Etching liquid for brazing layer, ceramic substrate and etching method thereof

Abstract

The invention provides an etching solution for a brazing layer, a ceramic substrate and an etching method of the ceramic substrate. The etching solution for the brazing layer comprises the following components in parts by mass: 20-30 parts of hydrogen peroxide; 2 to 10 parts of acid; 2-10 parts of a methylene phosphate compound; 20 parts to 40 parts of inorganic fluoride; wherein the aqueous solution of the inorganic fluoride is alkaline. The etching liquid for the brazing layer has better etching selectivity, can better realize sufficient etching of the brazing layer and can better realize the etching efficiency of the brazing layer, so that the productivity of a ceramic substrate can be improved.

Description

Technical Field

[0001] The invention relates to the technical field of semiconductor processing, in particular to an etching solution for a soldering layer and an etching method for a ceramic substrate. Background Art

[0002] Ceramic substrate refers to an ultra-thin composite substrate in which copper foil is bonded to the surface of an alumina ceramic substrate or an aluminum nitride ceramic substrate using a brazing material at high temperature. It has excellent electrical insulation properties, high thermal conductivity, excellent soft solderability and high adhesion strength. It can be etched with various patterns like a PCB board and has a large current-carrying capacity. Therefore, ceramic substrates have become the basic materials for high-power power electronic circuit structure technology and interconnection technology.

[0003] The selective etching effect of the soldering layer formed by the soldering material between the copper foil and the ceramic substrate in the subsequent graphic processing is a key factor affecting the quality of the ceramic substrate. The more commonly used etching solution for the soldering layer is a hydrogen peroxide-ammonia-phosphoric acid system, such as the invention patent application with application number CN200510068825.8, which has good selectivity for the soldering layer, but it adds phosphoric acid and phosphoric acid compounds as stabilizers for hydrogen peroxide, which has a great influence on the etching efficiency of the soldering layer in the subsequent graphic processing; for example, the invention patent application with application number CN202010344070.4 uses different etching solution systems to etch the soldering layer in steps. Although it achieves sufficient etching of the soldering layer well, it requires multi-step operation, which has a great influence on the etching efficiency of the soldering layer in the subsequent graphic processing, affecting the production capacity of the ceramic substrate. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and provide an etching solution for the soldering layer and an etching method for the ceramic substrate which have good etching selectivity, can better achieve sufficient etching of the soldering layer and can better achieve etching efficiency of the soldering layer, thereby improving the production capacity of the ceramic substrate.

[0005] The objective of the present invention is achieved through the following technical solutions:

[0006] An etching solution for a soldering layer comprises the following components in parts by weight:

[0007]

[0008] Wherein, the aqueous solution of the inorganic fluoride is alkaline.

[0009] In one embodiment, the methylene phosphonic acid compound includes at least one of nitrilo trimethylene phosphonic acid, ethylenediamine tetramethylene phosphonic acid, diethylene triamine pentamethylene phosphonic acid, diethylene triamine pentamethylene phosphonic acid and tetraethylene pentamine heptamethylene phosphonic acid.

[0010] In one embodiment, the inorganic fluoride includes at least one of sodium fluoride, ammonium fluoride and potassium fluoride.

[0011] A ceramic substrate etching method comprises etching the ceramic substrate by using the brazing layer etching solution described in any one of the above embodiments.

[0012] In one embodiment, the etching method of the ceramic substrate comprises the following steps:

[0013] obtaining a ceramic substrate;

[0014] The soldering layer etching solution is mixed and opened to obtain an etching treatment solution;

[0015] The ceramic substrate is placed in the etching solution to perform etching to obtain the ceramic substrate.

[0016] In one embodiment, the soldering layer is mixed with an etching solution and the specific steps are as follows:

[0017] Water is added to the solder layer etching solution to dilute it.

[0018] In one of the embodiments, the ratio of the solder layer etching solution to the water in the etching solution is 1:(4-5).

[0019] In one embodiment, the water is deionized water or pure water.

[0020] In one embodiment, placing the ceramic substrate in the etching solution for etching comprises the following steps:

[0021] Immersing the ceramic substrate in the etching solution to perform primary etching;

[0022] Hydrogen peroxide is added to the etching solution to perform secondary etching.

[0023] A ceramic substrate is obtained by the ceramic substrate etching method described in any one of the above embodiments.

[0024] Compared with the prior art, the present invention has at least the following advantages:

[0025] The soldering layer etching solution of the present invention uses phosphoric acid and methylene phosphate as stabilizers for hydrogen peroxide, thereby effectively achieving selective etching of the soldering layer; further, the hydrogen peroxide is coordinated with an inorganic fluoride, and the aqueous solution of the inorganic fluoride is alkaline, thereby effectively achieving efficient and sufficient etching of the soldering layer, thereby improving the production capacity of the ceramic substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0027] Figure 1 A flowchart of a ceramic substrate etching method according to an embodiment of the present invention;

[0028] Figure 2 Surface images of the ceramic substrate of Example 1 before and after etching;

[0029] Figure 3 Surface images of the ceramic substrate of Example 2 before and after etching;

[0030] Figure 4 Surface images of the ceramic substrate of Example 3 before and after etching;

[0031] Figure 5 Surface images of the ceramic substrate of Example 4 before and after etching;

[0032] Figure 6 Surface images of the ceramic substrate of Example 5 before and after etching;

[0033] Figure 7 These are the appearance pictures of the ceramic substrate of Example 6 before and after etching. DETAILED DESCRIPTION

[0034] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present invention are given in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thoroughly understood.

[0035] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only implementation method.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0037] The present application provides an etching solution for a soldering layer. In order to better understand the etching solution for a soldering layer of the present application, the etching solution for a soldering layer of the present application is further explained below:

[0038] The solder layer etching solution of one embodiment comprises the following components in parts by weight: 20 to 30 parts of hydrogen peroxide; 2 to 10 parts of acid; 2 to 10 parts of methylene phosphonic acid compound; and 20 to 40 parts of inorganic fluoride. The aqueous solution of the inorganic fluoride is alkaline.

[0039] The above-mentioned solder layer etching solution uses phosphoric acid and methylene phosphate as stabilizers for hydrogen peroxide, effectively achieving selective etching of the solder layer; further, hydrogen peroxide is combined with inorganic fluoride, and the aqueous solution of inorganic fluoride is alkaline, effectively achieving efficient and sufficient etching of the solder layer, thereby improving the production capacity of the ceramic substrate.

[0040] It should be noted that when the concentration of inorganic fluoride is low or high, it will affect the etching efficiency of the brazing layer. In addition, when the concentration of phosphoric acid and methylene phosphate is low, it will affect the selective etching of the brazing layer, while when the concentration is high, it will affect the etching sufficiency of the brazing layer. And, when the concentration of hydrogen peroxide is low, it will affect the etching efficiency of the brazing layer, while when the concentration is high, it will affect the selective etching of the brazing layer.

[0041] In one embodiment, the methylene phosphonic acid compound includes at least one of nitrilo trimethylene phosphonic acid, ethylenediamine tetramethylene phosphonic acid, diethylene triamine pentamethylene phosphonic acid, diethylene triamine pentamethylene phosphonic acid and tetraethylene pentamine heptamethylene phosphonic acid, which better ensures the stabilization effect of hydrogen peroxide.

[0042] In one embodiment, the inorganic fluoride includes at least one of sodium fluoride, ammonium fluoride and potassium fluoride. It can be understood that if the inorganic fluoride is a strong acidic substance, although the efficient etching of the brazing layer is achieved, the etching intensity of the copper layer outside the brazing layer is enhanced, thereby affecting the quality of the ceramic substrate. The inorganic fluoride is controlled to be alkaline, so that the pH of the etching solution for the brazing layer is maintained between 6 and 7, which is better to ensure the selective etching of the brazing layer, and achieve efficient and sufficient etching of the brazing layer, thereby improving the production capacity of the ceramic substrate.

[0043] In one embodiment, the method for preparing the solder layer etching solution comprises the following steps: mixing phosphoric acid and methylene phosphate in water, then adding hydrogen peroxide to mix, and then adding inorganic fluoride to mix. Furthermore, the volume percentage of hydrogen peroxide in the solder layer etching solution is 20% to 30%.

[0044] The present application also provides a ceramic substrate etching method, wherein the brazing layer etching solution of any of the above embodiments is used to etch the ceramic substrate. The above ceramic substrate etching method comprises the following steps: obtaining a ceramic substrate; mixing and opening the brazing layer etching solution to obtain an etching treatment solution; placing the ceramic substrate in the etching treatment solution for etching to obtain a ceramic substrate.

[0045] The above-mentioned ceramic substrate etching method uses the solder layer etching solution to etch the ceramic substrate, which effectively realizes the selective etching of the solder layer and effectively realizes the efficient and sufficient etching of the solder layer, thereby improving the production capacity of the ceramic substrate.

[0046] In order to better understand the etching method of the ceramic substrate of the present application, the etching method of the ceramic substrate of the present application is further explained below:

[0047] Please also read Figure 1 , a ceramic substrate etching method according to one embodiment comprises the following steps:

[0048] S100, obtaining a ceramic substrate. It can be understood that the ceramic substrate is an aluminum oxide ceramic substrate or a nitrogen oxide ceramic substrate, which better ensures the excellent performance of the ceramic substrate.

[0049] S200, the brazing layer etching solution is mixed and opened to obtain an etching treatment solution. It can be understood that the brazing layer etching solution is a basic etching solution with a high concentration, which is conducive to the storage and transportation of the brazing layer etching solution. Before the brazing layer etching solution is used to etch the ceramic substrate, it is necessary to open a cylinder to prepare a diluent of the brazing layer etching solution to etch the ceramic substrate.

[0050] S300, placing the ceramic substrate in an etching solution to perform etching operation to obtain a ceramic substrate, thereby ensuring that the brazing layer on the ceramic substrate is efficiently and fully etched away.

[0051] The above-mentioned ceramic substrate etching method uses the solder layer etching solution to etch the ceramic substrate, which effectively realizes the selective etching of the solder layer and effectively realizes the efficient and sufficient etching of the solder layer, thereby improving the production capacity of the ceramic substrate.

[0052] In one embodiment, the solder layer etching solution is mixed and opened, and the specific steps are as follows: water is added to the solder layer etching solution for dilution. Further, the ratio of the solder layer etching solution to water in the etching treatment solution is 1: (4-5). Further, the water is deionized water or pure water, which better ensures the etching effect of the solder layer.

[0053] In one embodiment, before the step of obtaining the ceramic substrate, the method for etching the ceramic substrate further includes the following steps:

[0054] After the ceramic substrate is dry filmed, exposed and developed, a copper etching solution is used to form a copper-clad pattern layer and expose the solder layer. It can be understood that the operation of dry filming, exposure and development of the ceramic substrate, and etching the copper layer with a copper etchant is a relatively conventional operation, so this application will not repeat it. In one embodiment, the ceramic substrate is placed in an etching treatment solution for etching, which specifically includes the following steps:

[0055] Immersing the ceramic substrate in an etching solution to perform primary etching;

[0056] Hydrogen peroxide is added to the etching solution to perform secondary etching.

[0057] In one embodiment, the ceramic substrate is immersed in an etching solution for primary etching, and the specific steps are as follows: the ceramic substrate is added into the etching solution and completely immersed, the temperature is 30° C. to 32° C., and the treatment time is 10 min to 15 min.

[0058] In one embodiment, hydrogen peroxide is added to the etching solution for secondary etching, and the specific steps are as follows: 30% hydrogen peroxide and solder layer etching solution are poured into the etching solution while stirring, and then allowed to stand. It can be understood that 30% hydrogen peroxide is an aqueous solution with a mass concentration of 30% hydrogen peroxide.

[0059] In one embodiment, the pouring speed of 30% hydrogen peroxide is 10 mL / s·L to 20 mL / s·L, where 10 mL / s·L means that 10 mL of 30% hydrogen peroxide is poured into each liter of etching solution per second.

[0060] In one embodiment, the pouring speed of the solder layer etching solution is 12 mL / s·L to 25 mL / s·L, and 10 mL / s·L means that 10 mL of the solder layer etching solution is poured into each liter of etching solution per second.

[0061] In one embodiment, the stirring speed is 60 r / min to 80 r / min.

[0062] In one embodiment, 50 mL to 100 ml of 30% hydrogen peroxide is added per liter of etching solution. In one embodiment, 80 mL to 150 ml of solder layer etching solution is added per liter of etching solution.

[0063] In one embodiment, 30% hydrogen peroxide and solder layer etching solution are poured into the etching solution while stirring, and the temperature is 35° C. to 38° C. Furthermore, stirring is stopped immediately after the solder layer etching solution is poured.

[0064] In one embodiment, the temperature of the static treatment is 35°C to 38°C, and the time is 5min to 8min. It can be understood that the ceramic substrate is initially etched in the etching solution. At this time, the concentration of hydrogen peroxide and inorganic fluoride in the etching solution cannot be controlled too high, otherwise metals that do not need to be etched, such as copper, will be etched, resulting in pits on the surface of the copper-clad pattern layer. Since the concentrations of phosphoric acid and methylene phosphate in the etching solution are relatively high, hydrogen peroxide has a good stabilizing effect and can better protect metals that do not need to be etched, such as copper, but it has a greater impact on the etching efficiency of the ceramic substrate. Further, the ceramic substrate is immersed in the etching solution for 10min to 8min. After 15 minutes, 30% hydrogen peroxide and solder layer etching solution are added to the etching solution, and the concentrations of hydrogen peroxide and inorganic fluoride in the etching solution are adjusted, thereby accelerating the etching efficiency of the solder layer of the ceramic substrate. In addition, due to the protective treatment of phosphoric acid and methylene phosphate with higher concentrations in the early stage, the selective etching of the ceramic substrate can still be ensured after the adjusted concentrations of phosphoric acid and methylene phosphate decrease, thereby better ensuring the selective etching of the ceramic substrate and better improving the etching efficiency of the ceramic substrate, thereby better ensuring the quality and production capacity of the ceramic substrate.

[0065] It should be noted that the ceramic substrate actually mainly contains Ag, Cu, Ti and Al. The general process is to first etch away the Ag on the surface of the ceramic substrate, then scoop up and wash the remaining etching solution, and further etch the Cu, Ti and Al. This will increase the operating steps of the ceramic substrate and extend the production capacity of the ceramic substrate.

[0066] It should also be noted that if the concentration of hydrogen peroxide in the secondary etching is too high, the local hydrogen peroxide concentration in the etching solution will be too high, which may easily cause the etching of metals that do not need to be etched, such as copper. If the concentration is too low, the amount of hydrogen peroxide added will be large and the addition time will be long. Excessive stirring of the etching solution will affect the etching uniformity of the ceramic substrate, thereby affecting the quality of the ceramic substrate.

[0067] It should also be noted that the step of pouring 30% hydrogen peroxide and solder layer etching solution into the etching solution while stirring is not a conventional refilling step. The purpose of refilling is to replenish the substances consumed in the etching solution. The pouring of 30% hydrogen peroxide and solder layer etching solution in the secondary etching is to control the concentration of each substance in the etching solution to change in stages over time, thereby achieving an increase in the production capacity of the ceramic substrate.

[0068] It should also be noted that after etching the ceramic substrate, a large amount of etching treatment liquid waste will be left over. The etching treatment liquid waste is tested for Cu ions. If the Cu ion concentration is less than 1g / L, the consumed substances are supplemented and adjusted to obtain the etching treatment liquid for recycling; if the Cu ion concentration is greater than 1g / L, the waste liquid is treated.

[0069] The present application also provides a ceramic substrate obtained by the etching method of the ceramic substrate of any of the above embodiments.

[0070] Compared with the prior art, the present invention has at least the following advantages:

[0071] The soldering layer etching solution of the present invention uses phosphoric acid and methylene phosphate as stabilizers for hydrogen peroxide, thereby effectively achieving selective etching of the soldering layer; further, the hydrogen peroxide is coordinated with an inorganic fluoride, and the aqueous solution of the inorganic fluoride is alkaline, thereby effectively achieving efficient and sufficient etching of the soldering layer, thereby improving the production capacity of the ceramic substrate.

[0072] Some specific examples are listed below, and if % is mentioned, it means percentage by weight. It should be noted that the following examples do not exhaust all possible situations, and the materials used in the following examples can be obtained from commercial sources unless otherwise specified.

[0073] Example 1

[0074] Prepare the etching solution for the soldering layer: put 2 kg of phosphoric acid and 2 kg of nitrilotrimethylenephosphonic acid into a stirring tank, then add 40 L of deionized water to stir and mix, then add 20 kg of hydrogen peroxide to the stirring tank to stir and mix, then add 20 kg of sodium fluoride to the stirring tank to stir and mix, then add deionized water to make the volume to 100 L, to obtain the etching solution for the soldering layer;

[0075] Add all the soldering layer etching solution into the etching tank, and add deionized water, the volume ratio of deionized water to the soldering layer etching solution is 1:4, to obtain an etching treatment solution;

[0076] The temperature of the etching solution was controlled at 30°C, and then the ceramic substrates were immersed in the etching solution, with the distance between the ceramic substrates being 4±0.5cm. After 10 minutes, the temperature of the etching solution was controlled at 35°C, and then 30% hydrogen peroxide and solder layer etching solution were poured in while stirring. The stirring speed was 60r / min, the total amount of solder layer etching solution poured in was 8L, and the pouring speed was 1.2L / s. The total amount of 30% hydrogen peroxide poured in was 5L, and the pouring speed was 1L / s. After the solder layer etching solution was poured, the stirring was stopped immediately, and then the solution was allowed to stand for 8 minutes. The solution was fished out and washed with water 3 times to obtain a ceramic substrate.

[0077] Example 2

[0078] Prepare the etching solution for the soldering layer: put 5 kg of phosphoric acid and 5 kg of nitrilotrimethylenephosphonic acid into a stirring tank, then add 40 L of deionized water to stir and mix, then add 25 kg of hydrogen peroxide to the stirring tank to stir and mix, then add 25 kg of sodium fluoride to the stirring tank to stir and mix, then add deionized water to make the volume to 100 L, to obtain the etching solution for the soldering layer;

[0079] Add all the soldering layer etching solution into the etching tank, and add deionized water, the volume ratio of deionized water to the soldering layer etching solution is 1:4, to obtain an etching treatment solution;

[0080] The temperature of the etching solution was controlled at 30°C, and then the ceramic substrates were immersed in the etching solution, with the distance between the ceramic substrates being 4±0.5cm. After 15 minutes, the temperature of the etching solution was controlled at 35°C, and then 30% hydrogen peroxide and solder layer etching solution were poured in while stirring. The stirring speed was 60r / min, the total amount of solder layer etching solution poured in was 8L, and the pouring speed was 1.2L / s. The total amount of 30% hydrogen peroxide poured in was 5L, and the pouring speed was 1L / s. After the solder layer etching solution was poured, stirring was stopped immediately, and then the solution was allowed to stand for 8 minutes. The solution was fished out and washed with water 3 times to obtain a ceramic substrate.

[0081] Example 3

[0082] Prepare the etching solution for the soldering layer: put 10 kg of phosphoric acid and 10 kg of nitrilotrimethylenephosphonic acid into a stirring tank, then add 40 L of deionized water to stir and mix, then add 30 kg of hydrogen peroxide to the stirring tank to stir and mix, then add 30 kg of sodium fluoride to the stirring tank to stir and mix, then add deionized water to make the volume to 100 L, to obtain the etching solution for the soldering layer;

[0083] Add all the soldering layer etching solution into the etching tank, and add deionized water, the volume ratio of deionized water to the soldering layer etching solution is 1:4, to obtain an etching treatment solution;

[0084] The temperature of the etching solution was controlled at 30°C, and then the ceramic substrates were immersed in the etching solution, with the distance between the ceramic substrates being 4±0.5cm. After 15 minutes, the temperature of the etching solution was controlled at 35°C, and then 30% hydrogen peroxide and solder layer etching solution were poured in while stirring. The stirring speed was 60r / min, the total amount of solder layer etching solution poured in was 8L, and the pouring speed was 1.2L / s. The total amount of 30% hydrogen peroxide poured in was 5L, and the pouring speed was 1L / s. After the solder layer etching solution was poured, stirring was stopped immediately, and then the solution was allowed to stand for 8 minutes. The solution was fished out and washed with water 3 times to obtain a ceramic substrate.

[0085] Example 4

[0086] Prepare the etching solution for the soldering layer: put 5 kg of phosphoric acid and 5 kg of nitrilotrimethylenephosphonic acid into a stirring tank, then add 40 L of deionized water to stir and mix, then add 25 kg of hydrogen peroxide to the stirring tank to stir and mix, then add 25 kg of sodium fluoride to the stirring tank to stir and mix, then add deionized water to make the volume to 100 L, to obtain the etching solution for the soldering layer;

[0087] Add all the soldering layer etching solution into the etching tank, and add deionized water, the volume ratio of deionized water to the soldering layer etching solution is 1:5, to obtain an etching treatment solution;

[0088] The temperature of the etching solution was controlled at 30°C, and then the ceramic substrates were immersed in the etching solution, with the distance between the ceramic substrates being 4±0.5cm. After 15 minutes, the temperature of the etching solution was controlled at 35°C, and then 30% hydrogen peroxide and solder layer etching solution were poured in while stirring. The stirring speed was 60r / min, the total amount of solder layer etching solution poured in was 8L, and the pouring speed was 1.2L / s. The total amount of 30% hydrogen peroxide poured in was 5L, and the pouring speed was 1L / s. After the solder layer etching solution was poured, stirring was stopped immediately, and then the solution was allowed to stand for 8 minutes. The solution was fished out and washed with water 3 times to obtain a ceramic substrate.

[0089] Example 5

[0090] Prepare the etching solution for the soldering layer: put 5 kg of phosphoric acid and 5 kg of nitrilotrimethylenephosphonic acid into a stirring tank, then add 40 L of deionized water to stir and mix, then add 25 kg of hydrogen peroxide to the stirring tank to stir and mix, then add 25 kg of sodium fluoride to the stirring tank to stir and mix, then add deionized water to make the volume to 100 L, to obtain the etching solution for the soldering layer;

[0091] Add all the soldering layer etching solution into the etching tank, and add deionized water, the volume ratio of deionized water to the soldering layer etching solution is 1:5, to obtain an etching treatment solution;

[0092] The temperature of the etching solution was controlled at 32°C, and then the ceramic substrates were immersed in the etching solution, with the distance between the ceramic substrates being 4±0.5cm. After 13min, the temperature of the etching solution was controlled at 36°C, and then 30% hydrogen peroxide and solder layer etching solution were poured in while stirring. The stirring speed was 70r / min, the total amount of solder layer etching solution poured in was 10L, and the pouring speed was 2.0L / s. The total amount of 30% hydrogen peroxide poured in was 8L, and the pouring speed was 1.5L / s. After the solder layer etching solution was poured in, stirring was stopped immediately, and then the solution was allowed to stand for 6min, and the solution was taken out and washed with water 3 times to obtain a ceramic substrate.

[0093] Example 6

[0094] Prepare the etching solution for the soldering layer: put 5 kg of phosphoric acid and 5 kg of nitrilotrimethylenephosphonic acid into a stirring tank, then add 40 L of deionized water to stir and mix, then add 25 kg of hydrogen peroxide to the stirring tank to stir and mix, then add 25 kg of sodium fluoride to the stirring tank to stir and mix, then add deionized water to make the volume to 100 L, to obtain the etching solution for the soldering layer;

[0095] Add all the soldering layer etching solution into the etching tank, and add deionized water, the volume ratio of deionized water to the soldering layer etching solution is 1:5, to obtain an etching treatment solution;

[0096] The temperature of the etching solution was controlled to be 32°C, and then the ceramic substrates were immersed in the etching solution, with the distance between the ceramic substrates being 4±0.5cm. After 10 minutes, the temperature of the etching solution was controlled to be 38°C, and then 30% hydrogen peroxide and solder layer etching solution were poured in while stirring, with a stirring speed of 80r / min. The total amount of solder layer etching solution poured in was 15L, and the pouring speed was 2.5L / s. The total amount of 30% hydrogen peroxide poured in was 10L, and the pouring speed was 2L / s. After the solder layer etching solution was poured in, stirring was stopped immediately, and then it was allowed to stand for 5 minutes, and then it was taken out and washed with water 3 times to obtain a ceramic substrate. Example 7

[0097] Prepare the etching solution for the soldering layer: put 5 kg of phosphoric acid and 5 kg of nitrilotrimethylenephosphonic acid into a stirring tank, then add 40 L of deionized water to stir and mix, then add 25 kg of hydrogen peroxide to the stirring tank to stir and mix, then add 25 kg of sodium fluoride to the stirring tank to stir and mix, then add deionized water to make the volume to 100 L, to obtain the etching solution for the soldering layer;

[0098] Add all the soldering layer etching solution into the etching tank, and add deionized water, the volume ratio of deionized water to the soldering layer etching solution is 1:5, to obtain an etching treatment solution;

[0099] The temperature of the etching solution was controlled at 32° C., and then the ceramic substrate was immersed in the etching solution, etched for 25 minutes, and then taken out and washed with water for 3 times to obtain a ceramic substrate.

[0100] Example 8

[0101] Prepare the etching solution for the soldering layer: put 5 kg of phosphoric acid and 5 kg of nitrilotrimethylenephosphonic acid into a stirring tank, then add 40 L of deionized water to stir and mix, then add 25 kg of hydrogen peroxide to the stirring tank to stir and mix, then add 25 kg of sodium fluoride to the stirring tank to stir and mix, then add deionized water to make the volume to 100 L, to obtain the etching solution for the soldering layer;

[0102] Add all the soldering layer etching solution into the etching tank, and add deionized water, the volume ratio of deionized water to the soldering layer etching solution is 1:5, then add 10L of 30% hydrogen peroxide and 15L of soldering layer etching solution, stir evenly, and obtain an etching treatment solution;

[0103] The temperature of the etching solution was controlled at 32° C., and then the ceramic substrate was immersed in the etching solution, etched for 25 minutes, and then taken out and washed with water for 3 times to obtain a ceramic substrate.

[0104] Example 9

[0105] Prepare the etching solution for the soldering layer: put 5 kg of phosphoric acid and 5 kg of nitrilotrimethylenephosphonic acid into a stirring tank, then add 40 L of deionized water to stir and mix, then add 25 kg of hydrogen peroxide to the stirring tank to stir and mix, then add 25 kg of sodium fluoride to the stirring tank to stir and mix, then add deionized water to make the volume to 100 L, to obtain the etching solution for the soldering layer;

[0106] Add all the soldering layer etching solution into the etching tank, and add deionized water, the volume ratio of deionized water to the soldering layer etching solution is 1:5, then add 10L of 30% hydrogen peroxide and 15L of soldering layer etching solution, stir evenly, and obtain an etching treatment solution;

[0107] The temperature of the etching solution was controlled at 35° C., and then the ceramic substrate was immersed in the etching solution, etched for 25 minutes, and then taken out and washed with water for 3 times to obtain a ceramic substrate.

[0108] Example 10

[0109] Prepare the etching solution for the soldering layer: put 5 kg of phosphoric acid and 5 kg of nitrilotrimethylenephosphonic acid into a stirring tank, then add 40 L of deionized water to stir and mix, then add 25 kg of hydrogen peroxide to the stirring tank to stir and mix, then add 25 kg of sodium fluoride to the stirring tank to stir and mix, then add deionized water to make the volume to 100 L, to obtain the etching solution for the soldering layer;

[0110] Add all the soldering layer etching solution into the etching tank, and add deionized water, the volume ratio of deionized water to the soldering layer etching solution is 1:5, then add 10L of 30% hydrogen peroxide and 15L of soldering layer etching solution, stir evenly, and obtain an etching treatment solution;

[0111] The temperature of the etching solution was controlled at 38° C., and then the ceramic substrate was immersed in the etching solution, etched for 25 minutes, and then taken out and washed with water for 3 times to obtain a ceramic substrate.

[0112] Embodiment 11

[0113] Prepare the etching solution for the soldering layer: put 5 kg of phosphoric acid and 5 kg of nitrilotrimethylenephosphonic acid into a stirring tank, then add 40 L of deionized water to stir and mix, then add 25 kg of hydrogen peroxide to the stirring tank to stir and mix, then add 25 kg of sodium fluoride to the stirring tank to stir and mix, then add deionized water to make the volume to 100 L, to obtain the etching solution for the soldering layer;

[0114] Add all the soldering layer etching solution into the etching tank, and add deionized water, the volume ratio of deionized water to the soldering layer etching solution is 1:5, then add 10L of 30% hydrogen peroxide and 15L of soldering layer etching solution, stir evenly, and obtain an etching treatment solution;

[0115] The temperature of the etching solution was controlled at 32°C, and then the ceramic substrates were immersed in the etching solution, with the distance between the ceramic substrates being 4±0.5cm. After 10 minutes, the temperature of the etching solution was controlled at 38°C, and then 30% hydrogen peroxide and solder layer etching solution were poured in while stirring. The stirring speed was 80r / min, the total amount of solder layer etching solution poured in was 15L, and the pouring speed was 1L / s. The total amount of 30% hydrogen peroxide poured in was 10L, and the pouring speed was 0.8L / s. After the solder layer etching solution was poured, stirring was stopped immediately, and then the solution was allowed to stand for 5 minutes, and the solution was taken out and washed with water 3 times to obtain a ceramic substrate.

[0116] Example 12

[0117] Prepare the etching solution for the soldering layer: put 5 kg of phosphoric acid and 5 kg of nitrilotrimethylenephosphonic acid into a stirring tank, then add 40 L of deionized water to stir and mix, then add 25 kg of hydrogen peroxide to the stirring tank to stir and mix, then add 25 kg of sodium fluoride to the stirring tank to stir and mix, then add deionized water to make the volume to 100 L, to obtain the etching solution for the soldering layer;

[0118] Add all the soldering layer etching solution into the etching tank, and add deionized water, the volume ratio of deionized water to the soldering layer etching solution is 1:5, then add 10L of 30% hydrogen peroxide and 15L of soldering layer etching solution, stir evenly, and obtain an etching treatment solution;

[0119] The temperature of the etching solution was controlled at 32°C, and then the ceramic substrates were immersed in the etching solution, with the distance between the ceramic substrates being 4±0.5cm. After 10 minutes, the temperature of the etching solution was controlled at 38°C, and then 30% hydrogen peroxide and solder layer etching solution were poured in while stirring. The stirring speed was 80r / min, the total amount of solder layer etching solution poured in was 15L, and the pouring speed was 2.8L / s. The total amount of 30% hydrogen peroxide poured in was 10L, and the pouring speed was 2.3L / s. After the solder layer etching solution was poured, stirring was stopped immediately, and then the solution was allowed to stand for 5 minutes, and the solution was removed and washed with water 3 times to obtain a ceramic substrate.

[0120] The ceramic substrates of Examples 1 to 12 were observed below. The number of ceramic substrates observed in each example was 1000. It was recorded whether the soldering layer was completely etched and whether the surface of the copper-clad pattern layer was bright. The recorded results are shown in Table 1:

[0121]

[0122]

[0123] Please see Figures 2 to 7 , which are respectively the appearance diagrams of the ceramic substrates of Examples 1 to 6 before etching (a) and after etching (b). From Table 1, Figures 2 to 7 It can be seen that the schemes of Examples 1 to 6 of the present application better achieve efficient and sufficient etching of the solder layer, and improve the production capacity and quality of the ceramic substrate; while Examples 11 to 12 change the addition speed of 30% hydrogen peroxide and the solder layer etching solution for the secondary etching, resulting in the formation of pits on the surface of the copper-clad graphic layer on the surface of the ceramic substrate, affecting the brightness of the surface of the copper-clad graphic layer, that is, the addition speed of 30% hydrogen peroxide and the solder layer etching solution for the secondary etching affects the local concentration of the ceramic substrate, thereby making the concentration too high or too low, affecting the quality or production capacity of the ceramic substrate.

[0124] The above embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for those of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. An etching solution for a solder layer, characterized in that: The composition comprises the following components in parts by weight: Wherein, the aqueous solution of the inorganic fluoride is alkaline.

2. The solder layer etching solution according to claim 1, characterized in that: The methylene phosphoric acid compound includes at least one of nitrilo trimethylene phosphonic acid, ethylenediamine tetramethylene phosphoric acid, diethylene triamine pentamethylene phosphonic acid, diethylene triamine pentamethylene phosphonic acid and tetraethylene pentamine heptamethylene phosphonic acid.

3. The solder layer etching solution according to claim 1, characterized in that: The inorganic fluoride includes at least one of sodium fluoride, ammonium fluoride and potassium fluoride.

4. A method for etching a ceramic substrate, characterized in that: The ceramic substrate is etched using the solder layer etching solution according to any one of claims 1 to 3.

5. The method for etching a ceramic substrate according to claim 4, characterized in that: The etching method of the ceramic substrate comprises the following steps: obtaining a ceramic substrate; The soldering layer etching solution is mixed and opened to obtain an etching treatment solution; The ceramic substrate is placed in the etching solution to perform etching to obtain the ceramic substrate.

6. The method for etching a ceramic substrate according to claim 5, characterized in that: The soldering layer is mixed with etching solution and the specific steps are as follows: Water is added to the solder layer etching solution to dilute it.

7. The method for etching a ceramic substrate according to claim 6, characterized in that: The ratio of the solder layer etching solution to the water in the etching solution is 1:(4-5).

8. The method for etching a ceramic substrate according to claim 6, wherein: The water is deionized water or pure water.

9. The method for etching a ceramic substrate according to claim 1, wherein: Placing the ceramic substrate in the etching solution for etching, specifically comprising the following steps: Immersing the ceramic substrate in the etching solution to perform primary etching; Hydrogen peroxide is added to the etching solution to perform secondary etching.

10. A ceramic substrate, characterized in that: Obtained by the method for etching a ceramic substrate according to any one of claims 4 to 9.

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