Chip resistor

Abstract

The utility model provides a chip resistor. The chip resistor comprises a substrate, a back electrode, a front electrode, a resistive layer, a protective layer and a side electrode, the protective layer comprises a first protective layer and a second protective layer; the first protective layer is made of a glass material, and the second protective layer is made of at least two layers of epoxy resin materials; a third protective layer is formed on the left electrode and the right electrode which are not covered, and the third protective layer is made of a resin silver material; through a multi-layer protection structure formed by the first protection layer made of the glass material and the second protection layer made of the epoxy resin material, invasion of moisture, chemical corrosion and mechanical damage is effectively prevented, the service life of the resistor in a severe environment is remarkably prolonged, and particularly, through the third protection layer made of the resin silver material, the service life of the resistor is prolonged. The anti-corrosion performance of the electrode part is enhanced, so that the resistor can keep stable electrical performance during long-time work.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of resistor, specifically, relate to a chip resistor. BACKGROUND

[0002] With the rapid development of new energy automobile industry, the demand for resistors increases significantly. The existing vehicle resistors are difficult to have high level of environmental adaptability, including waterproof, dustproof, anti-oxidation, anti-sulfurization and anti-vibration and many other abilities, to adapt to the complex and changeable automobile operating environment, ensure reliable work under unstable current and voltage conditions. This is very important to improve the service life and reliability of the resistor. SUMMARY

[0003] Therefore, the utility model discloses a chip resistor to solve the above problems.

[0004] The utility model discloses a scheme that adopts as follows:

[0005] The application provides a chip resistor, which comprises a substrate, back electrodes, front electrodes, a resistance layer, a protective layer and side electrodes; a pair of back electrodes are formed on the lower surface of the substrate and are separated from each other; a pair of front electrodes are formed on the upper surface of the substrate and are separated from each other, which comprises a left electrode arranged on the left side and a right electrode arranged on the right side; the resistance layer is covered between the left electrode and the right electrode; the protective layer is covered on the resistance layer, and the protective layer extends to the left electrode and the right electrode respectively; the side electrodes are arranged on the opposite sides of the substrate respectively, the side electrode on the left side is connected with the left electrode and the back electrode on the corresponding side, and the side electrode on the right side is connected with the right electrode and the back electrode on the corresponding side; wherein the protective layer comprises a first protective layer and a second protective layer; the first protective layer is composed of glass material, and the second protective layer is composed of at least two layers of epoxy resin material; a third protective layer is formed on the left electrode and the right electrode which are not covered, and the third protective layer is composed of resin silver material.

[0006] As a further improvement, the resistance layer and the first protective layer and the second protective layer extend to cover more than half of the left electrode and the right electrode, and the third protective layer is formed on the other part of the left electrode and the right electrode which are not covered.

[0007] As a further improvement, the uncovered area is smaller than the covered area, so as to increase the overlapping area of the resistance layer and the front electrode.

[0008] As a further improvement, the third protective layer intersects with the side electrode.

[0009] As a further improvement, the first protective layer and the third protective layer are each one layer, the second protective layer is two layers, and the thickness of the second protective layer is more than twice the thickness of the first protective layer.

[0010] As a further improvement, the resistance layer is provided with two laser cutting grooves adjacent to the left electrode and the right electrode respectively in a diagonal direction to perform laser resistance adjustment.

[0011] As a further improvement, the two laser cutting grooves are linear, one of which is adjacent to the left electrode, and the other of which is adjacent to the right electrode.

[0012] As a further improvement, the two laser cutting grooves are symmetrically arranged on the resistance layer, and have the same size and a depth less than 1 / 3 of the width of the resistance layer.

[0013] As a further improvement, a nickel plating layer is further included, which completely covers the back electrode, the side electrode, the front electrode, and the third protective layer, and further overlaps the end surface of the second protective layer.

[0014] As a further improvement, a tin plating layer is further included, which covers the nickel plating layer and overlaps the end surface of the second protective layer.

[0015] The application further provides a preparation method of a chip resistor, comprising the following steps:

[0016] S1: providing a substrate, forming a back electrode separated from each other on the lower surface of the substrate, and forming a left electrode and a right electrode separated from each other on the upper surface of the substrate;

[0017] S2: forming a resistance layer connected to the left electrode and the right electrode; wherein the resistance layer is laser cut to form two laser cutting grooves adjacent to the left electrode and the right electrode respectively in a diagonal direction;

[0018] S3: forming a first protective layer composed of glass on the resistance layer, and a second protective layer composed of at least two layers of epoxy resin;

[0019] S4: forming a third protective layer of resin silver material on the left electrode and the right electrode which are not covered;

[0020] S5: sputtering along the side to form a side electrode connecting the front electrode and the corresponding side back electrode.

[0021] As a further improvement, the method further comprises the following steps:

[0022] S6: electroplating a layer of metal nickel to form a nickel plating layer completely covering the back electrode, the side electrode, the front electrode, and the third protective layer;

[0023] S7: electroplating a layer of tin on the surface of the nickel plating layer to form a tin plating layer completely covering the nickel plating layer and overlapping the second protective layer.

[0024] By adopting the technical scheme, the following technical effects can be achieved:

[0025] 1. The chip resistor of the application has a multilayer protective structure formed by the first protective layer of glass material and the second protective layer of epoxy resin material, which effectively prevents the invasion of moisture, chemical corrosion and mechanical damage, significantly improves the service life of the resistor in harsh environments, and especially, the third protective layer of resin silver material enhances the corrosion resistance of the electrode part, so that the resistor can maintain stable electrical performance during long-term operation.

[0026] 2. The preparation method of the chip resistor forms laser cutting grooves adjacent to the left electrode and the right electrode on the resistance layer, which can accurately adjust and control the resistance value of the resistor, improve the manufacturing precision and consistency of the resistor, and optimizes the laser cutting mode by diagonal cutting to limit the laser cutting groove at the diagonal position and adjacent to the front electrode, which corresponds to the thermal effect of the resistor to improve the heat dissipation performance. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 is a structural schematic diagram of the chip resistor of the embodiment of the application;

[0028] Figure 2 is Figure 1 a partial disassembly schematic diagram in

[0029] Figure 3 is Figure 1 a cross-sectional schematic diagram in

[0030] Figure 4 is a schematic diagram of the thermal effect after laser cutting in the prior art;

[0031] Figure 5 is a schematic diagram of the thermal effect after diagonal cutting of the chip resistor of the embodiment of the application;

[0032] Figure 6 is a flowchart of the preparation method of the chip resistor of the embodiment of the application;

[0033] Figure 7 is Figure 6 a further flowchart of

[0034] Icon: 1 - substrate; 2 - back electrode; 3 - resistance layer; 4 - side electrode; 5 - left electrode; 6 - right electrode; 7 - first protective layer; 8 - second protective layer; 9 - third protective layer; 10 - laser cutting groove; 11 - nickel plating layer; 12 - tin plating layer. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme of the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments of the present application, all the other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but merely represents selected embodiments of the present application.

[0036] EMBODIMENT

[0037] In a first aspect, in combination with Figures 1 to 5 The present embodiment provides a chip resistor, which comprises a substrate 1, a back electrode 2, a front electrode, a resistance layer 3, a protective layer and a side electrode 4.

[0038] A pair of back electrodes 2 are formed on the lower surface of the substrate 1 and separated from each other. A pair of front electrodes are formed on the upper surface of the substrate 1 and separated from each other, which comprises a left electrode 5 arranged on the left side and a right electrode 6 arranged on the right side.

[0039] The resistance layer 3 is covered between the left electrode 5 and the right electrode 6. The protective layer is covered on the resistance layer 3, and the protective layer extends to the left electrode 5 and the right electrode 6 at both ends, respectively. The side electrode 4 is arranged on the opposite sides of the substrate 1, respectively, and the side electrode 4 on the left side is connected to the left electrode 5 and the corresponding back electrode 2, and the side electrode 4 on the right side is connected to the right electrode 6 and the corresponding back electrode 2.

[0040] The protective layer comprises a first protective layer 7 and a second protective layer 8. The first protective layer 7 is composed of glass material, and the second protective layer 8 is composed of at least two layers of epoxy resin material. A third protective layer 9 is formed on the left electrode 5 and the right electrode 6 which are not covered, and the third protective layer 9 is composed of resin silver material.

[0041] The patch resistor is provided with a multilayer protection structure formed by the first protection layer 7 made of glass and the second protection layer 8 made of epoxy resin, so that the resistor is effectively prevented from being damaged by moisture, chemical corrosion and mechanical damage, and the service life of the resistor in a harsh environment is significantly improved. In particular, the third protection layer 9 made of resin silver enhances the corrosion resistance of the electrode part, so that the resistor can maintain stable electrical performance during long-term operation.

[0042] In the embodiment, the resistance layer 3 and the first protection layer 7 and the second protection layer 8 extend to cover part of the left electrode 5 and the right electrode 6, and cover more than half of the left electrode 5 and the right electrode 6. The third protection layer 9 is formed on the other part of the left electrode 5 and the right electrode 6 which is not covered.

[0043] The uncovered area is smaller than the covered area, so as to increase the overlapping area of the resistance layer 3 and the front electrode. Since the coverage area of the resistance layer 3 on the left electrode 5 is larger, the contact area between the left electrode 5 and the resistance layer 3 is wider, which affects the current distribution. The asymmetric distribution is used to adjust the current path in the resistor, so as to achieve more ideal electrical performance in a specific application scenario (for example, in a harsh environment where the left side of the component is more humid). For example, the larger coverage area makes the protection layer of the left electrode 5 more complete, effectively reducing the risk of environmental damage to the left electrode 5, which is particularly important for electrode parts that require additional protection.

[0044] Further, the third protection layer 9 intersects with the side electrode 4, which ensures smooth transition of the electrode surface and external electrical connection, reduces the problem of poor contact caused by height difference, and improves the electrical connection reliability of the resistor. The resin silver material has good conductivity and protection performance, which not only provides additional physical protection for the electrode and further resists moisture erosion of the electrode from the external environment, but also maintains the conductivity of the electrode, effectively preventing resistance changes or failure caused by corrosion.

[0045] In the embodiment, the first protection layer 7 and the third protection layer 9 are both one layer, the second protection layer 8 is two layers, and the thickness of the second protection layer 8 is more than twice the thickness of the first protection layer 7. The third protection layer 9 is filled between the front electrode and the protection layer, which can significantly improve the anti-permeation ability. The second protection layer 8 has a larger thickness, which can provide layered protection effect for the resistor. The thicker epoxy resin material is mainly used to enhance the mechanical strength and wear resistance of the overall structure.

[0046] As Figure 2 and Figure 5As shown, in the embodiment, the resistance layer 3 is provided with laser tangent grooves 10 adjacent to the left electrode and the right electrode respectively in the diagonal direction for laser resistance adjustment. The resistance particle folding line is a specific structure distributed on the surface of the substrate 1, which is a V-shaped groove structure, facilitating cutting operation to achieve particle folding and strip effect. In addition, the protective layer covers the particle folding line. In the prior art, the starting point is not strictly controlled, which causes water vapor to penetrate into the combination of the side tangent groove and the protective layer, and the laser tangent groove 10 adjacent to the left electrode and the right electrode can not only reduce the structural damage caused by cutting, but also further enhance the protection of the cutting area, and ensure that the laser tangent groove 10 is not exposed to the particle folding line.

[0047] Preferably, the laser tangent groove 10 is linear. One of the laser tangent grooves 10 is adjacent to the left electrode 5 and the other is adjacent to the right electrode 6 by means of laser cutting. Diagonal cutting (cutting on both sides of the resistance layer 3) optimizes the way of laser cutting, limits the laser tangent groove 10 to the diagonal position and adjacent to the front electrode, and controls the thermal effect of the resistance to improve the heat dissipation performance. Since the laser tangent groove 10 is adjacent to the electrode, the heat can be conducted away more quickly, thereby effectively controlling the temperature rise in the cutting process and protecting the thermal stability of the resistor. Further, the two laser tangent grooves 10 are symmetrically arranged on the resistance layer 3, and the two laser tangent grooves 10 have the same size and a depth less than 1 / 3 of the width of the resistance layer 3.

[0048] In the embodiment, the chip resistor further comprises a nickel plating layer 11 covering the back electrode 2, the side electrode 4 and the front electrode, and covering the third protective layer 9 and further overlapping the end surface of the second protective layer 8. Further, the chip resistor further comprises a tin plating layer 12 covering the nickel plating layer 11 and overlapping the end surface of the second protective layer 8. It should be noted that the tin plating layer 12 and the nickel plating layer 11 are existing structures, so they will not be described here.

[0049] In the second aspect, in combination with Figures 6 to 7 The embodiment further provides a preparation method of a chip resistor, comprising the following steps:

[0050] S1: providing a substrate 1, forming a back electrode 2 separated from each other on the lower surface of the substrate 1, and forming a left electrode 5 and a right electrode 6 separated from each other on the upper surface of the substrate 1;

[0051] S2: forming a resistance layer 3 connected to the left electrode 5 and the right electrode 6; wherein the resistance layer 3 is subjected to laser cutting to form laser tangent grooves 10 adjacent to the left electrode and the right electrode in the diagonal direction;

[0052] S3: Forming a first protective layer 7 composed of glass material on the resistance layer 3, and a second protective layer 8 composed of at least two layers of epoxy resin material;

[0053] S4: Correspondingly forming a third protective layer 9 composed of resin silver material on the uncovered left electrode 5 and right electrode 6;

[0054] S5: Sputtering along the side surface to form a side electrode 4 connecting the front electrode and the corresponding side back electrode 2.

[0055] Further, it further comprises the steps of:

[0056] S6: Electroplating a layer of metal nickel to form a nickel plating layer 11 completely covering the back electrode 2, side electrode 4, front electrode and third protective layer 9;

[0057] S7: Electroplating a layer of metal tin on the surface of the nickel plating layer 11 to form a tin plating layer 12 completely covering the nickel plating layer 11 and overlapping on the second protective layer 8.

[0058] The above-mentioned resistance layer 3 is cut by laser cutting to form a laser cutting slot 10 adjacent to the left electrode and right electrode through multiple process steps, which can accurately adjust and control the resistance value of the resistor, improve the manufacturing precision and consistency of the resistor, and the diagonal cutting optimizes the laser cutting mode, limits the laser cutting slot 10 to the diagonal position and adjacent to the front electrode, and correspondingly controls the heat effect of the resistor to improve the heat dissipation performance.

[0059] The above is only the preferred embodiment of the present application, and the protection scope of the present application is not limited to the above-mentioned embodiments, and any technical solution belonging to the idea of the present application belongs to the protection scope of the present application.

Claims

1. A chip resistor characterized by, Comprising: a substrate; a pair of back electrodes formed on a lower surface of the substrate and separated from each other; a pair of front electrodes formed on an upper surface of the substrate and separated from each other, including a left electrode arranged on the left side, and a right electrode arranged on the right side; a resistance layer covering between the left electrode and the right electrode; a protective layer covering on the resistance layer, and the protective layer extends to cover the left electrode and the right electrode respectively at both ends; a side electrode arranged on opposite sides of the substrate respectively, the left side of the side electrode connects the left electrode and the corresponding side of the back electrode, and the right side of the side electrode connects the right electrode and the corresponding side of the back electrode; wherein, the protective layer includes a first protective layer and a second protective layer; the first protective layer is composed of glass material, and the second protective layer is composed of at least two layers of epoxy resin material; and, a third protective layer is formed on the left electrode and the right electrode which are not covered, and the third protective layer is composed of resin silver material.

2. The chip resistor of claim 1, wherein The resistance layer and the first protective layer and the second protective layer extend to cover more than half of the left electrode and the right electrode, and the third protective layer is correspondingly formed on the other part of the left electrode and the right electrode which are not covered.

3. The chip resistor of claim 2, wherein The uncovered area is less than the covered area, so as to increase the overlapping area of the resistance layer and the front electrode.

4. The chip resistor of claim 2, wherein The third protective layer intersects with the side electrode.

5. The chip resistor of claim 1, wherein The first protective layer and the third protective layer are both one layer, the second protective layer is two layers, and the thickness of the second protective layer is more than twice the thickness of the first protective layer.

6. The chip resistor of claim 1, wherein The resistance layer is provided with two laser tangent grooves adjacent to the left electrode and the right electrode respectively along the diagonal direction, so as to perform laser resistance adjustment.

7. The chip resistor of claim 6, wherein The laser tangent grooves are linear, and one of the laser tangent grooves is adjacent to the left electrode, and the other laser tangent groove is adjacent to the right electrode.

8. The chip resistor defined in Claim 7, wherein The two laser tangent grooves are centrally symmetrically arranged on the resistance layer, and the specifications and sizes of the two laser tangent grooves are the same, and the depth is less than 1 / 3 of the width of the resistance layer.

9. The chip resistor of claim 1, wherein Further comprising a nickel plating layer; the nickel plating layer completely covers the back electrode, the side electrode and the front electrode, and covers the third protective layer and further overlaps the end surface of the second protective layer.

10. The chip resistor of claim 1, wherein Further comprising a tin plating layer; the tin plating layer covers the nickel plating layer and overlaps the end surface of the second protective layer.

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