CN209607522U - A kind of linear PTC thermal resistor - Google Patents

Abstract

The utility model discloses a kind of linear PTC thermal resistors; including substrate; substrate upper surface middle position is equipped with resistor layer; protective film is equipped with above the resistor layer; it is equipped with face electrode at left and right sides of the resistor layer, is equipped with back electrode at left and right sides of the substrate lower end surface, the substrate, face electrode and back electrode are wrapped with internal electrode; the internal electrode is wrapped with target, and the target is wrapped with external electrode.The utility model compared with prior art the advantages of be: good linearity, stability is good, small in size, light-weight, long service life.

Description

A kind of linear PTC thermal resistor

Technical field

The utility model relates to thermistor technology field, in particular to a kind of linear PTC thermal resistors.

Background technique

PTC themistor is that one kind is increased with temperature, and the sensitive components that resistance value linearly increases is usually used in temperature survey Amount, temperature control, temperature-compensating.Its resistance change of existing PTC themistor is linearly poor, at a certain temperature, resistance Value is easily in sudden transformation, need to use linear compensation measure, and circuit design is complex；Existing PTC themistor simultaneously Protective film be mostly cuboid, use for a long time, the protective film of cuboid is easy to fall off, can not protect to resistor layer.

Utility model content

The technical problems to be solved in the utility model be traditional PTC themistor structurally and functionally the problem of, provide A kind of good linearity, stability is good, a kind of linear PTC thermal resistor small in size, light-weight, with long service life.

In order to solve the above technical problems, technical solution provided by the utility model are as follows: a kind of linear PTC thermal resistor, Including substrate, substrate upper surface middle position is equipped with resistor layer, is equipped with protective film, the electricity above the resistor layer It is equipped with face electrode at left and right sides of resistance body layer, is equipped with back electrode, the substrate, face electrode and back at left and right sides of the substrate lower end surface Electrode is wrapped with internal electrode, and the internal electrode is wrapped with target, and the target is wrapped with external electrical Pole.

The utility model compared with prior art the advantages of be: the linear PTC thermal resistor, have superior stabilization Property, repdocutbility, characteristic curve is constant, resistance value with temperature increase and increase, linearly change, good linearity, with PTC polymer ceramic The thermistor of synthesis is compared, good linearity, without taking linear compensation measure, makes circuit design simple, temperature coefficient routinely may be used Reach 2000ppm to 3000ppm, highest can achieve the temperature coefficient of 3500ppm, high sensitivity, high reliablity, volume at present Small, light-weight, shape standardization is suitable for the automation installation of printed wiring board.

As an improvement, the protective film is in trapezoidal shape, the internal electrode, target and external electrode are covered on protection On film side.

As an improvement, the internal electrode uses palladium-silver material.

As an improvement, the target uses nickel material.

As an improvement, the external electrode uses tin material.

As an improvement, the substrate uses alumina material.

Detailed description of the invention

Fig. 1 is a kind of structural schematic diagram of linear PTC thermal resistor of the utility model.

Fig. 2 is a kind of cross-sectional view of linear PTC thermal resistor of the utility model.

Fig. 3 is that a kind of linear PTC temperature coefficient of thermistor of the utility model is respectively 1000,2000,3000ppm/ DEG C when the canonical schema that varies with temperature of resistance value.

Fig. 4 is a kind of derating curve of linear PTC thermal resistor of the utility model.

It is as shown in the figure: 1, substrate, 2, resistor layer, 3, protective film, 4, face electrode, 5, back electrode, 6, internal electrode, 7, in Between electrode, 8, external electrode.

Specific embodiment

The following describes the utility model in further detail with reference to the accompanying drawings.

The utility model in the specific implementation, provides a kind of linear PTC thermal resistor, including substrate 1, feature exists In: the 1 upper surface middle position of substrate is equipped with resistor layer 2, is equipped with protective film 3, the resistance above the resistor layer 2 It is equipped with face electrode 4 at left and right sides of body layer 2, is equipped with back electrode 5, the substrate 1, face electrode 4 at left and right sides of 1 lower end surface of substrate It is wrapped with internal electrode 6 with back electrode 5, the internal electrode 6 is wrapped with target 7, wraps up outside the target 7 There is external electrode 8.

The protective film 3 is in trapezoidal shape, and the internal electrode 6, target 7 and external electrode 8 are covered on 3 side of protective film On face, so that protective film is not easily to fall off, resistor layer can be played and be effectively protected, prolonged the service life.

The internal electrode 6 uses palladium-silver material, and making it at normal temperature has good inoxidizability, and in high temperature ring With palladium content, it increases and increases its inoxidizability of border.

The target 7 uses nickel material, makes it have certain ductility, and its surface has oxidation film, energy Oxidation reaction further occurrence is enough prevented, there is preferable oxidation resistance.

The external electrode 8 uses tin material, so that it is not reacted with air and water, while being conveniently welded and fixed.

The substrate 1 uses alumina material, makes it have good heat conductivity.

Working principle of the utility model is: the linear PTC thermal resistor is when in use, external electrode is welded on route On plate, since external electrode is made of tin, so that the welding of the linear PTC thermal resistor is more convenient and secured, protective film At trapezoidal shape, and the side of protective film is covered by external point, target and internal electrode, so that protective film is not easily to fall off, electricity Resistance body layer is constantly in protected state, to extend the service life of linear PTC thermistor.When the linear PTC temperature-sensitive Resistor is applied in circuit protection, when circuit is in normal condition, passes through the electric current of overcurrent protection PTC themistor Less than rated current, overcurrent protection is in the normal state with PTC themistor, and resistance value very little will not influence by protection circuit just Often work.When circuit breaks down, when electric current substantially exceeds rated current, overcurrent protection is suddenly generated heat with PTC themistor, In high-impedance state, circuit is set to be in opposite " disconnection " state, so that circuit be protected not to be damaged.After troubleshooting, overcurrent protection Low resistance state is also automatically returned to PTC themistor, circuit restores to work normally.

The utility model and embodiments thereof are described above, this description is no restricted, shown in attached drawing Be also one of the embodiments of the present invention, actual structure is not limited to this.All in all if this field Those of ordinary skill is enlightened by it, without deviating from the purpose of the present invention, not inventively design with The similar frame mode of the technical solution and embodiment, all should belong to the protection range of the utility model.

Claims (6)

1. a kind of linear PTC thermal resistor, including substrate (1), it is characterised in that: substrate (1) the upper surface middle position Equipped with resistor layer (2), protective film (3) are equipped with above the resistor layer (2), are equipped at left and right sides of the resistor layer (2) Face electrode (4), substrate (1) the lower end surface left and right sides are equipped with back electrode (5), the substrate (1), face electrode (4) and back electricity Pole (5) is wrapped with internal electrode (6), and the internal electrode (6) is wrapped with target (7), and the target (7) is outside It is enclosed with external electrode (8).

2. a kind of linear PTC thermal resistor according to claim 1, it is characterised in that: the protective film (3) is in halfpace Shape, the internal electrode (6), target (7) and external electrode (8) are covered on protective film (3) side.

3. a kind of linear PTC thermal resistor according to claim 1, it is characterised in that: the internal electrode (6) uses Palladium-silver material.

4. a kind of linear PTC thermal resistor according to claim 1, it is characterised in that: the target (7) uses Nickel material.

5. a kind of linear PTC thermal resistor according to claim 1, it is characterised in that: the external electrode (8) uses Tin material.

6. a kind of linear PTC thermal resistor according to claim 1, it is characterised in that: the substrate (1) is using oxidation Aluminum material.