Thin film resistor with laser cutting knife

Abstract

The utility model discloses a film resistor with a laser cutting knife type, which comprises a ceramic substrate, an inner electrode layer arranged at the edge of the ceramic substrate, a laser cutting resistor layer lapped at the end part of the inner electrode layer, an outer electrode layer arranged on the outer surface of the inner electrode layer, a protective layer arranged on the outer surface of the laser cutting resistor layer, and a plurality of knife types arranged on the laser cutting resistor layer. Compared with a thick-film resistor, the thin-film resistor has the advantages that the NiCr alloy is used as the inner electrode to replace a silver layer, the material cost is reduced, the NiCr alloy is used as the resistance layer to replace paste printing ruthenium / silver oxide, the material cost is reduced, multi-cutter laser cutting is used, the resistance precision is improved, a G1 protective layer is not used, lead-free and environment-friendly effects are achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of thin film resistors, in particular to a thin film resistor with a laser cutter. Background Art

[0002] The property of a substance that blocks the passage of electric current is called resistance. Resistance is one of the most basic electronic components and is also the most used electronic component in all circuits. With the increasing development of science and technology, high-precision and small-volume industrial products have become the future trend. Therefore, whether it is active components (such as ICs) or passive components, manufacturers of resistors, capacitors, and inductors always take the above trend as the most important consideration in their designs.

[0003] Compared with traditional resistors, thick film resistors have the advantages of small size, light weight, high thermal efficiency, fast heating speed, long service life, energy saving and environmental protection, high mechanical strength, vibration resistance, safety and reliability, high temperature resistance (450 degrees Celsius), etc. They are widely used in small household appliances and various industrial heating equipment; injection molding process heating; aircraft, car, ship sealing strip vulcanization production line; automotive electronic heating components, etc.; industrial heat exchangers; metallurgy, chemical industry, pharmaceutical food processing, planting and breeding insulation and other fields.

[0004] However, with the differentiation of products, the requirements for resistors are getting higher and higher. Thick film resistors cannot meet the requirements of differentiated products. Compared with thick film resistors, thin film resistors have high resistance precision, high stability, higher / lower resistance, and smaller / larger size. They are often used in various instruments, medical equipment, power supplies, power equipment, electronic digital products, etc.

[0005] For this purpose, we propose a thin film resistor with a radium cutter type. Utility Model Content

[0006] The utility model aims to provide a thin film resistor with a laser cutter to solve the problems raised in the above background technology.

[0007] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a thin film resistor with a laser-cut knife shape, comprising a ceramic substrate, an inner electrode layer is provided at the edge of the ceramic substrate, a laser-cut resistor layer is overlapped at the end of the inner electrode layer, an outer electrode layer is provided on the outer surface of the inner electrode layer, a protective layer is provided on the outer surface of the laser-cut resistor layer, and a knife shape is laser-cut on the laser-cut resistor layer. The knife shape is divided into a knife shape with 6 knives structure, a knife shape with 2 knives structure, and a knife shape with 2 knives structure on the same side.

[0008] Preferably, the inner electrode layer comprises an inner electrode front track-NiCr alloy layer located on the top surface of the ceramic substrate, an inner electrode back track-NiCr alloy layer located on the bottom surface of the ceramic substrate, and an inner electrode side track-NiCr alloy layer located on the side surface of the ceramic substrate.

[0009] Preferably, an electroplating layer is provided on the outer electrode layer, and the electroplating layer includes a Ni barrier layer and a Sn barrier layer arranged in sequence from the inside to the outside, the protective layer is an epoxy resin layer, and the thickness of the radium-cut resistor layer is set to be less than 1 um.

[0010] Compared with the prior art, the beneficial effects of the utility model are:

[0011] Compared with thick film resistors, the thin film resistor of the utility model has the following advantages: the inner electrode uses NiCr alloy instead of the silver layer to reduce material cost; the resistor layer uses real NiCr alloy plated to replace the slurry printed ruthenium oxide / silver to reduce material cost; and multi-knife laser cutting is used to improve the accuracy of resistance value. There is no need to use G1 protective layer on the laser-cut resistor layer, so it is lead-free and environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0013] Figure 2 The schematic diagram of the knife-shaped traditional thick film resistor is shown in FIG.

[0014] Figure 3 It is a schematic diagram of the knife-shaped thin film resistor of the utility model.

[0015] In the figure: 1-ceramic substrate; 2-inner electrode layer; 3-radium-cut resistor layer; 4-outer electrode layer; 5-protective layer; 6-knife shape; 7-inner electrode positive track-NiCr alloy layer; 8-inner electrode back track-NiCr alloy layer; 9-inner electrode side track-NiCr alloy layer. DETAILED DESCRIPTION

[0016] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0017] See also Figure 1 The utility model provides a technical solution: a thin film resistor with a laser cut knife shape, comprising a ceramic substrate 1, an inner electrode layer 2 is provided at the edge of the ceramic substrate 1, a laser cut resistor layer 3 is overlapped at the end of the inner electrode layer 2, an outer electrode layer 4 is provided on the outer surface of the inner electrode layer 2, a protective layer 5 is provided on the outer surface of the laser cut resistor layer 3, and a laser cut knife shape 6 is provided on the laser cut resistor layer 3.

[0018] The inner electrode layer 2 includes an inner electrode positive track-NiCr alloy layer 7 located on the top surface of the ceramic substrate 1, an inner electrode back track-NiCr alloy layer 8 located on the bottom surface of the ceramic substrate 1, and an inner electrode side track-NiCr alloy layer 9 located on the side of the ceramic substrate 1. An electroplating layer is provided on the outer electrode layer 4, and the electroplating layer includes a Ni barrier layer and a Sn barrier layer arranged in sequence from the inside to the outside. The protective layer 5 is an epoxy resin layer, and the thickness of the radium-cut resistor layer 3 is set to be less than 1um.

[0019] In this embodiment, the conventional thick film resistor is composed of: a ceramic substrate 1, an inner electrode positive track-palladium silver, an inner electrode back track-palladium silver, an inner electrode side track-NiCr alloy, a resistor layer of ruthenium oxide / silver, a resistor thickness layer of 8 to 20 um, a G1 protective layer (glass layer, wherein the GI protection is a G1 protective layer covered on the resistor layer), a laser cutter 1, a G2 protective layer (epoxy resin layer), and an electroplating layer (Ni barrier layer and Sn barrier layer);

[0020] The traditional manufacturing method of thick film resistors is as follows:

[0021] Prepare ceramic substrate 1 - print palladium silver on the back side as the internal electrode, then print palladium silver on the front side as the internal electrode and sinter at 850°C, then print the resistor layer of ruthenium oxide / silver, sinter at 850°C, then print the glass layer for the first time, sinter at 600°C, then do a laser trimming, then print epoxy resin for the second time, finally print and sinter at 200°C, and pass QC inspection.

[0022] The thin film resistor in this scheme is composed of: ceramic substrate 1, inner electrode positive track-NiCr alloy, inner electrode back track-NiCr alloy, inner electrode side track-NiCr alloy, resistor layer NiCr alloy (resistor layer thickness less than 1um), laser cutting multiple knives, protective layer 5 (epoxy resin layer), electroplating layer (Ni barrier layer and Sn barrier layer);

[0023] The manufacturing method of the thin film resistor is as follows: prepare the ceramic substrate 1, then mask print NiCr alloy, then truly plate the R value, then age to 400°C, then wash the mask and perform QC inspection, then mask print, expose the electrode position and truly plate the electrode NiCr alloy, then wash the mask and perform QC inspection, then laser cutting (multi-knife) and QC inspection, finally print the protective layer 5 and print the code, and then sinter to 200°C to complete the QC inspection.

[0024] In terms of the layer structure, thin film resistors are different from thick film resistors in that the inner electrode uses NiCr alloy instead of silver layer to reduce the material cost.

[0025] The resistor layer uses NiCr alloy plating instead of slurry printing ruthenium oxide / silver to reduce material costs;

[0026] And use multi-knife laser cutting to improve the accuracy of resistance value;

[0027] No need to use G1 protective layer on the laser-cut resistor layer, lead-free, environmentally friendly.

[0028] Reasons for resistor laser cutting: Due to the screen printing operation, equipment, slurry fluidity and uneven sintering conditions / non-uniformity of true ion sputtering, the resistance layer often has a large resistance difference. In order to improve the accuracy of the resistor, the resistance must be adjusted to reach the target value;

[0029] Principle of resistor laser cutting: The principle of laser laser cutting resistance adjustment is to use an extremely fine laser beam to hit thick and thin film resistors, and realize the cutting of thick and thin film resistor layers by vaporizing and evaporating the resistor body, that is, by changing the geometric shape of the thick and thin film resistors, thereby changing the resistance value of the resistor. While cutting, the resistance value of the resistor is measured in real time. As the resistance value continues to approach the target resistance value, the laser beam is turned off until the target resistance value is reached, thereby realizing the entire laser resistance adjustment process (R=ρ*L / S (ρ: resistivity, L: resistor length, S: cross-sectional area of ​​the resistor layer)).

[0030] See also Figure 2 , the blade type of traditional thick film resistors is 6: divided into L-shaped blade type and I-shaped blade type, both with 1 blade;

[0031] See also Figure 3 The blade type 6 of the thin film resistor in this scheme is divided into a blade type with 6 blades against each other, a blade type with 2 blades against each other, and a blade type with 2 blades on the same side;

[0032] Blade type of thin film resistor: more than 2 blades;

[0033] Thick film resistor knife type 6: one knife;

[0034] Cuttable range (ΔR) ΔR = (initial resistance value - target value) / target value * 100%;

[0035] Comparison results:

[0036] Film: -40% or more;

[0037] Thick film: -40%~0;

[0038] Laser cutting magnification results:

[0039] Thin film: several times to dozens of times;

[0040] Thick film laser cutting ratio is less than 2 times;

[0041] Get higher precision results:

[0042] Film: 0.01%, 0.1%, 0.25%, 0.5%, 1%, 5%;

[0043] Thick film: 0.1%, 0.5%, 1%, 2%, 5%.

[0044] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0045] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A thin film resistor with a laser cutter, characterized in that: include: A ceramic substrate (1), wherein an inner electrode layer (2) is provided at the edge of the ceramic substrate (1), a laser-cut resistor layer (3) is overlapped at the end of the inner electrode layer (2), an outer electrode layer (4) is provided on the outer surface of the inner electrode layer (2), a protective layer (5) is provided on the outer surface of the laser-cut resistor layer (3), and a knife shape (6) is laser-cut on the laser-cut resistor layer (3); The internal electrode layer (2) comprises an internal electrode positive track-NiCr alloy layer (7) located on the top surface of the ceramic substrate (1), an internal electrode back track-NiCr alloy layer (8) located on the bottom surface of the ceramic substrate (1), and an internal electrode side track-NiCr alloy layer (9) located on the side surface of the ceramic substrate (1).

2. The thin film resistor with a laser cutter according to claim 1, characterized in that: An electroplating layer is provided on the outer electrode layer (4).

3. The thin film resistor with a laser cutter according to claim 2, characterized in that: The electroplating layer includes a Ni barrier layer and a Sn barrier layer which are sequentially arranged from the inside to the outside.

4. The thin film resistor with a laser cutter according to claim 1, characterized in that: The protective layer (5) is an epoxy resin layer.

5. The thin film resistor with a laser cutter according to claim 1, characterized in that: The thickness of the laser-cut resistor layer (3) is set to be less than 1 um.

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