Micro gear electroforming method

Abstract

The invention discloses an electroforming method for a micro gear. The electroforming method comprises the following steps: step 1, preparing polydimethylsiloxane insulating layer slurry and conductive layer slurry; 2, preparing a conductive core film; step 3, electroforming the micro gear; and fourthly, the miniature gear is subjected to demolding and aftertreatment, and the miniature gear is obtained. According to the method, polydimethylsiloxane is poured into a gear template, a conductive core film with an original template structure is obtained through copying and serves as a cathode, sheet metal serves as an anode, the conductive core film is immersed into an electroforming solution, electroforming is conducted in an electrodeposition mode, the micro gear is obtained through polishing aftertreatment, the precision of copying the original template of the micro gear is improved, and the yield of the micro gear is improved. The problems of gear deformation, tooth number errors, tooth shape errors and the like in traditional cutting machining are solved, the method has the advantages of being simple, efficient, high in gear precision, good in size control and the like, the high-precision miniature gear is manufactured in a short-process and low-cost mode, and the forming effect of the miniature gear is further improved.

Description

Technical Field

[0001] The invention belongs to the technical field of micro-manufacturing and forming, and in particular relates to a micro-gear electroforming forming method. Background Art

[0002] Micro gears are gear elements used in mechanical transmission. Compared with other types of gears, they have the following advantages: First, they are highly accurate. The manufacturing process of small-particle gears is relatively complicated, but they can produce gears with high accuracy and small errors, which can meet the requirements of high-precision transmission. Second, they are low in noise. The tooth surface of small-particle gears has high processing accuracy, large tooth surface contact area, good tooth shape matching, and low friction during transmission, so the noise is low. Third, they have a long life. The tooth surface of small-particle gears has high hardness and good wear resistance, so they have a long life. Therefore, micro gears are usually used in precision machinery, instruments, clocks, toys and other equipment that need to transmit small power. With the continuous advancement of manufacturing processes, material innovation and intelligent technology, micro gears have shown their unique value and application potential in various fields such as medical devices, high-precision optical instruments, micro robots and automation equipment, smart wearable devices, and space science and aerospace devices.

[0003] However, due to the limitations of the development of micro gear processing technology, the processing accuracy and size control of micro gears are difficult to guarantee. Micro gear processing is an extremely complex process. At present, micro gears are mainly manufactured by cutting. In the process of micro gear processing, some problems are often encountered, such as uneven tooth surface wear, gear deformation, wrong number of teeth, tooth shape error, substandard tooth surface roughness, uneven gear hardness, and cracks on the tooth surface. These problems have a great impact on the quality and accuracy of micro gears.

[0004] Therefore, a method for electroforming a micro gear is needed. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a method for electroforming a micro gear in view of the shortcomings of the above-mentioned prior art. The method first drips an insulating layer slurry and performs uniform coating, then places a gear template and pours a conductive layer slurry to obtain a conductive core film, and then electroforms a component in the conductive core film by electrodeposition to obtain a micro gear, thereby overcoming the problems of gear deformation, tooth number error, and tooth shape error that occur in traditional cutting processing, and realizing the preparation of micro gears with high precision in a short process and at a low cost.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is: a micro gear electroforming method, characterized in that the method comprises the following steps:

[0007] Step 1, preparing polydimethylsiloxane insulating layer slurry and conductive layer slurry: adding polydimethylsiloxane to a curing agent and mixing them, then placing them in a vacuum drying oven for vacuum degassing to obtain an insulating layer slurry, adding polydimethylsiloxane to conductive particles, then ultrasonically dispersing them, then adding a curing agent and mixing them, then placing them in a vacuum drying oven for vacuum degassing to obtain a conductive layer slurry;

[0008] Step 2, preparation of a conductive core film: drip the insulating layer slurry obtained in step 1 on a metal sheet and perform a coating treatment. After the coating is completed, place the gear template on the metal sheet dripped with the insulating layer slurry, and then put it into an oven for heat preservation. After the heat preservation is completed, pour the conductive layer slurry on the gear template and cover it. At the same time, lead out a metal wire from the conductive layer slurry as a conductor, and then put it into an oven for heat preservation. After the heat preservation is completed, remove the gear template and the insulating layer slurry corresponding to the gear template to obtain a conductive core film;

[0009] Step 3: Electroforming of micro gears: The conductive core film obtained in step 2 is fixed with a clip as an electroforming cathode, and a sheet metal is used as an electroforming anode, and is placed in an electroforming liquid to be electroformed by electrodeposition;

[0010] Step 4: Demolding and post-processing of micro-gears: After the electroforming described in step 3 is completed, a demoulding tool is used to remove the electroformed component in the conductive core film, and then post-processing is performed to obtain a micro-gear.

[0011] The present invention uses polydimethylsiloxane and a curing agent to prepare an insulating layer slurry, removes bubbles by vacuum degassing, and ensures that the insulating layer structure is dense. Polydimethylsiloxane, a curing agent and conductive particles are used to prepare a conductive layer slurry, and removes bubbles by vacuum degassing to increase conductivity.

[0012] The present invention first drips an insulating layer slurry and performs uniform coating to obtain a uniform insulating layer, which is convenient for accurately replicating the pattern of a gear template and for subsequent demolding. The gear template is then placed and a conductive layer slurry is poured to allow the conductive layer slurry to replicate the structure of the gear template, thereby improving the accuracy of micro-gears replicating the original template. A metal wire is installed in the conductive layer slurry as a conductor to facilitate electroplating to obtain a conductive core film, and then a component is electroformed in the conductive core film by electroplating. Finally, post-processing is performed to obtain a micro-gear.

[0013] The above-mentioned method for electroforming a micro gear is characterized in that the conductive particles in step 1 are nanometer- or micrometer-sized silver particles, copper particles or silver-copper alloy particles. The present invention ensures the conductivity of the conductive core film by controlling the particle size and material of the conductive particles, thereby ensuring the effect of electroforming and improving the quality of the micro gear.

[0014] The above-mentioned method for electroforming of micro gears is characterized in that the volume of the curing agent in the insulating layer slurry in step 1 is 10% to 40% of the volume of polydimethylsiloxane; the volume of the curing agent in the conductive layer slurry is 10% to 40% of the mass of polydimethylsiloxane, wherein the unit of volume is mL, the unit of mass is g, and the mass of the conductive particles in the conductive layer slurry is 2 to 6 times the mass of polydimethylsiloxane. The present invention ensures the strength of the insulating layer slurry and the conductive layer slurry after solidification by controlling the ratio of the curing agent and polydimethylsiloxane, which is convenient for subsequent demolding and electroforming. By controlling the mass ratio of the conductive particles and polydimethylsiloxane, the content of the conductive particles in the conductive layer slurry is controlled to ensure the conductivity of the conductive core film, thereby ensuring the effect of electroforming and improving the quality of the micro gears.

[0015] The above-mentioned micro-gear electroforming method is characterized in that the vacuum degassing time in step 1 is 10 minutes to 60 minutes, and the ultrasonic dispersion time is 120 minutes to 240 minutes. The present invention controls the vacuum degassing time to fully remove the bubbles in the insulating layer slurry and the conductive layer slurry, and controls the ultrasonic dispersion time to ensure that the conductive particles in the conductive layer slurry are evenly distributed, and ensures that the conductivity of each part of the conductive core film is the same.

[0016] The above-mentioned micro gear electroforming method is characterized in that the coating time in the coating treatment in step 2 is 5s to 120s and the coating speed is 500rpm to 5000rpm. The present invention controls the parameters of the coating treatment so that the insulating layer slurry forms an insulating layer with uniform thickness.

[0017] It should be noted that the coating process can be performed multiple times.

[0018] The above-mentioned micro-gear electroforming method is characterized in that the electroforming liquid in step 3 is a water-based electroforming liquid or an ionic liquid electroforming liquid. The present invention selectively uses the electroforming liquid according to the preparation requirements by controlling the composition of the electroforming liquid.

[0019] The above-mentioned micro-gear electroforming method is characterized in that the electro-deposition in step 3 is direct current electro-deposition or pulse electro-deposition, and the current density of the electro-deposition is -5mA / cm 2 ~15mA / cm 2 , the potential is -0.05V to -5V, the temperature is 30°C to 80°C, and the electro-deposition is performed using an electrochemical workstation. The present invention ensures the effect of electroforming by using an electrochemical workstation for electro-deposition and controlling the electro-deposition parameters, thereby obtaining a micro gear with excellent quality.

[0020] It should be noted that the wire of the conductive core membrane is connected to the working electrode of the electrochemical workstation.

[0021] The above-mentioned micro gear electroforming method is characterized in that the post-processing in step 4 includes manual polishing, chemical polishing and electrochemical polishing. The present invention ensures that the micro gear has a surface with excellent performance by performing manual polishing, chemical polishing and electrochemical polishing.

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] 1. The present invention first drips an insulating layer slurry and performs uniform coating to obtain a uniform insulating layer, which is convenient for accurately replicating the pattern of the gear template, and then places the gear template and pours a conductive layer slurry, so that the conductive layer slurry replicates the structure of the gear template, improves the accuracy of the micro-gear replicating the original template, and is convenient for electroplating to obtain a conductive core film, and then electroforms a component in the conductive core film by electroplating, and finally performs post-processing to obtain a micro-gear, which overcomes the problems of gear deformation, tooth number error and tooth shape error that occur in traditional cutting processing, has the advantages of simplicity and high efficiency, high gear precision and good size control, and realizes the preparation of micro-gears with high precision in a short process and at a low cost.

[0024] 2. The present invention ensures the conductivity of the conductive core film by controlling the particle size and material of the conductive particles, thereby ensuring the effect of electroforming and improving the quality of the micro gear.

[0025] 3. The present invention uses an electrochemical workstation for electrodeposition and controls the electrodeposition parameters to ensure the effect of electroforming and obtain micro gears of excellent quality.

[0026] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the structure when preparing the conductive core film of the present invention.

[0028] Figure 2 Schematic diagram of the structure of the conductive core film prepared by the present invention.

[0029] Figure 3 This is a morphology image of the copper micro gear prepared in Example 1 of the present invention.

[0030] Figure 4 Schematic diagram of the tooth shape of the nickel micro gear prepared in Example 2 of the present invention.

[0031] Figure 5 Schematic diagram of the tooth shape of the nickel-iron alloy micro gear prepared in Example 3 of the present invention.

[0032] Description of reference numerals:

[0033] 1—insulation layer slurry; 2—metal sheet; 3—gear template;

[0034] 4—conductive layer slurry; 5—conductive wire; 6—conductive core film;

[0035] 7—Cavity. DETAILED DESCRIPTION

[0036] Figure 1 This is a schematic diagram of the structure of the conductive core film prepared in the present invention, from Figure 1 It can be seen that in the present invention, an insulating layer slurry 1 is dripped on the metal sheet 2, a gear template 3 is placed on the insulating layer slurry 1, a conductive layer slurry 4 is poured on the gear template 3 and the insulating layer slurry 1, and a wire 5 is inserted into the conductive layer slurry 4.

[0037] Figure 2 The schematic diagram of the structure of the conductive core film prepared by the present invention is as follows: Figure 2 It can be seen that the conductive core film 6 prepared by the present invention includes a conductive layer slurry 4 with a cavity 7, the conductive layer slurry 4 has an outer surface with an insulating layer slurry 1 on one side of the cavity, and a wire 5 is inserted into the conductive layer slurry 4.

[0038] Example 1

[0039] This embodiment includes the following steps:

[0040] Step 1: Prepare polydimethylsiloxane insulating layer slurry and conductive layer slurry:

[0041] 2 mL of polydimethylsiloxane was added to 0.2 mL of curing agent to form a mixed slurry, which was then placed in a vacuum drying oven for vacuum degassing for 10 minutes to obtain an insulating layer slurry; at the same time, 2 g of polydimethylsiloxane was added to 4 g of copper nanoparticles, ultrasonically dispersed in an ultrasonic cleaner for 120 minutes, and then 0.2 mL of curing agent was added to form a mixed slurry, which was then placed in a vacuum drying oven for vacuum degassing for 10 minutes to obtain a conductive layer slurry;

[0042] Step 2: Preparation of conductive core film:

[0043] The insulating layer slurry obtained in step 1 is dripped onto the metal nickel sheet, and the coating is treated at 500 rpm for 5 seconds, and then at 2000 rpm for 30 seconds. After the coating is completed, the gear template is placed on the metal nickel sheet dripped with the insulating layer slurry, and then placed in an oven at 120°C for 30 minutes to solidify and form. After the insulation is completed, the conductive layer slurry is poured on the gear template and covered, and a metal wire is drawn out from the conductive layer slurry as a conductor, and then placed in an oven at 120°C for 30 minutes to solidify and form. After the insulation is completed, the gear template and the insulating layer slurry corresponding to the gear template are removed to obtain a conductive core film;

[0044] Step 3: Micro gear electroforming:

[0045] The conductive core membrane obtained in step 2 was fixed with a clip, and the wire was connected to the electrochemical workstation as the electroforming cathode. A copper sheet with a purity greater than 99% was selected as the electroforming anode and connected to the electrochemical workstation. The copper sheet was placed in a copper sulfate water-based electroforming solution and a direct current electrodeposition method was used with a current density of 0.1 mA / cm 2 , the potential is -1V for electroforming, and the temperature of the copper sulfate water-based electroforming solution is 30°C;

[0046] Step 4: Demolding and post-processing of micro gears:

[0047] After the electroforming described in step three is completed, the electroformed component in the conductive core film is taken out using a demoulding tool, and then manually polished to obtain a copper micro gear.

[0048] Figure 3 This is the morphology of the copper micro-gear prepared in this example. Figure 3 It can be seen that the copper micro-gear prepared in this embodiment has a diameter of 5 mm, a smooth surface, a complete structure without defects, and good replication forming accuracy.

[0049] The potential in step three of this embodiment may also be -0.05V or -5V.

[0050] Example 2

[0051] This embodiment includes the following steps:

[0052] Step 1: Prepare polydimethylsiloxane insulating layer slurry and conductive layer slurry:

[0053] 4 mL of polydimethylsiloxane was added to 1 mL of curing agent to form a mixed slurry, which was then placed in a vacuum drying oven for vacuum degassing for 30 minutes to obtain an insulating layer slurry; at the same time, 4 g of polydimethylsiloxane was added to 16 g of silver nanoparticles, ultrasonically dispersed in an ultrasonic cleaner for 180 minutes, and then 1 mL of curing agent was added to form a mixed slurry, which was then placed in a vacuum drying oven for vacuum degassing for 30 minutes to obtain a conductive layer slurry;

[0054] Step 2: Preparation of conductive core film:

[0055] The insulating layer slurry obtained in step 1 is dripped onto the metal titanium sheet, and the coating is treated at 1000 rpm for 30 seconds, and then at 3500 rpm for 20 seconds. After the coating is completed, the gear template is placed on the metal titanium sheet dripped with the insulating layer slurry, and then placed in an oven at 110°C for 40 minutes to solidify. After the insulation is completed, the conductive layer slurry is poured on the gear template and covered, and a metal wire is drawn out from the conductive layer slurry as a conductor, and then placed in an oven at 110°C for 40 minutes to solidify. After the insulation is completed, the gear template and the insulating layer slurry corresponding to the gear template are removed to obtain a conductive core film;

[0056] Step 3: Micro gear electroforming:

[0057] The conductive core membrane obtained in step 2 was fixed with a clip, and the wire was connected to the electrochemical workstation as the electroforming cathode. A nickel sheet with a purity greater than 99% was selected as the anode and connected to the electrochemical workstation. The nickel sheet was placed in a nickel chloride and choline chloride type ionic liquid electroforming solution and pulsed electrodeposition was performed at a current density of -5 mA / cm 2 , pulse electrodeposition for 100 s, then at a current density of 5 mA / cm 2 , pulse electrodeposition for 20s, the frequency is 100Hz for electroforming, and the temperature of the nickel chloride and choline chloride type ionic liquid electroforming solution is 80°C;

[0058] Step 4: Demolding and post-processing of micro gears:

[0059] After the electroforming described in step three is completed, the electroformed component in the conductive core film is taken out using a demoulding tool, and then electrochemical polishing is performed to obtain a nickel micro-gear.

[0060] Figure 4 The tooth profile of the nickel micro-gear prepared in this embodiment is shown in FIG. Figure 4 It can be seen that the nickel micro-gear prepared in this embodiment has a complete structure without defects and has good replication forming accuracy.

[0061] Example 3

[0062] This embodiment includes the following steps:

[0063] Step 1: Prepare polydimethylsiloxane insulating layer slurry and conductive layer slurry:

[0064] 5 mL of polydimethylsiloxane was added to 2 mL of curing agent to form a mixed slurry, which was then placed in a vacuum drying oven for vacuum degassing for 60 minutes to obtain an insulating layer slurry; at the same time, 5 g of polydimethylsiloxane was added to 30 g of silver-copper alloy micron particles, ultrasonically dispersed in an ultrasonic cleaner for 240 minutes, and then 2 mL of curing agent was added to form a mixed slurry, which was then placed in a vacuum drying oven for vacuum degassing for 60 minutes to obtain a conductive layer slurry;

[0065] Step 2: Preparation of conductive core film:

[0066] The insulating layer slurry obtained in step 1 is dripped onto the metal copper sheet, and then the coating is treated at 2000 rpm for 120 seconds and then at 5000 rpm for 10 seconds. After the coating is completed, the gear template is placed on the metal copper sheet dripped with the insulating layer slurry, and then placed in an oven at 100°C for 60 minutes to solidify. After the insulation is completed, the conductive layer slurry is poured on the gear template and covered, and a metal wire is drawn out from the conductive layer slurry as a conductor, and then placed in an oven at 100°C for 60 minutes to solidify. After the insulation is completed, the gear template and the insulating layer slurry corresponding to the gear template are removed to obtain a conductive core film;

[0067] Step 3: Micro gear electroforming:

[0068] The conductive core film obtained in step 2 was fixed with a clip, and the wire was connected to the electrochemical workstation as the electroforming cathode. A nickel sheet with a mass purity greater than 99% and an iron sheet with a mass purity greater than 99% with an area ratio of 3:1 were selected as the anode and connected to the electrochemical workstation. The anode was placed in a water-based electroforming solution of nickel chloride and ferrous chloride and a direct current deposition method was used at a current density of 15 mA / cm 2 Electroforming is performed, and the temperature of the water-based electroforming liquid of nickel chloride and ferrous chloride is 50° C.;

[0069] Step 4: Demolding and post-processing of micro gears:

[0070] After the electroforming in step 3 is completed, a demoulding tool is used to remove the electroformed component in the conductive core film, and then chemical polishing is performed to obtain a nickel-iron alloy micro gear.

[0071] Figure 5 The tooth profile of the nickel-iron alloy micro gear prepared in this embodiment is shown in FIG. Figure 5 It can be seen that the nickel-iron alloy micro-gear prepared in this embodiment has a complete structure without defects and has good replication forming accuracy.

[0072] The above is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent change made to the above embodiment according to the technical essence of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A micro gear electroforming method, characterized in that: The method comprises the following steps: Step 1, preparing polydimethylsiloxane insulating layer slurry and conductive layer slurry: adding polydimethylsiloxane to a curing agent and mixing them, then placing them in a vacuum drying oven for vacuum degassing to obtain an insulating layer slurry, adding polydimethylsiloxane to conductive particles, then ultrasonically dispersing them, then adding a curing agent and mixing them, then placing them in a vacuum drying oven for vacuum degassing to obtain a conductive layer slurry; Step 2, preparation of a conductive core film: drip the insulating layer slurry obtained in step 1 on a metal sheet and perform a coating treatment. After the coating is completed, place the gear template on the metal sheet dripped with the insulating layer slurry, and then put it into an oven for heat preservation. After the heat preservation is completed, pour the conductive layer slurry on the gear template and cover it. At the same time, lead out a metal wire from the conductive layer slurry as a conductor, and then put it into an oven for heat preservation. After the heat preservation is completed, remove the gear template and the insulating layer slurry corresponding to the gear template to obtain a conductive core film; Step 3: Electroforming of micro gears: The conductive core film obtained in step 2 is fixed with a clip as an electroforming cathode, and a sheet metal is used as an electroforming anode, and is placed in an electroforming liquid to be electroformed by electrodeposition; Step 4: Demolding and post-processing of micro-gears: After the electroforming described in step 3 is completed, a demoulding tool is used to remove the electroformed component in the conductive core film, and then post-processing is performed to obtain a micro-gear.

2. A micro gear electroforming method according to claim 1, characterized in that: The conductive particles in step 1 are nano-scale or micro-scale silver particles, copper particles or silver-copper alloy particles.

3. A micro gear electroforming method according to claim 1, characterized in that: The volume of the curing agent in the insulating layer slurry in step one is 10% to 40% of the volume of polydimethylsiloxane; the volume of the curing agent in the conductive layer slurry is 10% to 40% of the mass of polydimethylsiloxane, where the unit of volume is mL and the unit of mass is g, and the mass of the conductive particles in the conductive layer slurry is 2 to 6 times the mass of polydimethylsiloxane.

4. A micro gear electroforming method according to claim 1, characterized in that: The vacuum degassing time in step 1 is 10 min to 60 min, and the ultrasonic dispersion time is 120 min to 240 min.

5. A micro gear electroforming method according to claim 1, characterized in that: In the coating process described in step 2, the coating time is 5s to 120s, and the coating speed is 500rpm to 5000rpm.

6. The micro gear electroforming method according to claim 1, characterized in that: The electroforming liquid in step three is a water-based electroforming liquid or an ionic liquid electroforming liquid.

7. A micro gear electroforming method according to claim 1, characterized in that: The electrodeposition in step 3 is direct current electrodeposition or pulse electrodeposition, and the current density of the electrodeposition is -5 mA / cm 2 ~15mA / cm 2 , the potential is -0.05V to -5V, the temperature is 30°C to 80°C, and the electrodeposition is performed using an electrochemical workstation.

8. A micro gear electroforming method according to claim 1, characterized in that: The post-processing described in step 4 includes manual polishing, chemical polishing and electrochemical polishing.

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