bi2O3, Co3O4, Sb2O3, MnCO3, Ni2O3, B2O3, CuO, Al2O3 Powder, Bi2O3, Co3O4, Sb2O3, MnCO3, Ni2O3, B2O3, CuO, Al2O3 Powder is mixed and grinds, then after grinding the mixture is mixed with ZnO and grinds, after adding glue spray drying and preparing zinc oxide voltage-dependent porcelain powder;Press green body: the size of mould is 4.1x2.9R0.1mm, on dry press machine platform, press green body piece, thickness is 2.36mm, tablet density e: 3.4g / cm 3 ;Glue is discharged and is burned: after pre-dispensing glue, green body piece is burned, and voltage-dependent porcelain piece 1 is formed;At this time, in muffle furnace, pre-dispensing glue is carried out for 3 hours under 560 ° temperature, and then burned for 4.5 hours under 1185 ° temperature, and the size of voltage-dependent porcelain piece 1 It is 3.5x2.5x2.0mm;Then make electrode 2: take 80% silver paste, and print 2.0x2.0mm electrode 2 on the length direction both ends of voltage-dependent porcelain piece 1 respectively;After drying, silver furnace is burned silver;Finally make solder resist layer 3: take 471K corresponding yellow UV light curing ink, and print 3.4x2.5mm solder resist layer 3 on both sides in height direction respectively;UV light curing is prepared sample, this device adopts fixed length, it is convenient for PCB board soldering point layout, and simultaneously has no lead, size is accurate and controllable, and it is convenient for low-cost large-scale production.

[0028] The above merely describes a preferred embodiment of the present application, but the protection scope of the present application is not limited thereto, and any skilled person in the art, according to the technical scheme and the inventive concept of the present application, makes equivalent replacement or change within the technical range disclosed by the present application, which should be covered within the protection scope of the present application.

Claims

1. A zinc oxide chip varistor, comprising a varistor ceramic (1), characterized in that: The pressure-sensitive ceramic sheet (1) can be provided with a solder resist layer (3) on all four sides, and electrodes (2) are provided on both sides of the pressure-sensitive ceramic sheet (1). The electrodes (2) are made by printing and sputtering. The solder resist layer (3) is fixed to both sides of the pressure-sensitive ceramic sheet (1) by coating. The coating method includes electroplating, brush plating, chemical plating, physical vapor deposition, chemical vapor deposition, thermal spraying, surfacing, laser beam and electron beam surface cladding, and hot dip plating. The solder resist layer (3) is made of UV light-curing ink with different colorants. The UV light-curing ink refers to an ink that uses ultraviolet light of different wavelengths and energies under ultraviolet irradiation to polymerize monomers in the ink binder into polymers until the ink forms a film and dries.

2. A chip zinc oxide varistor according to claim 1, characterized in that: The pressure-sensitive ceramic sheet (1) has a length of 2.5-5 mm, a width of 1.5-3.5 mm, and a height of 1-3 mm.

3. The zinc oxide chip varistor according to claim 1, characterized in that: The electrode (2) is fully coated on the edge of the pressure-sensitive ceramic sheet (1).

Images