Integrated circuit board etching machine

Abstract

An integrated circuit board etching machine of the present invention comprises an etching chamber, a substrate electrode, an induction electrode, a gas injection tube and a self-checking mechanism, wherein the self-checking mechanism comprises a first electric slide, a connecting rod, a simulation substrate, a penetration plate, a magnetic plate, a shielding block, a second electric slide, an electric push rod, a travel rod, a clamping mechanism, a main control unit and a laser radar, wherein the simulation substrate is moved onto the substrate electrode, and then the second electric slide and the electric push rod drive the travel rod to extend into the cross groove of the shielding block, and the clamping mechanism clamps the travel rod, and after controlling the corresponding magnetic plate to cut off power, the connection between the shielding blocks can be cut off, and then the travel rod can drive the shielding block to move and form a groove on the penetration plate, and when plasma etching is performed, the plasma can pass through the penetration plate from the groove to etch the simulation substrate, and the self-checking of the etching machine can be completed by detecting the data of the etching groove on the penetration plate, thereby avoiding the etching deviation of the integrated circuit board caused by the failure of the etching machine.

Description

Technical Field

[0001] The invention relates to the technical field of PCB board processing, in particular to an integrated circuit board etching machine. Background Art

[0002] PCB, or printed circuit board, is also called integrated circuit board. It is an indispensable part of electrical components. Various electronic components will be installed on the integrated circuit board for connection. The combined complete circuit board can realize certain functions of electrical components. When the integrated circuit board is produced and processed, its surface needs to be etched. Etching refers to removing the unprotected non-conductor part (such as copper) on the surface of the integrated circuit board by chemical reaction or physical method to form the required circuit line. The current etching methods are divided into wet etching and dry etching, among which dry etching is plasma etching. The principle of plasma etching is to use the plasma generated by rare gas discharge to remove the non-conductor part of the surface of the integrated circuit board. However, in the long-term use of the current etching machine, there may be differences in its gas system, vacuum system and plasma generation, resulting in deviations in the etching of the integrated circuit board. Due to the lack of etching self-checking function, the performance of the etching machine cannot be self-checked before etching the target integrated circuit board, resulting in the integrated circuit board directly etching. After the board is directly etched, it cannot meet the needs of electrical components, resulting in a waste of cost and delaying the efficiency of electrical component processing. Summary of the invention

[0003] In view of this, the present invention proposes an integrated circuit board etching machine, which can perform self-inspection on the entire etching process to ensure that the equipment will not fail to cause etching deviations, and ensure that the target integrated circuit board can be accurately etched.

[0004] The technical solution of the present invention is achieved in this way:

[0005] An integrated circuit board etching machine comprises an etching chamber, a substrate electrode, a sensing electrode, a gas injection tube and a self-testing mechanism, wherein the substrate electrode is arranged on the bottom surface of the etching chamber, and the sensing electrode and the gas injection tube are arranged on the top surface of the etching chamber; the self-testing mechanism comprises a first electric slide, a connecting rod, a simulation substrate, a penetration plate, a magnetic plate, a shielding block, a second electric slide, an electric push rod, a travel rod, a clamping mechanism, a main control unit and a laser radar, wherein the first electric slide is relatively embedded in the inner side wall of the etching chamber, the penetration plate is located between the first electric slides, one end of the connecting rod is connected to the side wall of the mover of the first electric slide, and the other end is connected to the side wall of the penetration plate, the simulation substrate is arranged on the bottom surface of the penetration plate, the magnetic plate is arranged in an array on the top surface of the penetration plate, and the simulation substrate is arranged on the bottom surface of the penetration plate, and the magnetic plate is arranged on the top surface of the penetration plate. The top surface of the simulated substrate is covered, the shielding block is arranged on the magnetic plate, a cross-shaped groove is arranged therein, the inner wall of the magnetic plate is provided with electromagnets in four directions, the cross-shaped groove extends to the side wall of the shielding block, the second electric slide is arranged on the top surface of the penetration plate and is located on the outside of the shielding block, the electric push rod is arranged on the top surface of the mover of the second electric slide, and its output shaft is connected with the traveling rod, the cross-shaped groove is located on one side of the moving path of the traveling rod, the traveling rod is inserted into the cross-shaped groove and is clamped by a clamping mechanism, the laser radar is arranged on the bottom surface of the connecting rod and faces the simulated substrate; the main control unit is arranged on the inner wall of the etching chamber, and is respectively connected with the first electric slide, the magnetic plate, the second electric slide, the electric push rod, the clamping mechanism and the laser radar data.

[0006] Preferably, it also includes a radio frequency power supply, which is arranged on the outer wall of the etching chamber and is electrically connected to the substrate electrode and the sensing electrode respectively, and the main control unit is data-connected to the radio frequency power supply.

[0007] Preferably, the clamping mechanism includes a dual-axis motor, a screw rod, a sliding plate and an insertion rod, a receiving groove is provided at the end of the traveling rod away from the electric push rod, the receiving groove is connected to the outside of the traveling rod through a through hole, the dual-axis motor is arranged in the receiving groove, the output shaft of the dual-axis motor is connected to one end of the screw rod, the other end of the screw rod is rotatably connected to the inner wall of the receiving groove, the sliding plate is slidably connected to the side of the accommodating groove, the screw rod passes through the sliding plate and is screwed to the sliding plate, the insertion rod is arranged on the side wall of the sliding plate, the through hole is located on the moving path of the insertion rod, and the main control unit is data-connected to the dual-axis motor.

[0008] Preferably, the clamping mechanism further comprises a bearing, and the bearing is arranged on the side wall of the accommodating groove, and the end of the lead screw away from the dual-axis motor is connected to the bearing.

[0009] Preferably, a sliding block is provided on the side of the sliding plate, a sliding groove is provided on the side wall of the accommodating groove, and the sliding block is located in the sliding groove.

[0010] Preferably, a vacuum pump is further included, wherein the vacuum pump is arranged on the top surface of the etching chamber and is used to evacuate the inside of the etching chamber, and the main control unit is data-connected with the vacuum pump.

[0011] Preferably, it further comprises a key panel, wherein the key panel is arranged on the outer wall of the etching cavity, and the main control unit is data-connected with the key panel.

[0012] Preferably, the self-inspection mechanism also includes a transmitting tube, a receiving tube and a reflector, the transmitting tube and the receiving tube are symmetrically arranged on the end face of the traveling rod and are inclined toward the center direction of the line connecting the two, the reflector is arranged on the bottom surface at the center of the cross-shaped groove and is located below the moving path of the transmitting tube and the receiving tube, and the main control unit is data-connected with the transmitting tube and the receiving tube.

[0013] Preferably, it further comprises a sealing door, which is arranged on the side wall of the etching chamber and located on one side of the substrate electrode.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] An integrated circuit board etching machine of the present invention etches the integrated circuit board by plasma etching, wherein the target integrated circuit board can be placed on the substrate electrode, after the gas is injected through the gas injection tube, the induction electrode generates an electric field, and the gas is excited to form plasma, so that the target integrated circuit board can be etched, and before the formal etching, the simulated substrate can be moved to the substrate electrode through the first electric slide, and then the travel rod can be moved and extended under the drive of the second electric slide and the electric push rod, the travel rod can be extended into the cross groove of the shielding block, and clamped by the clamping mechanism, after the power on and off of the magnetic plate is controlled, the travel rod can drive the shielding block and the magnetic plate to move under the drive of the second electric slide and the electric push rod, so as to form a concave cavity on the penetration plate, the concave cavity is used to simulate the etching position of the integrated circuit board, when the plasma is excited in the etching cavity, the simulated substrate can be etched through the penetration plate at the concave cavity, and then the depth and width of the etching groove on the simulated substrate can be detected by the laser radar for comparison, so as to realize the self-inspection process of the etching machine and avoid the etching deviation caused by the failure of the etching machine. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only preferred embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0017] Figure 1It is a structural schematic diagram of an integrated circuit board etching machine of the present invention;

[0018] Figure 2 It is a top view structural schematic diagram of a self-test mechanism of an integrated circuit board etching machine of the present invention;

[0019] Figure 3 It is a structural schematic diagram of a traveling rod and a shielding block of an integrated circuit board etching machine of the present invention;

[0020] In the figure, 1. etching chamber; 2. substrate electrode; 3. sensing electrode; 4. gas injection tube; 5. first electric slide; 6. connecting rod; 7. analog substrate; 8. penetration plate; 9. magnetic plate; 10. shielding block; 11. second electric slide; 12. electric push rod; 13. travel rod; 14. main control unit; 15. laser radar; 16. cross groove; 17. RF power supply; 18. dual-axis motor; 19. lead screw; 20. sliding plate; 21. insertion rod; 22. through hole; 23. receiving groove; 24. bearing; 25. slider; 26. slide groove; 27. vacuum pump; 28. key panel; 29. ​​transmitting tube; 30. receiving tube; 31. reflector; 32. sealing door. DETAILED DESCRIPTION

[0021] In order to better understand the technical content of the present invention, a specific embodiment is provided below, and the present invention is further described in conjunction with the accompanying drawings.

[0022] See also Figures 1 to 3The present invention provides an integrated circuit board etching machine, comprising an etching chamber 1, a substrate electrode 2, a sensing electrode 3, a gas injection tube 4 and a self-testing mechanism, wherein the substrate electrode 2 is arranged on the bottom surface of the etching chamber 1, and the sensing electrode 3 and the gas injection tube 4 are arranged on the top surface of the etching chamber 1; the self-testing mechanism comprises a first electric slide 5, a connecting rod 6, a simulation substrate 7, a penetration plate 8, a magnetic plate 9, a shielding block 10, a second electric slide 11, an electric push rod 12, a travel rod 13, a clamping mechanism, a main control unit 14 and a laser radar 15, wherein the first electric slide 5 is relatively embedded in the inner wall of the etching chamber 1, the penetration plate 8 is located between the first electric slides 5, one end of the connecting rod 6 is connected to the side wall of the mover of the first electric slide 5, and the other end is connected to the side wall of the penetration plate 8, the simulation substrate 7 is arranged on the bottom surface of the penetration plate 8, and the magnetic plate 9 is arranged in an array on the top surface of the penetration plate 8, and the simulation The top surface of the substrate 7 is covered, the shielding block 10 is arranged on the magnetic plate 9, and a cross-shaped groove 16 is arranged therein, and electromagnets are arranged in four directions of the inner wall of the magnetic plate 9, and the cross-shaped groove 16 extends to the side wall of the shielding block 10, the second electric slide 11 is arranged on the top surface of the penetration plate 8 and is located on the outside of the shielding block 10, the electric push rod 12 is arranged on the top surface of the mover of the second electric slide 11, and its output shaft is connected with the traveling rod 13, the cross-shaped groove 16 is located on one side of the moving path of the traveling rod 13, and the traveling rod 13 is inserted into the cross-shaped groove 16 and is clamped by a clamping mechanism, the laser radar 15 is arranged on the bottom surface of the connecting rod 6 and faces the simulation substrate 7; the main control unit 14 is arranged on the inner wall of the etching chamber 1, and is respectively connected with the first electric slide 5, the magnetic plate 9, the second electric slide 11, the electric push rod 12, the clamping mechanism and the laser radar 15 data.

[0023] An integrated circuit board etching machine of the present invention is provided with a substrate electrode 2 in its etching chamber 1, an integrated circuit board to be etched is placed on the substrate electrode 2, fluoride gas is injected into the etching chamber 1 through a gas injection tube 4, and then the substrate electrode 2 and the sensing electrode 3 are energized, the sensing electrode 3 can excite the gas in the etching chamber 1 to form plasma, and the plasma can etch the surface of the integrated circuit board to be etched, and after the etching is completed, the integrated circuit board can be taken out from the etching chamber 1.

[0024] In order to ensure the accuracy of etching the integrated circuit board, the present invention is provided with a self-checking mechanism. Before etching, the first electric slide 5 is started. The first electric slide 5 moves the simulated substrate 7 to the substrate electrode 2 through the connecting rod 6 and contacts the substrate electrode 2. A plurality of magnetic plates 9 are arranged in an array above the penetration plate 8. A shielding block 10 is also arranged on the top of the magnetic plate 9. The mutually connected magnetic plates 9 completely shield the top of the simulated substrate 7, and a cross-shaped groove 16 is arranged in the shielding block 10. The second electric slide 11 located outside all the shielding blocks 10 can drive the electric push rod 12 to move. The electric push rod 12 can drive the traveling rod 13 to move synchronously so that the traveling rod 13 is aligned with the cross-shaped groove 16 of one of the shielding blocks 10, and then the electric push rod 12 can drive the traveling rod 13 to move so that the traveling rod 13 extends into the cross-shaped groove 16. According to the different extension lengths of the output shaft of the electric push rod 12, the traveling rod 13 can extend into different shielding blocks 10. After the traveling rod 13 stops moving, it can be connected by a clamping machine The structure is connected so that the traveling rod 13 is connected with the shielding block 10 at its end position. When the electric push rod 12 drives the traveling rod 13 to retract, the traveling rod 13 can drive the shielding block 10 to move, thereby changing the arrangement of the shielding block 10 and forming a groove above the penetration plate 8 to simulate the etching position. The second electric slide 11 and the electric push rod 12 on the four sides can drive the traveling rod 13 at different positions to move, so that grooves of different positions and sizes can be formed on the penetration plate 8 to simulate different etching schemes. Finally, the induction electrode 3 is started to excite the gas, and the plasma can pass through the penetration plate 8 from the groove to etch the simulated substrate 7, and obtain a simulated etching groove on the simulated substrate 7, and the laser radar 15 on the connecting rod 6 can detect the depth and width of the simulated etching groove. The main control unit 14 can determine whether the function of the etching machine is abnormal according to the width and depth of the formed groove and the depth and width of the etching groove, and realize self-checking to ensure that there is no deviation in the etching of the integrated circuit board.

[0025] As for the shielding block 10, it is arranged on the magnetic plate 9, and the magnetic plates 9 are in contact with each other. Electromagnets are arranged on the four sides thereof. Through the special design of the polarity orientation of the electromagnet, the adjacent electromagnetic plates can be magnetically attracted to each other when powered on, so that the integrity of the shielding block 10 is improved. When the shielding block 10 and the magnetic plate 9 need to be moved to simulate the etching groove, the power supply of the electromagnet in the magnetic plate 9 under the shielding block 10 that needs to be moved can be cut off, so that the magnetic attraction between the magnetic plate 9 under the shielding block 10 that needs to be moved and the surrounding magnetic plates 9 disappears, so that part of the shielding block 10 can be moved separately. At the same time, during the movement, other shielding blocks 10 can be limited by the traveling rod 13 to assist the movement.

[0026] The penetration plate 13 of the present invention is made of materials such as polytetrafluoroethylene (PTFE, Teflon), polyimide, silicone resin, etc., which can allow plasma to penetrate effectively, and the shielding block 10 is made of heavy metal materials or relatively thick insulating materials, such as glass, ceramics or polymer layers, which can effectively block plasma and prevent the simulated substrate 7 below the covering position of the shielding block 10 from contacting the plasma.

[0027] Preferably, a radio frequency power supply 17 is further included, which is arranged on the outer wall of the etching chamber 1 and is electrically connected to the substrate electrode 2 and the sensing electrode 3 respectively, and the main control unit 14 is data-connected to the radio frequency power supply 17 .

[0028] The radio frequency power source 17 can provide power to the sensing electrode 3 and the substrate electrode 2 , so that the sensing electrode 3 can excite the gas in the etching chamber 1 , thereby performing etching.

[0029] Preferably, the clamping mechanism includes a dual-axis motor 18, a screw rod 19, a sliding plate 20 and an insertion rod 21, and a receiving groove 23 is provided at the end of the traveling rod 13 away from the electric push rod 12, and the receiving groove 23 is connected to the outside of the traveling rod 13 through a through hole 22. The dual-axis motor 18 is arranged in the receiving groove 23, and its output shaft is connected to one end of the screw rod 19, and the other end of the screw rod 19 is rotatably connected to the inner wall of the receiving groove 23, the sliding plate 20 is slidably connected to the side of the receiving groove 23, the screw rod 19 passes through the sliding plate 20 and is screwed to the sliding plate 20, the insertion rod 21 is arranged on the side wall of the sliding plate 20, and the through hole 22 is located on the moving path of the insertion rod 21, and the main control unit 14 is data-connected to the dual-axis motor 18.

[0030] When the traveling rod 13 moves in the cross-shaped groove 16 and moves to the middle of the cross-shaped groove 16, the dual-axis motor 18 can be started, and the dual-axis motor 18 will drive the screw rod 19 to rotate. The sliding plate 20 converts the rotational motion of the screw rod 19 into linear motion and drives the insertion rod 21 to move outward. The insertion rod 21 can pass through the through hole 22 and enter the cross-shaped groove 16. Finally, the insertion rod 21 will abut against the inner wall of the cross-shaped groove 16. When the traveling rod 13 moves back, the insertion rod 21 can drive the shielding block 10 to move.

[0031] Preferably, the clamping mechanism further includes a bearing 24 , and the bearing 24 is disposed on a side wall of the accommodating groove 23 , and the end of the screw rod 19 away from the dual-axis motor 18 is connected to the bearing 24 .

[0032] When the screw rod 19 rotates, it can rotate under the support of the bearing 24 to ensure that the movement of the sliding plate 20 will not deviate.

[0033] Preferably, a sliding block 25 is disposed on the side of the sliding plate 20 , a sliding groove 26 is disposed on the side wall of the accommodating groove 23 , and the sliding block 25 is located in the sliding groove 26 .

[0034] When the sliding plate 20 slides, the slider 25 can move along the slide groove 26 to ensure that the insertion rod 21 can be smoothly extended from the through hole 22. At the same time, the slide groove 26 can limit the slider 25 and the sliding plate 20 to prevent the sliding plate 20 from rotating synchronously with the screw rod 19.

[0035] Preferably, a vacuum pump 27 is further included. The vacuum pump 27 is arranged on the top surface of the etching chamber 1 and is used to evacuate the inside of the etching chamber 1 . The main control unit 14 is data-connected with the vacuum pump 27 .

[0036] When etching is performed, it is necessary to ensure the vacuum state in the etching chamber 1, so the vacuum state can be formed in the etching chamber 1 through the vacuum pump 27. In addition, after the etching is completed, the vacuum pump 27 can also extract the volatile gas generated by etching in the etching chamber 1 to the outside.

[0037] Preferably, a key panel 28 is further included, and the key panel 28 is arranged on the outer wall of the etching chamber 1 , and the main control unit 14 is data-connected with the key panel 28 .

[0038] The key panel 28 is used to send instructions to the main control unit 14 so that self-test or normal etching of the integrated circuit board can be performed.

[0039] Preferably, the self-inspection mechanism also includes a transmitting tube 29, a receiving tube 30 and a reflector 31. The transmitting tube 29 and the receiving tube 30 are symmetrically arranged on the end face of the traveling rod 13 and are inclined toward the center direction of the line connecting the two. The reflector 31 is arranged on the bottom surface at the center of the cross groove 16 and is located below the moving path of the transmitting tube 29 and the receiving tube 30. The main control unit 14 is data-connected with the transmitting tube 29 and the receiving tube 30.

[0040] When the traveling rod 13 moves inside the cross-shaped groove 16, the transmitting tube 29 and the receiving tube 30 will move over the reflector 31, wherein the infrared light emitted by the transmitting tube 29 will be reflected by the reflector 31 and transmitted to the receiving tube 30. When the receiving tube 30 receives the infrared light, it represents that the position of the through hole 22 is located in the middle area of ​​the cross-shaped groove 16. At this time, after the insertion rod 21 moves, it will abut against the inner wall of the cross-shaped groove 16, so that the insertion rod 21 can drive the shielding block 10 to move.

[0041] Preferably, a sealing door 32 is further included, and the sealing door 32 is arranged on the side wall of the etching chamber 1 and located on one side of the substrate electrode 2 .

[0042] The sealing door 32 is used to open and close the etching chamber 1 so as to place the integrated circuit board to be etched on the substrate electrode 2, and to seal the etching chamber 1 so that the vacuum pump 27 can draw the internal air into a vacuum state.

[0043] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An integrated circuit board etching machine, characterized in that: It includes an etching chamber, a substrate electrode, a sensing electrode, a gas injection tube and a self-testing mechanism, wherein the substrate electrode is arranged on the bottom surface of the etching chamber, and the sensing electrode and the gas injection tube are arranged on the top surface of the etching chamber; the self-testing mechanism includes a first electric slide, a connecting rod, a simulation substrate, a penetration plate, a magnetic plate, a shielding block, a second electric slide, an electric push rod, a travel rod, a clamping mechanism, a main control unit and a laser radar, wherein the first electric slide is relatively embedded in the inner side wall of the etching chamber, the penetration plate is located between the first electric slides, one end of the connecting rod is connected to the side wall of the mover of the first electric slide, and the other end is connected to the side wall of the penetration plate, the simulation substrate is arranged on the bottom surface of the penetration plate, the magnetic plate is arranged in an array on the top surface of the penetration plate, and the top surface of the simulation substrate is subjected to The shielding block is arranged on a magnetic plate, in which a cross-shaped groove is arranged, and electromagnets are arranged in four directions of the inner wall of the magnetic plate, and the cross-shaped groove extends to the side wall of the shielding block. The second electric slide is arranged on the top surface of the penetration plate and is located on the outside of the shielding block. The electric push rod is arranged on the top surface of the mover of the second electric slide, and its output shaft is connected with the traveling rod. The cross-shaped groove is located on one side of the moving path of the traveling rod, and the traveling rod is inserted into the cross-shaped groove and is clamped by a clamping mechanism. The laser radar is arranged on the bottom surface of the connecting rod and faces the simulation substrate; the main control unit is arranged on the inner wall of the etching chamber, and is respectively connected with the first electric slide, the magnetic plate, the second electric slide, the electric push rod, the clamping mechanism and the laser radar data.

2. An integrated circuit board etching machine according to claim 1, characterized in that: It also includes a radio frequency power supply, which is arranged on the outer wall of the etching chamber and is electrically connected to the substrate electrode and the sensing electrode respectively, and the main control unit is data-connected to the radio frequency power supply.

3. An integrated circuit board etching machine according to claim 1, characterized in that: The clamping mechanism includes a dual-axis motor, a lead screw, a sliding plate and an insertion rod. A receiving groove is provided at the end of the travel rod away from the electric push rod, and the receiving groove is connected to the outside of the travel rod through a through hole. The dual-axis motor is arranged in the receiving groove, and its output shaft is connected to one end of the lead screw, and the other end of the lead screw is rotatably connected to the inner wall of the receiving groove. The sliding plate is slidably connected to the side of the receiving groove, the lead screw passes through the sliding plate and is screwed to the sliding plate, the insertion rod is arranged on the side wall of the sliding plate, and the through hole is located on the moving path of the insertion rod, and the main control unit is data-connected to the dual-axis motor.

4. An integrated circuit board etching machine according to claim 3, characterized in that: The clamping mechanism further comprises a bearing, which is arranged on the side wall of the accommodating groove, and the end of the lead screw away from the dual-axis motor is connected to the bearing.

5. An integrated circuit board etching machine according to claim 3, characterized in that: A sliding block is arranged on the side of the sliding plate, a sliding groove is arranged on the side wall of the accommodating groove, and the sliding block is located in the sliding groove.

6. An integrated circuit board etching machine according to claim 1, characterized in that: It also includes a vacuum pump, which is arranged on the top surface of the etching chamber and is used to evacuate the inside of the etching chamber. The main control unit is data-connected with the vacuum pump.

7. An integrated circuit board etching machine according to claim 1, characterized in that: It also includes a key panel, which is arranged on the outer wall of the etching cavity, and the main control unit is data-connected with the key panel.

8. An integrated circuit board etching machine according to claim 1, characterized in that: The self-inspection mechanism also includes a transmitting tube, a receiving tube and a reflector. The transmitting tube and the receiving tube are symmetrically arranged on the end surface of the traveling rod and are inclined toward the center direction of the line connecting the two. The reflector is arranged on the bottom surface at the center of the cross groove and is located below the moving path of the transmitting tube and the receiving tube. The main control unit is data-connected with the transmitting tube and the receiving tube.

9. An integrated circuit board etching machine according to claim 1, characterized in that: It also includes a sealing door, which is arranged on the side wall of the etching chamber and located on one side of the substrate electrode.

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