Line edge step-shaped etching method for improving DBC (Direct Bonding Copper) reliability

Abstract

The invention relates to a circuit edge step-shaped etching method for improving DBC (Direct Bonding Copper) reliability. The circuit edge step-shaped etching method comprises the following steps: A, cleaning and drying a ceramic circuit board; b, the ceramic circuit board is covered with a dry film, and a gap is formed in the position, away from the edge of the ceramic circuit board, of the dry film to form an inner dry film and an outer dry film; c, exposing and developing the ceramic circuit board pasted with the dry film; d, etching the ceramic circuit board, namely etching the etching liquid towards the gap and the ceramic circuit board; and E, during etching, the outer dry film falls off, and etching continues to enable the two sides of the cross section of the ceramic circuit board to form a step shape. According to the circuit edge step-shaped etching method for improving the reliability of the DBC, the gap with the width of 50-150 microns is designed at the position 50-150 microns away from the edge of the ceramic circuit board, so that in the circuit etching process, a dry film outside the gap of the ceramic circuit board falls off in the etching process, and the circuit edge step shape can be formed at a time.

Description

Technical Field

[0001] The invention belongs to the technical field of circuit edge step etching, and in particular relates to a circuit edge step etching method for improving DBC reliability. Background Art

[0002] The existing technology generally adopts the dimple method, that is, the nail hole method, which has disadvantages and occupies a large space. The hole is generally designed to be 0.6mm before etching, and it will reach about 1.0mm after etching. In order to ensure that the nail hole is not cut, the hole edge is 0.05mm away from the edge of the circuit. Therefore, after etching, the nail hole will occupy at least 1.05mm of the circuit edge space. When the circuit design space is tight, there is no space to design this method, and it will have to be abandoned.

[0003] There are also some practices that use multiple exposure, development and etching to achieve the purpose of line edge steps to improve the TCT performance of the product, but the process is cumbersome and there are many problems such as deviation in the two alignments. Summary of the invention

[0004] In view of the shortcomings of the prior art, the technical problem to be solved by the present invention is to provide a circuit edge step etching method for improving the reliability of DBC, which can form steps on both sides of the cross section of the ceramic circuit board in a single etching.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: a circuit edge step etching method for improving DBC reliability, comprising the following steps: A. Clean and dry the ceramic circuit board; B. A dry film is applied to the ceramic circuit board, and a gap is provided between the dry film and the edge of the ceramic circuit board to form an inner dry film and an outer dry film; C. Expose and develop the ceramic circuit board with dry film; D. Etching of the ceramic circuit board, that is, etching liquid etches toward the gap and the ceramic circuit board; E. The outer dry film falls off during etching, and etching continues to form steps on both sides of the cross section of the ceramic circuit board.

[0006] In step B, the width of the slit is 50-150 microns.

[0007] In step A, the ceramic circuit board is cleaned and dried using a cleaning and drying device, the cleaning and drying equipment comprising a receiving box, a cleaning tunnel and a grabbing assembly, a water supply and drying device is installed in the cleaning tunnel, the grabbing assembly is placed on the top of the cleaning tunnel, the receiving box is placed on the water supply and drying device, and a grabbing assembly for grabbing the receiving box and moving is installed on the top of the cleaning tunnel.

[0008] The placing box includes a cleaning box, a placing bracket, a water spray head and two one-way valves. The placing bracket is placed in the cleaning box, the water spray head is installed at the bottom of the cleaning box and is located below the placing bracket. The two one-way valves are installed below the cleaning box and are both connected to the water spray head. The one-way valve comprises an inner tube, an outer tube, a first sealing block and a second sealing block, the inner tube is placed in the outer tube, the outer wall of one end of the outer tube placed in the cleaning box is provided with a plurality of through holes, and the outer tube is located at the upper end of the through holes and is connected to the water spray head, the second sealing block is placed in the outer tube, and covers the gap between the inner tube and the outer tube and the plurality of through holes, the second sealing block is provided with a receiving hole, the first sealing block covers the receiving hole, and the second sealing block is provided with a first spring connected to the first sealing block, the outer tube is provided with a second spring connected to the second sealing block, the second spring is sleeved on the outer tube, the water supply and drying device is provided with two docking components respectively connected to the two one-way valves, the docking components comprise a water supply pipe and a water guide pipe respectively connected to the inner tube and the outer tube, the water supply pipe is placed in the water guide pipe, the output end of the water supply pipe is connected with a connecting pipe protruding from the water guide pipe, the connecting pipe is adapted to the receiving hole, and the water guide pipe is provided with an automatic connector connected to the outer tube.

[0009] The automatic connector includes a drive motor and a nut. The drive motor is installed on the outside of the water pipe. The nut is rotatably installed on the output port of the water pipe. The drive motor is rotatably connected to the nut. The outer wall of the outer tube is provided with an external thread that is threadably connected to the nut.

[0010] The upper cover of the receiving box is provided with a sealing assembly, which includes a cover plate, a mounting plate and four studs. The four studs are rotatably mounted on the cover plate, and the mounting plate is mounted on the cover plate. The mounting plate is provided with a hexagonal screw, which is transmission-connected to four connecting rods. The four connecting rods are respectively transmission-connected to the four studs through bevel gears, and a sealing ring is provided on the surface of the cover plate facing the receiving box.

[0011] The water supply and drying device also includes a dryer, a recovery box, a water supply box connected to a water supply pipe and a water guide pipe, a water pump connected to the water supply pipe is installed in the water supply box, the dryer is provided with a first control pipe connected to the water supply pipe, a first solenoid valve is installed on the first control pipe, the recovery box is provided with a second control pipe connected to the water guide pipe, a second solenoid valve is installed on the second control pipe, and the recovery box is connected to the water supply tank.

[0012] The water supply and drying device is provided with an ultrasonic vibrator between two docking components. The ultrasonic vibrator is arranged below the receiving box, and the vibration end of the ultrasonic vibrator is in contact with the bottom of the receiving box.

[0013] The water supply and drying device includes a moving seat, a lifting cylinder and a vacuum suction gripper. The moving seat is movably arranged at the top of the cleaning tunnel. A screw rod assembly for driving the moving seat to move is installed at the top of the cleaning tunnel. The lifting cylinder is installed on the moving seat, and the vacuum suction gripper is installed on the output end of the lifting cylinder.

[0014] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention provides a circuit edge step etching method for improving DBC reliability. A gap with a width of 50-150 microns is designed at a distance of 50-150 microns from the edge of a ceramic circuit board. In this way, during the circuit etching process, the dry film outside the gap of the ceramic circuit board falls off during the etching process, and the circuit edge step can be formed in one step. 2. The present invention provides a circuit edge step etching method for improving DBC reliability. Multiple ceramic circuit boards are placed in a receiving box through parts, and automatic cleaning and drying are performed in conjunction with a cleaning tunnel and a grabbing component, thereby achieving simultaneous automatic cleaning of multiple ceramic circuit boards.

[0015] 3. The present invention provides a line edge step etching method for improving the reliability of DBC. During cleaning and drying, the one-way valve is used to connect the docking assembly, that is, the outer tube and the water pipe are connected by an automatic connector, and the connecting tube of the water supply pipe passes through the inner tube and moves upward against the first sealing block, so that the outer wall of the connecting tube fits with the inner wall of the accommodating hole to form a seal, and the water outlet is located above the second sealing block. The connecting tube continues to move upward to pull the second sealing block upward through the first spring, so that the interior of the cleaning box is connected to the gap through multiple through holes to form a reflux, thereby realizing water circulation in the box for continuous cleaning.

[0016] 4. The present invention provides a line edge step etching method for improving the reliability of DBC, wherein a cover plate is placed on a receiving box, and four studs are driven to rotate simultaneously through four connecting rods by rotating a hexagonal screw, thereby stably connecting with the receiving box, so that the cover plate is stably placed on the receiving box, thereby sealing the receiving box to prevent impurities from entering during the cleaning process or transportation, and can be disassembled by only rotating a hexagonal screw.

[0017] 5. The present invention provides a circuit edge step etching method for improving the reliability of DBC. During cleaning, the first solenoid valve and the second solenoid valve are closed, and water is delivered through the water delivery pipe, and the ceramic circuit board is flushed in cooperation with the inner tube and the water spray head. The flushed water flows into the gap between the inner tube and the outer tube through the through hole of the outer tube and then flows back to the water supply tank for reuse. During drying, after the water in the receiving box flows out, the first solenoid valve and the second solenoid valve are opened, and hot air is delivered through the second control tube in cooperation with the inner tube, and then the hot air that has been used in the receiving box is sucked back through the recovery box in cooperation with the second control tube and the outer tube, so that a drying cycle is formed in the receiving box. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic structural diagram of the ceramic circuit board coating of the present invention; Figure 2 It is a schematic diagram of the structure of the existing ceramic circuit board coating; Figure 3 It is a schematic diagram of the structure of an existing ceramic circuit board after the first etching; Figure 4 It is a structural schematic diagram of the first etching process of the ceramic circuit board of the present invention; Figure 5 It is a structural schematic diagram of the cleaning and drying equipment of the present invention; Figure 6 It is a structural schematic diagram of the receiving box of the present invention; Figure 7 It is a schematic diagram of the internal structure of the receiving box of the present invention; Figure 8 It is a structural schematic diagram of the one-way valve of the present invention; Fig. 9 It is a structural schematic diagram of the docking assembly of the present invention; Fig.10 It is a structural schematic diagram of the connection between the docking assembly and the one-way valve of the present invention; Fig.11 It is a schematic structural diagram of the sealing assembly of the present invention; Fig.12 This is a schematic diagram of the structure of the cleaning tunnel of the present invention; Fig.13 This is a schematic diagram of the internal structure of the cleaning tunnel of the present invention; Fig.14 It is a structural schematic diagram of the grabbing assembly of the present invention.

[0019] Markings in the figure: 1, ceramic circuit board; 2, inner dry film; 3, outer dry film; 4, receiving box; 5, cleaning tunnel; 6, grab assembly; 7, cleaning box; 8, placement bracket; 9, sprinkler head; 10, one-way valve; 11, inner tube; 12, outer tube; 13, first sealing block; 14, second sealing block; 15, through hole; 16, receiving hole; 17, first spring; 18, second spring; 19, docking assembly; 20, water supply pipe; 21, water guide pipe; 2 2. Drive motor; 23. Nut; 24. Sealing assembly; 25. Cover plate; 26. Mounting plate; 27. Stud; 28. Hexagon socket screw; 29. ​​Connecting rod; 30. Bevel gear; 31. Dryer; 32. Recovery box; 33. Water supply tank; 34. First control tube; 35. First solenoid valve; 36. Second control tube; 37. Second solenoid valve; 38. Ultrasonic vibrator; 39. Moving seat; 40. Lifting cylinder; 41. Vacuum grab. DETAILED DESCRIPTION

[0020] In order to make the above features and advantages of the present invention more obvious and easy to understand, embodiments are given below with reference to the accompanying drawings for detailed description as follows.

[0021] like Figure 1-Figure 14 As shown, this embodiment provides a line edge step etching method for improving DBC reliability, comprising the following steps: A. Cleaning and drying the ceramic circuit board 1; B. A dry film is coated on the ceramic circuit board 1, and a gap is provided between the dry film and the edge of the ceramic circuit board 1 to form an inner dry film 2 and an outer dry film 3; C. exposing and developing the ceramic circuit board 1 with the dry film attached thereto; D. The ceramic circuit board 1 is etched, that is, the etching liquid etches toward the gap and the ceramic circuit board 1; E. The outer dry film 3 falls off during etching, and etching continues so that steps are formed on both sides of the cross section of the ceramic circuit board 1.

[0022] Specifically, in step B, the width of the gap is 50-150 microns. During the etching process, the gap and the sidewall of the ceramic circuit board are etched first, and then the etching is continued so that the ceramic circuit board 1 under the outer dry film 3 gradually disappears, and then the outer dry film 3 falls off, and the ceramic circuit board 1 continues to be etched to form a step shape.

[0023] By designing a gap with a width of 50-150 microns at a distance of 50-150 microns from the edge of the ceramic circuit board 1, the dry film outside the gap of the ceramic circuit board 1 falls off during the etching process, and the circuit edge can be formed into a step shape at one time.

[0024] Furthermore, in step A, the ceramic circuit board 1 is cleaned and dried using a cleaning and drying device, which includes a receiving box 4, a cleaning tunnel 5, and a grabbing assembly 6. A water supply and drying device is installed in the cleaning tunnel 5. The grabbing assembly 6 is placed on the top of the cleaning tunnel 5. The receiving box 4 is placed on the water supply and drying device. A grabbing assembly 6 for grabbing and moving the receiving box 4 is installed on the top of the cleaning tunnel 5. Multiple ceramic circuit boards 1 are loaded into the receiving box 4 through parts, and the cleaning tunnel 5 and the grabbing assembly 6 are used to automatically clean and dry, so that multiple ceramic circuit boards 1 can be automatically cleaned at the same time.

[0025] Furthermore, the placing box 4 includes a cleaning box 7, a placing bracket 8, a water spray head 9 and two one-way valves 10. The placing bracket 8 is placed in the cleaning box 7, the water spray head 9 is installed at the bottom of the cleaning box 7 and is located below the placing bracket 8. The two one-way valves 10 are installed below the cleaning box 7 and are both connected to the water spray head 9. Specifically, the one-way valve 10 includes an inner tube 11, an outer tube 12, a first sealing block 13 and a second sealing block 14. The inner tube 11 is placed in the outer tube 12. The outer tube 12 is placed in the cleaning box 7. The outer wall of one end is provided with a plurality of through holes 15, and the outer tube 12 is located at the upper end of the through holes 15 and is connected to the water spray head 9. The second sealing block 14 is placed in the outer tube 12 and covers the gap between the inner tube 11 and the outer tube 12 and the plurality of through holes 15. The second sealing block 14 is provided with a accommodating hole 16, the first sealing block 13 is covered on the accommodating hole 16, and the second sealing block 14 is provided with a first spring 17 connected to the first sealing block 13, the outer tube 12 is provided with a second spring 18 connected to the second sealing block 14, the second spring 18 is sleeved on the outer tube 12, and the water supply and drying device is provided with two docking components 19 respectively connected to the two one-way valves 10, the docking component 19 includes a water supply pipe 20 and a water guide pipe 21 respectively connected to the inner tube 11 and the outer tube 12, the water supply pipe 20 is placed in the water guide pipe 21, the output end of the water supply pipe 20 is connected to a connecting pipe protruding from the water guide pipe 21, the connecting pipe is adapted to the accommodating hole 16, the side wall of the connecting pipe is provided with a water outlet hole connected to the inner tube 11, and the water guide pipe 21 is provided with an automatic connector connected to the outer tube 12. When cleaning and drying, the one-way valve 10 is connected to the docking assembly 19, that is, the outer tube 12 and the water pipe 21 are connected through an automatic connector, and the connecting pipe of the water supply pipe 20 passes through the inner tube 11 and moves upward against the first sealing block 13, so that the outer wall of the connecting pipe fits with the inner wall of the accommodating hole 16 to form a seal, and the outer wall of the water supply pipe 20 fits tightly with the inner wall of the inner tube 11 to form a seal, and the water outlet is located above the second sealing block 14, and the connecting pipe continues to move upward to pull the second sealing block 14 upward through the first spring 17, so that the interior of the cleaning box 7 is connected to the gap through multiple through holes 15 to form a reflux, so as to realize water circulation in the box for continuous cleaning, and the connection between the bottom of the cleaning box 7 and the outer tube 12 is conical, so as to facilitate drainage.

[0026] Furthermore, the automatic connection part includes a driving motor 22 and a nut 23. The driving motor 22 is mounted on the outside of the water pipe 21, and the nut 23 is rotatably mounted on the output port of the water pipe 21. The driving motor 22 is rotatably connected to the nut 23, and the outer wall of the outer tube 12 is provided with an outer thread that is threadedly connected to the nut 23. The driving motor 22 drives the nut 23 to rotate forward and reversely, so that the nut 23 is connected to or separated from the outer tube 12.

[0027] Further, the upper cover of the receiving box 4 is provided with a sealing assembly 24, which includes a cover plate 25, a mounting plate 26 and four studs 27. The four studs 27 are rotatably mounted on the cover plate 25, the mounting plate 26 is mounted on the cover plate 25, a hexagon socket screw 28 is provided on the mounting plate 26, the hexagon socket screw 28 is transmission-connected to four connecting rods 29, the four connecting rods 29 are transmission-connected to the four studs 27 respectively through bevel gears 30, and a sealing ring is provided on the surface of the cover plate 25 facing the receiving box 4. That is, by covering the cover plate 25 on the receiving box 4, the four studs 27 are driven to rotate simultaneously through the four connecting rods 29 by rotating the hexagon socket screw 28, so as to stably connect with the receiving box 4, so that the cover plate 25 is stably covered on the receiving box 4, thereby closing the receiving box 4, preventing impurities from entering during the cleaning process or transportation, and only needs to rotate a hexagon socket screw 28 to achieve disassembly.

[0028] Furthermore, the water supply and drying device also includes a dryer 31, a recovery box 32, a water supply box 33 connected to the water supply pipe 20 and the water guide pipe 21, a water pump connected to the water supply pipe 20 is installed in the water supply box 33, the dryer 31 is provided with a first control pipe 34 connected to the water supply pipe 20, a first solenoid valve 35 is installed on the first control pipe 34, the recovery box 32 is provided with a second control pipe 36 connected to the water guide pipe 21, and a suction fan is provided in the recovery box 32, a second solenoid valve 37 is installed on the second control pipe 36, and the recovery box 32 is connected to the water supply box 33. When cleaning, the first solenoid valve 35 and the second solenoid valve 37 are closed, and water is delivered through the water delivery pipe 20, and the ceramic circuit board 1 is flushed in cooperation with the inner tube 11 and the water spray head 9. The flushed water flows into the gap between the inner tube 11 and the outer tube 12 through the through hole 15 of the outer tube 12 and then flows back to the water supply tank 33 for reuse. When drying, after the water in the receiving box 4 flows out, the first solenoid valve 35 and the second solenoid valve 37 are opened, and hot air is delivered through the second control tube 36 in cooperation with the inner tube 11, and then the hot air that has been used in the receiving box 4 is sucked back through the recovery box 32 in cooperation with the second control tube 36 and the outer tube 12, so that a drying cycle is formed in the receiving box 4.

[0029] Furthermore, the water supply and drying device is provided with an ultrasonic vibrator 38 between the two docking assemblies 19, the ultrasonic vibrator 38 is arranged below the receiving box 4, and the vibration end of the ultrasonic vibrator 38 is in contact with the bottom of the receiving box 4. The ultrasonic vibrator 38 makes the receiving box 4 vibrate to cooperate with the water in the receiving box 4 to realize ultrasonic cleaning.

[0030] Furthermore, the water supply and drying device includes a moving seat 39, a lifting cylinder 40 and a vacuum suction gripper 41. The moving seat 39 is movably arranged at the top of the cleaning tunnel 5. A screw assembly for driving the moving seat 39 to move is installed at the top of the cleaning tunnel 5. The lifting cylinder 40 is installed on the moving seat 39, and the vacuum suction gripper 41 is installed on the output end of the lifting cylinder 40. The lifting cylinder 40 and the vacuum suction gripper 41 are driven by the moving seat 39 to realize the transportation of the receiving box 4.

[0031] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for illustrating the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which shall fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A circuit edge step etching method for improving DBC reliability, characterized in that: The steps include: A. Clean and dry the ceramic circuit board; B. A dry film is applied to the ceramic circuit board, and a gap is provided between the dry film and the edge of the ceramic circuit board to form an inner dry film and an outer dry film; C. Expose and develop the ceramic circuit board with dry film; D. Etching of the ceramic circuit board, that is, etching liquid etches toward the gap and the ceramic circuit board; E. The outer dry film falls off during etching, and etching continues to form steps on both sides of the cross section of the ceramic circuit board.

2. A circuit edge step etching method for improving DBC reliability according to claim 1, characterized in that: In step B, the width of the slit is 50-150 microns.

3. A circuit edge step etching method for improving DBC reliability according to claim 1, characterized in that: In step A, the ceramic circuit board is cleaned and dried using a cleaning and drying device, the cleaning and drying equipment comprising a receiving box, a cleaning tunnel and a grabbing assembly, a water supply and drying device is installed in the cleaning tunnel, the grabbing assembly is placed on the top of the cleaning tunnel, the receiving box is placed on the water supply and drying device, and a grabbing assembly for grabbing the receiving box and moving is installed on the top of the cleaning tunnel.

4. A circuit edge step etching method for improving DBC reliability according to claim 3, characterized in that: The placing box includes a cleaning box, a placing bracket, a water spray head and two one-way valves. The placing bracket is placed in the cleaning box, the water spray head is installed at the bottom of the cleaning box and is located below the placing bracket. The two one-way valves are installed below the cleaning box and are both connected to the water spray head. The one-way valve comprises an inner tube, an outer tube, a first sealing block and a second sealing block, the inner tube is placed in the outer tube, the outer wall of one end of the outer tube placed in the cleaning box is provided with a plurality of through holes, and the outer tube is located at the upper end of the through holes and is connected to the water spray head, the second sealing block is placed in the outer tube, and covers the gap between the inner tube and the outer tube and the plurality of through holes, the second sealing block is provided with a receiving hole, the first sealing block covers the receiving hole, and the second sealing block is provided with a first spring connected to the first sealing block, the outer tube is provided with a second spring connected to the second sealing block, the second spring is sleeved on the outer tube, the water supply and drying device is provided with two docking components respectively connected to the two one-way valves, the docking components comprise a water supply pipe and a water guide pipe respectively connected to the inner tube and the outer tube, the water supply pipe is placed in the water guide pipe, the output end of the water supply pipe is connected with a connecting pipe protruding from the water guide pipe, the connecting pipe is adapted to the receiving hole, and the water guide pipe is provided with an automatic connector connected to the outer tube.

5. A circuit edge step etching method for improving DBC reliability according to claim 4, characterized in that: The automatic connector includes a drive motor and a nut. The drive motor is installed on the outside of the water pipe. The nut is rotatably installed on the output port of the water pipe. The drive motor is rotatably connected to the nut. The outer wall of the outer tube is provided with an external thread that is threadably connected to the nut.

6. A circuit edge step etching method for improving DBC reliability according to claim 4, characterized in that: The upper cover of the receiving box is provided with a sealing assembly, which includes a cover plate, a mounting plate and four studs. The four studs are rotatably mounted on the cover plate, and the mounting plate is mounted on the cover plate. The mounting plate is provided with a hexagonal screw, which is transmission-connected to four connecting rods. The four connecting rods are respectively transmission-connected to the four studs through bevel gears, and a sealing ring is provided on the surface of the cover plate facing the receiving box.

7. A circuit edge step etching method for improving DBC reliability according to claim 4, characterized in that: The water supply and drying device also includes a dryer, a recovery box, a water supply box connected to a water supply pipe and a water guide pipe, a water pump connected to the water supply pipe is installed in the water supply box, the dryer is provided with a first control pipe connected to the water supply pipe, a first solenoid valve is installed on the first control pipe, the recovery box is provided with a second control pipe connected to the water guide pipe, a second solenoid valve is installed on the second control pipe, and the recovery box is connected to the water supply tank.

8. A circuit edge step etching method for improving DBC reliability according to claim 4, characterized in that: The water supply and drying device is provided with an ultrasonic vibrator between two docking components. The ultrasonic vibrator is arranged below the receiving box, and the vibration end of the ultrasonic vibrator is in contact with the bottom of the receiving box.

9. A circuit edge step etching method for improving DBC reliability according to claim 3, characterized in that: The water supply and drying device includes a moving seat, a lifting cylinder and a vacuum suction gripper. The moving seat is movably arranged at the top of the cleaning tunnel. A screw rod assembly for driving the moving seat to move is installed at the top of the cleaning tunnel. The lifting cylinder is installed on the moving seat, and the vacuum suction gripper is installed on the output end of the lifting cylinder.

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