Chip resistor and preparation method thereof

Abstract

According to the chip resistor and the preparation method thereof, the laser wire cutting grooves adjacent to the left electrode and the right electrode are formed in the resistance layer through laser cutting, the resistance value of the resistor can be accurately adjusted and controlled, the manufacturing precision and consistency of the resistor are improved, the laser cutting mode is optimized through diagonal cutting, and the production efficiency is improved. The laser wire cutting groove is limited at the diagonal position and is adjacent to the front electrode, and the heat effect of the resistor is correspondingly controlled, so that the heat dissipation performance is improved; according to the chip resistor, 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, the 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 present invention relates to the technical field of resistors, and in particular to a chip resistor and a preparation method thereof. Background Art

[0002] With the rapid development of the new energy vehicle industry, the demand for resistors has increased significantly. Resistors play a key role in the "three-electric" system of a car, controlling voltage and current to ensure the stability and safety of the electronic system. Therefore, the performance of resistors directly affects the efficiency and driving experience of new energy vehicles. Since new energy vehicles are highly dependent on electric drive and electronic control systems, resistors have become key components to ensure efficient operation of vehicles.

[0003] At present, automotive resistors need to have a high level of environmental adaptability, including waterproof, dustproof, anti-oxidation, anti-sulfurization and anti-vibration capabilities, in order to adapt to the complex and changeable automobile operating environment and ensure reliable operation under unstable current and voltage conditions. This is crucial to improving the service life and reliability of resistors.

[0004] In view of this, it is particularly important to develop new types of chip resistors to meet the current development trends of the automotive electronics industry, especially the needs of electrification, intelligence and networking. Summary of the invention

[0005] In view of this, an object of the present invention is to provide a chip resistor and a method for preparing the same to solve the above problems.

[0006] The present invention adopts the following scheme:

[0007] The present application provides a chip resistor, comprising a substrate, a back electrode, a front electrode, a resistance layer, a protective layer and a side electrode; a pair of back electrodes are formed on the lower surface of the substrate and separated from each other; a pair of front electrodes are formed on the upper surface of the substrate and separated from each other, and include a left electrode arranged on the left side, and a right electrode arranged on the right side; the resistance layer covers between the left electrode and the right electrode; the protective layer covers the resistance layer, and the protective layer extends to both ends to cover the left electrode and the right electrode respectively; the side electrodes are respectively arranged on opposite sides of the substrate, the side electrode on the left side connects the left electrode and the back electrode on the corresponding side, and the side electrode on the right side connects the right electrode and the back electrode on the corresponding side; wherein the protective layer includes a first protective layer and a second protective layer; the first protective layer is composed of a 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 uncovered left electrode and right electrode, and the third protective layer is composed of a resin silver material.

[0008] As a further improvement, the resistance layer and the first protective layer and the second protective layer extend to cover a portion of the left electrode and the right electrode, and the third protective layer is correspondingly formed on another portion of the left electrode and the right electrode in the uncovered area.

[0009] As a further improvement, the uncovered area is smaller than the covered area to increase the overlapping area between the resistance layer and the front electrode.

[0010] As a further improvement, the third protection layer is arranged to intersect with the side electrode.

[0011] 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.

[0012] As a further improvement, the resistor layer is provided with two laser cutting grooves adjacent to the left electrode and the right electrode along a diagonal direction to perform laser resistance adjustment.

[0013] As a further improvement, the laser cutting grooves are linear, and one of the laser cutting grooves is adjacent to the left electrode, and the other of the laser cutting grooves is adjacent to the right electrode.

[0014] As a further improvement, the two laser cutting grooves are centrally symmetrically arranged on the resistance layer, have the same specifications and dimensions, and have a length less than 1 / 3 of the width of the resistance layer.

[0015] As a further improvement, it also includes a nickel-plated layer; the nickel-plated 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.

[0016] As a further improvement, it also includes a tin-plated layer; the tin-plated layer covers the nickel-plated layer and overlaps the end surface of the second protective layer.

[0017] The present application further provides a method for preparing a chip resistor, comprising the following steps:

[0018] S1: providing a substrate, forming back electrodes separated from each other on the lower surface of the substrate, and forming left electrodes and right electrodes separated from each other on the upper surface of the substrate;

[0019] S2: forming a resistance layer connected to the left electrode and the right electrode; wherein the resistance layer is laser cut to open laser cutting grooves adjacent to the left electrode and the right electrode in a diagonal direction;

[0020] S3: forming a first protective layer composed of a glass material and a second protective layer composed of at least two layers of epoxy resin material on the resistance layer;

[0021] S4: forming a third protective layer made of resin silver material on the uncovered left electrode and the right electrode;

[0022] S5: Sputtering is performed along the side surface to form a side electrode connecting the front electrode and the back electrode on the corresponding side.

[0023] As a further improvement, the following steps are also included:

[0024] S6: electroplating a layer of metal nickel to form a nickel-plated layer that completely covers the back electrode, the side electrode, the front electrode and the third protective layer;

[0025] S7: electroplating a layer of metallic tin on the surface of the nickel-plated layer to form a tin-plated layer that completely covers the nickel-plated layer and overlaps the second protective layer.

[0026] By adopting the above technical solution, the present invention can achieve the following technical effects:

[0027] 1. The chip resistor of the present application has a multi-layer protection structure formed by a first protective layer of glass material and a second protective layer of epoxy resin material, which effectively prevents moisture, chemical corrosion and mechanical damage, and significantly improves the service life of the resistor in harsh environments. In particular, the third protective layer of resin silver material enhances the corrosion resistance of the electrode part, so that the resistor can maintain stable electrical properties during long-term operation.

[0028] 2. The preparation method of the chip resistor forms a laser cutting groove adjacent to the left electrode and the right electrode on the resistor layer by laser cutting, which can accurately adjust the resistance value of the control resistor and improve the manufacturing accuracy and consistency of the resistor. The diagonal cutting is used to optimize the laser cutting method, and the laser cutting groove is limited to the diagonal position and adjacent to the front electrode, corresponding to the thermal effect of the control resistor to improve the heat dissipation performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a schematic structural diagram of a chip resistor according to an embodiment of the present invention;

[0030] Figure 2 yes Figure 1 Partial disassembly diagram in ;

[0031] Figure 3 yes Figure 1 Schematic cross-section diagram in ;

[0032] Figure 4 It is a schematic diagram of the thermal effect produced after laser cutting in the prior art;

[0033] Figure 5 Schematic diagram of thermal effect after diagonal cutting of the chip resistor according to the embodiment of the present invention;

[0034] Figure 6 is a flowchart of a method for preparing a chip resistor according to an embodiment of the present invention;

[0035] Figure 7 yes Figure 6 Further flow chart of .

[0036] 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

[0037] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention.

[0038] Example

[0039] In the first aspect, combined Figures 1 to 5 This embodiment provides a chip resistor, including a substrate 1, a back electrode 2, a front electrode, a resistor layer 3, a protective layer and a side electrode 4.

[0040] A pair of back electrodes 2 are formed on the lower surface of the substrate 1 and are separated from each other. A pair of front electrodes are formed on the upper surface of the substrate 1 and are separated from each other, and include a left electrode 5 arranged on the left side and a right electrode 6 arranged on the right side.

[0041] The resistor layer 3 covers between the left electrode 5 and the right electrode 6. The protective layer covers the resistor layer 3, and the protective layer extends to both ends to cover the left electrode 5 and the right electrode 6. The side electrodes 4 are respectively arranged on opposite sides of the substrate 1, the side electrode 4 on the left side connects the left electrode 5 and the back electrode 2 on the corresponding side, and the side electrode 4 on the right side connects the right electrode 6 and the back electrode 2 on the corresponding side.

[0042] The protective layer includes a first protective layer 7 and a second protective layer 8. The first protective layer 7 is made of glass material, and the second protective layer 8 is made of at least two layers of epoxy resin material. A third protective layer 9 is formed on the uncovered left electrode 5 and right electrode 6, and the third protective layer 9 is made of resin silver material.

[0043] The chip resistor mentioned above has a multi-layer protection structure formed by a first protective layer 7 made of glass and a second protective layer 8 made of epoxy resin, which effectively prevents moisture, chemical corrosion and mechanical damage, and significantly improves the service life of the resistor in harsh environments. In particular, the third protective layer 9 made of resin silver enhances the corrosion resistance of the electrode part, so that the resistor can maintain stable electrical properties during long-term operation.

[0044] In this embodiment, the resistance layer 3, the first protective layer 7 and the second protective layer 8 extend to cover a portion of the left electrode 5 and the right electrode 6, and cover more than half of the left and right electrodes, and the third protective layer 9 is correspondingly formed on the other portion of the left electrode 5 and the right electrode 6 in the uncovered area.

[0045] Among them, the uncovered area is smaller than the covered area to increase the overlapping area between the resistor layer 3 and the front electrode. Since the coverage area of ​​the resistor layer 3 on the left electrode 5 is larger, the contact area between the left electrode 5 and the resistor layer 3 is wider, thereby affecting the current distribution, and the asymmetric distribution is used to adjust the current path inside the resistor so that it can achieve more ideal electrical performance in specific application scenarios (such as in a more humid and harsh environment on the left side of the component). For example, a larger coverage area makes the protective layer of the left electrode 5 more complete, effectively reducing the risk of the left electrode 5 being damaged by the environment, which is especially important for the electrode part that needs additional protection.

[0046] Furthermore, the third protective layer 9 is arranged to intersect with the side electrode 4, ensuring a smooth transition between the electrode surface and the external electrical connection, reducing the poor contact problem caused by height difference, thereby improving the electrical connection reliability of the resistor. The resin silver material has good conductivity and protection performance. Applying it to the third protective layer 9 not only provides additional physical protection for the electrode, further resists water vapor erosion of the electrode by the external environment, but also maintains the conductivity of the electrode, effectively preventing resistance changes or failures caused by corrosion.

[0047] In this embodiment, the first protective layer 7 and the third protective layer 9 are both one layer, the second protective layer 8 is two layers, and the thickness of the second protective layer 8 is more than twice the thickness of the first protective layer 7. Among them, the third protective layer 9 is filled between the front electrode and the protective layer, which can significantly improve the anti-penetration ability, and the second protective layer 8 is thicker, which can provide a layered protection effect for the resistor, and the thicker epoxy resin material is mainly used to enhance the mechanical strength and wear resistance of the overall structure.

[0048] like Figure 2 and Figure 5 As shown, in this embodiment, the resistor layer 3 is provided with two laser cutting grooves 10 adjacent to the left electrode and the right electrode in the diagonal direction for laser resistance adjustment. Among them, the folding line of the resistor is a specific structure distributed on the surface of the substrate 1, which is a V-shaped groove structure, which is convenient for cutting operations to achieve folding and strip folding effects. In addition, the protective layer covers the folding line. In the prior art, the control of the starting point of the knife is not strict, resulting in water vapor penetrating through the junction of the side cutting groove and the protective layer. Placing the laser cutting groove 10 adjacent to the left electrode and the right electrode can not only reduce the structural damage caused by cutting, but also, in particular, the protective layer covers the folding line, which further enhances the protection of the cutting area and ensures that the laser cutting groove 10 is not exposed to the folding line.

[0049] Preferably, the laser cutting groove 10 is in a straight line. By using a laser cutting method, one of the laser cutting grooves 10 is adjacent to the left electrode 5, and the other laser cutting groove 10 is adjacent to the right electrode 6. Thus, the diagonal cutting is optimized in a laser cutting manner, and the laser cutting groove 10 is limited to a diagonal position and adjacent to the front electrode, corresponding to controlling the thermal effect of the resistor to improve the heat dissipation performance. Since the laser cutting groove 10 is adjacent to the electrode, the heat can be conducted away more quickly, thereby effectively controlling the temperature rise during the cutting process and protecting the thermal stability of the resistor. Furthermore, the two laser cutting grooves 10 are centrally symmetrically arranged on the resistor layer 3, and the two have the same specifications and dimensions, and the length is less than 1 / 3 of the width of the resistor layer 3.

[0050] In this embodiment, the chip resistor further includes a nickel-plated layer 11, which completely covers the back electrode 2, the side electrode 4 and the front electrode, and covers the third protective layer 9 and further overlaps the end surface of the second protective layer 8. Furthermore, the chip resistor further includes a tin-plated layer 12, which covers the nickel-plated layer 11 and overlaps the end surface of the second protective layer 8. It should be mentioned that the tin-plated layer 12 and the nickel-plated layer 11 are existing structures, so they are not described here.

[0051] In the second aspect, combined Figure 6 to Figure 7 This embodiment further provides a method for preparing a chip resistor, comprising the following steps:

[0052] S1: providing a substrate 1, forming back electrodes 2 separated from each other on the lower surface of the substrate 1, and forming left electrodes 5 and right electrodes 6 separated from each other on the upper surface of the substrate 1;

[0053] S2: forming a resistor layer 3 connected to the left electrode 5 and the right electrode 6; wherein the resistor layer 3 is laser cut to open laser cutting grooves 10 adjacent to the left electrode and the right electrode in a diagonal direction;

[0054] S3: forming a first protective layer 7 composed of a glass material and a second protective layer 8 composed of at least two layers of epoxy resin material on the resistor layer 3;

[0055] S4: forming a third protective layer 9 made of resin silver material on the uncovered left electrode 5 and right electrode 6;

[0056] S5: Sputtering is performed along the side surface to form the side electrode 4 connecting the front electrode and the back electrode 2 on the corresponding side.

[0057] Furthermore, the method further comprises the steps of:

[0058] S6: electroplating a layer of metal nickel to form a nickel-plated layer 11 that completely covers the back electrode 2, the side electrode 4, the front electrode and the third protective layer 9;

[0059] S7: electroplating a layer of metallic tin on the surface of the nickel-plated layer 11 to form a tin-plated layer 12 that completely covers the nickel-plated layer 11 and overlaps the second protective layer 8 .

[0060] In the above, through multiple process steps, laser cutting is used to form laser cutting grooves 10 adjacent to the left electrode and the right electrode on the resistor layer 3, which can accurately adjust the resistance value of the control resistor and improve the manufacturing accuracy and consistency of the resistor. The diagonal cutting is used to optimize the laser cutting method, and the laser cutting grooves 10 are limited to the diagonal position and adjacent to the front electrode, corresponding to the thermal effect of the control resistor to improve the heat dissipation performance.

[0061] In step S2, it also includes:

[0062] The laser cutting grooves 10 are arranged in a straight line, wherein one laser cutting groove is adjacent to the left electrode, and another laser cutting groove is adjacent to the right electrode.

[0063] It should be mentioned that a first protective layer 7 of glass material is formed first, and then linear laser cutting grooves are cut diagonally (cutting is performed on both sides of the resistor layer 3), and then a second protective layer 8 of multi-layer epoxy resin material is formed.

[0064] In step S1, it also includes:

[0065] The resistance layer 3 and the protection layer extend to cover a portion of the left electrode 5 and the right electrode 6, and the resistance layer covers more of the front electrode, while the uncovered area reserves space for filling the third protection layer 9.

[0066] In step S5, it also includes:

[0067] The side electrode 4 is sputtered to a height that is flush with the third protective layer 9, and after sputtering, the side electrode 4 and the third protective layer 9 are in an intersecting state. Specifically, by sputtering the side electrode 4 to a height that is flush with the third protective layer 9, it is possible to ensure precise docking between the electrode and the protective layer, which helps to improve the stability of the electrical connection and avoid poor contact or electrical performance problems that may be caused by the height difference between the electrode and the protective layer.

[0068] The above are only preferred implementations of the present invention. The protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention.

Claims

1. A method for preparing a chip resistor, characterized in that: The steps include: S1: providing a substrate, forming back electrodes separated from each other on the lower surface of the substrate, and forming left electrodes and right electrodes separated from each other on the upper surface of the substrate; S2: forming a resistance layer connected to the left electrode and the right electrode; wherein the resistance layer is laser cut to open laser cutting grooves adjacent to the left electrode and the right electrode in a diagonal direction; S3: forming a first protective layer composed of a glass material and a second protective layer composed of at least two layers of epoxy resin material on the resistance layer; S4: forming a third protective layer made of resin silver material on the uncovered left electrode and the right electrode; S5: Sputtering is performed along the side surface to form a side electrode connecting the front electrode and the back electrode on the corresponding side.

2. The method for preparing a chip resistor according to claim 1, characterized in that: In step S2, it also includes: A laser cutting method is adopted to make one of the laser cutting grooves adjacent to the left electrode and the other laser cutting groove adjacent to the right electrode.

3. The method for preparing a chip resistor according to claim 2, characterized in that: The two laser cutting grooves are centrally symmetrically arranged on the resistance layer, have the same specifications and dimensions, and have a length less than 1 / 3 of the width of the resistance layer.

4. The method for preparing a chip resistor according to claim 3, characterized in that: First, a first protective layer of glass material is formed, and then a straight laser cutting groove is cut by a knife, and then a second protective layer of multi-layer epoxy resin material is formed.

5. The method for preparing a chip resistor according to claim 1, characterized in that: In step S1, it also includes: The resistance layer extends to cover more than half of the left electrode and the right electrode, and the first protection layer completely covers the resistance layer, while the area not covered by the first protection layer reserves space for filling the third protection layer.

6. The method for preparing a chip resistor according to claim 1, characterized in that: In step S5, it also includes: The side electrode is sputtered to a height that is flush with the third protective layer, and after sputtering, the side electrode and the third protective layer are in an intersecting state.

7. The method for preparing a chip resistor according to claim 1, characterized in that: The first protective layer and the third protective layer are configured as a one-layer protective layer structure, the second protective layer is configured as a two-layer protective layer structure, and the thickness of the second protective layer is limited to be greater than twice the thickness of the first protective layer.

8. The method for preparing a chip resistor according to claim 1, characterized in that: Also includes the steps: S6: electroplating a layer of metal nickel to form a nickel-plated layer that completely covers the back electrode, the side electrode, the front electrode and the third protective layer.

9. The method for preparing a chip resistor according to claim 8, characterized in that: Also includes the steps: S7: electroplating a layer of metallic tin on the surface of the nickel-plated layer to form a tin-plated layer that completely covers the nickel-plated layer and overlaps the second protective layer.

10. A chip resistor, characterized in that: Produced based on the preparation method according to any one of claims 1 to 9.

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