Electroplating-free thick film chip resistor

Abstract

The utility model discloses an electroplating-free thick film chip resistor which comprises a ceramic substrate, front electrodes are arranged at the tops of the two sides of the ceramic substrate, a resistance layer is arranged at the top of the ceramic substrate, an outer protection layer is arranged at the top of the resistance layer, and the front electrodes and back electrodes form a parallel structure. The first protective layer is made of a silver protective agent, the first protective layer and the outer protective layer are integrally of a T-shaped structure in an overlook mode, the length of the outer protective layer is larger than that of the resistance layer, back electrodes are arranged at the bottoms of the two sides of the ceramic substrate, the first protective layer is arranged on the outer walls of the front electrode and the back electrodes, and the first protective layer is of an L-shaped structure. According to the device, the front electrode and the back electrode can be protected, the problem that the front electrode and the back electrode are oxidized in the cutting process is avoided, and the quality of the front electrode and the quality of the back electrode are guaranteed.

Description

Technical Field

[0001] This utility model relates to the field of thick film wafer resistor technology, specifically to electroplating-free thick film wafer resistors. Background Technology

[0002] Thick film wafer resistors are a common electronic component. They are manufactured using thick film technology, which refers to a technique that prints or sprays conductive and resistive materials onto an insulating substrate in the form of paste, and then sintersects them at high temperatures to form a circuit.

[0003] Currently, thick film wafer resistors are typically electroplated and laser-cut to meet application requirements. While these processes improve performance, the high temperatures during laser cutting can cause oxidation of the electrodes. Furthermore, the edge effect after electroplating can affect subsequent installation and connection, and also increase production costs. Therefore, improvements are needed. Utility Model Content

[0004] The purpose of this invention is to provide an electroplating-free thick film wafer resistor to solve the problem of electrode oxidation during the processing of thick film wafer resistors as mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution: an electroplating-free thick film wafer resistor, comprising a ceramic substrate, with front electrodes disposed on the top of both sides of the ceramic substrate and back electrodes disposed on the bottom of both sides of the ceramic substrate. A first protective layer is disposed on the outer wall of the front and back electrodes, the first protective layer having an "L" shaped structure. A sheet-like ceramic substrate is disposed at the bottom of the front electrode, and a folded strip is disposed on the sheet-like ceramic substrate. The two sides of the folded strip correspond to the two sides of the front electrode, respectively, for separating the folded strip. A cutting line is disposed on the front electrode, the cutting line having an "L" shaped structure.

[0006] Preferably, the front electrode and the back electrode form a parallel structure, and the material of the first protective layer is a silver protective agent.

[0007] Preferably, a resistive layer is provided on the top of the ceramic substrate, and an outer protective layer is provided on the top of the resistive layer.

[0008] Preferably, the first protective layer and the outer protective layer together form a "T" shape when viewed from above, and the length of the outer protective layer is greater than the length of the resistive layer.

[0009] Compared with the prior art, the beneficial effects of this utility model are:

[0010] (1) This device can protect the front electrode and the back electrode, avoid oxidation of the front electrode and the back electrode during the cutting process, and ensure the quality of the front electrode and the back electrode.

[0011] (2) This device sets a first protective layer on the outer wall of the front electrode and the back electrode. The first protective layer is mainly made of silver protective agent, which can play an anti-oxidation role for the front electrode and the back electrode while ensuring the subsequent welding effect.

[0012] (3) This device improves the accuracy by setting folded strips and folded grain lines on the sheet ceramic substrate during the printing process of the front electrode and the back electrode, and by using laser cutting to make the resistance value more accurate. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the electroplating-free thick film wafer resistor structure of this utility model;

[0014] Figure 2 This is a top view of the electroplating-free thick film wafer resistor of this utility model;

[0015] Figure 3 This is a top view of the connection between the front electrode and the sheet ceramic substrate of the electroplating-free thick film wafer resistor of this utility model.

[0016] Figure 4 This utility model relates to an electroplating-free thick film wafer resistor. Figure 3 Enlarged view of point A in the middle.

[0017] In the figure: 1. First protective layer; 2. Front electrode; 3. Outer protective layer; 4. Resistive layer; 6. Back electrode; 7. Ceramic substrate; 8. Folded strip; 9. Sheet ceramic substrate; 10. Cutting line. Detailed Implementation

[0018] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0019] Please see Figure 1-4This utility model provides a technical solution: an electroless thick-film wafer resistor, including a ceramic substrate 7, with front electrodes 2 disposed on the top of both sides of the ceramic substrate 7, and folded strips 8 disposed on the sheet-like ceramic substrate 9; the two sides of the folded strips 8 are respectively positioned on the two sides of the front electrodes 2, used for separating the folded strips 8; this structure facilitates the separation of the resistor by setting the folded strips 8, and also avoids damage to the resistor; the front electrodes 2 are laser-cut, and the cutting line 10 is in the shape of an "L"; this structure, by setting the blade shape and position of the cutting line 10, makes the cutting accuracy more accurate and reduces damage to the front electrode 2. Damage to electrode 2; A resistive layer 4 is provided on the top of the ceramic substrate 7, and an outer protective layer 3 is provided on the top of the resistive layer 4; the outer protective layer 3 of this structure can protect the resistive layer 4 and ensure the service life of the resistive layer 4; Back electrodes 6 are provided on the bottom of both sides of the ceramic substrate 7, and a first protective layer 1 is provided on the outer wall of the front electrode 2 and the back electrode 6. The back electrode 6 uses an electroplating-free silver electrode material, which can be directly reflow soldered and bonded, and the bonding force can reach 15KG. Moreover, the product does not need to undergo an electroplating process, which can greatly reduce the discharge of electroplating wastewater. The design meets the national requirements for green and environmentally friendly development. The first protective layer 1 has an "L"-shaped structure and is made of silver protective agent. The front electrode 2 is a smooth and delicate electrode material with a high silver content, which, after being integrated with the first protective layer 1, facilitates bonding processing. The production process of the first protective layer 1 in this structure is as follows: add 3 / 4 volume of pure water and heat to 60±10℃; dissolve 100ml of silver protective agent in pure water at 60±10℃ and dilute to 1 liter; after cleaning the front electrode 2 and the back electrode 6, immerse them in the prepared protective solution for 2~3 minutes. Remove; then immerse in still cold water at a temperature not exceeding 30°C for more than 1 minute and remove; then rinse thoroughly in running water; after rinsing in pure water, place in a centrifuge with hot air to dry; after drying, the surface should be free of water stains and moisture, and the equipment should meet HSF and halogen-free standards; the outer walls of the front electrode 2 and the back electrode 6 are provided with a first protective layer 1, and the first protective layer 1 and the outer protective layer 3 are arranged in a "T" shape when viewed from above, and the length of the outer protective layer 3 is greater than the length of the resistive layer 4; this structure, by setting the two sides of the "T" shape, facilitates the installation and connection work.

[0020] Working principle: In the production of this electroless thick film wafer resistor, firstly, add 3 / 4 volume of pure water and heat to 60±10℃; dissolve 100ml of silver protective agent in pure water at 60±10℃ and dilute to 1 liter; after cleaning the front electrode 2 and the back electrode 6, immerse them in the prepared protective solution for 2~3 minutes and then take them out; then immerse them in still cold water at a temperature not exceeding 30℃ for more than 1 minute and then take them out; then immerse them in running water to clean them; after immersing them in pure water to clean them, place them in a centrifuge with hot air to dry them; after drying, there are no water stains or moisture on the surface, thus forming the first protective layer 1 on the surface of the front electrode 2 and the back electrode 6. Then, the front electrode 2, the back electrode 6 and the resistive layer 4 are sprayed and connected to the ceramic substrate 7.

[0021] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A thick-film chip resistor free of plating, comprising a ceramic substrate (7), characterized in that: The top of both sides of the ceramic substrate (7) is provided with a front electrode (2), the bottom of both sides of the ceramic substrate (7) is provided with a back electrode (6), the outer wall of the front electrode (2) and the back electrode (6) is provided with a first protective layer (1), the first protective layer (1) is in an "L" shape structure, the bottom of the front electrode (2) is provided with a sheet-shaped ceramic substrate (9), the sheet-shaped ceramic substrate (9) is provided with a folding strip (8), the two sides of the folding strip (8) correspond to the two sides of the front electrode (2) respectively, and the folding strip (8) is used for separating the folding strip (8), the front electrode (2) is provided with a cutting line (10), and the cutting line (10) is in an "L" shape structure.

2. The electroless plated thick film chip resistor of claim 1 wherein: The front electrode (2) and the back electrode (6) constitute a parallel structure, and the material of the first protective layer (1) is a silver protective agent.

3. The electroless plated thick film chip resistor of claim 1 wherein: The top of the ceramic substrate (7) is provided with a resistance layer (4), and the top of the resistance layer (4) is provided with an outer protective layer (3).

4. The electroless plated thick film chip resistor of claim 2, wherein: The first protective layer (1) and the outer protective layer (3) are in a "T" shape structure as a whole in the top view, and the length of the outer protective layer (3) is greater than the length of the resistance layer (4).

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