CN113345670B - Resistor with low resistance and high power - Google Patents

Abstract

The present invention relates to the field of electronic components, and specifically to a low-resistance, high-power resistor, comprising a substrate, a back electrode, a positive electrode, a resistor layer, a side electrode and a protective layer, wherein the front side of the substrate is provided with positive electrodes on both sides along the length direction, the back side of the substrate is provided with the back electrode opposite to the positive electrode, the resistor layer is provided between the positive electrodes, the side electrode is located on the side of the substrate, and the upper end contacts the positive electrode, and the lower end contacts the back electrode, the positive electrode comprises a connection site, the resistor layer is provided between two connection sites opposite to each other along the width direction of the substrate, and a broken band is provided between adjacent connection sites along the length direction of the substrate. The low-resistance, high-power resistor of the invention greatly reduces the resistance of the entire resistor by connecting multiple resistors in parallel on the surface of the substrate, while increasing the power of the entire resistor and the service life of the resistor.

Description

A low resistance, high power resistor

Technical Field

The invention relates to the field of electronic components, and in particular to a resistor with low resistance and high power.

Background Art

When electric charge moves in a conductor, it will be collided and rubbed by other particles such as molecules and atoms. The result of collision and friction forms the conductor's resistance to the current. The most obvious feature of this resistance is that the conductor consumes electrical energy and generates heat (or light). This resistance of an object to the current is called the resistance of the object. Resistors are generally called resistors in daily life. It is a current limiting component. After the resistor is connected to the circuit, the resistance of the resistor is fixed, usually with two pins, which can limit the current through the branch it is connected to. The resistance value cannot be changed is called a fixed resistor. The resistance value is variable. It is called a potentiometer or a variable resistor. The ideal resistor is linear, that is, the instantaneous current passing through the resistor is proportional to the applied instantaneous voltage. Variable resistor used for voltage division. On the exposed resistor body, one or two movable metal contacts are pressed tightly. The position of the contact determines the resistance between either end of the resistor body and the contact.

At present, our company produces a batch of resistors. Since the manufacturer specifies the resistors and limits the resistance and power of the resistors, when the resistor material and the coating thickness of the resistor are not changed, the resistance of the resistor prepared by traditional one-time integral printing is low, and the maximum power that the electronic lock can withstand is relatively small. In addition, since the resistor is a whole, due to the existence of the resistor repair cut point, no current passes through the resistor at the location where the resistor repair cut point exists, resulting in the heat dissipation of the resistor concentrated in the middle of the resistor layer. The heat dissipation effect of the resistor is also relatively poor, which does not meet the customer's requirements.

Summary of the invention

In order to solve the deficiencies in the prior art, the present invention provides a low-resistance and high-power resistor, which reduces the resistance of the resistor, increases the power of the resistor, and improves the heat dissipation performance of the resistor by setting multiple connection sites and setting the resistor layers on the substrate in parallel.

The technical solution of the present invention is:

The present invention provides a low-resistance and high-power resistor, comprising a substrate, a back electrode, a positive electrode, a resistor layer, a side electrode and a protective layer. The front side of the substrate is provided with positive electrodes on both sides along the length direction, the back side of the substrate is provided with the back electrode at a position opposite to the positive electrode, the resistor layer is provided between the positive electrodes, the side electrode is located on the side of the substrate, and the upper end is in contact with the positive electrode, and the lower end is in contact with the back electrode. The positive electrode comprises a connection site, the resistor layer is provided between two connection sites opposite to each other along the width direction of the substrate, and a broken band is provided between adjacent connection sites along the length direction of the substrate. The protective layer is coated on the surface of the entire resistor layer, and the protective layer comprises a first heat dissipation layer, a second heat dissipation layer and a waterproof layer. The first heat dissipation layer is coated on the surface of the resistor layer, the second heat dissipation layer is located on the surface of the first heat dissipation layer, and the waterproof layer is located on the surface of the second heat dissipation layer.

Preferably, there are 4 to 8 connection sites, and the distances between adjacent connection sites are equal, and the resistance values of the resistance layers between corresponding connection sites are also equal.

Preferably, the second heat dissipation layer is composed of glass and lead powder, wherein the mass fraction of the lead powder is controlled to be 3-5%.

Preferably, there are 4 attachment sites.

Preferably, there are 8 attachment sites.

Preferably, each of the connection sites is provided with repair cutting points on both sides.

Preferably, it further comprises a nickel plating layer and a tin plating layer, wherein the nickel plating layer is located on the surface of the side electrode, and the tin plating layer is located on the surface of the nickel plating layer.

The beneficial effects achieved by the present invention are:

By setting the connection site, the resistance layers on the substrate are connected in parallel in the circuit, thereby reducing the resistance value of the entire resistance group;

By providing the plurality of parallel resistor layers, the heat generated by the entire resistor can be evenly dispersed to the entire resistor surface, thereby improving the load capacity of the resistor and the load power of the resistor.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of the overall cross-sectional structure of the present invention.

FIG. 2 is a top view of the resistor layer and the substrate, showing the broken bands and connection sites.

FIG3 is a curve showing the variation of heat flux with the number of connection sites.

In the figure, 1, substrate; 2, back electrode; 3, positive electrode; 4, resistor layer; 5, first heat dissipation layer; 6, second heat dissipation layer; 7, waterproof layer; 8, resistor repair point; 9, side electrode; 11, nickel plating; 12, tin plating; 31, connection point; 32, broken belt.

DETAILED DESCRIPTION

To facilitate those skilled in the art to understand the present invention, specific implementations of the present invention are described below with reference to the accompanying drawings.

As shown in Figs. 1 to 3, the present invention provides a low-resistance and high-power resistor, comprising a substrate 1, a back electrode 2, a positive electrode 3, a resistor layer 4, a side electrode 9 and a protective layer. The front side of the substrate 1 is provided with positive electrodes 3 on both sides along the length direction. The substrate 1 is used to load the positive electrode 3 and the back electrode 2, and becomes the main skeleton of the entire electron, providing a carrier for the subsequent coating of the resistor layer 4. The back side of the substrate 1 is provided with the back electrode 2 opposite to the positive electrode 3, and the resistor layer 4 is provided between the positive electrodes 3. The side electrode 9 is located on the side of the substrate 1, and the upper end is in contact with the positive electrode 3, and the lower end is in contact with the back electrode 2. The positive electrode 3 includes a connection site 31. By setting the connection site 31, the connection of the two ends of the resistor layer 4 is realized, so that the resistor is connected to the circuit. Along the width of the substrate 1 The resistor layer 4 is provided between two connecting sites 31 opposite to each other in the length direction, and a broken band 32 is provided between the connecting sites 31 adjacent to each other in the length direction of the substrate 1. By providing the broken band 32, the original resistor layer 4 is divided into multiple parts and connected in parallel in the circuit, thereby reducing the resistance value of the entire resistor, and greatly reducing the resistance value of the entire resistor in the circuit. The protective layer is coated on the surface of the entire resistor layer 4. The protective layer includes a first heat dissipation layer 5, a second heat dissipation layer 6 and a waterproof layer 7. The first heat dissipation layer 5 is coated on the surface of the resistor layer 4, the second heat dissipation layer 6 is located on the surface of the first heat dissipation layer 5, and the waterproof layer 7 is located on the surface of the second heat dissipation layer 6. The first heat dissipation layer 5 and the second heat dissipation layer 6 are used to assist the heat dissipation of the resistor layer 4, and the waterproof layer 7 is used to isolate the resistor layer 4 from air, so as to protect the resistor layer 4. The first heat dissipation layer 5 is made of pure glass and is coated on the surface of the resistor layer 4 after the resistor layer is coated. The second heat dissipation layer 6 is composed of glass and lead powder, wherein the mass fraction of the lead powder is controlled at 3-5%. By adding the lead powder, the second heat dissipation layer 6 can quickly dissipate the heat. The mass fraction of the lead powder is preferably controlled within 5%. At this time, the heat flux density and insulation performance of the second heat dissipation layer 6 are optimal, as shown in Table 1, wherein the heat flux density is determined by referring to 360 Encyclopedia (https://baike.so.com/doc/591329-625970.html), and the insulation performance is determined by referring to the national standard GB/T10064-2006 "Test Method for Determining Insulation Resistance of Solid Insulating Materials".

Table 1 Relationship between heat flux density and insulation performance of the second heat dissipation layer and the amount of lead powder added

It can be seen that as the lead powder is heated, the heat flux density of the second heat dissipation layer 6 increases, indicating that the heat dissipation performance of the second heat dissipation layer 6 increases. When the content of the lead powder is higher than 5%, although the heat flux performance increases, the second heat dissipation layer 6 is no longer insulated and is not suitable as a protective layer for resistors. Therefore, the optimal amount of lead powder added is 5%.

In this embodiment, there are 4 to 8 connection sites 31, and the distances between adjacent connection sites 31 are equal, and the resistance values of the resistor layer 4 between the corresponding connection sites 31 are also equal. The more connection sites 31 there are, the more parallel resistors there are, and the lower the resistance value of the entire resistor is. The heat dissipation coefficient of the prepared resistor element is simulated by using CFD computer software. The specific relationship between the heat dissipation coefficient and the number of connection sites is shown in Figure 3, where the horizontal axis represents the number of connection sites and the vertical axis represents the heat flux density (W/ ^cm2 ) of the resistor at the rated voltage. Among them, when the heat flux density is lower than 0.8W/ ^cm2 , the resistor element cannot solve its own cooling problem through natural cooling. In order to achieve the purpose of natural cooling of the resistor as much as possible, the heat flux density of the resistor must be reduced. When a single resistor layer 4 is set, the length of the resistor trimming point 8 is too large, resulting in a small effective heat dissipation area of the resistor layer 4. When more resistor trimming points 8 are set, the resistor trimming points 8 will occupy more cross-sectional areas of the resistor layer 4, resulting in excessive current in the resistor layer 4, and the resistor layer 4 itself generates more heat, which increases the difficulty of heat dissipation of the resistor layer 4. Therefore, an appropriate number of connection points 31 must be selected.

In this embodiment, there are four connection sites 31.

In this embodiment, there are 8 connection sites 31.

In this embodiment, resistance trimming points 8 are provided on both sides of each connection point 31. By providing the resistance trimming points 8, the resistance value of a single resistor layer 4 is corrected, and the accuracy of the resistance value of the resistor is ensured. The resistance trimming points 8 can be in a "I" shape, an "L" shape, or other shapes.

In this embodiment, a nickel plating layer 11 and a tin plating layer 12 are also included, wherein the nickel plating layer 11 is located on the surface of the side electrode 9, and the tin plating layer 12 is located on the surface of the nickel plating layer 11. By providing the nickel plating layer 11 and the tin plating layer 12, the side of the substrate 1 is covered, and the back electrode 2 can be covered, so that the back electrode 2 is connected to the circuit.

The beneficial effects achieved by the present invention are:

By setting the connection site 31, the resistance layers 4 on the substrate 1 are connected in parallel in the circuit, thereby reducing the resistance value of the entire resistance group;

By providing the plurality of parallel resistor layers 4, the heat generated by the entire resistor can be evenly dispersed to the entire resistor surface, thereby avoiding the heat dissipation of the resistor concentrated at one point, improving the load capacity of the resistor, and improving the load power of the resistor.

The above-described embodiments of the present invention do not constitute a limitation on the protection scope of the present invention. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention shall be included in the protection scope of the claims of the present invention.

Claims (4)

1. A low-resistance, high-power resistor, characterized in that it comprises a substrate (1), a back electrode (2), a positive electrode (3), a resistor layer (4), a side electrode (9) and a protective layer, wherein the front side of the substrate (1) is provided with positive electrodes (3) on both sides along the length direction, the back side of the substrate (1) is provided with the back electrode (2) at a position opposite to the positive electrode (3), the resistor layer (4) is provided between the positive electrodes (3), the side electrode (9) is located on the side of the substrate (1), and the upper end is in contact with the positive electrode (3), and the lower end is in contact with the back electrode (2), and the positive electrode (3) comprises a connecting A connection point (31), the resistor layer (4) is provided between two connection points (31) opposite to each other along the width direction of the substrate (1), a break zone (32) is provided between adjacent connection points (31) along the length direction of the substrate (1), the protective layer is coated on the surface of the entire resistor layer (4), the protective layer comprises a first heat dissipation layer (5), a second heat dissipation layer (6) and a waterproof layer (7), the first heat dissipation layer (5) is coated on the surface of the resistor layer (4), the second heat dissipation layer (6) is located on the surface of the first heat dissipation layer (5), and the waterproof layer (7) is located on the surface of the second heat dissipation layer (6); There are 4 to 8 connection sites (31), and the distances between adjacent connection sites (31) are equal, and the resistance values of the resistor layer (4) between the corresponding connection sites (31) are also equal; the second heat dissipation layer (6) is composed of glass and lead powder, wherein the mass fraction of the lead powder is controlled at 3 to 5%, and resistance repair points (8) are provided on both sides of each connection site (31). 2. A low-resistance, high-power resistor according to claim 1, characterized in that there are 4 connection sites (31). 3. A low-resistance, high-power resistor according to claim 1, characterized in that there are 8 connection sites (31). 4. A low-resistance, high-power resistor according to claim 1, characterized in that it also includes a nickel plating layer (11) and a tin plating layer (12), wherein the nickel plating layer (11) is located on the surface of the side electrode (9), and the tin plating layer (12) is located on the surface of the nickel plating layer (11).