Thick-film chip resistor with anti-sulfuration sputter coating layer

Abstract

The utility model relates to the technical field of chip resistors, in particular to a thick-film chip resistor with an anti-sulfuration sputter coating layer. The utility model relates to a high-voltage resistor, which comprises a ceramic substrate, front electrodes arranged on both sides of the upper surface of the ceramic substrate, back electrodes arranged on both sides of the lower surface of the ceramic substrate, a resistor body arranged on the upper surface of the ceramic substrate and connected with the front electrodes on both sides, and a first protective layer printed on the upper surface of the resistor body, a first protective layer is printed on the upper surface of the ceramic substrate, a mask paste layer is printed on the first protective layer, a coating layer is formed on the upper surface of the ceramic substrate through vacuum sputtering, a second protective layer is further printed on the first protective layer, and side electrodes are further formed on the left side and the right side of the ceramic substrate through vacuum sputtering. The beneficial effects of the utility model are that according to the technical scheme, the coating layer is sputtered on the front electrode and covers the front electrode, so that the silver paste front electrode is prevented from being vulcanized and reducing the product performance, and the production cost is reduced on the premise of not influencing the product characteristics.

Description

Technical Field

[0001] The utility model relates to the technical field of chip resistors, in particular to a thick film chip resistor with a sputtered coating layer resistant to sulfidation. Background Art

[0002] The existing sulfur-resistant thick film chip resistor uses a ceramic substrate as a carrier. It forms a circuit by screen-printing silver-palladium paste with a specific pattern, and prints resistor ink on the upper surface of the ceramic substrate as the resistor body, connecting the silver-palladium paste circuits at both ends. The thick film resistor made by this method has a mature process, but the cost is relatively high, and it cannot gain an advantage in the highly competitive resistor market.

[0003] Therefore, it is necessary to design a thick film chip resistor with a sputtered coating layer resistant to sulfidation to solve the above problems. Summary of the Utility Model

[0004] The purpose of the utility model is to provide a thick film chip resistor with a sputtered coating layer resistant to sulfidation to overcome the above-mentioned deficiencies existing in the current prior art.

[0005] To achieve the above purpose, the utility model adopts the following technical solutions:

[0006] A thick film chip resistor with a sputtered coating layer resistant to sulfidation, which includes a ceramic substrate, front electrodes are arranged on both sides of the upper surface of the ceramic substrate, back electrodes are arranged on both sides of the lower surface of the ceramic substrate, and a resistor body is arranged on the upper surface of the ceramic substrate and is connected to the front electrodes on both sides. It is characterized in that: a trimming resistor with an L-shaped structure is cut by laser on the resistor, a first protective layer is printed on the upper surface of the resistor body, a layer of mask paste is printed on the first protective layer, a coating layer is vacuum sputtered on the upper surface of the ceramic substrate, the coating layer covers the mask paste, the coating layer completely covers the front electrodes, and the width of the coating layer is greater than the width of the front electrodes. A second protective layer is also printed on the first protective layer, the second protective layer completely covers the first protective layer and partially covers the coating layer on the front electrodes. An identification character code layer is also arranged on the second protective layer. Side electrodes are also vacuum sputtered on the left and right sides of the ceramic substrate, and the side electrodes are respectively connected to the adjacent front electrodes and back electrodes; an outer protective layer is plated on the outer surfaces of the coating layer and the side electrodes.

[0007] Preferably, the resistor body is formed by screen-printing silver-palladium paste.

[0008] Preferably, through ultrasonic cleaning, the coating layer on the mask paste is cleaned off, and only the coating layer on the front electrodes is left.

[0009] Preferably, the vacuum sputtered coating layer is specifically a Ni / Cr alloy.

[0010] Preferably, the material of the outer protective layer is nickel or tin, and the outer protective layer forms end electrodes between the coating layer, the side electrodes, and the back electrodes.

[0011] The beneficial effects of the present utility model are as follows: By sputtering a coating layer on the front electrode to cover the front electrode, the silver paste front electrode is prevented from sulfidation and the product performance is reduced, thereby reducing the production cost without affecting the product characteristics. Description of the Drawings

[0012] Figure 1 It is a side sectional view of a thick film chip resistor with a sputtered coating layer resistant to sulfidation according to the present utility model;

[0013] Figure 2 It is a top view of a thick film chip resistor with a sputtered coating layer resistant to sulfidation according to the present utility model;

[0014] In the figure: 1, ceramic substrate; 2, front electrode; 3, back electrode; 4, resistor body; 5, resistor trimming; 6, first protective layer; 7, coating layer; 8, second protective layer; 9, identification character code layer; 10, side electrode; 11, outer protective layer; 12, masking paste; 13, second outer protective layer. Detailed Embodiments

[0015] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all of the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0016] In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present utility model.

[0017] Referring to Figure 1 and Figure 2 , a thick film chip resistor with a sputtered coating layer resistant to sulfidation, which includes a ceramic substrate 1, front electrodes 2 are provided on both sides of the upper surface of the ceramic substrate, back electrodes 3 are provided on both sides of the lower surface of the ceramic substrate, and a resistor body 4 is provided on the upper surface of the ceramic substrate and is connected to the front electrodes on both sides;

[0018] The resistor body is formed by screen printing with silver-palladium paste, and a trimming resistor 5 with an L-shaped structure is cut by laser on the resistor to obtain the resistance value.

[0019] A first protective layer 6 is printed on the upper surface of the resistor body to protect the surface of the resistor body by printing a mask paste, and a mask paste 12 is printed on the first protective layer 6.

[0020] A coating layer 7 is vacuum sputtered on the upper surface of the ceramic substrate 1, and the coating layer covers the front electrode 2 and the mask paste; through ultrasonic cleaning, the mask paste layer is cleaned off, so that the coating layer on the mask paste is cleaned off, and only the coating layer on the front electrode remains.

[0021] The coating layer completely covers the front electrode, and the width of the coating layer is greater than the width of the front electrode; and part of it is placed on the first protective layer 6.

[0022] The coating layer formed by vacuum sputtering is specifically a Ni / Cr alloy.

[0023] A second protective layer 8 is also printed on the first protective layer 6. The second protective layer 8 completely covers the first protective layer 6 and part of it is placed on the coating layer 7 on the front electrode 2.

[0024] An identification character code layer 9 is also provided on the second protective layer 8; used to print some data and characters for convenient identification and understanding.

[0025] Side electrodes 10 are also vacuum sputtered on the left and right sides of the ceramic substrate 1, and the side electrodes are respectively connected to the adjacent front electrode and back electrode; an outer protective layer 11 is plated on the outer surfaces of the coating layer 7 and the side electrodes, and the material of the outer protective layer is nickel or tin; the outer protective layer 11 forms end electrodes between the coating layer 7, the side electrodes 10 and the back electrode. The material of the first outer protective layer 11 is Ni; in order to enhance the protection ability, a second outer protective layer 13 can be electroplated outside the first outer protective layer 11, and the second outer protective layer completely covers the first outer protective layer 11, and the material of the second outer protective layer is Sn.

[0026] In this embodiment, silver paste is printed and coated on the lower surface of the alumina ceramic body by screen thick film printing and sintered, and a back electrode is formed on the lower surface of the body.

[0027] Then, silver-palladium paste is printed and coated on the upper surface of the body by screen thick film printing and sintered, and a front electrode is formed on the upper surface of the body.

[0028] Print and coat a resistor paste layer between the positive electrodes, and sinter it to form a resistor body. The two sides of the resistor body are connected to the positive electrodes, and part of it is placed on the positive electrodes;

[0029] Then, on the above resistor body, print and coat a layer of epoxy resin paste by screen thick film printing method, and sinter it to form a first protective layer for protecting the resistor body. The first protective layer completely covers the surface of the resistor body, and both ends are partially placed on the positive electrodes;

[0030] Then, use laser cutting to modify the resistor body to the resistance value and accuracy required by the customer application end, forming a laser cutting line, and the cut laser cutting line is in an L-shaped structure; thereby changing the cross-sectional area of the resistor to adjust the impedance value;

[0031] Then print a mask paste on the upper surface of the ceramic substrate, and a layer of mask paste is printed on the first protective layer placed on the upper surface of the ceramic substrate;

[0032] Vacuum sputter a coating layer outside the mask paste on the upper surface of the ceramic substrate, and fill the entire upper surface of the ceramic substrate, covering the entire upper surface structure;

[0033] Then perform ultrasonic water washing, and only retain the vacuum sputtered coating layer on the positive electrodes;

[0034] After cleaning, print and coat a layer of epoxy resin paste on the upper surface of the first protective layer by screen thick film printing method, and sinter it to form a second protective layer. The second protective layer completely covers the first protective layer, and both ends are partially placed on the positive electrodes;

[0035] Print and coat a layer of character code paste on the second protective layer by screen thick film printing method, and sinter it to form an identification character code layer for identifying the resistance value size;

[0036] A coating layer is vacuum sputtered on both sides of the ceramic substrate to form side electrodes, and the side electrodes are respectively connected to the adjacent positive electrodes and back electrodes;

[0037] An outer protective layer is deposited on the outer surfaces of the coating layer 7, side electrodes, back electrodes, and the vacuum sputtered coating layer, and the material of the outer protective layer 11 is nickel or tin; the outer protective layer 11 forms end electrodes between the coating layer 7, side electrodes 10, and back electrodes.

[0038] The beneficial effect of the present utility model is that in this technical solution, a coating layer is sputtered on the positive electrodes to cover the positive electrodes, so that the silver paste positive electrodes are prevented from vulcanization and the product performance is reduced, thereby reducing the production cost without affecting the product characteristics.

[0039] The above are only the preferred specific embodiments of the present utility model, but the protection scope of the present utility model is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present utility model, according to the technical solution of the present utility model and its inventive concept, makes equivalent substitutions or changes, and should be covered by the protection scope of the present utility model.

Claims

1. A thick film chip resistor with anti-sulfuration sputtering coating layer, which comprises a ceramic substrate, front electrodes are arranged on both sides of the upper surface of the ceramic substrate, back electrodes are arranged on both sides of the lower surface of the ceramic substrate, and a resistor body is arranged on the upper surface of the ceramic substrate and is connected to the front electrodes on both sides, and is characterized in that: A trimming resistor with an L-shaped structure is cut on the resistor by laser ablation. A first protective layer is printed on the upper surface of the resistor body. A layer of mask paste is printed on the first protective layer. A coating layer is vacuum sputtered on the upper surface of the ceramic substrate. The coating layer covers the mask paste. The coating layer completely covers the front electrode, and the width of the coating layer is greater than the width of the front electrode. A second protective layer is also printed on the first protective layer. The second protective layer completely covers the first protective layer and partially covers the coating layer on the front electrode. An identification character code layer is also provided on the second protective layer. Side electrodes are also vacuum sputtered on the left and right sides of the ceramic substrate, and the side electrodes are respectively connected to the adjacent front electrode and back electrode. An outer protective layer is deposited on the outer surfaces of the coating layer and the side electrodes.

2. A thick film chip resistor with sulfur-resistant sputtering coating layer according to claim 1, characterized in that: The resistor body is formed by screen printing with silver palladium paste.

3. A thick film chip resistor with a sputtered coating layer resistant to sulfidation according to claim 1, characterized in that: Through ultrasonic cleaning, the coating layer on the mask paste is removed, leaving only the coating layer on the front electrode.

4. A thick film chip resistor with a sputtering coating layer resistant to sulfidation according to claim 1, characterized in that: The coating layer formed by vacuum sputtering is specifically a Ni / Cr alloy.

5. A thick film chip resistor with a sputtering coating resistant to sulfidation according to claim 1, characterized in that: The material of the outer protective layer is nickel or tin. The outer protective layer forms terminal electrodes between the coating layer, the side electrodes, and the back electrode.

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