Electroplating liquid storage tank

Abstract

The utility model provides an electroplating liquid storage tank, which is used for circulating and storing electroplating liquid, and comprises a tank body, an electroplating liquid storage tank, an electroplating liquid storage tank and an electroplating liquid storage tank, the cooling part is arranged in the tank body, the density of the cooling part is lower than that of the electroplating liquid, and the cooling part is used for reducing the temperature of bubbles in the electroplating liquid; the filtering part is arranged at the outlet of the tank body, and the filtering part is used for preventing bubbles in the electroplating liquid from flowing out of the tank body along with the electroplating liquid in a circulating manner. The cooling part is arranged to reduce the temperature, so that the surface tension of the electroplating liquid is increased, the solubility of nitrogen is increased, and bubbles are not prone to being generated. And meanwhile, the surface tension is increased, so that the negative pressure condition for generating nitrogen bubbles is harsh, and newly added bubbles are not easy to generate. And the filtering part is arranged to assist in breaking bubbles and block the bubbles in the tank body. And the number of bubbles in the electroplating liquid is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of semiconductor electroplating, in particular to an electroplating liquid storage tank. Background Art

[0002] In the electroplating process of semiconductor manufacturing, ensuring uniform deposition of the metal layer on the wafer surface is crucial, as it directly affects chip performance and the quality of the final product. In the traditional electroplating process, when the plating solution circulates from the plating chamber back to the storage tank, the negative pressure of the circulating vortex may cause the nitrogen in the storage tank to mix with the liquid, forming tiny bubbles. These bubbles remain stable under the relatively slow liquid flow in the storage tank due to the surface tension of the plating solution. However, as the plating solution circulates into the pipeline, the local positive pressure caused by the turbulence that the plating solution cannot withstand will cause the bubbles to break and form a large number of bubbles in the negative pressure area. The bubbles in the plating solution may accumulate and increase, affecting the uniformity of the electroplating. Utility Model Content

[0003] The technical problem to be solved by the utility model is to overcome the defect of bubbles in the electroplating solution in the prior art and to provide an electroplating solution storage tank.

[0004] The utility model solves the above technical problems through the following technical solutions:

[0005] A plating liquid storage tank, which is used for circulating and storing plating liquid, and includes:

[0006] a tank body, the tank body being used to store the electroplating solution;

[0007] a cooling unit disposed in the tank body, wherein the cooling unit has a density lower than that of the electroplating solution and is used to reduce the temperature of bubbles in the electroplating solution;

[0008] The filter part is arranged at the outlet of the tank body, and is used to prevent bubbles in the electroplating solution from flowing out of the tank body as the electroplating solution circulates.

[0009] In this solution, a cooling unit is provided. When the plating solution circulates back from the plating chamber to the tank, the negative pressure of the circulating vortex in the tank causes the nitrogen in the tank to mix with the liquid, forming tiny bubbles. These bubbles then undergo heat exchange with the bubbles floating on the surface of the plating solution via the cooling unit, reducing the bubble temperature. This increases the solubility of the nitrogen, making it easier for the nitrogen in the bubbles to dissolve back into the plating solution during the bubble formation phase, thus reducing the generation of bubbles in the plating solution. Furthermore, the reduced bubble temperature increases the surface tension of the plating solution. This increased surface tension makes the negative pressure conditions for nitrogen bubbles more stringent, making it difficult for new bubbles to form. However, the increased surface tension makes it more difficult to burst existing bubbles during the bubble formation phase. The filter unit is provided to effectively capture and filter undissolved bubbles. The filter unit assists in breaking up the bubbles and traps them within the tank. This significantly reduces the number of bubbles in the plating solution, improves the purity of the plating solution and the uniformity of the electroplating layer, and ultimately enhances the quality of the electroplated product.

[0010] Preferably, the cooling portion includes a cooling pipe, and the cooling pipe has a cavity therein for accommodating a cooling medium.

[0011] In this solution, the above arrangement is used to achieve heat exchange with nitrogen bubbles in the electroplating solution, thereby dissolving the nitrogen in the electroplating solution.

[0012] Preferably, the cooling part also includes a liquid inlet and a liquid outlet, the liquid inlet and the liquid outlet extend from outside the tank body to inside the tank body and are connected to the cooling pipe. When the electroplating liquid circulates into the tank body, the cooling pipe introduces the cooling medium through the liquid inlet.

[0013] In this solution, the above arrangement is used to enable the cooling medium to be introduced into and discharged from the cooling pipe in the tank body.

[0014] Preferably, the diameter of the cooling tube is 20-25 mm.

[0015] In this solution, the above arrangement is used to achieve effective contact with the liquid surface of the electroplating solution.

[0016] Preferably, the cooling pipe is made of any one of PP, PVDF and PVC.

[0017] In this solution, the above arrangement is used to enable the cooling tube to float on the surface of the electroplating solution, thereby performing heat exchange with the electroplating solution containing nitrogen bubbles.

[0018] Preferably, the filter portion is a filter mesh.

[0019] In this solution, through the above-mentioned setting, compared with other filtering structures, the space occupied in the tank is smaller and the structure is simpler.

[0020] Preferably, the filter screen is provided with a plurality of grids for the electroplating solution to flow, and the size of the grids is 30-50 μm.

[0021] In this solution, the above-mentioned setting is used to effectively block nitrogen bubbles.

[0022] Preferably, the tank body is further provided with a nitrogen inlet, and the tank body is replenished with nitrogen through the nitrogen inlet.

[0023] In this solution, the above-mentioned setting is used to fill nitrogen into the tank body to ensure the stability of the electroplating solution.

[0024] Preferably, the tank body further includes an inlet, and the electroplating solution circulates into the tank body through the inlet.

[0025] In this solution, the above-mentioned arrangement is used in conjunction with the outlet to achieve circulation of the electroplating solution.

[0026] Preferably, along the height direction of the tank body, the height of the inlet is higher than the height of the outlet.

[0027] The positive and progressive effects of this utility model lie in the following: By providing a cooling unit, when the electroplating solution circulates from the electroplating chamber back to the tank, the negative pressure of the circulating vortex in the tank causes nitrogen in the tank to mix with the liquid, forming tiny bubbles. These bubbles then undergo heat exchange with the bubbles floating on the surface of the electroplating solution via the cooling unit, lowering the bubble temperature and increasing the solubility of the nitrogen. This, in turn, makes it easier for the nitrogen in the bubbles to dissolve back into the electroplating solution during the bubble formation phase, reducing the generation of bubbles in the electroplating solution. Furthermore, the lower bubble temperature increases the surface tension of the electroplating solution, which creates more stringent negative pressure conditions for nitrogen bubbles, making it less likely for new bubbles to form. However, increased surface tension makes it more difficult to break existing bubbles during the bubble formation phase. The filter unit effectively captures and filters undissolved bubbles. The filter unit assists in breaking up the bubbles and traps them within the tank. This significantly reduces the number of bubbles in the electroplating solution, improving the purity of the electroplating solution and the uniformity of the electroplated layer, ultimately enhancing the quality of the electroplated product. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a schematic structural diagram of a tank body according to a preferred embodiment of the present invention.

[0029] Figure 2 This is a top view of a tank body according to a preferred embodiment of the present invention.

[0030] Figure 3 This is a schematic structural diagram of a cooling pipe according to a preferred embodiment of the present invention.

[0031] Figure 4 This is a schematic structural diagram of a filter screen according to a preferred embodiment of the present invention.

[0032] Description of reference numerals:

[0033] Tank 1

[0034] Import 11

[0035] Exit 12

[0036] Electroplating solution 2

[0037] Cooling unit 3

[0038] Cooling pipe 31

[0039] Liquid inlet 32

[0040] Liquid outlet 33

[0041] Filter 4

[0042] Nitrogen inlet 5 DETAILED DESCRIPTION

[0043] A preferred embodiment is given below, and the present invention is described more clearly and completely in conjunction with the accompanying drawings.

[0044] This embodiment provides a plating solution storage tank, the specific structure of which is as follows Figure 1 、 Figure 2 、 Figure 3 and Figure 4 As shown, the plating liquid storage tank is used to circulate and store the plating liquid. The plating liquid storage tank includes:

[0045] Tank body 1, tank body 1 is used to store electroplating solution 2;

[0046] The cooling part 3 is provided in the tank body 1, and the density of the cooling part 3 is lower than the density of the electroplating solution 2. The cooling part 3 is used to reduce the temperature of the bubbles in the electroplating solution 2;

[0047] The filter part 4 is provided at the outlet 12 of the tank body 1 , and is used to prevent bubbles in the electroplating solution 2 from circulating out of the tank body 1 with the electroplating solution 2 .

[0048] Specifically, the tank body 1 is a sealed structure and the tank body 1 has a holding cavity for accommodating the electroplating liquid 2. The electroplating liquid 2 is a material for semiconductor electroplating in the prior art. This embodiment has not improved it and will not be described in detail here. It can be understood that the electroplating liquid 2 is a liquid, which is discharged from the tank body 1 through the electroplating cavity in the prior art and circulated to the tank body 1 for storage. In this embodiment, a cooling part 3 is also provided in the tank body 1. The density of the cooling part 3 is lower than the density of the electroplating liquid 2, so that the cooling part 3 can float on the liquid surface of the electroplating liquid 2. During electroplating, when the electroplating liquid 2 circulates back to the tank body 1 from the electroplating cavity, the liquid in the tank body 1 will mix the nitrogen in the storage tank with the electroplating liquid 2 due to the negative pressure of the circulating vortex, forming tiny bubbles. These bubbles remain stable under the relatively slow flow of liquid in the tank 1 due to the surface tension of the plating solution 2. However, as the plating solution 2 flows into the pipeline, the surface tension of the plating solution 2 cannot withstand the local positive pressure caused by the turbulence caused by the pipe diameter change or the structure of the joint, causing the bubbles to break and form a large number of bubbles in the negative pressure area. By providing a cooling unit 3, when the plating solution 2 circulates from the plating chamber into the tank 1, nitrogen mixes with the plating solution 2 to form tiny bubbles. After heat exchange occurs with the bubbles floating on the surface of the plating solution 2 through the cooling unit 3, the temperature of the nitrogen bubbles in the plating solution 2 is reduced. As the temperature decreases, the solubility of nitrogen in the plating solution 2 increases during the bubble formation stage, making it easier for the nitrogen in the bubbles to dissolve back into the plating solution 2, thereby reducing the generation of bubbles in the plating solution 2.

[0049] In addition, it should be noted that the decrease in bubble temperature also increases the surface tension of the electroplating solution 2. The increase in the surface tension of the electroplating solution 2 makes the negative pressure conditions for the generation of nitrogen bubbles more stringent, that is, in the bubble formation stage, it makes it difficult for new bubbles to be generated. But at the same time, the increase in the surface tension of the electroplating solution 2 also increases the difficulty of bursting existing bubbles in the bubble formation stage. By setting the filter part 4, the filter part 4 is covered on the outlet 12 to effectively capture and filter undissolved bubbles. The filter part 4 assists in breaking the bubbles and blocks the bubbles in the tank body 1. This significantly reduces the number of bubbles in the electroplating solution 2, so that the purity of the electroplating solution 2 circulated out of the tank body 1 and used for electroplating is correspondingly improved, while improving the uniformity of the electroplating layer on the semiconductor during electroplating, and ultimately improving the quality of the electroplated product.

[0050] Furthermore, in this embodiment, the cooling portion 3 includes a cooling pipe 31 , and the cooling pipe 31 has a cavity (not shown in the figure) for accommodating a cooling medium.

[0051] Specifically, the cooling tube 31 is a tube. Compared to a conventional condenser, the cooling tube 31 in this embodiment has only a cavity. Unlike conventional condensers, which have a housing outside the cavity to accommodate the cooling medium, the cooling medium in this embodiment is directly injected into the cavity to reduce manufacturing costs. At the same time, heat exchange is achieved with the bubbles on the liquid surface of the electroplating solution 2, thereby dissolving nitrogen in the electroplating solution 2. It is understood that the cooling medium can be condensate, water, or other medium used for heat exchange in the prior art, and will not be described in detail here.

[0052] In this embodiment, the cooling part 3 also includes a liquid inlet 32 and a liquid outlet 33. The liquid inlet 32 and the liquid outlet 33 extend from outside the tank body 1 to inside the tank body 1 and are connected to the cooling pipe 31. When the electroplating liquid 2 circulates into the tank body 1, the cooling pipe 31 introduces the cooling medium through the liquid inlet 32.

[0053] Specifically, the cooling tube 31 floats on the liquid surface of the electroplating solution 2, and the liquid inlet 32 and the liquid outlet 33 are made of pipes and are arranged at intervals. The liquid inlet 32 and the liquid outlet 33 are respectively connected to the cooling tube 31 to supply cooling medium into the cooling tube 31 through the liquid inlet 32, and to discharge the cooling medium through the liquid outlet 33 after cooling is completed. The introduction and discharge of the cooling medium from the outside of the tank body 1 through the liquid inlet 32 and the liquid outlet 33 can be achieved by the pump body in the existing technology. This is the existing technology and will not be elaborated on here.

[0054] In this embodiment, the diameter of the cooling tube 31 is 20-25 mm. The cooling tube 31 is arranged in an "S" shape in the tank body 1. Compared with other arrangements, it can achieve effective contact with the liquid surface of the electroplating solution 2, thereby improving the heat exchange efficiency.

[0055] In this embodiment, the cooling tube 31 is made of any of PP, PVDF, and PVC. PP is a conventional polypropylene material, PVDF is a conventional polyvinylidene fluoride material, and PVC is a conventional polyvinyl chloride material. This embodiment does not modify these materials. This allows the cooling tube 31 to float on the surface of the electroplating solution 2, thereby exchanging heat with the nitrogen bubbles within the electroplating solution 2.

[0056] Of course, in other embodiments, the cooling tube 31 may also be made of other materials with a density lower than that of the electroplating solution 2 . This is a prior art and will not be elaborated on herein.

[0057] In this embodiment, the filter unit 4 is a filter screen. The filter screen is located at the outlet 12 to help break up bubbles and effectively block bubbles in the electroplating solution 2, preventing them from circulating out of the tank 1. Consequently, during the electroplating process, the bubble-free and more uniform electroplating solution 2 forms a more uniform electroplating layer, improving the electroplating effect. Compared to other filter structures, the filter screen occupies less space within the tank 1 and has a simpler structure.

[0058] It is understandable that the filter screen can be connected to the outlet 12 by screw connection or clamping, so as to achieve the fixation of the filter screen. This is the existing technology and will not be described in detail here.

[0059] In this embodiment, a plurality of grids are provided on the filter screen for the plating solution 2 to flow, and the size of the grids is 30-50 μm.

[0060] Specifically, the filter mesh has the same shape as outlet 12. The mesh is formed by holes extending through the filter mesh. The mesh can be rectangular or circular, and can be selected based on the desired bubble filtering effect. By limiting the mesh size, it is possible to achieve more effective nitrogen bubble blocking than meshes of other sizes. It is understood that the mesh size can be determined through multiple tests using conventional filtration tests. This is conventional technology and will not be elaborated upon here.

[0061] In this embodiment, a nitrogen inlet 5 is further provided on the tank body 1 , and the tank body 1 is replenished with nitrogen through the nitrogen inlet 5 .

[0062] Specifically, nitrogen inlet 5 is disposed at the top of tank body 1 and spaced apart from liquid inlet 32 and liquid outlet 33 of cooling tube 31 to avoid structural interference. Nitrogen is introduced into tank body 1 to fill the space above the surface of electroplating solution 2, thereby utilizing the inherently high stability of nitrogen to ensure the stability of electroplating solution 2.

[0063] In this embodiment, the tank body 1 further includes an inlet 11 , and the electroplating solution 2 circulates into the tank body 1 through the inlet 11 .

[0064] Specifically, the inlet 11 and the outlet 12 are arranged on opposite sides of the tank body 1 to reduce the increase in the flow path when the plating solution 2 circulates in the tank body 1, thereby reducing eddy currents. That is, the plating solution 2 flows out directly without flowing from the side of the inlet 11 to the inner wall of the tank body 1 away from the side of the inlet 11 and then returning to the inner wall on the side of the inlet 11, so as to cooperate with the outlet 12 to realize the circulation of the plating solution 2.

[0065] Although specific embodiments of the present invention have been described above, those skilled in the art will appreciate that these are merely illustrative and that the scope of protection of the present invention is defined by the appended claims. Those skilled in the art may make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, and such changes and modifications are intended to fall within the scope of protection of the present invention.

Claims

1. A plating solution storage tank, which is used for circulating and storing plating solution, characterized in that: The electroplating solution storage tank includes: a tank body, the tank body being used to store the electroplating solution; a cooling unit disposed in the tank body, wherein the cooling unit has a density lower than that of the electroplating solution and is used to reduce the temperature of bubbles in the electroplating solution; The filter part is arranged at the outlet of the tank body, and is used to prevent bubbles in the electroplating solution from flowing out of the tank body as the electroplating solution circulates.

2. The electroplating solution storage tank according to claim 1, wherein: The cooling part includes a cooling pipe, and a cavity for accommodating a cooling medium is formed in the cooling pipe.

3. The electroplating solution storage tank according to claim 2, wherein: The cooling part also includes a liquid inlet and a liquid outlet, which extend from outside the tank body to inside the tank body and are connected to the cooling pipe. When the electroplating solution circulates into the tank body, the cooling pipe introduces the cooling medium through the liquid inlet.

4. The electroplating solution storage tank according to claim 2, wherein: The diameter of the cooling tube is 20-25 mm.

5. The electroplating solution storage tank according to claim 4, wherein: The cooling pipe is made of any one of PP, PVDF and PVC.

6. The electroplating solution storage tank according to claim 1, wherein: The filter portion is a filter mesh.

7. The electroplating solution storage tank according to claim 6, wherein: The filter screen is provided with a plurality of grids for the electroplating solution to flow, and the size of the grids is 30-50 μm.

8. The electroplating solution storage tank according to claim 1, wherein: The tank body is also provided with a nitrogen inlet, and the tank body is replenished with nitrogen through the nitrogen inlet.

9. The electroplating solution storage tank according to claim 1, wherein: The tank body further comprises an inlet, and the electroplating solution circulates into the tank body through the inlet.

10. The electroplating solution storage tank according to claim 9, wherein: Along the height direction of the tank body, the height of the inlet is higher than the height of the outlet.

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