Copper and copper alloy selective etching solution and etching test equipment

Abstract

The invention relates to the field of precise conductor surface treatment, in particular to copper and copper alloy selective etching liquid and etching test equipment. The invention provides the copper and the etching liquid, which can be used for rapidly etching the copper and the copper alloy and inhibiting the etching of other metals to the greatest extent while realizing the rapid etching of the copper and the copper alloy, and is suitable for a copper bump process containing a precise conductor pattern and a process using nickel, tin, lead, titanium and the like as an etching barrier layer or a final surface treatment process; on the basis, the invention further provides etching test equipment for testing the etching liquid, etching, cleaning and drying treatment of a copper-clad plate test piece can be completed in one step, and meanwhile, the weighing work of the copper-clad plate test piece is sequentially carried out through a miniature waterproof scale on a carrying disc; and the whole etching test work flow of the copper-clad plate test piece can be quickly completed.

Description

Technical Field

[0001] The present invention relates to the field of precision conductor surface treatment, and in particular to a copper and copper alloy selective etching solution and etching test equipment. Background Art

[0002] As the size of electronic devices decreases, the size of printed circuit board conductors is getting smaller and smaller. For example, in IC substrates used to interconnect with semiconductor devices, copper alloy lead frames for packaging, DRAM or NAND chip packaging substrates interconnected by copper bumps, and copper electrode wiring of panel displays, the manufacture of the above printed circuit boards involves wet etching of copper or copper alloy precision conductor patterns. Traditional wet etching methods for copper and copper alloys include the acidic ferric chloride system, acidic copper chloride system, and alkaline copper chloride-ammonium chloride high-speed copper etching systems well known in the industry. In addition, there are acid-based low-speed copper micro-etching systems such as persulfate-sulfuric acid, sulfuric acid-hydrogen peroxide or nitric acid.

[0003] However, due to the high etching rate of the copper chloride-based high-speed etching system, it is difficult to accurately control the etching amount when making precise conductor surface patterns (such as Line / Space=30 / 30μm), which can easily lead to over-etching and is not conducive to the formation of precise conductor patterns. The acid-based low-speed copper micro-etching system has been widely used in the modified semi-additive process (MSAP) process for manufacturing IC substrates and is suitable for the manufacture of precise conductor patterns. However, due to the poor selectivity of the acid-based low-speed copper micro-etching system for other metals such as nickel, tin, lead, and titanium, it cannot etch when the precise conductor patterns use the above metals as etching barriers (hard masks).

[0004] To solve the above problems, the present invention provides a copper and copper alloy selective etching solution and etching test equipment, which can quickly etch copper and copper alloys while maximally suppressing the etching of other metals. It is suitable for copper bump processes containing precise conductor patterns and processes using nickel, tin, lead, titanium, etc. as etching barriers or final surface treatments. Summary of the Invention

[0005] The purpose of the present invention is to provide a selective etching solution for copper and copper alloys and an etching test device, which can rapidly etch copper and copper alloys while maximally suppressing the corrosion of other metals. The etching solution is particularly suitable for copper bump processes containing precise conductor patterns and processes using nickel, tin, lead, titanium, etc. as etching barriers or final surface treatments.

[0006] The invention discloses a copper ion selective etching solution for copper alloys. The copper is used as a divalent copper ion source of copper chloride, copper bromide, copper sulfate, copper nitrate, copper acetate, and copper carbonate. The content of copper ions in the etching solution is 0.1%-10%.

[0007] The invention discloses an etching solution, which contains divalent copper ions, organic acid, pH regulator and halogen ions.

[0008] Preferably, the content of copper ions in the etching solution is 0.5%-6%.

[0009] Preferably, the organic acid includes but is not limited to formic acid, acetic acid, propionic acid, butyric acid, oxalic acid, malonic acid, succinic acid, glutaric acid, maleic acid, acrylic acid, lactic acid, and citric acid, and the content of the organic acid in the etching solution is 0.1%-20%.

[0010] Preferably, the content of the organic acid in the etching solution is 1%-10%.

[0011] Preferably, the pH regulator is a mixture of ammonia water and organic amine, wherein the organic amine includes but is not limited to monoethanolamine, diethanolamine, triethanolamine, ethylenediamine, diethylenetriamine, and triethylenetetramine, and the ratio of ammonia water to organic amine in the etching solution is ammonia water to organic amine = 1:10-20:1.

[0012] Preferably, the ratio of ammonia water to organic amine in the etching solution is ammonia water to organic amine = 1:5-5:1.

[0013] Preferably, the halogen ion source includes but is not limited to hydrochloric acid, sodium chloride, ammonium chloride, potassium chloride, calcium chloride, magnesium chloride, aluminum chloride, nickel chloride, ferric chloride, hydrobromic acid, sodium bromide, potassium bromide, ammonium bromide, calcium bromide, magnesium bromide, aluminum bromide, nickel bromide, ferric bromide, sodium iodide, and potassium iodide, and the content of the halogen ion in the etching solution is 0.001%-30%.

[0014] Preferably, the content of halogen ions in the etching solution is 0.01%-15%.

[0015] An etching test device includes a mounting frame, a liquid storage tank, a liquid outlet pipe, a carrier plate, a waste liquid pipe, a micro waterproof scale, a cover plate and an electric push rod; the mounting frame is fixedly connected to the liquid storage tank; an inlet end structure is provided at the top of the liquid storage tank; a liquid outlet trough structure is provided at the bottom of the liquid storage tank; a liquid outlet pipe is slidably connected to the liquid storage tank; a through groove structure corresponding to the liquid outlet trough structure is provided on the liquid outlet pipe; the mounting frame is fixedly connected to the carrier plate; a positioning groove structure for placing a copper clad laminate test piece is provided on the carrier plate; a waste liquid pipe is fixedly connected to the bottom of the carrier plate; a plurality of waste liquid trough structures surrounding the positioning groove structure are provided on the inner edge of the carrier plate, and the waste liquid trough structure is connected to the waste liquid pipe; a micro waterproof scale is installed in the positioning groove structure of the carrier plate; the carrier plate is slidably connected to the carrier plate; a liquid inlet structure connected to the liquid outlet pipe is provided in the middle of the cover plate; an electric push rod for controlling the up and down movement of the cover plate is installed on the carrier plate.

[0016] Preferably, an electric heating coil is installed in the liquid storage tank; a liquid infusion tube is installed in the liquid storage tank, and a liquid spray port is provided on the liquid infusion tube; and a fan is installed in the inlet end structure of the liquid storage tank.

[0017] Preferably, a waterproof barrier strip for covering the gap between the carrier plate and the copper-clad laminate test piece is fixedly connected to the cover plate; a compression spring is fixedly connected between the slide bar and the cover plate.

[0018] Preferably, a concave cavity structure is provided at the bottom of the cover plate; a hydrophobic microporous membrane covering the concave cavity structure is fixed to the bottom of the cover plate; the cover plate is provided with a plurality of guide groove structures connected to the concave cavity structure, and the guide groove structures are aligned above the corresponding waste liquid trough structures.

[0019] The beneficial effects of the present invention are as follows: the present invention provides a selective etching solution for copper and copper alloys, which can rapidly etch copper and copper alloys while maximally suppressing the etching of other metals. The solution is suitable for copper bump processes containing precise conductor patterns and processes using nickel, tin, lead, titanium, etc. as etching barriers or final surface treatments. On this basis, the present invention also provides an etching test device for testing the etching solution, wherein a copper clad laminate test piece is placed between a carrier and a cover plate, with only a single-layer gap remaining between the carrier and the cover plate. The etching solution and deionized water for cleaning are successively delivered to the surface of the copper clad laminate test piece by a liquid storage tank, and the etching, cleaning and drying processes of the copper clad laminate test piece are completed in one step in conjunction with the electric heating coil and the fan in the liquid storage tank. At the same time, the copper clad laminate test piece is weighed in turn by a miniature waterproof scale on the carrier, thereby quickly completing the entire etching test workflow of the copper clad laminate test piece. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A structural diagram for describing an etching test device of the present invention; Figure 2 A structural diagram of a carrier plate and a cover plate for describing an etching test device of the present invention; Figure 3 A structural diagram of a carrier plate for describing an etching test device of the present invention; Figure 4 A cross-sectional structural diagram of a cover plate for describing an etching test device of the present invention; Figure 5 A structural diagram of a waterproof barrier strip for describing an etching test device of the present invention; Figure 6 The present invention is a cross-sectional structural diagram of a liquid storage tank of an etching test device.

[0021] Explanation of the accompanying drawings: 1-mounting frame, 2-liquid storage tank, 201-inlet end structure, 202-liquid outlet tank structure, 21-liquid outlet pipe, 2101-through groove structure, 22-electric heating coil, 23-infusion tube, 24-fan, 3-carrying plate, 301-positioning groove structure, 302-waste liquid tank structure, 31-waste liquid pipe, 4-micro waterproof scale, 5-cover plate, 501-liquid inlet structure, 502-concave cavity structure, 503-guide groove structure, 51-electric push rod, 52-waterproof baffle, 53-hydrophobic microporous membrane. DETAILED DESCRIPTION

[0022] The following description is merely a preferred embodiment of the present invention and does not limit the scope of protection of the present invention.

[0023] Example The invention discloses an etching solution, which contains divalent copper ions, organic acid, pH regulator and halogen ions.

[0024] Copper is used as the divalent copper ion source of the etching solution, and any one or more of copper chloride, copper bromide, copper sulfate, copper nitrate, copper acetate, and copper carbonate are used, and the content of copper ions in the etching solution is 0.1%-10%. Preferably, the content of copper ions in the etching solution is 0.5%-6%. When the content is lower than 0.5%, the etching rate is slow, and the copper and copper alloy layers cannot be etched quickly. When the content is higher than 6%, the etching rate is too high, which may cause excessive etching of the copper layer in the hole, destroying the conductive properties of the hole and even destroying the conductor pattern. In addition, ultra-high copper ions may cause the etching solution to produce precipitates.

[0025] Organic acids include but are not limited to formic acid, acetic acid, propionic acid, butyric acid, oxalic acid, malonic acid, succinic acid, glutaric acid, maleic acid, acrylic acid, lactic acid, and citric acid, and the content of organic acids in the etching solution is 0.1%-20%, and the content of organic acids in the etching solution is 1%-10%. When the content is lower than 0.1%, the pH value of the etching solution fluctuates greatly, the etching rate is unstable, and the copper ions dissolved during etching cannot be fully dissolved. When the content is higher than 20%, the economic efficiency is poor, and it may precipitate salts with copper ions, reducing the service life of the etching solution.

[0026] Preferably, the pH regulator is a mixture of ammonia water and an organic amine, wherein the organic amine includes but is not limited to monoethanolamine, diethanolamine, triethanolamine, ethylenediamine, diethylenetriamine, and triethylenetetramine, and the ratio of ammonia water: organic amine in the etching solution is ammonia water: organic amine = 1:10-20:1, and the ratio of ammonia water: organic amine in the etching solution is ammonia water: organic amine = 1:5-5:1. When the ratio is lower than 1:5, the organic amine content is too high and the etching rate is too low. When the ratio is higher than 5:1, the ammonia content is too high, and the volatility of ammonia water will cause the pH of the system to be unstable, thereby affecting the etching stability.

[0027] Preferably, the halogen ion source includes but is not limited to hydrochloric acid, sodium chloride, ammonium chloride, potassium chloride, calcium chloride, magnesium chloride, aluminum chloride, nickel chloride, ferric chloride, hydrobromic acid, sodium bromide, potassium bromide, ammonium bromide, calcium bromide, magnesium bromide, aluminum bromide, nickel bromide, ferric bromide, sodium iodide, and potassium iodide, and the halogen ion content in the etching solution is 0.001%-30%, and the halogen ion content in the etching solution is 0.01%-15%. When the content is lower than 0.01%, the specific gravity of the etching solution is low and the etching uniformity is poor. When the content is higher than 20%, it may precipitate with copper ions to form salts, affecting the stability of the etching solution system.

[0028] An etching test device is used to perform etching test work on etching liquid, such as Figures 1-6 As shown, it includes a mounting frame 1, a liquid storage tank 2, a liquid outlet pipe 21, a carrier plate 3, a waste liquid pipe 31, a micro waterproof scale 4, a cover plate 5 and an electric push rod 51; the mounting frame 1 is fixed with the liquid storage tank 2; the top of the liquid storage tank 2 is provided with an inlet end structure 201; the bottom of the liquid storage tank 2 is provided with a plurality of liquid outlet trough structures 202; the liquid storage tank 2 is slidably connected with the liquid outlet pipe 21; the liquid outlet pipe 21 is provided with a plurality of through-groove structures 2101 corresponding to the position and number of the liquid outlet trough structures 202, and the through-groove structures 2101 are initially not connected to the liquid outlet trough structures 202; an electric heating coil 22 is installed at the bottom of the liquid storage tank 2; a liquid infusion pipe 23 is installed at the top of the liquid storage tank 2, and the liquid infusion pipe 23 is provided with a plurality of pairs of A liquid spray port is provided on the inner wall of the liquid storage tank 2; a fan 24 is installed in the inlet end structure 201 of the liquid storage tank 2; a carrier plate 3 is fixedly connected to the mounting frame 1; a positioning groove structure 301 for placing the copper clad laminate test piece is provided on the carrier plate 3; a waste liquid pipe 31 is fixedly connected to the bottom of the carrier plate 3; a plurality of waste liquid tank structures 302 surrounding the positioning groove structure 301 are provided on the inner edge of the carrier plate 3, and the waste liquid tank structure 302 is connected to the waste liquid pipe 31; a miniature waterproof scale 4 is installed in the positioning groove structure 301 of the carrier plate 3; a cover plate 5 is slidably connected to the carrier plate 3; a liquid inlet structure 501 connected to the liquid outlet pipe 21 is provided in the middle of the cover plate 5; two electric push rods 51 are installed on the carrier plate 3; the telescopic ends of the two electric push rods 51 are fixedly connected to the cover plate 5.

[0029] like Figure 3 and Figure 4 As shown, a waterproof baffle 52 is fixed on the cover plate 5, and the waterproof baffle 52 is located below the cover plate 5; a compression spring is fixed between each of the four sliding rods and the cover plate 5, and the compression spring is sleeved on the outer surface of the corresponding sliding rod; a concave cavity structure 502 is provided at the bottom of the cover plate 5; a hydrophobic microporous membrane 53 covering the bottom of the concave cavity structure 502 is fixed to the bottom of the cover plate 5; a plurality of guide groove structures 503 connected to the concave cavity structure 502 are provided at the bottom of the cover plate 5, and the guide groove structure 503 is aligned above the corresponding waste liquid tank structure 302.

[0030] The following are the processing steps of the entire etching test workflow of the etching solution using an etching test device of the present invention.

[0031] First, the operator needs to connect the waste liquid pipe 31 to the waste liquid treatment equipment and the infusion pipe 23 to the deionized water delivery equipment, and then place the clean copper clad laminate test piece on the positioning groove structure 301 of the carrier 3. The copper clad laminate test piece is weighed for the first time by the micro waterproof scale 4 on the carrier 3 to obtain the mass m1, and the prepared etching liquid is poured into the liquid storage tank 2 through the inlet end structure 201. At this time, the through groove structure 2101 is not connected to the liquid outlet groove structure 202, so the etching liquid in the liquid storage tank 2 will not flow out through the liquid outlet groove structure 202. The etching liquid in the liquid storage tank 2 is heated to 35°C by the electric heating coil 22. Then, the electric push rod 51 pulls the cover plate 5 down to cover the carrier 3. At this time, only a single-layer gap of no more than 5 mm is retained between the upper surface of the copper clad laminate test piece and the cover plate 5 and the hydrophobic microporous membrane 53, and the waterproof baffle 52 on the cover plate 5 will also be tightly attached downward between the edge of the copper clad laminate test piece and the gap between the carrier 3.

[0032] At the same time, the cover plate 5 will also pull the liquid outlet pipe 21 to move downward until the through groove structure 2101 of the liquid outlet pipe 21 is connected with the liquid outlet groove structure 202 of the liquid storage tank 2, so that the heated etching liquid in the liquid storage tank 2 flows through the liquid outlet pipe 21 through the liquid outlet groove structure 202 and the through groove structure 2101 in turn, and the etching liquid then flows downward through the liquid inlet structure 501 of the cover plate 5 and flows through the single-layer gap between the upper surface of the copper clad laminate test piece and the cover plate 5 and the hydrophobic microporous membrane 53. The etching liquid flows through the waste liquid tank structure 302 through the waste liquid pipe 31 and is discharged to the external waste liquid treatment equipment. Since the flow of the etching liquid is limited by the height of the single-layer gap between the cover plate 5 and the hydrophobic microporous membrane 53, the etching liquid flows evenly through various areas of the surface of the copper-clad laminate test piece in a continuous flow state with a thickness not exceeding 5 mm. On the basis of uniformly etching various areas of the surface of the copper-clad laminate test piece, the consumption of the etching liquid is reduced, thereby reducing the amount of raw materials required for the etching liquid in each batch of testing.

[0033] A large amount of ammonia gas will be generated during the etching process of the etching liquid continuously flowing through the surface of the copper clad laminate test piece. The generated ammonia gas will first pass upward through the hydrophobic microporous membrane 53 and enter the concave cavity structure 502 of the cover plate 5. Then, the ammonia gas will flow out along the guide groove toward the adjacent waste liquid tank structure 302 and into the waste liquid pipe 31, so as to timely separate the ammonia gas from the etching liquid flowing through the surface of the copper clad laminate test piece, thereby preventing the etching residue from forming colloidal precipitation due to large-area gas accumulation in the etching liquid flowing through the surface of the copper clad laminate test piece, thereby affecting the etching efficiency and quality.

[0034] After the etching liquid is used to etch the surface of the copper clad laminate test piece, the external deionized water delivery device delivers deionized water to various areas of the inner wall of the liquid storage tank 2 through the liquid delivery pipe 23. The deionized water cleans the etching liquid remaining on the inner wall of the liquid storage tank 2. The deionized water then flows through the liquid outlet pipe 21 along the liquid outlet trough structure 202 and the through-trough structure 2101 and enters the single-layer gap between the cover plate 5 and the hydrophobic microporous membrane 53 to clean the surface of the copper clad laminate test piece. The waste water formed by cleaning passes through the waste liquid trough structure 302 and the waste liquid pipe 31 and is discharged to the external waste liquid treatment equipment. After that, the external deionized water delivery device stops working, and the fan 24 is used to blow water into the liquid storage tank. An air flow is continuously blown in the cabin 2, and at the same time, the electric heating coil 22 heats the air flow to form a hot air flow, which dries the liquid storage cabin 2. The hot air flow also flows through the liquid outlet pipe 21 through the liquid outlet trough structure 202 and the through-groove structure 2101 and enters the single-layer gap between the cover plate 5 and the hydrophobic microporous membrane 53 to dry the surface of the copper clad laminate test piece, thereby completing the etching, cleaning and drying of the copper clad laminate test piece in one step. Finally, the electric push rod 51 pushes the cover plate 5 upward and away from the carrier plate 3, and the micro waterproof scale 4 on the carrier plate 3 weighs the copper clad laminate test piece for the second time to obtain the mass m2, which can quickly complete the entire etching test workflow of the copper clad laminate test piece.

[0035] In addition, after replacing the copper clad laminate test piece with a nickel test piece, the nickel test piece can also be etched and tested according to the above steps.

[0036] The etching effect of the etching solution of the present invention is described below by conducting four groups of implementation experiments and one group of comparative experiments.

[0037] The components shown in the four groups of implementation experiments and one group of comparative experiments in Table 1 were mixed to obtain the etching solution of the present invention. Then, an etching test device of the present invention was used to perform etching tests on each group of experiments. The etching rate was calculated according to the difference in weight (m1-m2) of the copper clad laminate test piece or the nickel test piece before and after treatment with the etching solution (copper etching rate = (m1-m2) ÷ 8.92 ÷ S ÷ 2, nickel etching rate = (m1-m2) ÷ 8.9 ÷ S ÷ 2). The nickel test piece was obtained by electroplating on the surface of the copper clad laminate using a common method in the industry. The test method was consistent with the copper clad laminate test method, with only the calculation formula being different. After the rate was tested, the appearance of the test piece was observed. The results are shown in Table 1.

[0038]

[0039] Comparing Table 1, we can see that the etching solutions used in the four experimental groups all have good etching selectivity for copper metal, with little effect on the etching of nickel metal. They can also achieve a uniform etching effect on copper metal, achieving rapid etching of copper and copper alloys while minimizing the etching of other metals. They are suitable for copper bump processes containing precise conductor patterns, as well as processes using nickel, tin, lead, titanium, etc. as etch barriers or final surface treatments.

[0040] The above description is merely an example of the present invention and is not intended to limit the present invention. Any equivalent substitutions made within the principles of the present invention are intended to be included within the scope of protection of the present invention. Any content not elaborated in detail herein is already known to those skilled in the art.

Claims

1. A copper compound, characterized in that The copper compound used is any one or more of copper chloride, copper bromide, copper sulfate, copper nitrate, copper acetate, and copper carbonate.

2. An etching solution using the copper compound of claim 1, wherein the copper compound is used as a divalent copper ion source of the etching solution, characterized in that: The etching solution also includes but is not limited to organic acids, pH regulators, and halogen ions; The copper ion content in the etching solution is 0.1%-10%.

3. An etching solution according to claim 2, characterized in that: The organic acid includes but is not limited to formic acid, acetic acid, propionic acid, butyric acid, oxalic acid, malonic acid, succinic acid, glutaric acid, maleic acid, acrylic acid, lactic acid, and citric acid, and the content of the organic acid in the etching solution is 0.1%-20%.

4. An etching solution according to claim 2, characterized in that: The pH adjuster is a mixture of ammonia water and organic amine, wherein the organic amine includes but is not limited to monoethanolamine, diethanolamine, triethanolamine, ethylenediamine, diethylenetriamine, and triethylenetetramine, and the ratio of ammonia water to organic amine in the etching solution is ammonia water to organic amine = 1:10-20:

1.

5. An etching solution according to claim 2, characterized in that: Halogen ion sources include, but are not limited to, hydrochloric acid, sodium chloride, ammonium chloride, potassium chloride, calcium chloride, magnesium chloride, aluminum chloride, nickel chloride, ferric chloride, hydrobromic acid, sodium bromide, potassium bromide, ammonium bromide, calcium bromide, magnesium bromide, aluminum bromide, nickel bromide, ferric bromide, sodium iodide, and potassium iodide, and the content of halogen ions in the etching solution is 0.001%-30%.

6. An etching test device, which performs etching test using an etching solution according to any one of claims 2 to 5, characterized in that: The invention comprises a mounting frame (1); a liquid storage tank (2) is fixedly connected to the mounting frame (1); an inlet end structure (201) is provided on the top of the liquid storage tank (2); a liquid outlet trough structure (202) is provided on the bottom of the liquid storage tank (2); a liquid outlet pipe (21) is slidably connected to the liquid storage tank (2); a through groove structure (2101) corresponding to the liquid outlet trough structure (202) is provided on the liquid outlet pipe (21); a carrier plate (3) is fixedly connected to the mounting frame (1); a positioning groove structure (301) for placing a copper clad plate test piece is provided on the carrier plate (3); a bottom of the carrier plate (3) is provided. A waste liquid pipe (31) is fixedly connected to the carrier plate (3); a plurality of waste liquid tank structures (302) surrounding the positioning tank structure (301) are provided on the inner edge of the carrier plate (3), and the waste liquid tank structure (302) is connected to the waste liquid pipe (31); a miniature waterproof scale (4) is installed in the positioning tank structure (301) of the carrier plate (3); a cover plate (5) is slidably connected to the carrier plate (3); a liquid inlet structure (501) connected to the liquid outlet pipe (21) is provided in the middle of the cover plate (5); and an electric push rod (51) for controlling the up and down movement of the cover plate (5) is installed on the carrier plate (3).

7. The etching test equipment according to claim 6, characterized in that: An electric heating coil (22) is installed in the liquid storage tank (2); a liquid infusion pipe (23) is installed in the liquid storage tank (2), and a liquid spray port is provided on the liquid infusion pipe (23).

8. The etching test equipment according to claim 6, characterized in that: A fan (24) is installed in the inlet end structure (201) of the liquid storage tank (2).

9. The etching test equipment according to claim 6, characterized in that: A waterproof barrier strip (52) for covering the gap between the carrier plate (3) and the copper-clad laminate test piece is fixedly connected to the cover plate (5); a compression spring is fixedly connected between the slide bar and the cover plate (5).

10. The etching test equipment according to claim 6, characterized in that: The bottom of the cover plate (5) is provided with a concave cavity structure (502); the bottom of the cover plate (5) is fixedly connected with a hydrophobic microporous membrane (53) covering the concave cavity structure (502); the cover plate (5) is provided with a plurality of guide groove structures (503) connected to the concave cavity structure (502), and the guide groove structures (503) are aligned above the corresponding waste liquid tank structures (302).

Images