PTC (Positive Temperature Coefficient) heating film suitable for large current

Abstract

The PTC heating film comprises a base layer, a conductive layer and a heating layer, wherein the conductive layer and the heating layer are arranged on the base layer; the conductive layer comprises an upper-layer main silver paste line, a middle-layer main silver paste line and a lower-layer main silver paste line which are transversely arranged at intervals from top to bottom; a first fine silver paste line connected with the upper-layer main silver paste line and a second fine silver paste line connected with the middle-layer main silver paste line are arranged between the upper-layer main silver paste line and the middle-layer main silver paste line; a plurality of third fine silver paste lines connected with the lower-layer main silver paste line and a plurality of fourth fine silver paste lines connected with the middle-layer main silver paste line are arranged between the lower-layer main silver paste line and the middle-layer main silver paste line; a copper foil strip is arranged on the middle-layer main silver paste line; the heating layer comprises a plurality of first heating wires and a plurality of second heating wires, and the first heating wires and the second heating wires are transversely arranged on the first fine silver paste wire, the second fine silver paste wire, the third fine silver paste wire and the fourth fine silver paste wire respectively. Compared with the existing heating film, the PTC heating film provided by the utility model has higher current-carrying capability.

Description

TECHNICAL FIELD

[0001] The utility model belongs to PTC heating film technical field, specifically relates to a PTC heating film suitable for large current. BACKGROUND

[0002] The PTC heating film is widely applied in the battery module heating field because of high starting power and strong safety. Figure 1 The traditional PTC heating film adopts PI film as the base material, is equipped with two main silver paste 51 on the two sides of the base material, and is provided with fine silver paste 52 and carbon paste 53 between the two main silver paste, so as to realize the electric conduction and heating function. SUMMARY

[0003] The utility model discloses a PTC heating film suitable for large current.

[0004] To realize above-mentioned purpose, the utility model discloses a PTC heating film suitable for large current, including base layer and the conductive layer and heating layer being located on the base layer,

[0005] The conductive layer includes the upper layer main silver paste line, the middle layer main silver paste line and the lower layer main silver paste line that are arranged horizontally and are spaced from top to bottom, a plurality of first fine silver paste lines and second fine silver paste lines are arranged longitudinally between the upper layer main silver paste line and the middle layer main silver paste line, the first fine silver paste line is connected with the upper layer main silver paste line, and the second fine silver paste line is connected with the middle layer main silver paste line, a plurality of third fine silver paste lines and fourth fine silver paste lines are arranged longitudinally between the lower layer main silver paste line and the middle layer main silver paste line, the third fine silver paste line is connected with the lower layer main silver paste line, and the fourth fine silver paste line is connected with the middle layer main silver paste line,

[0006] The copper foil strip is arranged on the middle layer main silver paste line.

[0007] The heating layer includes a plurality of first heating lines and a plurality of second heating lines, the first heating lines are arranged horizontally on the first fine silver paste line and the second fine silver paste line, and the second heating lines are arranged horizontally on the third fine silver paste line and the fourth fine silver paste line.

[0008] Preferably, the copper foil strip completely covers the middle layer main silver paste line.

[0009] Preferably, the width of the copper foil is 1mm-2mm less than the line width of the middle layer main silver paste line.

[0010] Preferably, the width of the copper foil is 2mm less than the line width of the middle layer main silver paste line.

[0011] Preferably, the width of the copper foil is equal to the line width of the middle layer main silver paste line.

[0012] Preferably, the line width of the upper layer main silver paste line and the lower layer main silver paste line is equal.

[0013] Preferably, the first fine silver paste line and the second fine silver paste line are arranged at intervals, and / or

[0014] The third fine silver paste line and the fourth fine silver paste line are arranged at intervals.

[0015] Compared with the prior art, the PTC heating film has the beneficial effects that:

[0016] The PTC heating film of the utility model, through add a main silver paste line, make middle layer main silver paste line and upper layer main silver paste line and lower layer main silver paste line form parallel structure simultaneously, wherein middle layer main silver paste line can be used as positive or negative, upper layer main silver paste line and lower layer main silver paste line are corresponding negative or positive, like this, PTC heating film is used in the scene of large current, this parallel structure has the effect of shunt, this can avoid the problem that upper layer, lower layer main silver line and fine silver paste heat a large amount of heat and cause the deformation of the substrate at the corresponding position or even burn through, thereby damaging the heating film.

[0017] The copper foil strip is arranged on the middle layer main silver paste line, which improves the current carrying capacity of the middle layer main silver paste line and avoids the problem that the middle layer main silver paste line generates a large amount of heat, which causes the deformation of the substrate at the position or even burns through, thereby damaging the heating film. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is a structural schematic view of the existing PTC heating film;

[0019] Figure 2 It is a structural schematic view of the PTC heating film suitable for large current in the embodiment;

[0020] Base layer 1;

[0021] Upper layer main silver paste line 21; middle layer main silver paste line 22; lower layer main silver paste line 23; first fine silver paste line 24; second fine silver paste line 25; third fine silver paste line 26; fourth fine silver paste line 27;

[0022] First heating line 31; second heating line 32;

[0023] Copper foil strip 4;

[0024] Main silver paste 51; fine silver paste 52; carbon paste 53. DETAILED DESCRIPTION

[0025] In order to make the above-mentioned purposes, features and advantages of the utility model more obvious and easy to understand, the utility model will be further described in detail in combination with the drawings and specific embodiments.

[0026] A PTC heating film suitable for large current, see Figure 2 , comprising a base layer 1 and a conductive layer and a heating layer arranged on the base layer 1. Wherein the base layer is a PI film; the conductive layer comprises upper layer main silver paste line 21, middle layer main silver paste line 22 and lower layer main silver paste line 23 arranged transversely and spaced from top to bottom, a plurality of first fine silver paste lines 24 and second fine silver paste lines 25 arranged longitudinally are arranged between the upper layer main silver paste line 21 and the middle layer main silver paste line 22, the first fine silver paste line 24 is connected with the upper layer main silver paste line 21, and the second fine silver paste line 25 is connected with the middle layer main silver paste line 22; a plurality of third fine silver paste lines 26 and fourth fine silver paste lines 27 arranged longitudinally are arranged between the lower layer main silver paste line 23 and the middle layer main silver paste line 22, the third fine silver paste line 26 is connected with the lower layer main silver paste line 23, and the fourth fine silver paste line 27 is connected with the middle layer main silver paste line 22. The heating layer comprises first heating line 31 and second heating line 32 formed by conductive carbon paste coating, the first heating line 31 has a plurality of first heating lines 31 arranged transversely on the first fine silver paste line 24 and the second fine silver paste line 25, and the second heating line 32 has a plurality of second heating lines 32 arranged transversely on the third fine silver paste line 26 and the fourth fine silver paste line 27.

[0027] In this embodiment, for example, the upper layer main silver paste line 21 and the lower layer main silver paste line 23 are positive, and the middle layer main silver paste line 22 is negative. After the current flows through the upper layer main silver paste line 21 and the lower layer main silver paste line 23, the current of the upper layer main silver paste line 21 flows to the middle layer main silver paste line 22 through the first fine silver paste line 24, the first heating line 31 and the second fine silver paste line 25, and the current of the lower layer main silver paste line 23 flows to the middle layer main silver paste line 22 through the third fine silver paste line 26, the second heating line 32 and the fourth fine silver paste line 27, and finally flows out from the middle layer main silver paste line 22. The PTC heating film of the present embodiment, by adding one main silver paste line, forms a parallel structure between the middle layer main silver paste line 22 and the upper layer main silver paste line 21 and the lower layer main silver paste line 23, wherein the middle layer main silver paste line 22 can be used as a positive or negative electrode, and the upper layer main silver paste line 21 and the lower layer main silver paste line 23 are correspondingly negative or positive. In this way, the PTC heating film is used in a large current scenario, and the parallel structure has a shunt effect, which can avoid the problem of deformation or even burning of the base material at the corresponding position due to the large heating capacity of the upper layer and lower layer main silver lines and fine silver paste, thereby damaging the heating film.

[0028] In the embodiment, the copper foil strip 4 is arranged on the middle layer main silver paste line 22, specifically, the copper foil strip 4 is pasted on the middle layer main silver paste line 22, the copper foil strip 4 comprises a self-adhesive layer and a copper foil layer, the self-adhesive layer is made of conductive acrylic pressure-sensitive adhesive, the thickness of the self-adhesive layer is 0.035-0.04 mm, the thickness of the copper foil layer is 0.018 mm-0.05 mm, and the total thickness of the copper foil strip 4 is 0.053-0.09 mm. By arranging the copper foil strip 4 on the middle layer main silver paste line 22, the current carrying capacity of the middle layer main silver paste line 22 is improved, and the problem that the middle layer main silver paste line 22 generates large heat, the substrate at the position is deformed or even burnt, and the heating film is damaged is avoided.

[0029] In the embodiment, the copper foil strip 4 completely covers the middle layer main silver paste line 22, so that the current carrying capacity of the whole middle layer main silver paste line 22 is improved, and the problem that the middle layer main silver paste line 22 generates large heat, the substrate at the position is deformed or even burnt, and the heating film is damaged is avoided.

[0030] In the embodiment, the width of the copper foil is smaller than the line width of the middle layer main silver paste line 22 by 1 mm-2 mm, so that the problem that the copper foil cannot be completely aligned with the middle layer main silver paste line 22 due to assembly error and part of the copper foil is located outside the middle layer main silver paste line 22, and the use safety problem is avoided. The width of the copper foil is smaller than the line width of the middle layer main silver paste line 22 by 2 mm.

[0031] In another embodiment, the width of the copper foil is equal to the line width of the middle layer main silver paste line 22, so that the current carrying capacity of the middle layer main silver paste line 22 and the copper foil is maximized, and the problem of heat generation is maximally solved.

[0032] In the embodiment, the line width of the upper layer main silver paste line 21 is equal to the line width of the lower layer main silver paste line 23, so that the current carrying capacity of the two main silver paste lines is equal, and the problem of uneven heat generation due to uneven current carrying is avoided.

[0033] In the embodiment, the first thin silver paste line 24 and the second thin silver paste line 25 are arranged at intervals, and the third thin silver paste line 26 and the fourth thin silver paste line 27 are arranged at intervals.

[0034] Obviously, the above embodiments of the utility model are only examples for clearly illustrating the utility model, and are not the limitation of the embodiments of the utility model. For ordinary skilled in the art, other different forms of changes or variations can be made on the basis of the above description. Here, all the embodiments are not enumerated. Any modification, equivalent replacement and improvement made within the spirit and principle of the utility model should be included in the protection scope of the utility model claim.

Claims

1. A PTC heating film suitable for large current, characterized in that: The base layer, the conductive layer and the heating layer are arranged on the base layer; The conductive layer comprises upper, middle and lower main silver paste lines arranged from top to bottom in a transverse and spaced manner, a plurality of first and second fine silver paste lines arranged in a longitudinal manner between the upper and middle main silver paste lines, the first fine silver paste line being connected with the upper main silver paste line, and the second fine silver paste line being connected with the middle main silver paste line; a plurality of third and fourth fine silver paste lines arranged in a longitudinal manner between the lower and middle main silver paste lines, the third fine silver paste line being connected with the lower main silver paste line, and the fourth fine silver paste line being connected with the middle main silver paste line; The copper foil strip is arranged on the middle main silver paste line; The heating layer comprises a plurality of first and second heating lines, the first heating lines being arranged in a transverse manner on the first and second fine silver paste lines, and the second heating lines being arranged in a transverse manner on the third and fourth fine silver paste lines.

2. The PTC heating film suitable for large current according to claim 1, characterized in that: The copper foil strip completely covers the middle main silver paste line.

3. The PTC heating film suitable for large current according to claim 2, characterized in that: The width of the copper foil is 1mm-2mm smaller than the line width of the middle main silver paste line.

4. The PTC heating film suitable for large current according to claim 3, characterized in that: The width of the copper foil is 2mm smaller than the line width of the middle main silver paste line.

5. The PTC heating film suitable for large current according to claim 1, characterized in that: The width of the copper foil is equal to the line width of the middle main silver paste line.

6. The PTC heating film suitable for large current according to claim 1, characterized in that: The line width of the upper main silver paste line is equal to the line width of the lower main silver paste line.

7. The PTC heating film suitable for large current according to claim 1, characterized in that: The first and second fine silver paste lines are arranged in a spaced manner, and / or The third and fourth fine silver paste lines are arranged in a spaced manner.

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