A tool and process for coating with conformal coating

Abstract

The present invention discloses a tool and process for coating three-proof paint, the tool comprising a substrate (1), the substrate (1) being provided with a first coating port (11) and a second coating port (12), the first coating port (11) and the second coating port (12) being respectively used for installing a PCBA (13), and the installation directions of the two PCBAs (13) are opposite. The present invention has a simple structural design, the top layer A surface and the bottom layer B surface of the coating tool are arranged in a completely mirror image, the front and back sides of the tool are the same, and the same set of coating lines can be used during coating, the set of three-proof paint tools and the circulating operation method are used, the efficiency is high, one set of three-proof coating equipment and one-time fixture clamping can complete the coating of both sides of the PCBA, saving manpower and equipment investment.

Description

Technical Field

[0001] The invention belongs to the technical field of triple-conformal paint coating, and relates to a tool and process for triple-conformal paint coating. Background Art

[0002] Conformal coating is a polymer insulation protection product that can effectively improve the durability and reliability of electronic circuit boards (PCBA). It is usually provided in a single component form, which is easy to use in a simple coating process. After curing, it forms a dense protective layer to protect the circuit from environmental hazards such as chemicals, moisture, acid, alkali, salt spray, dust accumulation, etc., and prevent environmental corrosion, mildew, electrical failure, and stress on the circuit.

[0003] Currently, the more common three-conformal paint coating adopts a single-sided circuit board placement tool, that is, one side of the circuit board is uniformly coated first, and then the other side is uniformly coated after the three-conformal paint is dried; this operation method has low product production efficiency, and because the protection area cannot be accurately shielded, it leads to many quality problems; the coating on the front and back of the PCBA cannot be quickly flipped over and switched, and the circuit board needs to be manually removed, turned over, and fixed in the middle of the process, which wastes manpower, has a long production turnover time, and is inefficient. Manual disassembly and assembly of the circuit board is prone to damage.

[0004] At present, the more common PCBA, when there are many wire harnesses, generally must be manually coated with three-conformal paint to prevent contamination of the wire harnesses, terminals, and PCBA components, which may lead to quality problems; manual coating will bring many problems such as high production costs, low efficiency, and difficulty in ensuring consistency.

[0005] The patent CN211184464U proposes a structure in which the bottom plate and the upper cover plate are matched with each other in two halves. Although it solves the problem of rapid flipping and effective shielding, this type of tooling is composed of multiple plates, which is bulky and has high production costs. In addition, it cannot be easily fixed when the circuit board has a harness that needs to be fixed. At the same time, due to the different coating trajectories on the front and back of the PCBA, two sets of coating procedures or two sets of coating equipment are required when coating the front and back of the PCBA, which increases the operation steps and hardware equipment. Summary of the invention

[0006] The object of the present invention is to provide a tool and process for three-conformal paint coating to improve the efficiency of PCBA three-conformal paint coating.

[0007] The technical solution adopted by the present invention is:

[0008] A tool for coating with conformal coating comprises a substrate, wherein a first coating port and a second coating port are provided on the substrate, wherein the first coating port and the second coating port are respectively used for installing a PCBA, and the installation directions of the two PCBAs are opposite.

[0009] Further, a wire pressing mechanism is provided between the first coating port and the second coating port on the first surface of the substrate, and another wire pressing mechanism is provided between the first coating port and the second coating port on the second surface of the substrate, and the first surface and the second surface are opposite to each other.

[0010] Further, the wire pressing mechanism includes a wire pressing mechanism body and a wire pressing mechanism buckle assembly. The wire pressing mechanism buckle assembly includes a wire pressing mechanism buckle, a wire pressing mechanism buckle spacer, a first spring, and a first screw. One end of the wire pressing mechanism body is hinged to the substrate, the wire pressing mechanism buckle assembly is located at the other end of the substrate, the wire pressing mechanism buckle spacer is fixed on the substrate, the wire pressing mechanism buckle is located above the wire pressing mechanism buckle spacer, the first screw passes through the wire pressing mechanism buckle and is threadedly connected to the upper surface of the wire pressing mechanism buckle spacer, the first spring is sleeved outside the first screw and is located between the screw head of the first screw and the upper surface of the wire pressing mechanism buckle. Rotating the wire pressing mechanism buckle can press against the upper surface of the other end of the wire pressing mechanism body.

[0011] Further, a retaining wall is provided between the first coating port and the second coating port on the first surface of the substrate, and another retaining wall is provided between the first coating port and the second coating port on the second surface of the substrate.

[0012] Further, a first square groove is formed on the side of the substrate corresponding to the first coating port, and a second square groove is formed on the side of the substrate corresponding to the second coating port.

[0013] Further, at least one three-proof shielding cap is respectively provided at the opening of the first coating port on the first surface of the substrate and at the opening of the second coating port on the second surface of the substrate.

[0014] Further, a circuit board positioning groove and a three-proof shielding block are respectively provided at the opening of the first coating port on the second surface of the substrate and at the opening of the second coating port on the first surface of the substrate.

[0015] Further, a pressing plate buckle mechanism is respectively provided at the four corners of the opening of the first coating port on the second surface of the substrate and at the opening of the second coating port on the first surface of the substrate.

[0016] Further, the pressing plate buckle mechanism includes a pressing plate buckle, a second screw, and a second spring. The second screw passes through the pressing plate buckle and is threadedly connected to the substrate. The second spring is sleeved outside the second screw and is located between the screw head of the second screw and the upper surface of the pressing plate buckle.

[0017] According to the coating process of the above-mentioned tooling for three-proof paint coating, it includes the following steps:

[0018] Step 1: Clamp the PCBA: At the starting point, load two PCBA into the first coating port and the second coating port respectively, and then lock the pressure plate buckle mechanism and the wire pressing mechanism to ensure that the installation directions of the two PCBA are opposite.

[0019] Step 2: Coat the first surface of the coating tooling: Manually identify the tooling direction through the first square groove and the second square groove on the substrate, and send the tooling to the area to be coated. The three-proof paint equipment sensor identifies the tooling through the first square groove and the second square groove on the substrate. When the square groove is detected, the sensor will generate two switching signals simultaneously to ensure that the tooling is recognized as entering and the direction is correct. Otherwise, if the tooling is not detected as entering, the next step will not be performed and wait for manual processing. After the tooling is recognized as entering and the direction is correct, coat the first surface according to the preset trajectory. After coating, send the tooling to the high-temperature baking area for baking.

[0020] Step 3: Coat the second surface of the coating tooling: After returning the baked tooling to the starting point, flip the tooling by °, manually identify the tooling direction through the first square groove and the second square groove on the substrate, and send the tooling to the area to be coated. The three-proof paint equipment sensor identifies the tooling through the first square groove and the second square groove on the substrate. When the square groove is detected, the sensor will generate two switching signals simultaneously to ensure that the tooling is recognized as entering and the direction is correct. Otherwise, if the tooling is not detected as entering, the next step will not be performed and wait for manual processing. After the tooling is recognized as entering and the direction is correct, coat the second surface according to the preset trajectory. After coating, send the tooling to the high-temperature baking area for baking. After baking is completed, return the tooling to the starting point to complete the three-proof paint coating.

[0021] The beneficial effects of the present invention are:

[0022] (1) The structure of the present invention is designed simply. The mechanisms on the top layer A surface and the bottom layer B surface of the coating tooling are arranged in a completely mirror image setting, and the front and back sides of the tooling are the same. The same set of coating lines can be used during coating.

[0023] (2) A wire pressing mechanism is provided on the tooling to fix and shield the wire harness.

[0024] (3) To prevent the fixture from being placed in the wrong direction when entering the coating equipment, square grooves are provided on the fixture, which can facilitate manual identification of the fixture direction and at the same time take into account the automatic identification of the fixture by the three-proof paint equipment.

[0025] (4) Regarding the setting of the PCBA three-proof paint coating trajectory, in the same working interface of the PC, two working areas and two coating trajectories are set, corresponding to the front and back sides of the PCBA respectively, and the alternating coating efficiency is high.

[0026] (5) Using this set of three-prevention tools and adopting a cyclic operation method, the efficiency is high: with one three-prevention coating equipment, the fixtures are clamped once, and the coating of both sides of the PCBA is completed; it saves labor and equipment investment.

[0027] In addition to the purposes, features and advantages described above, the present invention has other purposes, features and advantages. The present invention will be further described in detail below with reference to the drawings. Brief Description of the Drawings

[0028] Figure 1 is a first-perspective three-dimensional structural schematic diagram of the tooling for three-prevention paint coating of the present invention.

[0029] Figure 2 is a second-perspective three-dimensional structural schematic diagram of the tooling for three-prevention paint coating of the present invention.

[0030] Figure 3 is a structural schematic diagram of the coating port.

[0031] Figure 4 is an installation schematic diagram of the wire pressing mechanism.

[0032] Figure 5 is Figure 4 a partial enlarged view of part A in

[0033] Figure 6 is Figure 4 a partial enlarged view of part A in

[0034] Figure 7 is a structural schematic diagram of the PCBA.

[0035] Figure 8 is a three-dimensional schematic diagram of the completed installation state of the PCBA.

[0036] Figure 9 is a side view of the completed installation state of the PCBA.

[0037] Figure 10 is a top view of the completed installation state of the PCBA.

[0038] Figure 11 is a coating trajectory diagram.

[0039] Figure 12 is a process flow diagram.

[0040] Figure numerals: 1, substrate; 2, circuit board positioning groove; 3, three-proof shielding block; 4, three-proof shielding cap; 5, first square groove; 6, second square groove; 7, retaining wall; 8, wire pressing mechanism; 9, pressure plate buckle; 10, hinge; 11, first coating port; 12, second coating port; 13, PCBA; 13a, front side of PCBA; 13b, back side of PCBA; 14, first screw; 15, wire pressing mechanism buckle; 16, wiring harness; 17, coating track on the front side of PCBA; 18, coating track on the back side of PCBA; 19, first spring; 20, wire pressing mechanism body; 21, wire pressing mechanism buckle pad; 22, second screw; 23, second spring. DETAILED DESCRIPTION

[0041] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0042] Combination Figure 1-10 A tool for coating with conformal coating, the coating tooling fixture is designed with a substrate 1, which is divided into a top layer A surface and a bottom layer B surface. The substrate is preferably an epoxy board, and a bakelite board, a metal plate, etc. can also be selected. The substrate thickness is ≥3mm. The substrate 1 is provided with a first coating port 11 and a second coating port 12. The first coating port 11 and the second coating port 12 are respectively used to install a PCBA 13. The installation directions of the two PCBAs 13 are opposite. A wire pressing mechanism 8 is arranged on the first surface of the substrate 1 between the first coating port 11 and the second coating port 12. The second surface of the substrate 1 is provided with a wire pressing mechanism 8 between the first coating port 11 and the second coating port 12. Another wire pressing mechanism is arranged between the first surface and the second surface, that is, the first coating port of the top layer A surface of the coating jig is arranged to be the front side of the circuit board 1 (PCBA1), and the second coating port is arranged to be the back side of the circuit board 2 (PCBA2); the first coating port of the top layer B surface of the coating jig is arranged to be the front side of the circuit board 2 (PCBA2), and the second coating port is arranged to be the back side of the circuit board 1 (PCBA1), so that one set of jigs can be used to clamp two PCBAs at the same time, the wiring harness is reliably fixed, and the two three-conformal paint coating tracks of the front and back sides of the PCBA are preset in the same interface of the PC software; that is, the three-conformal coating of the front and back sides of two sets of PCBAs can be completed by clamping the jig once, and the installation completion state is as follows: Figure 8-9 As shown, the top layer A surface and the bottom layer B surface of the coating jig are arranged in a completely mirror image.

[0043] Furthermore, combined with Figure 4-5, the wire pressing mechanism includes a wire pressing mechanism body 20 and a wire pressing mechanism buckle assembly. The wire pressing mechanism buckle assembly includes a wire pressing mechanism buckle 15, a wire pressing mechanism buckle spacer 21, a first spring 19, and a first screw 14. One end of the wire pressing mechanism body 20 is hinged to the substrate 1 through a hinge 10. The wire pressing mechanism buckle assembly is located at the other end of the substrate 1. The wire pressing mechanism buckle spacer 21 is fixed on the substrate 1. The wire pressing mechanism buckle 15 is located above the wire pressing mechanism buckle spacer 21. The first screw 14 passes through the wire pressing mechanism buckle 15 and is threadedly connected to the upper surface of the wire pressing mechanism buckle spacer 21. The first spring 19 is sleeved outside the first screw 14 and is located between the screw head of the first screw 14 and the upper surface of the wire pressing mechanism buckle 15. Rotating the wire pressing mechanism buckle 15 can press against the upper surface of the other end of the wire pressing mechanism body 20. The pre-tightening force of the first spring 19 can be adjusted by adjusting the first screw 14.

[0044] Further, a retaining wall 7 is provided between the first coating port 11 and the second coating port 12 on the first surface of the substrate 1, and another retaining wall 7 is provided between the first coating port 11 and the second coating port 12 on the second surface of the substrate 1. The retaining wall 7 is used to fixedly restrict the movement of the wire during the coating process to prevent interference with the second coating port for applying the three-proof paint and avoid contamination of the wire harness terminals.

[0045] Further, a first square groove 5 is formed on the side of the substrate 1 corresponding to the first coating port 11, and a second square groove 6 is formed on the side of the substrate 1 corresponding to the second coating port 12. The square grooves can prevent the fixture from being placed in the wrong direction when entering the coating equipment, facilitate manual identification of the fixture direction, and at the same time take into account the automatic identification of the fixture by the three-proof paint equipment. The three-proof paint equipment generally uses mirror reflection and diffuse reflection sensors. When the square grooves on the fixture are detected, the sensor will generate two switch signals simultaneously to ensure that the fixture enters and the direction is correct; otherwise, if the fixture is not detected to enter, the next step will not be performed to prevent damage to the fixture or PCBA. The sensor preferably selects types such as optoelectronic, Hall, and inductive sensors.

[0046] Further, in combination with Figure 1 , 3 , at least one three-proof shielding cap 4 is respectively provided at the opening of the first coating port 11 on the first surface of the substrate 1 and at the opening of the second coating port 12 on the second surface of the substrate 1. Circuit board positioning grooves 2 and three-proof shielding blocks 3 are respectively provided at the opening of the first coating port 11 on the second surface of the substrate 1 and at the opening of the second coating port 12 on the first surface of the substrate 1.

[0047] Further, in combination with Figure 4 , 6A pressure plate buckle mechanism is respectively arranged at the four corners of the opening of the first coating port 11 located at the second surface of the substrate 1 and the opening of the second coating port 12 located at the first surface of the substrate 1, wherein the pressure plate buckle mechanism comprises a pressure plate buckle 9, a second screw 22 and a second spring 23. The second screw 22 passes through the pressure plate buckle 9 and is threadedly connected to the substrate 1. The second spring 23 is sleeved outside the second screw 22 and is located between the screw head of the second screw 22 and the upper surface of the pressure plate buckle 9. The preload force of the second spring 23 can be adjusted by adjusting the second screw 22.

[0048] Combination Figure 12 The present invention, according to the above-mentioned coating process of tooling for triple-conformal coating, comprises the following steps:

[0049] Step 1: Clamp PCBA: At the starting point, install the two PCBAs 13 into the first coating port 11 and the second coating port 12 respectively, and then lock the plate buckle mechanism and the wire pressing mechanism to ensure that the installation directions of the two PCBAs 13 are opposite. The schematic diagram after installation is as follows Figure 8-9 As shown;

[0050] Step 2: Coating the first surface of the tooling: The direction of the tooling is manually identified through the first square groove 5 and the second square groove 6 on the substrate 1, and the tooling is sent to the area to be coated. The sensor of the three-proof coating equipment identifies the tooling through the first square groove 5 and the second square groove 6 on the substrate 1. When the square groove is detected, the sensor will simultaneously generate two switch signals to ensure that the tooling is identified to enter and the direction is correct. Otherwise, the tooling is not detected to enter, and the next step is not performed, waiting for manual processing. When the tooling is identified to enter and the direction is correct, the first surface is coated according to the preset trajectory (the coating trajectory is as shown in FIG. Figure 11 As shown), after coating, the tooling is sent to the high-temperature baking area for baking. The fixture and coating track settings are cleverly coordinated. The PCBA three-proof coating track setting has two working areas and two coating tracks on the same PC working interface, corresponding to the front and back of the PCBA respectively. The alternating coating efficiency is high. See the coating track Figure 11 ;

[0051] Step 3: Coating the second surface of the tooling: After returning the baked tooling to the starting point, flip the tooling 180°, manually identify the direction of the tooling through the first square groove 5 and the second square groove 6 on the substrate 1, and send the tooling to the area to be coated. The sensor of the three-conformal coating equipment identifies the tooling through the first square groove 5 and the second square groove 6 on the substrate 1. When the square groove is detected, the sensor will simultaneously generate two switch signals to ensure that the entry of the jig is recognized and the direction is correct. Otherwise, the entry of the jig cannot be detected, and the next step is not performed, waiting for manual processing. When the entry of the jig is recognized and the direction is correct, the second surface is coated according to the preset trajectory. After the coating is completed, the tooling is sent to the high-temperature baking area for baking. After the baking is completed, the tooling is returned to the starting point to complete the three-conformal coating.

[0052] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A coating process for a tool for coating conformal coating, the tool for coating conformal coating comprising a substrate (1), the substrate (1) being provided with a first coating port (11) and a second coating port (12), the first coating port (11) and the second coating port (12) being respectively used for installing a PCBA (13), the two PCBAs (13) being installed in opposite directions; A wire pressing mechanism is provided on the first surface of the substrate (1) between the first coating port (11) and the second coating port (12), and another wire pressing mechanism is provided on the second surface of the substrate (1) between the first coating port (11) and the second coating port (12), the first surface and the second surface being opposite to each other; A first square groove (5) is provided on the side of the substrate (1) corresponding to the first coating opening (11), and a second square groove (6) is provided on the side of the substrate (1) corresponding to the second coating opening (12); The first coating port (11) is located at the opening of the second surface of the substrate (1), and the second coating port (12) is located at the four corners of the opening of the first surface of the substrate (1), and a pressing plate buckle mechanism is respectively provided; It is characterized in that The coating process comprises the following steps: Step 1: Clamping the PCBA: After respectively inserting the two PCBAs (13) into the first coating port (11) and the second coating port (12) at the starting point, the plate pressing mechanism and the wire pressing mechanism are locked to ensure that the two PCBAs (13) are installed in opposite directions; Step 2: coating the first surface of the tooling: manually identifying the direction of the tooling through the first square groove (5) and the second square groove (6) on the substrate (1), sending the tooling to the area to be coated, and the three-conformal coating equipment sensor identifying the tooling through the first square groove (5) and the second square groove (6) on the substrate (1). When the first square groove (5) and the second square groove (6) are detected, the three-conformal coating equipment sensor will simultaneously generate two switch signals to ensure that the tooling is identified to have entered and the direction is correct. Otherwise, the tooling is not detected to have entered, and the next step of operation is not performed, waiting for manual processing. When the tooling is identified to have entered and the direction is correct, the first surface is coated according to the preset trajectory. After the coating is completed, the tooling is sent to the high-temperature baking area for baking; Step 3: coating the second surface of the tooling: after returning the baked tooling to the starting point, the tooling is flipped 180 degrees, the direction of the tooling is manually identified through the first square groove (5) and the second square groove (6) on the substrate (1), and the tooling is sent to the area to be coated. The three-conformal coating equipment sensor identifies the tooling through the first square groove (5) and the second square groove (6) on the substrate (1). When the first square groove (5) and the second square groove (6) are detected, the three-conformal coating equipment sensor will simultaneously generate two switch signals to ensure that the tooling is identified to enter and the direction is correct. Otherwise, the tooling is not detected to enter, and the next step is not performed, waiting for manual processing. When the tooling is identified to enter and the direction is correct, the second surface is coated according to the preset trajectory. After the coating is completed, the tooling is sent to the high-temperature baking area for baking. After the baking is completed, the tooling is returned to the starting point to complete the three-conformal coating.

2. The coating process of the tooling for conformal coating according to claim 1, It is characterized in that The wire pressing mechanism comprises a wire pressing mechanism body (20) and a wire pressing mechanism buckle assembly, wherein the wire pressing mechanism buckle assembly comprises a wire pressing mechanism buckle (15), a wire pressing mechanism buckle cushion block (21), a first spring (19), and a first screw (14); one end of the wire pressing mechanism body (20) is hinged to the base plate (1); the wire pressing mechanism buckle assembly is located at the other end of the base plate (1); the wire pressing mechanism buckle cushion block (21) is fixed on the base plate (1); and the wire pressing mechanism The wire pressing mechanism buckle (15) is located on the upper part of the wire pressing mechanism buckle cushion block (21); the first screw (14) passes through the wire pressing mechanism buckle (15) and is threadedly connected to the upper surface of the wire pressing mechanism buckle cushion block (21); the first spring (19) is sleeved outside the first screw (14) and is located between the screw head of the first screw (14) and the upper surface of the wire pressing mechanism buckle (15); the wire pressing mechanism buckle (15) can be crimped to the upper surface of the other end of the wire pressing mechanism body (20) by rotating the wire pressing mechanism buckle (15).

3. The coating process of tooling for three-conformal coating according to claim 1, It is characterized in that A retaining wall is provided on the first surface of the substrate (1) between the first coating port (11) and the second coating port (12), and another retaining wall is provided on the second surface of the substrate (1) between the first coating port (11) and the second coating port (12).

4. The coating process of tooling for three-conformal coating according to claim 1, It is characterized in that At least one triple-proof shielding cap (4) is provided at the opening of the first coating port (11) located on the first surface of the substrate (1) and at the opening of the second coating port (12) located on the second surface of the substrate (1).

5. The coating process of tooling for three-conformal coating according to claim 4, It is characterized in that The first coating port (11) is located at the opening of the second surface of the substrate (1), and the second coating port (12) is located at the opening of the first surface of the substrate (1), and circuit board positioning grooves (2) and three-proof shielding blocks (3) are respectively provided.

6. The coating process of the tooling for coating with conformal coating according to claim 5, It is characterized in that The pressure plate buckle mechanism comprises a pressure plate buckle (9), a second screw (22) and a second spring (23); the second screw (22) passes through the pressure plate buckle (9) and is threadedly connected to the base plate (1); the second spring (23) is sleeved outside the second screw (22) and is located between the screw head of the second screw (22) and the upper surface of the pressure plate buckle (9).

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