A method for manufacturing a double-sided ground type thin film resistor

Abstract

The application belongs to the technical field of thin film circuit manufacturing, and particularly relates to a preparation method of a double-side grounding type thin film resistor. The application first prepares a front functional layer and a front resistance layer on the front surface of an insulating substrate, obtains a front resistor semi-finished product, then performs laser resistance adjustment on the front resistor semi-finished product, and then performs slotting on the insulating substrate of the front resistor semi-finished product. The application realizes, by adjusting the slotting step, that after the front independent semi-product is prepared, accurate measurement is realized, laser resistance adjustment is preferentially performed, then the slotting of the insulating substrate is performed, and finally the side wall and the back metallization grounding conduction are manufactured. The resistance precision of the double-side grounding type thin film resistor product obtained by the preparation method provided by the application is less than ±1%, and the alignment precision and the laser resistance adjustment efficiency of the double-side grounding type thin film resistor are greatly improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of thin film circuit manufacturing, and particularly relates to a preparation method of a double-side grounding type thin film resistor. BACKGROUND

[0002] The classification of thin film circuits includes power dividers, attenuators, resistors and the like, wherein the resistor is a major important classification in the thin film circuit, and according to the structure, there are usually four kinds: a double-side metal type thin film resistor (structure schematic diagram as shown in Figure 1 and Figure 2 ), a single-side grounding type thin film resistor (structure schematic diagram as shown in Figure 3 and Figure 4 ), a double-side grounding type thin film resistor (structure schematic diagram as shown in Figure 5 and Figure 6 ), and a single-side metal type thin film resistor (structure schematic diagram as shown in Figure 7 and Figure 8 ). Among them, the double-side grounding type thin film resistor has the largest manufacturing process difficulty.

[0003] At present, the manufacturing process of the conventional double-side grounding type thin film resistor is as follows: firstly, a ceramic substrate is slotted according to the design drawing specification, and then the sputtering of the resistance layer, the adhesion layer, the barrier layer and the seed layer is performed, and finally the thickening by electroplating, the lithography etching and the like are performed. The slotting is to use a diamond cutting knife to cut the ceramic at equal intervals, and the position of the ceramic cutting is covered by the metal film layer during sputtering to form a conduction, and the electroplating causes the growth of the metal in the slot. The front surface of the grounding resistance of the double-side grounding type thin film resistor is an independent resistance unit, but the conduction of the side wall causes the independent resistance unit on the front surface to form a parallel connection. Therefore, the manufacturing process of the above double-side grounding type thin film resistor has the disadvantage that the resistance value cannot be accurately tested after the whole piece is completed patterning, and the resistance value can only be tested after the independent resistance unit is cut by cutting and the front surface resistance is connected in series. However, the laser resistance adjustment is performed one by one at this time, which not only has a large alignment difficulty, but also has a very low resistance adjustment efficiency and a poor precision.

[0004] Therefore, due to the limitation of the above current manufacturing process, the double-side grounding type thin film resistor cannot be accurately laser adjusted as a whole during the manufacturing process, that is, the double-side grounding type thin film resistor with high precision (less than ±1%) cannot be produced.

[0005] In summary, the manufacturing process of the existing double-side grounding type thin film resistor can ensure the grounding conduction effect of the side wall metal, but has the disadvantage of poor precision. SUMMARY

[0006] The application aims to provide a preparation method of a double-side grounding type thin film resistor.

[0007] In order to achieve the above-mentioned purpose, the application provides the following technical scheme.

[0008] The application provides a preparation method of a double-side grounding type thin film resistor, comprising the following steps.

[0009] (1) performing first deposition on the front surface of the insulating substrate to obtain a first semi-finished product, wherein the first deposition comprises sequentially depositing a front surface resistance film, a front surface adhesion film, a front surface barrier film and a front surface seed film;

[0010] (2) coating photoresist on the front surface of the first semi-finished product, then transferring the pattern of the front surface functional layer to the front surface of the first semi-finished product by using a mask, and forming a front surface functional layer patterned surface after development to obtain a first patterned semi-finished product;

[0011] (3) performing first electroplating on the first patterned semi-finished product, then removing the photoresist to obtain a front surface electroplated layer, etching the front surface seed film, the front surface barrier film and the front surface adhesion film outside the region of the front surface electroplated layer to obtain a front surface adhesion layer, a front surface barrier layer and a front surface seed layer, wherein the front surface seed layer and the front surface electroplated layer form a front surface functional layer, and a second semi-finished product is obtained;

[0012] (4) coating photoresist on the front surface of the second semi-finished product, then transferring the pattern of the front surface resistance layer to the front surface of the second semi-finished product by using a mask, and forming a front surface resistance layer patterned surface after development to obtain a second patterned semi-finished product;

[0013] (5) etching the resistance layer patterned surface of the second patterned semi-finished product, then removing the photoresist to form a front surface resistance layer on the front surface of the insulating substrate, and obtaining a front surface resistor semi-finished product;

[0014] (6) performing laser resistance adjustment on the front surface resistor semi-finished product, then slotting the insulating substrate, wherein the slotting position contacts the edge of the front surface functional layer, and a semi-finished product with a through slot is obtained;

[0015] (7) performing second deposition on the back surface and the side wall of the through slot of the semi-finished product with a through slot to obtain a third semi-finished product, wherein the second deposition comprises sequentially depositing a back surface adhesion film and a side wall adhesion layer, a back surface barrier film and a side wall barrier layer, and a back surface seed film and a side wall seed layer;

[0016] (8) performing second electroplating on the third semi-finished product to obtain a fourth semi-finished product;

[0017] (9) after obtaining the fourth semi-finished product, or coating the back of the fourth semi-finished product with photoresist, then using a mask to transfer the back functional layer pattern to the back of the fourth semi-finished product, after developing, etching, removing the photoresist, obtaining the back adhesive layer, back barrier layer, back seed layer and back electroplating layer on the back of the insulating substrate, the back seed layer and the back electroplating layer forming the back functional layer, and then removing the electroplating film formed on the surface of the front resistance layer of the fourth semi-finished product during the second electroplating, obtaining the double-sided grounding type thin film resistor;

[0018] or removing the electroplating film formed on the surface of the front resistance layer of the fourth semi-finished product during the second electroplating; then coating the back of the fourth semi-finished product with photoresist, using a mask to transfer the back functional layer pattern to the back of the fourth semi-finished product, after developing, etching, removing the photoresist, obtaining the back adhesive layer, back barrier layer, back seed layer and back electroplating layer on the back of the insulating substrate, the back seed layer and the back electroplating layer forming the back functional layer, and obtaining the double-sided grounding type thin film resistor.

[0019] Preferably, in step (3), the material of the front electroplating layer is gold, and the thickness of the front electroplating layer is 1-4 μm.

[0020] Preferably, in step (8), the second electroplating forms an electroplating film on the front, sidewall and back of the third semi-finished product, the material of the electroplating film formed during the second electroplating is gold, and the thickness of the electroplating film obtained on the back of the third semi-finished product during the second electroplating is 3-10 μm.

[0021] Preferably, the material of the front resistance layer is tantalum nitride, and the thickness of the front resistance layer is 0.01-0.1 μm.

[0022] Preferably, the material of the front adhesive layer, sidewall adhesive layer and back adhesive layer is titanium-tungsten alloy, and the thickness of the front adhesive layer and back adhesive layer is independently 0.1-0.5 μm.

[0023] Preferably, the material of the front barrier layer, sidewall barrier layer and back barrier layer is nickel, and the thickness of the front barrier layer and back barrier layer is independently 0.1-0.5 μm.

[0024] Preferably, the material of the front seed layer, sidewall seed layer and back seed layer is gold, and the thickness of the front seed layer and back seed layer is independently 1-3 μm.

[0025] Preferably, the insulating substrate is a ceramic substrate.

[0026] Preferably, the method of the first deposition and second deposition is magnetic control sputtering.

[0027] The magnetron sputtering is completed by a tunnel line type magnetron sputtering device for carrying a board.

[0028] Preferably, in step (3), the etching method of the front surface seed film outside the front surface plating layer region is dry etching; the etching method of the front surface barrier film and the front surface adhesion film outside the front surface plating layer region is wet etching.

[0029] In step (5), the etching method of the patterned surface of the resistance layer of the second patterned semi-product is wet etching.

[0030] In step (9), the etching method of the fourth semi-product after the back surface development is as follows: the etching method of the back surface plating film is wet etching, the etching method of the back surface seed film is wet etching, and the etching method of the back surface barrier film and the back surface adhesion film is wet etching.

[0031] The application provides a preparation method of a double-side grounding type thin film resistor, which comprises the following steps: (1) performing first deposition on the front surface of an insulating substrate to obtain a first semi-finished product, wherein the first deposition comprises sequentially depositing a front surface resistance film, a front surface adhesive film, a front surface barrier film and a front surface seed film; (2) coating photoresist on the front surface of the first semi-finished product, then transferring the pattern of the front surface functional layer to the front surface of the first semi-finished product by using a mask, and forming a front surface functional layer patterned surface after development to obtain a first patterned semi-finished product; (3) performing first electroplating on the first patterned semi-finished product, then removing the photoresist to obtain a front surface electroplated layer, etching the front surface seed film, the front surface barrier film and the front surface adhesive film outside the region of the front surface electroplated layer to obtain a front surface adhesive layer, a front surface barrier layer and a front surface seed layer, and forming a front surface functional layer by combining the front surface seed layer and the front surface electroplated layer to obtain a second semi-finished product; (4) coating photoresist on the front surface of the second semi-finished product, then transferring the pattern of the front surface resistance layer to the front surface of the second semi-finished product by using a mask, and forming a front surface resistance layer patterned surface after development to obtain a second patterned semi-finished product; (5) etching the resistance layer patterned surface of the second patterned semi-finished product, then removing the photoresist to form a front surface resistance layer on the front surface of the insulating substrate, and obtaining a front surface resistor semi-finished product; (6) performing laser resistance adjustment on the front surface resistor semi-finished product, then slotting the insulating substrate, and making the slotting position contact the edge of the front surface functional layer to obtain a semi-finished product with a penetrating slot; (7) performing second deposition on the back surface and the side wall of the penetrating slot of the semi-finished product with the penetrating slot to obtain a third semi-finished product, wherein the second deposition comprises sequentially depositing a back surface adhesive film and a side wall adhesive layer, a back surface barrier film and a side wall barrier layer, and a back surface seed film and a side wall seed layer; (8) performing second electroplating on the third semi-finished product to obtain a fourth semi-finished product; (9) after obtaining the fourth semi-finished product, or coating photoresist on the back surface of the fourth semi-finished product, then transferring the pattern of the back surface functional layer to the back surface of the fourth semi-finished product by using a mask, etching after development, and obtaining a back surface adhesive layer, a back surface barrier layer, a back surface seed layer and a back surface electroplated layer on the back surface of the insulating substrate after removing the photoresist, wherein the back surface seed layer and the back surface electroplated layer form a back surface functional layer; after removing the electroplated film formed during the second electroplating on the surface of the front surface resistance layer of the fourth semi-finished product, the double-side grounding type thin film resistor is obtained; or the electroplated film formed during the second electroplating on the surface of the front surface resistance layer of the fourth semi-finished product is removed; then coating photoresist on the back surface of the fourth semi-finished product, transferring the pattern of the back surface functional layer to the back surface of the fourth semi-finished product by using a mask, etching after development, and obtaining a back surface adhesive layer, a back surface barrier layer, a back surface seed layer and a back surface electroplated layer on the back surface of the insulating substrate after removing the photoresist, wherein the back surface seed layer and the back surface electroplated layer form a back surface functional layer, and the double-side grounding type thin film resistor is obtained.The preparation method provided by the present application discards the prior art method of first slotting the ceramic substrate according to the drawing specifications, and then performing sputtering of the resistance film layer, the adhesion layer, the barrier layer and the seed layer, the present application first prepares a front functional layer and a resistance layer on the front surface of the insulating substrate, obtains a front resistor semi-finished product, then performs laser resistance adjustment on the front resistor semi-finished product, and then slots the insulating substrate of the front resistor semi-finished product, the present application realizes the following by adjusting the slotting step: after the product completes the front independent series semi-product, accurate measurement is realized, laser resistance adjustment is preferentially performed, then the insulating substrate is slotted, and finally the side wall and the back metallization ground conduction are made, thereby providing a high-precision double-sided ground thin film resistor manufacturing method capable of laser resistance adjustment, and the resistance precision of the double-sided ground thin film resistor product obtained by the preparation method is less than ±1%, which greatly improves the alignment accuracy and laser resistance adjustment efficiency of the double-sided ground thin film resistor. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 It is a sectional view of a double-sided metal type thin film resistor;

[0033] Figure 2 It is a top view of a double-sided metal type thin film resistor;

[0034] Figure 3 It is a sectional view of a single-sided ground type thin film resistor;

[0035] Figure 4 It is a top view of a single-sided ground type thin film resistor;

[0036] Figure 5 It is a sectional view of a double-sided ground type thin film resistor;

[0037] Figure 6 It is a top view of a double-sided ground type thin film resistor;

[0038] Figure 7 It is a sectional view of a single-sided metal type thin film resistor;

[0039] Figure 8 It is a top view of a single-sided metal type thin film resistor;

[0040] In the figure: 1 is a ceramic substrate; 2 is a front resistance layer; 3 is a front adhesion layer; 4 is a front barrier layer; 5 is a front functional layer; 6 is a side wall adhesion layer; 7 is a side wall barrier layer; 8 is a side wall functional layer; 9 is a back adhesion layer; 10 is a back barrier layer; 11 is a back functional layer. DETAILED DESCRIPTION

[0041] The present application provides a preparation method of a double-sided ground type thin film resistor, comprising the following steps:

[0042] (1) performing first deposition on the front surface of the insulating substrate to obtain a first semi-finished product, the first deposition comprising sequentially depositing a front surface resistance film, a front surface adhesion film, a front surface barrier film and a front surface seed film;

[0043] (2) coating photoresist on the front surface of the first semi-finished product, then using a mask to transfer the pattern of the front surface functional layer to the front surface of the first semi-finished product, and after developing, forming a front surface functional layer patterned surface to obtain a first patterned semi-finished product;

[0044] (3) performing first electroplating on the first patterned semi-finished product, then removing the photoresist to obtain a front surface electroplated layer, and etching the front surface seed film, the front surface barrier film and the front surface adhesion film outside the region of the front surface electroplated layer to obtain a front surface adhesion layer, a front surface barrier layer and a front surface seed layer, the front surface seed layer and the front surface electroplated layer forming a front surface functional layer, thereby obtaining a second semi-finished product;

[0045] (4) coating photoresist on the front surface of the second semi-finished product, then using a mask to transfer the pattern of the front surface resistance layer to the front surface of the second semi-finished product, and after developing, forming a front surface resistance layer patterned surface to obtain a second patterned semi-finished product;

[0046] (5) etching the resistance layer patterned surface of the second patterned semi-finished product, then removing the photoresist to form a front surface resistance layer on the front surface of the insulating substrate, thereby obtaining a front surface resistor semi-finished product;

[0047] (6) performing laser resistance adjustment on the front surface resistor semi-finished product, and then slotting the insulating substrate, the slotting position contacting the edge of the front surface functional layer, thereby obtaining a semi-finished product with a through slot;

[0048] (7) performing second deposition on the back surface and the side wall of the through slot of the semi-finished product with a through slot to obtain a third semi-finished product; the second deposition comprises sequentially depositing a back surface adhesion film and a side wall adhesion layer, a back surface barrier film and a side wall barrier layer, a back surface seed film and a side wall seed layer;

[0049] (8) performing second electroplating on the third semi-finished product to obtain a fourth semi-finished product;

[0050] (9) after obtaining the fourth semi-finished product, or coating photoresist on the back surface of the fourth semi-finished product, then using a mask to transfer the pattern of the back surface functional layer to the back surface of the fourth semi-finished product, and after developing, etching, and after removing the photoresist, obtaining a back surface adhesion layer, a back surface barrier layer, a back surface seed layer and a back surface electroplated layer on the back surface of the insulating substrate, the back surface seed layer and the back surface electroplated layer forming a back surface functional layer; after removing the electroplated film formed during the second electroplating on the surface of the front surface resistance layer of the fourth semi-finished product, obtaining the double-sided grounding type thin film resistor;

[0051] Or remove the second electroplating film formed by the second electroplating of the front surface resistance layer surface of the fourth semi-finished product; then coat the back surface of the fourth semi-finished product with photoresist, transfer the back surface functional layer pattern to the back surface of the fourth semi-finished product using a mask, after development, etch, after removing the photoresist, obtain the back surface adhesion layer, the back surface barrier layer, the back surface seed layer and the back surface electroplating layer on the back surface of the insulating substrate, the back surface seed layer and the back surface electroplating layer form the back surface functional layer, and obtain the double-sided ground type thin film resistor.

[0052] The present application performs first deposition on the front surface of the insulating substrate to obtain a first semi-finished product, and the first deposition includes sequentially depositing a front surface resistance film, a front surface adhesion film, a front surface barrier film and a front surface seed film. In the present application, the insulating substrate is preferably a ceramic substrate. In the present application, the thickness of the insulating substrate is preferably 0.1-0.6mm, and is particularly preferably 0.127mm, 0.254mm, 0.381mm or 0.508mm. Before the deposition, the present application sequentially performs cleaning and drying on the insulating substrate. The present application has no special requirements for the specific implementation of the cleaning and drying. The first deposition method is preferably magnetron sputtering. The magnetron sputtering is completed by a tunnel line column type magnetron sputtering device transported by a carrier plate.

[0053] After obtaining the first semi-finished product, photoresist is coated on the front surface of the first semi-finished product, and then a mask is used to transfer the pattern of the front surface functional layer to the front surface of the first semi-finished product, and after development, a front surface functional layer patterned surface is formed to obtain a first patterned semi-finished product. The present application has no special requirements for the coating of the photoresist, the pattern transfer of the front surface functional layer and the development.

[0054] After obtaining the first patterned semi-finished product, the present application performs first electroplating on the first patterned semi-finished product, then removes the photoresist to obtain a front surface electroplating layer, and etches the front surface seed film, the front surface barrier film and the front surface adhesion film outside the front surface electroplating layer area to obtain a front surface adhesion layer, a front surface barrier layer and a front surface seed layer, the front surface seed layer and the front surface electroplating layer form a front surface functional layer, and obtain a second semi-finished product.

[0055] The first electroplating of the present application has no special requirements for the specific implementation. The material of the front electroplating layer obtained by the first electroplating is preferably gold, and the thickness of the front electroplating layer is preferably 1-4 μm. The thickness of the front electroplating layer is greater than the thickness of the front seed film. The etching method of the front seed film outside the front electroplating layer region is dry etching, specifically argon ion etching. In the present application, the dry etching is performed on the front electroplating layer and the front seed film outside the front electroplating layer region at the same time. Since the thickness of the front electroplating layer obtained by the first electroplating is greater than the thickness of the front seed film, after the front seed film outside the front electroplating layer region is etched, the front electroplating layer still remains, and the front functional layer is composed of the front electroplating layer remaining after etching and the underlying front seed layer. The etching method of the front barrier layer and the front adhesion layer is preferably wet etching. The present application has no special requirements for the specific implementation of the wet etching.

[0056] In the present application, the material of the front adhesion layer is specifically preferably titanium-tungsten alloy; and the thickness of the front adhesion layer is preferably 0.1-0.5 μm. The material of the front barrier layer is specifically preferably nickel; and the thickness of the front barrier layer is preferably 0.1-0.5 μm. The material of the front seed layer is specifically preferably gold; and the thickness of the front seed layer is preferably 1-3 μm.

[0057] After obtaining the second semi-finished product, the present application coats photoresist on the front of the second semi-finished product, then transfers the front resistance layer pattern to the front of the second semi-finished product using a mask, and forms a front resistance layer patterned surface after development, thereby obtaining a second patterned semi-finished product. The present application has no special requirements for the coating of the photoresist, the transfer of the resistance layer pattern, and the development.

[0058] After obtaining the second patterned semi-finished product, the present application etches the resistance layer patterned surface of the second patterned semi-finished product, then removes the photoresist, and forms a front resistance layer on the front of the insulating substrate, thereby obtaining a front resistor semi-finished product. In the present application, the etching method of the resistance layer patterned surface of the second patterned semi-finished product is preferably wet etching. The present application has no special requirements for the specific implementation of the wet etching.

[0059] In the present application, the material of the front resistance layer is specifically preferably tantalum nitride; and the thickness of the front resistance layer is preferably 0.01-0.1 μm.

[0060] In the present application, a plurality of front resistor semi-finished products are formed on the front of the insulating substrate, and the plurality of front resistor semi-finished products on the front of the insulating substrate are arranged in an array.

[0061] After obtaining the front resistor semi-finished product, the present application carries out laser resistance adjustment on the front resistor semi-finished product, then slots the insulating substrate, the slotting position contacts the edge of the functional layer, and a semi-finished product with a through slot is obtained. In the present application, the slotting position contacts the edge of the functional layer, so that after subsequent back second deposition, the front functional layer, the sidewall seed layer and the back seed film form a conduction, and the second electroplating is thickened.

[0062] The present application has no special requirements for the specific implementation of the laser adjustment group. After obtaining the front resistor semi-finished product, that is, completing the front independent series product of the double-sided grounding type thin film resistor, laser resistance adjustment is carried out, which can realize accurate laser resistance adjustment on multiple front resistor semi-finished products on the insulating substrate, thereby obtaining a preparation method of a laser-adjustable high-precision double-sided grounding type thin film resistor. The resistance precision of the double-sided grounding type thin film resistor product obtained by the present application is less than ±1%. In the present application, the insulating substrate of the fixed strip part at both ends of the slot is reserved. The slotting is carried out by equipment.

[0063] After obtaining the semi-finished product with a through slot, the present application carries out second deposition on the back of the semi-finished product with a through slot and the sidewall of the through slot to obtain a third semi-finished product; the second deposition includes sequentially depositing a back adhesive film and a sidewall adhesive layer, a back barrier film and a sidewall barrier layer, and a back seed film and a sidewall seed layer. In the present application, the material of the back adhesive film is specifically preferably titanium-tungsten alloy; the thickness of the back adhesive film is preferably 0.1-0.5 μm. The material of the back barrier film is specifically preferably nickel; the thickness of the back barrier film is preferably 0.1-0.5 μm. The material of the back seed film is specifically preferably gold; the thickness of the back seed film is preferably 1-3 μm. The second deposition method is preferably magnetron sputtering. The present application has no special requirements for the specific implementation of the magnetron sputtering.

[0064] After obtaining the third semi-finished product, the present application carries out second electroplating on the third semi-finished product to obtain a fourth semi-finished product. The present application has no special requirements for the specific implementation of the second electroplating. In the present application, the second electroplating forms an electroplating film on the front, sidewall and back of the third semi-finished product, the material of the electroplating film formed by the second electroplating is gold, and the thickness of the electroplating film obtained on the back of the third semi-finished product by the second electroplating is 3-10 μm.

[0065] In the present application, the second electroplating forms second electroplating films on the surface of the front surface resistance layer, the front surface functional layer, the sidewall seed layer and the back surface seed film of the third semi-finished product. The front surface functional layer of the front surface resistance semi-finished product (and the third semi-finished product) and the second electroplating film formed on the front surface functional layer by the second electroplating together serve as the front surface functional layer of the double-side grounding type thin film resistor. The second electroplating film formed on the surface of the sidewall seed layer together constitutes the sidewall functional layer.

[0066] After obtaining the fourth semi-finished product, the present application either coats the back surface of the fourth semi-finished product with photoresist, then transfers the pattern of the back surface functional layer to the back surface of the fourth semi-finished product using a mask, performs etching after development, and after removing the photoresist, obtains the back surface adhesion layer, the back surface barrier layer, the back surface seed layer and the back surface electroplating layer on the back surface of the insulating substrate, wherein the back surface seed layer and the back surface electroplating layer form the back surface functional layer; and after removing the electroplating film formed on the surface of the front surface resistance layer of the fourth semi-finished product during the second electroplating, obtains the double-side grounding type thin film resistor. In the present application, after obtaining the back surface functional layer, the present application preferably protects the back surface of the semi-finished product obtained at this time by pasting UV glue, and finally removes the electroplating film formed on the surface of the front surface resistance layer of the fourth semi-finished product during the second electroplating. The specific implementation of the removal is preferably dip glue removal.

[0067] After obtaining the fourth semi-finished product, the present application either removes the electroplating film formed on the surface of the front surface resistance layer of the fourth semi-finished product during the second electroplating; then coats the back surface of the fourth semi-finished product with photoresist, then transfers the pattern of the back surface functional layer to the back surface of the fourth semi-finished product using a mask, performs etching after development, and after removing the photoresist, obtains the back surface adhesion layer, the back surface barrier layer, the back surface seed layer and the back surface electroplating layer on the back surface of the insulating substrate, wherein the back surface seed layer and the back surface electroplating layer form the back surface functional layer, and obtains the double-side grounding type thin film resistor. In the present application, the specific implementation of removing the electroplating film formed on the surface of the front surface resistance layer of the fourth semi-finished product during the second electroplating is preferably dip glue removal.

[0068] In the present application, the etching method after development of the back surface of the fourth semi-finished product is preferably: the etching method of the back surface electroplating film is wet etching, the etching method of the back surface seed film is wet etching, and the etching method of the back surface barrier film and the back surface adhesion film is wet etching.

[0069] In the present application, after obtaining the back surface functional layer and removing the electroplating film formed on the surface of the front surface resistance layer of the fourth semi-finished product during the second electroplating, the present application preferably obtains single double-side grounding type thin film resistors by scribing. In the present application, during the scribing, the present application preferably expands the appropriate interval on the blue film.

[0070] In the present application, the scribing insulating substrate obtains the single rough product of the double-side grounding type thin film resistor, and the single rough product of the double-side grounding type thin film resistor is preferably trimmed to obtain the single finished product of the double-side grounding type thin film resistor.

[0071] In order to further illustrate the present application, the technical solutions provided by the present application are described in detail below in combination with examples, but they should not be understood as limiting the scope of protection of the present application.

[0072] Example 1

[0073] In this example, a ceramic substrate with a thickness of 0.127 mm is used. The ceramic substrate is first cleaned and then dried. Then, on the front surface of the ceramic substrate, a tantalum nitride film (front surface resistance film, 0.01 μm), a titanium-tungsten alloy film (front surface adhesion film, 0.1 μm), a nickel film (front surface barrier film, 0.1 μm), and a gold film (front surface seed film, 1.0 μm) are sputtered in sequence. After sputtering, a photoresist is coated on the surface of the front surface seed film on the front surface of the ceramic substrate. A mask plate is used to transfer the pattern of the front surface functional layer to the front surface seed film on the ceramic substrate, and the front surface functional layer pattern is developed. Then, the first electroplating is performed, and the thickness of the gold film obtained by the first electroplating is 1-4 μm (for example, 2 μm, 3 μm, 4 μm, and the thickness of the gold film obtained by electroplating is greater than the thickness of the front surface seed layer). The photoresist is stripped to obtain the front surface electroplated layer. Dry etching (argon ion etching) is performed on the front surface seed layer of the ceramic front surface to obtain the front surface functional layer. The nickel film and the titanium-tungsten alloy film of the bottom layer of the front surface seed layer are etched once by wet method to obtain the front surface barrier layer and the front surface adhesion layer, and the front surface tantalum nitride film is exposed.

[0074] A photoresist is coated on the surface of the front surface functional layer and the surface of the front surface tantalum nitride film. A mask plate is used to transfer the pattern of the front surface resistance layer to the tantalum nitride film on the ceramic substrate, and the front surface resistance layer pattern is developed. The resistance layer pattern is etched, and then the photoresist is removed to form the front surface resistance layer and the front surface functional layer on the front surface of the ceramic substrate to obtain the front surface resistor semi-finished product.

[0075] The front surface resistor semi-finished product is subjected to laser resistance adjustment, and the initial resistance is 8.24±10% Ω, and the final resistance is 12.50±1% Ω. The scribing equipment is slotted, and the part of the ceramic retaining the fixed strip at both ends is retained. The slotted position contacts the edge of the front surface functional layer to obtain a through slot.

[0076] Then, on the back surface of the ceramic substrate and the side wall obtained by slitting, a titanium-tungsten alloy film (back surface adhesion film 0.1 μm, and side wall adhesion layer), a nickel film (back surface barrier film 0.1 μm, and side wall barrier layer), and a gold film (back surface seed film 1.0 μm, and side wall seed layer) are sputtered in sequence to obtain a third semi-finished product.

[0077] After sputtering, the third finished product obtained is subjected to second electroplating, and the thickness of the gold film obtained on the surface of the back surface seed film on the back surface is 3-10 μm (for example, 3 μm, 4 μm, 6 μm, 8 μm). Then, photoresist is coated on the surface of the back surface plating film obtained on the back surface after the second electroplating, a mask plate is used to transfer the pattern of the back surface functional layer to the back surface plating film, and the pattern of the back surface functional layer is developed; then, wet etching is sequentially performed, the back surface plating layer and the back surface seed layer are obtained, the back surface plating layer and the back surface seed layer form the back surface functional layer, the nickel film and the titanium-tungsten alloy film on the bottom layer of the back surface seed layer are once etched by wet method, the back surface barrier layer and the back surface adhesion layer are obtained, and the back surface nitrogenized tantalum film is exposed.

[0078] Example 2

[0079] In this embodiment, a ceramic substrate with a thickness of 0.254 mm is used. The ceramic substrate is first cleaned and dried, and then the front surface of the ceramic substrate is sputtered with a tantalum nitride film (front surface resistance film, 0.01 μm), a titanium-tungsten alloy film (front surface adhesion film, 0.1 μm), a nickel film (front surface barrier film, 0.1 μm), and a gold film (front surface seed film, 1.0 μm) in sequence. After sputtering, photoresist is coated on the surface of the front surface seed film on the front surface of the ceramic substrate, a mask plate is used to transfer the pattern of the front surface functional layer to the front surface seed film of the ceramic substrate, and the pattern of the front surface functional layer is developed. Then, first electroplating is performed, and the thickness of the gold film obtained by the first electroplating is 1-4 μm (for example, 2 μm, 3 μm, 4 μm, and the thickness of the gold film obtained by electroplating is greater than the thickness of the front surface seed layer). The photoresist is stripped to obtain the front surface plating layer. The front surface seed layer is obtained by dry etching (argon ion etching) on the front surface of the ceramic, and the front surface plating layer and the front surface seed layer form the front surface functional layer. The nickel film and the titanium-tungsten alloy film on the bottom layer of the front surface seed layer are once etched by wet method to obtain the front surface barrier layer and the front surface adhesion layer, and the front surface tantalum nitride film is exposed.

[0080] Photoresist is coated on the surface of the front surface functional layer and the surface of the front surface tantalum nitride film, a mask plate is used to transfer the pattern of the front surface resistance layer to the tantalum nitride film of the ceramic substrate, and the pattern of the front surface resistance layer is developed. The resistance layer pattern is etched, and then the photoresist is removed to form the front surface resistance layer and the front surface functional layer on the front surface of the ceramic substrate, and a front surface resistor semi-finished product is obtained.

[0081] The front surface resistor semi-finished product is subjected to laser resistance adjustment, the initial resistance is 11.65±10% Ω, and the final resistance is 25.00±1% Ω. The cutting device is slotted, and the portions of the ceramic with fixed strips at both ends are retained. The slotted position contacts the edge of the front surface functional layer to obtain a through slot.

[0082] Then, the back surface of the ceramic substrate and the side wall obtained by slotting are sputtered with a titanium-tungsten alloy film (back surface adhesion film 0.1 μm, and side wall adhesion layer), a nickel film (back surface barrier film 0.1 μm, and side wall barrier layer), and a gold film (back surface seed film 1.0 μm, and side wall seed layer) in sequence to obtain a third semi-finished product;

[0083] After the sputtering, the third semi-finished product obtained is subjected to a second electroplating. The thickness of the gold film obtained on the surface of the back surface seed film of the back surface by the second electroplating is 3-10 μm (for example, 3 μm, 4 μm, 6 μm, 8 μm). Then, a photoresist is coated on the surface of the back surface electroplating film obtained on the back surface by the second electroplating, a mask plate is used to transfer the pattern of the back surface functional layer to the back surface electroplating film, and the pattern of the back surface functional layer is developed. Then, wet etching is performed in sequence to obtain the back surface electroplating layer and the back surface seed layer, the back surface electroplating layer and the back surface seed layer form the back surface functional layer, the nickel film and the titanium-tungsten alloy film of the back surface are etched once by wet etching to obtain the back surface barrier layer and the back surface adhesion layer. Then, UV glue is pasted on the back surface, and the front surface is dipped in glue to remove the excess gold film (formed by the second electroplating) on the front surface resistance layer. The single finished product is cut, and the side wall ground excess metal burrs are trimmed to obtain a single double-sided ground thin film resistor.

[0084] Example 3

[0085] In this example, a ceramic substrate with a thickness of 0.381 mm is used. The ceramic substrate is first cleaned and dried, and then the front surface of the ceramic substrate is sputtered with a tantalum nitride film (front surface resistance film, 0.01 μm), a titanium-tungsten alloy film (front surface adhesion film, 0.1 μm), a nickel film (front surface barrier film, 0.1 μm), and a gold film (front surface seed film, 1.0 μm) in sequence. After sputtering, a photoresist is coated on the surface of the front surface seed film of the ceramic substrate, a mask plate is used to transfer the pattern of the front surface functional layer to the front surface seed film of the ceramic substrate, and the pattern of the front surface functional layer is developed. Then, a first electroplating is performed. The thickness of the gold film obtained by the first electroplating is 1-4 μm (for example, 2 μm, 3 μm, 4 μm, the thickness of the gold film obtained by the electroplating is greater than the thickness of the front surface seed layer). The photoresist is stripped to obtain the front surface electroplating layer. Dry etching (argon ion etching) is performed on the front surface seed layer of the ceramic front surface to obtain the front surface electroplating layer and the front surface seed layer, the front surface electroplating layer and the front surface seed layer form the front surface functional layer, the nickel film and the titanium-tungsten alloy film of the bottom layer of the front surface seed layer are etched once by wet etching to obtain the front surface barrier layer and the front surface adhesion layer, and the front surface tantalum nitride film is exposed.

[0086] A photoresist is coated on the surface of the front surface functional layer and the surface of the front surface tantalum nitride film, a mask plate is used to transfer the pattern of the front surface resistance layer to the tantalum nitride film of the ceramic substrate, and the pattern of the front surface resistance layer is developed. The resistance layer pattern is etched, and then the photoresist is removed to form the front surface resistance layer and the front surface functional layer on the front surface of the ceramic substrate to obtain a front surface resistor semi-finished product.

[0087] The front resistor semi-finished product is laser resistance-regulated, the initial resistance is 27.21±10%Ω, and the final resistance is 50.00±1%Ω; the device is cut and grooved, and the ceramic part of the fixed strip at both ends is reserved; the groove position contacts the edge of the front functional layer, and a through groove is obtained.

[0088] Then, the back surface of the ceramic substrate and the sidewall obtained by grooving are successively sputtered with a titanium-tungsten alloy film (0.1 μm of back surface adhesion film and 0.1 μm of sidewall adhesion layer), a nickel film (0.1 μm of back surface barrier film and 0.1 μm of sidewall barrier layer), and a gold film (1.0 μm of back surface seed film and 1.0 μm of sidewall seed layer); a third semi-finished product is obtained;

[0089] After the sputtering is completed, the third semi-finished product obtained is subjected to second electroplating, and the thickness of the gold film obtained on the surface of the back surface seed film of the back surface after the second electroplating is 3-10 μm (for example, 3 μm, 4 μm, 6 μm, or 8 μm). Then, photoresist is coated on the surface of the back surface plating film obtained on the back surface after the second electroplating, a mask plate is used to transfer the pattern of the back surface functional layer to the back surface plating film, and the pattern of the back surface functional layer is developed. Then, wet etching is successively performed, a back surface plating layer and a back surface seed layer are obtained, the back surface plating layer and the back surface seed layer form the back surface functional layer, the nickel film and the titanium-tungsten alloy film of the back surface seed layer bottom layer are once etched by wet method, and a back surface barrier layer and a back surface adhesion layer are obtained. Then, UV glue is pasted on the back surface, and the front surface is dipped in glue to remove the excess gold film (formed by the second electroplating) on the front surface resistance layer; a single finished product is cut, and the excess metal burrs of the sidewall ground are trimmed, and a single double-sided ground thin film resistor is obtained.

[0090] Example 4

[0091] In this embodiment, a ceramic substrate with a thickness of 0.508 mm is used. The ceramic substrate is first cleaned and then dried. Then, a tantalum nitride film (0.01 μm of front surface resistance film), a titanium-tungsten alloy film (0.1 μm of front surface adhesion film), a nickel film (0.1 μm of front surface barrier film), and a gold film (1.0 μm of front surface seed film) are successively sputtered on the front surface of the ceramic substrate. After the sputtering is completed, photoresist is coated on the surface of the front surface seed film of the front surface of the ceramic substrate, a mask plate is used to transfer the pattern of the front surface functional layer to the front surface seed film of the ceramic substrate, and the pattern of the front surface functional layer is developed. Then, first electroplating is performed, and the thickness of the gold film obtained by the first electroplating is 1-4 μm (for example, 2 μm, 3 μm, or 4 μm, and the thickness of the gold film obtained by the electroplating is greater than the thickness of the front surface seed layer). The photoresist is stripped, and a front surface plating layer is obtained. Dry etching (argon ion etching) is performed on the front surface seed layer of the front surface of the ceramic, and the front surface plating layer and the front surface seed layer form the front surface functional layer. The nickel film and the titanium-tungsten alloy film of the front surface seed layer bottom layer are once etched by wet method, a front surface barrier layer and a front surface adhesion layer are obtained, and the front surface tantalum nitride film is exposed.

[0092] The photoresist is coated on the surface of the front functional layer and the surface of the front tantalum nitride film, the pattern of the front resistance layer is transferred to the tantalum nitride film of the ceramic substrate using a mask plate, and the front resistance layer pattern is developed; the resistance layer pattern is etched, and then the photoresist is removed, thereby forming the front resistance layer and the front functional layer on the front surface of the ceramic substrate, and obtaining a front resistor semi-finished product.

[0093] The front resistor semi-finished product is subjected to laser resistance adjustment, the initial resistance is 67.54±10%Ω, and the final resistance is 100.00±1%Ω; the slotting device is slotted, and the part of the ceramic with the fixed strip is reserved at both ends; the slotting position contacts the edge of the front functional layer, and a through slot is obtained.

[0094] Then, the back surface of the ceramic substrate and the side wall obtained by slotting are successively sputtered with a titanium-tungsten alloy film (0.1 μm of back adhesion film and 0.1 μm of side wall adhesion layer), a nickel film (0.1 μm of back barrier film and 0.1 μm of side wall barrier layer), and a gold film (1.0 μm of back seed film and 1.0 μm of side wall seed layer); a third semi-finished product is obtained.

[0095] After the sputtering is completed, the third semi-finished product obtained is subjected to second electroplating, and the thickness of the gold film obtained on the surface of the back seed film of the back surface after the second electroplating is 3-10 μm (for example, 3 μm, 4 μm, 6 μm, or 8 μm). Then, the surface of the back plating film obtained on the back surface after the second electroplating is coated with photoresist, the pattern of the back functional layer is transferred to the back plating film using a mask plate, and the back functional layer pattern is developed; then, wet etching is successively performed, thereby obtaining a back plating layer and a back seed layer, the back plating layer and the back seed layer forming a back functional layer, the nickel film and the titanium-tungsten alloy film are once wet etched, thereby obtaining a back barrier layer and a back adhesion layer. Then, UV glue is pasted on the back surface, and the front surface is dipped to remove the excess gold film (formed by the second electroplating) on the front resistance layer; a single finished product is cut, and the excess metal burrs on the side wall ground are trimmed, thereby obtaining a single double-sided ground type thin film resistor.

[0096] From the above embodiments, the preparation method provided by the application discards the method in the prior art that first slots a ceramic substrate according to a drawing specification, and then performs sputtering of a resistance film layer, an adhesion layer, a barrier layer and a seed layer; the application first prepares a front functional layer and a front resistance layer on the front surface of an insulating substrate, obtains a front resistor semi-finished product, then performs laser resistance adjustment on the front resistor semi-finished product, and then slots the insulating substrate of the front resistor semi-finished product; the application realizes, by adjusting the slotting step, that after a product completes a front independent series semi-product, accurate measurement is performed, laser resistance adjustment is preferentially performed, then slotting of the insulating substrate is performed, and finally a side wall and a back metallization ground conduction are made, thereby providing a high-precision double-sided ground thin-film resistor manufacturing method capable of laser resistance adjustment; the resistance precision of the double-sided ground thin-film resistor product obtained by the preparation method provided by the application is less than ±1%, and the alignment precision and the laser resistance adjustment efficiency of the double-sided ground thin-film resistor are greatly improved.

[0097] Although the above embodiments have made a detailed description of the application, it is only a part of the embodiments of the application, not all the embodiments, and other embodiments can be obtained according to the embodiments without creativity, and these embodiments all belong to the protection scope of the application.

Claims

1. A method for preparing a double-side grounded thin film resistor, characterized in that: The following steps are involved: (1) performing a first deposition on the front surface of the insulating substrate to obtain a first semi-finished product, wherein the first deposition includes sequentially depositing a front resistance film, a front adhesion film, a front barrier film, and a front seed film; (2) coating a photoresist on the front surface of the first semi-finished product, then transferring the pattern of the front functional layer to the front surface of the first semi-finished product using a mask, and forming a patterned surface of the front functional layer after development to obtain a first patterned semi-finished product; (3) performing a first electroplating on the first patterned semi-finished product, then removing the photoresist to obtain a front electroplating layer, etching the front seed film, the front barrier film, and the front adhesion film outside the front electroplating layer area to obtain a front adhesion layer, a front barrier layer, and a front seed layer, wherein the front seed layer and the front electroplating layer form a front functional layer to obtain a second semi-finished product; (4) coating a photoresist on the front surface of the second semi-finished product, then transferring the front resistance layer pattern to the front surface of the second semi-finished product using a mask, and forming a patterned surface of the front resistance layer after development to obtain a second patterned semi-finished product; (5) etching the patterned surface of the resistor layer of the second patterned semi-finished product, then removing the photoresist, forming a front resistor layer on the front surface of the insulating substrate, and obtaining a front resistor semi-finished product; (6) laser trimming the resistance of the front resistor semi-finished product, and then slotting the insulating substrate, where the slots are located so as to contact the edge of the front functional layer, to obtain a semi-finished product having a through-groove; (7) performing a second deposition on the back surface of the semi-finished product having the through-groove and on the sidewalls of the through-groove to obtain a third semi-finished product; the second deposition comprises sequentially depositing a back adhesive film and a sidewall adhesive layer, a back barrier film and a sidewall barrier layer, a back seed film and a sidewall seed layer; (8) performing a second electroplating on the third semi-finished product to obtain a fourth semi-finished product; (9) After obtaining the fourth semi-finished product, or coating the back of the fourth semi-finished product with a photoresist, then transferring the back functional layer pattern to the back of the fourth semi-finished product using a mask, performing etching after development, and removing the photoresist to obtain a back adhesion layer, a back barrier layer, a back seed layer, and a back electroplating layer on the back of the insulating substrate, wherein the back seed layer and the back electroplating layer form a back functional layer; After removing the electroplated film formed during the second electroplating on the surface of the front resistance layer of the fourth semi-finished product, the double-side grounded thin film resistor is obtained; or removing the electroplated film formed during the second electroplating on the surface of the front resistance layer of the fourth semi-finished product; Then, the back side of the fourth semi-finished product is coated with photoresist, and the back functional layer pattern is transferred to the back side of the fourth semi-finished product using a mask. After development, etching is performed, and after removing the photoresist, a back adhesion layer, a back barrier layer, a back seed layer and a back electroplating layer are obtained on the back side of the insulating substrate. The back seed layer and the back electroplating layer form a back functional layer to obtain the double-sided grounded thin film resistor.

2. The preparation method according to claim 1, characterized in that In step (3): the material of the front electroplating layer is gold, and the thickness of the front electroplating layer is 1 to 4 μm.

3. The preparation method according to claim 1, characterized in that In step (8): the second electroplating forms an electroplated film on the front, sidewall and back of the third semi-finished product, the material of the electroplated film formed by the second electroplating is gold, and the thickness of the electroplated film obtained by the second electroplating on the back of the third semi-finished product is 3 to 10 μm.

4. The preparation method according to any one of claims 1 to 3, characterized in that The material of the front resistance layer is tantalum nitride; the thickness of the front resistance layer is 0.01-0.1 μm.

5. The preparation method according to any one of claims 1 to 3, characterized in that The front adhesive layer, the sidewall adhesive layer and the back adhesive layer are made of titanium-tungsten alloy; the thickness of the front adhesive layer and the back adhesive layer are independently 0.1-0.5 μm.

6. The preparation method according to any one of claims 1 to 3, characterized in that The front barrier layer, the sidewall barrier layer and the back barrier layer are made of nickel; and the thickness of the front barrier layer and the back barrier layer are independently 0.1 to 0.5 μm.

7. The preparation method according to any one of claims 1 to 3, characterized in that The front seed layer, the sidewall seed layer and the back seed layer are made of gold; the thickness of the front seed layer and the back seed layer are independently 1 to 3 μm.

8. The preparation method according to any one of claims 1 to 3, characterized in that The insulating substrate is a ceramic substrate.

9. The preparation method according to claim 1, characterized in that The first deposition and the second deposition method are magnetron sputtering, The magnetron sputtering is completed by a tunnel inline magnetron sputtering device transported by a carrier plate.

10. The preparation method according to claim 1, characterized in that In step (3), the etching method for the front seed film outside the front electroplating layer area is dry etching; the etching method for the front barrier film and the front adhesion film outside the front electroplating layer area is wet etching; In step (5), the etching method for the patterned surface of the resistor layer of the second patterned semi-finished product is wet etching; In step (9), the etching method of the back side of the fourth semi-finished product after development is: the etching method of the back electroplating film is wet etching, the etching method of the back seed film is wet etching, and the etching method of the back barrier film and the back adhesion film is wet etching.

Images