Vulcanization-resistant moisture-resistant thick-film resistor

Abstract

The utility model relates to the technical field of resistors, in particular to an anti-vulcanization moisture-resistant thick-film resistor. According to the technical scheme, the resistor comprises an aluminum oxide ceramic substrate, a resistor body is printed on the upper surface of the aluminum oxide ceramic substrate, front electrodes are printed at the two ends of the resistor body, extending parts of the two ends of the resistor body are covered with the front electrodes, back electrodes are printed on the lower surface of the aluminum oxide ceramic substrate, and the aluminum oxide ceramic substrate is provided with side electrodes. The front electrode, the back electrode and the side electrode are all silver electrodes, a nickel electrode is arranged outside the silver electrodes, a tin electrode is arranged outside the nickel electrode, and a first anti-vulcanization layer is arranged between the silver electrode and the nickel electrode at the two ends of the resistor body. A second anti-vulcanization layer is arranged between the nickel electrode and the tin electrode at the two ends of the resistor body, and a first protective layer and a second protective layer are arranged on the surface of the resistor body.

Description

Technical Field

[0001] The utility model relates to the technical field of resistors, in particular to a sulfurization-resistant and moisture-resistant thick-film resistor. Background Art

[0002] Thick film resistors are important components in electronic product applications and are also widely used in thick film circuits. They are a commonly used resistor, characterized by screen printing the resistor paste on a ceramic substrate, and then solidifying the resistor paste on the printed ceramic substrate through a subsequent sintering process to stabilize it. Existing thick film resistors are prone to vulcanization and have poor moisture resistance. When the external packaging structure is damaged, the silver electrode inside the thick film resistor reacts with the external sulfur-containing gas, causing the silver electrode to fail. At the same time, the moisture in the air and the chemical components in the humid environment come into contact with the internal structure of the thick film resistor, which may cause corrosion and oxidation on the resistor surface, thereby affecting the performance of the thick film resistor. Utility Model Content

[0003] The utility model provides a thick film resistor which has the characteristics of anti-sulfurization and moisture resistance.

[0004] In order to solve the above technical problems, the utility model provides a sulfurization-resistant and moisture-resistant thick film resistor, comprising an alumina ceramic substrate; a resistor body is printed on the upper surface of the alumina ceramic substrate, front electrodes are printed at both ends of the resistor body, and the extension parts at both ends of the resistor body are covered by the front electrodes;

[0005] A back electrode is printed on the lower surface of the alumina ceramic substrate, and the alumina ceramic substrate is provided with a side electrode so that the front electrode is electrically connected to the back electrode;

[0006] The front electrode, the back electrode and the side electrode are all silver electrodes, a nickel electrode is provided outside the silver electrode, and a tin electrode is provided outside the nickel electrode;

[0007] A first anti-sulfurization layer is provided between the silver electrode and the nickel electrode at both ends of the resistor, a second anti-sulfurization layer is provided between the nickel electrode and the tin electrode at both ends of the resistor, and a first and a second protective layer are provided in sequence on the surface of the resistor along the thickness direction.

[0008] In a preferred embodiment, the first anti-sulfurization layer is a silver-nickel alloy, and the second anti-sulfurization layer is a nickel-tin alloy.

[0009] In a preferred embodiment: the first protective layer and the second protective layer are glass. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 This is a schematic diagram of the structure of the utility model

[0011] In the figure: 1. Alumina ceramic substrate; 2. Silver electrode; 3. Nickel layer; 4. Tin layer; 5. Resistor; 6. First protective layer; 7. Second protective layer; 8. First anti-sulfurization layer; 9. Second anti-sulfurization layer. DETAILED DESCRIPTION

[0012] The technical solutions in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model; it is obvious that the described embodiments are only part of the embodiments of the utility model, rather than all of the embodiments, and all other embodiments obtained by ordinary technicians in this field based on the embodiments of the utility model without making creative work are within the scope of protection of the utility model.

[0013] In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "top / bottom" and the like indicate positions or positional relationships based on the positions or positional relationships described in the drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0014] In the description of the present utility model, it should be noted that, unless otherwise clearly stipulated and limited, the terms "installed", "provided with", "installed / connected", "connected", etc. should be understood in a broad sense. For example, "connection" can be a wall-mounted connection, a detachable connection, or an integral connection. It can be a mechanical connection or an electrical connection. It can be a direct connection or an indirect connection through an intermediate medium. It can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the utility model can be understood according to specific circumstances.

[0015] refer to Figure 1 A sulfur-resistant and moisture-resistant thick film resistor includes an alumina ceramic substrate 1, a resistor body 5, a silver electrode 2, a nickel layer 3, and a tin layer 4.

[0016] A resistor 5 is screen-printed on an alumina ceramic substrate 1, and silver electrodes are screen-printed at both ends of the resistor 5, and the silver electrode 2 completely covers the resistor 5, so that the resistor 5 and the silver electrode 2 are in conduction. The screen-printed back electrode of the alumina ceramic substrate 1 is also made of the silver electrode 2, and the silver electrode 2 is coated on the side end of the alumina ceramic substrate 1, so that the front electrode on the alumina ceramic substrate 1 is conductive with the back electrode, and a nickel layer and a tin layer are electroplated on the surface of the silver electrode 2 in sequence through an electroplating process.

[0017] A first anti-sulfurization layer 8 is provided at both ends of the connection between the resistor 5 and the silver electrode 2, and its material is a silver-nickel alloy layer. At the same time, a second anti-sulfurization layer 9 is also provided on the silver-nickel alloy layer 8, and its material is a nickel-tin alloy. This effectively prevents the silver electrode 2 from directly contacting the external environment, thereby improving the resistance to sulfurization.

[0018] A first protective layer 6 and a second protective layer 7 are sequentially provided on the surface of the resistor 5, the main component of which is glass, which prevents the resistor from directly contacting the external environment and improves the moisture resistance of the resistor. When the second protective layer 7 is damaged, the first protective layer 6 can still protect the resistor 5, thereby improving the durability of the resistor.

[0019] The above is only a preferred specific implementation method of the utility model, but the design concept of the utility model is not limited to this. Any technician familiar with the technical field who uses this concept to make non-substantial changes to the utility model within the technical scope disclosed by the utility model shall be deemed to infringe the protection scope of the utility model.

Claims

1. A sulfur-resistant and moisture-resistant thick film resistor, characterized in that: It comprises an alumina ceramic substrate; a resistor is printed on the upper surface of the alumina ceramic substrate, front electrodes are printed at both ends of the resistor, and the extension parts at both ends of the resistor are covered by the front electrodes; A back electrode is printed on the lower surface of the alumina ceramic substrate, and the alumina ceramic substrate is provided with a side electrode so that the front electrode is electrically connected to the back electrode; The front electrode, the back electrode and the side electrode are all silver electrodes, a nickel electrode is provided outside the silver electrode, and a tin electrode is provided outside the nickel electrode; A first anti-sulfurization layer is provided between the silver electrode and the nickel electrode at both ends of the resistor, a second anti-sulfurization layer is provided between the nickel electrode and the tin electrode at both ends of the resistor, and a first protective layer and a second protective layer are provided in sequence on the surface of the resistor along the thickness direction.

2. A sulfur-resistant and moisture-resistant thick film resistor according to claim 1, characterized in that: The first anti-sulfurization layer is a silver-nickel alloy, and the second anti-sulfurization layer is a nickel-tin alloy.

3. The anti-sulfurization and moisture-resistant thick film resistor according to claim 1, characterized in that: The first protective layer and the second protective layer are glass.

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