阅读说明：本技术 一种小型封装尺寸的表面贴装高分子ptc过电流保护元件 (Small-size surface-mounted polymer PTC over-current protection element with packaging size ) 是由 方勇 夏坤 吴国臣 周阳 侯晓旭 于 2020-06-17 设计创作，主要内容包括：本发明涉及一种小型封装尺寸的表面贴装高分子PTC过电流保护元件,一种小型封装尺寸的表面贴装高分子PTC过电流保护元件,包括PTC芯片、绝缘层、端电极,至少一导电件,其中,在第一导电电极设计分割间隙,形成第一、二导电区,导电件设置在PTC芯片的第一导电区侧的边缘处或至少一角,用于导通PTC芯片上的第一导电区和第二导电电极,且不与端电极接触,第一导电电极的分割间隙包含的主要部分与第一端电极和第二端电极的纵向平行。本发明还提供了该保护元件的制备方法。本发明使得小型化过电流保护元件可满足目前PCB工艺,实现量产的要求。便于设计过电流保护元件电阻的方案,减少对PTC芯材配方的调整。(The invention relates to a surface-mounted polymer PTC (positive temperature coefficient) overcurrent protection element with small packaging size, which comprises a PTC chip, an insulating layer, a terminal electrode and at least one conductive piece, wherein a partition gap is designed on the first conductive electrode to form a first conductive area and a second conductive area, the conductive piece is arranged at the edge or at least one corner of the first conductive area side of the PTC chip and is used for conducting the first conductive area and the second conductive electrode on the PTC chip and is not contacted with the terminal electrode, and the main part contained in the partition gap of the first conductive electrode is longitudinally parallel to the first terminal electrode and the second terminal electrode. The invention also provides a preparation method of the protective element. The invention can lead the miniaturized overcurrent protection element to meet the requirements of the prior PCB process and realize mass production. The scheme of designing the resistance of the over-current protection element is convenient, and the adjustment of the formula of the PTC core material is reduced.)

1. A surface-mounted polymer PTC over-current protection element with small packaging size comprises a PTC chip, an insulating layer, a terminal electrode and at least one conductive piece, and is characterized in that a separation gap is designed on a first conductive electrode of the PTC chip to form a first conductive area and a second conductive area, the conductive piece is arranged at the edge or at least one corner of the side of the first conductive area of the PTC chip and used for conducting the first conductive area and the second conductive electrode on the PTC chip and is not contacted with the terminal electrode, and the main part contained in the separation gap of the first conductive electrode is longitudinally parallel to the first terminal electrode and the second terminal electrode.

2. A small package size surface mount polymer PTC overcurrent protection component according to claim 1, wherein: comprises a PTC chip, an insulating layer, a terminal electrode and at least one conductive member, wherein,

1) the PTC chip consists of a PTC core material, a first conductive electrode covering the first surface of the PTC core material and a second conductive electrode covering the second surface of the PTC core material, wherein the first conductive electrode is divided into a first conductive area and a second conductive area by a gap;

2) the at least one conductive piece is positioned at the edge of the PTC chip and is used for conducting a first conductive area of a first conductive electrode on the PTC chip and a second conductive electrode without contacting with the terminal electrode;

3) the insulating layer is arranged between the first conductive electrode and the first and second terminal electrode layers and used for electric isolation, and the first and second conductive holes penetrate through the insulating layer and are respectively and electrically connected with the first conductive area and the second conductive area of the first conductive electrode;

4) the dividing gap includes a main portion parallel to the longitudinal direction of the first terminal electrode and the second terminal electrode;

5) the terminal electrodes comprise a first terminal electrode and a second terminal electrode, wherein the first terminal electrode is positioned at one end of the surface of the insulating layer and is electrically connected with the first conductive area through the first conductive hole to be used as a bonding pad; and a second terminal electrode disposed at the other end opposite to the surface of the insulating layer and electrically connected to the second conductive region through the second conductive via to serve as a pad.

3. A small package size surface mount polymer PTC overcurrent protection device according to claim 1 or 2, wherein the relative positions of the first conductive region and the second conductive region on the first conductive electrode are adjusted and set by dividing the gap, and the effective area of the PTC core is determined by the area of the second conductive region.

4. A small form factor surface mount polymer PTC overcurrent protection device according to claim 3, wherein the dividing gap is filled with the insulating resin material.

5. The PTC overcurrent protection element according to claim 4, wherein the dividing gap is rectangular, triangular, circular arc, oval, polygonal, or a combination thereof.

6. A small package size surface mount polymer PTC over-current protection device according to claim 1, wherein said PTC chip has insulation reinforcement at four corners or one or two or four edges.

7. A small form factor surface mount polymer PTC over-current protection device according to claim 6, wherein said insulation enhancing member is disposed at said conductive member.

8. A small package size surface mount polymeric PTC overcurrent protection element according to claim 1 or 2, wherein the PTC overcurrent protection element is a single solder side surface mount element.

9. The small form factor surface mount polymer PTC overcurrent protection device of claim 8, wherein the outermost non-solder side of the device is further coated with an insulating layer, a metal foil layer, or any combination thereof to enhance the strength of the device.

10. A method for manufacturing a small package size surface mount polymer PTC overcurrent protection device according to any one of claims 1 to 9, comprising the steps of:

step one, preparing a PTC chip: mixing a high molecular polymer and a conductive filler which are used as base components of a conductive high molecular composite material in a high-speed mixer, then mixing the mixture at the temperature of 100-200 ℃, and then preparing the mixture into a product with the area of 100-5000 cm by a mould pressing or extruding method²A composite material base layer with the thickness of 0.1-3.0 mm; then the first and second conductive electrodes are combined on the first and second surfaces of the material base layer by hot pressing method to obtain composite material sheet, and then the composite sheet is treated by gamma ray (Co)⁶⁰) Or performing electron beam irradiation crosslinking with the dose of 2-100 Mrad, and cutting to obtain a rectangular PTC chip;

preparing a division gap on the first conductive electrode in an etching and cutting mode, and filling the division gap with an insulating material to form a first conductive region and a second conductive region, wherein the area of the first conductive region is larger than that of the second conductive region and is determined according to the resistance value requirement of the PTC chip;

etching a groove at the end edge or the corner of the first conductive area of the PTC chip and plating a metal conductive piece to ensure that the first conductive area of the first conductive electrode is conducted with the second conductive electrode;

fourthly, covering an insulating layer on the first conductive electrode;

step five, arranging a first end electrode and a second end electrode which are longitudinally parallel, enabling the main part of the divided gap to be parallel to the end electrodes, drilling and electroplating the first end electrode and the second end electrode to form a first conductive hole and a second conductive hole, and enabling the first end electrode to be electrically connected with the first conductive area through the first conductive hole to be used as a bonding pad; electrically connected to the second conductive region through the second conductive via and functioning as a bonding pad.

11. The method for manufacturing a surface-mounted polymer PTC over-current protection device with small package size as claimed in claim 10, wherein in the second step, the gap is divided into linear grooves parallel to the terminal electrodes; or an arc wire groove with one end parallel to the terminal electrode.

12. The method as claimed in claim 10, wherein the conductive member is disposed at one edge, one corner, or two corners of the PTC chip.

Technical Field

The invention relates to a surface-mounted polymer PTC (positive temperature coefficient) overcurrent protection element with a small packaging size.

Background

The overcurrent protection element is applied to electronic circuits and protects the electronic circuits from faults or even burning due to overheating or overcurrent. The core component of the overcurrent protection element is a core material made of a high polymer conductive composite material and a chip formed by conductive electrodes covering two sides of the core material. The chip is in a low-resistance state at room temperature, and an electronic circuit is in a path state; when the temperature rises or the circuit has a fault and large current, the resistance of the circuit jumps to more than thousands of times, so that the effect of reducing the current in the circuit is achieved, and the circuit is protected. When the temperature recovers or the fault current is eliminated, the resistance of the PTC chip recovers to be normal. This is achieved for repeated use, and is therefore a self-healing fuse (PTC).

At present, electronic products are increasingly functionalized and thinned, electronic circuits are also increasingly complex, and the application of overcurrent protection elements tends to be miniaturized and developed, smaller and thinner. The conventional packaging size of 1206, 0805 and the like is quite mature in technology and is widely applied. And the requirements of 0402, 0201 and 01005 packaging are gradually met with corresponding market demands. Such miniaturized products will be a great technical challenge for the process capability and circuit design of PCB processing.

Disclosure of Invention

The invention aims to provide a surface-mounted polymer PTC over-current protection element with a small packaging size, which is provided with a miniaturized over-current protection element capable of being produced in mass production, and improves the effective area and the current capacity of PTC while being miniaturized.

Yet another object of the present invention is to: the preparation method of the surface-mounted polymer PTC over-current protection element with the small packaging size is provided.

The purpose of the invention is realized by the following scheme: a surface-mounted polymer PTC over-current protection element with small packaging size comprises a PTC chip, an insulating layer, a terminal electrode and at least one conductive piece, wherein a separation gap is designed on a first conductive electrode of the PTC chip to form a first conductive area and a second conductive area, the conductive piece is arranged at the edge or at least one corner of the side of the first conductive area of the PTC chip and is used for conducting the first conductive area and the second conductive electrode on the PTC chip and is not in contact with the terminal electrode, and the main part contained in the separation gap is longitudinally parallel to the first terminal electrode and the second terminal electrode.

The invention is different from the design of through holes at two ends of a conventional surface-mounted PTC, and a conductive piece is arranged at the edge of one end of a PTC chip or at least one corner through a special design to connect conductive electrodes at two sides of a PTC core material, and meanwhile, a separation gap is designed at a first conductive electrode, so that a miniaturized over-current protection element can meet the requirements of the current PCB technology and mass production. The scheme of designing the resistance of the over-current protection element is convenient, and the adjustment of the formula of the PTC core material is reduced.

In particular, the invention provides a surface-mounted polymer PTC over-current protection element with small packaging size, which comprises a PTC chip, an insulating layer, a terminal electrode and at least one conductive piece, wherein,

1) the PTC chip consists of a PTC core material, a first conductive electrode covering the first surface of the PTC core material and a second conductive electrode covering the second surface of the PTC core material, wherein the first conductive electrode is divided into a first conductive area and a second conductive area by a gap;

2) the at least one conductive piece is positioned at the edge of the PTC chip and is used for conducting a first conductive area of a first conductive electrode on the PTC chip and a second conductive electrode without contacting with the terminal electrode;

3) the insulating layer is arranged between the first conductive electrode and the first and second terminal electrode layers and used for electric isolation, and the first and second conductive holes penetrate through the insulating layer and are respectively and electrically connected with the first conductive area and the second conductive area of the first conductive electrode;

4) the dividing gap includes a main portion parallel to the longitudinal direction of the first terminal electrode and the second terminal electrode;

5) the terminal electrodes comprise a first terminal electrode and a second terminal electrode, wherein the first terminal electrode is positioned at one end of the surface of the insulating layer and is electrically connected with the first conductive area through the first conductive hole to be used as a bonding pad; and a second terminal electrode disposed at the other end opposite to the surface of the insulating layer and electrically connected to the second conductive region through the second conductive via to serve as a pad. To prevent the first conductive electrode from becoming weak in bonding strength with the PTC core material and even being separated.

On the basis of the scheme, the relative positions of the first conductive area and the second conductive area on the first conductive electrode are adjusted and set through the dividing gap, and the effective area of the PTC core material is determined through the area of the second conductive area.

On the basis of the scheme, the dividing gaps are filled with the insulating layer resin material.

Furthermore, the dividing gaps are in shapes of rectangles, triangles, circular arcs, ellipses, polygons and combinations thereof.

On the basis of the scheme, the insulation reinforcing parts are arranged at the four corners, one end edge, two end edges or four end edges of the PTC chip so as to increase the strength of the element.

On the basis of the scheme, the PTC over-current protection element is a single-welding-surface mounting element.

Furthermore, an insulating layer, a metal foil layer or any combination of the two layers are added on the outermost layer of the non-welding surface of the element so as to enhance the strength of the element.

The invention also provides a manufacturing method of the surface-mounted polymer PTC over-current protection element with small packaging size, which comprises the following steps:

step one, preparing a PTC chip: mixing a high molecular polymer and a conductive filler which are used as base components of a conductive high molecular composite material in a high-speed mixer, then mixing the mixture at the temperature of 100-200 ℃, and then preparing the mixture into a product with the area of 100-5000 cm by a mould pressing or extruding method²0.1-3.0 mm thick composite material baseA layer; then the first and second conductive electrodes are combined on the first and second surfaces of the material base layer by hot pressing method to obtain composite material sheet, and then the composite sheet is treated by gamma ray (Co)⁶⁰) Or performing electron beam irradiation crosslinking with the dose of 2-100 Mrad, and cutting to obtain a rectangular PTC chip 1;

preparing a division gap on the first conductive electrode in an etching and cutting mode, and filling the division gap with an insulating material to form a first conductive region and a second conductive region, wherein the area of the first conductive region is larger than that of the second conductive region and is determined according to the resistance value requirement of the PTC chip;

etching a groove at the end edge or the corner of the first conductive area of the PTC chip and plating a metal conductive piece to ensure that the first conductive area of the first conductive electrode is conducted with the second conductive electrode;

fourthly, covering an insulating layer on the first conductive electrode;

step five, arranging a first end electrode and a second end electrode which are longitudinally parallel, enabling the main part of the divided gap to be parallel to the end electrodes, drilling and electroplating the first end electrode and the second end electrode to form a first conductive hole and a second conductive hole, and enabling the first end electrode to be electrically connected with the first conductive area through the first conductive hole to be used as a bonding pad; electrically connected to the second conductive region through the second conductive via and functioning as a bonding pad.

The invention has the following characteristics:

1. a conductive piece is arranged at the edge or one corner of one end of the PTC chip and connected with the conductive electrodes on the two sides of the PTC core material, and meanwhile, a separation gap is designed in the first conductive electrode, so that the design can realize batch production in the PCB processing technology;

2. the resistance of the over-current protection element can be designed and adjusted by designing and adjusting the relative position of the segmentation gap on the first conductive electrode, so that the designability of the over-current protection element is higher;

3. the element of the invention is of a single welding surface mounting type, and the single welding surface mounting element is characterized in that: the outermost layer of the non-welding surface of the element can be added with an insulating layer, a metal foil layer or any combination layer of the insulating layer and the metal foil layer to enhance the strength of the element;

4. the circuit design of the invention is particularly suitable for the manufacturing process of the subminiature PTC paster.

Drawings

FIG. 1: embodiment 1 is a three-dimensional structure diagram of a surface-mounted polymer PTC over-current protection element with a small packaging size;

FIG. 2: an explosion schematic of example 1;

FIG. 3: embodiment 2 is a three-dimensional structure diagram of a surface-mounted polymer PTC over-current protection element with a small package size;

FIG. 4: embodiment 3 is a three-dimensional structure diagram of a surface-mounted polymer PTC over-current protection element with a small package size;

FIG. 5: example 3 small package size surface mount polymer PTC overcurrent protection element second conductive electrode bottom view;

FIG. 6: example 4 small package size surface mount polymer PTC overcurrent protection element second conductive electrode bottom view;

FIG. 7: example 5 small package size surface mounting polymer PTC over-current protection element first conductive electrode structure diagram;

description of the reference symbols

10-PTC core material;

21. 22-first conductive electrode, second conductive electrode;

211. 212-first and second conductive regions of the first conductive electrode;

30-insulating layer;

41. 42-first, two terminal electrode;

51. 52-first and second conductive vias;

60. 60' -an electrically conductive member; 61. 62-first and second conductive members;

70-dividing the gap;

80-insulation reinforcement;

90-an enhancement layer;

in fig. 7:

21' -a first conductive electrode;

211 ', 212' — the first and second conductive regions of the first conductive electrode;

70' -dividing the gap.

Detailed Description

Preparing materials:

mixing a high molecular polymer and a conductive filler which are used as base components of a conductive high molecular composite material in a high-speed mixer, then mixing the mixture at the temperature of 100-200 ℃, and then preparing the mixture into a product with the area of 100-5000 cm by a mould pressing or extruding method²A PTC core material 10 with a thickness of 0.1-3.0 mm; then the first and second conductive electrodes 21, 22 are compounded on the first and second surfaces of the PTC core material 10 on the hot press by the hot pressing method to prepare a composite material sheet, and then the composite sheet is processed by gamma ray (Co)⁶⁰) Or electron beam irradiation crosslinking is carried out, and the dosage is 2-100 Mrad, so that the PTC chip is obtained.