Pouring sealant pouring device and method applied to PCBA electronic module sealing

Abstract

The invention relates to a pouring sealant pouring device and method applied to PCBA electronic module sealing, a preheating bin is used for preheating pouring sealant and a to-be-poured PCBA electronic module, so that the flowability of the pouring sealant after pouring is improved, it is ensured that the pouring sealant can completely wrap all electronic elements of the PCBA electronic module, and meanwhile due to the good flowability, the pouring sealant can be prevented from falling off due to the good flowability. The pouring sealant can effectively discharge gas generated in the pouring process, in the normal-temperature environment between the preheating bin and the drying bin, the PCBA electronic module subjected to pouring is slowly cooled, meanwhile, the pouring sealant continues to discharge gas and finally enters the drying bin, the pouring sealant is rapidly cured through high temperature, the curing speed of the pouring sealant is shortened, and the production efficiency of the PCBA electronic module is improved. And finally, the technical effects of improving the encapsulation exhaust effect and the encapsulation speed of the PCBA electronic module are achieved. The technical problem that the curing speed and the exhaust effect are difficult to consider in the pouring sealant curing process is effectively solved.

Description

Technical Field

[0001] The invention belongs to the technical field of printed circuits, and in particular relates to a potting glue potting device and method for PCBA electronic module sealing. Background Art

[0002] With the continuous development and progress of society, products that need to have certain protection capabilities (or insulation, or waterproof and moisture-proof, or dustproof, or vibration and impact resistance, or corrosion resistance, etc.), such as power tools, outdoor lamps, medical equipment, etc., are becoming more and more widely used in various fields such as industry, construction, home, manufacturing, and medical care, and have become an indispensable part of our daily life and work.

[0003] To achieve these protection capabilities, it is not enough to rely on the protection of the product shell alone. The control working core of the product (i.e., the PCBA electronic module) itself must also have certain protection capabilities. To achieve this protection, using potting glue to wrap and seal the PCBA for protection is a common method. Common types of potting glue include: silicone potting glue, epoxy resin potting glue, polyurethane potting glue, acrylic potting glue, etc. These potting glues need to be cured, generally at room temperature or heated, and can be carried out in an air environment or a vacuum environment. During the curing process, how to effectively discharge the gases carried or generated by the PCBA itself, as well as the gases carried and generated by the potting glue itself during curing before the potting glue is cured, and at the same time increase the curing speed of the potting glue is a technical difficulty in the potting glue process. Summary of the invention

[0004] The first technical problem to be solved by the present invention is: to provide a potting glue potting device applied to PCBA electronic module sealing, so as to solve the technical problem that it is difficult to balance the curing speed and the exhaust effect during the potting glue curing process.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: a potting glue potting device for PCBA electronic module sealing, comprising a belt conveyor and a preheating bin and a drying bin arranged in sequence along the conveying direction of the belt conveyor, wherein the two opposite side walls of the preheating bin are respectively provided with a material port for the upper conveyor belt and the PCBA electronic module to enter and exit, and a through hole for the lower conveyor belt to pass through, an upper partition located above the upper conveyor belt is arranged in the preheating bin, and the upper partition isolates the upper part of the preheating bin into a storage cavity, and the storage cavity is used to store the potting glue, an electric heating rod is arranged inside the upper partition, which is used to heat the preheating bin, increase the temperature in the preheating bin, and preheat the potting glue at the same time, a glue outlet is arranged on the upper partition, a glue injection pump is connected to the glue outlet, and the outlet of the glue injection pump is connected to a glue injection pipe extending downward, and a downstream side of the glue injection pipe is provided with a nozzle for detecting P The detector of the CBA electronic module, when the upper conveyor belt conveys the PCBA electronic module to the bottom of the glue injection tube, the detector just detects the PCBA electronic module; the two opposite side walls of the drying bin are also respectively provided with material ports for the upper conveyor belt and the PCBA electronic module to enter and exit, and through holes for the lower conveyor belt to pass through; a plurality of electric heating rods are also arranged in the drying bin; the preheating bin and the drying bin are arranged separately; the belt conveyor and the glue injection pump are respectively electrically connected to a controller and controlled by the controller; the detector is electrically connected to the controller; when the detector detects the PCBA electronic module, it sends a signal to the controller; after receiving the signal, the controller pauses the belt conveyor, so that the PCBA electronic module located below the glue injection tube stops moving; then, the controller controls the glue injection pump to start, and injects the sealing glue into the PCBA electronic module; after the injection is completed, the belt conveyor is resumed.

[0006] As a preferred solution, a baffle is provided above the upper conveyor belt between the preheating bin and the drying bin, and the baffle is used to block the dust layer to prevent the potting glue in the PCBA electronic module from being contaminated by the dust layer.

[0007] As a preferred solution, the detector is a through-beam laser sensor.

[0008] As a preferred solution, at least two hair dryers are arranged above the upper conveyor belt between the preheating chamber and the drying chamber. Any hair dryer blows obliquely downward along the conveying direction of the conveyor belt, and the inclination directions of two adjacent hair dryers are opposite. The hair dryer is located above the conveying path of the PCBA electronic module and blows the surface of the potting glue on the passing PCBA electronic module.

[0009] As a preferred solution, at least two hair dryers are arranged above the upper conveyor belt in the drying bin, and any hair dryer blows obliquely downward along the conveying direction of the conveyor belt, and the inclination directions of two adjacent hair dryers are opposite. The hair dryer is located above the conveying path of the PCBA electronic module and blows the surface of the potting glue on the passing PCBA electronic module.

[0010] As a preferred solution, a cooling bin is connected to the downstream side of the drying bin, and the cooling bin shares a side wall with the drying bin. A material port for the upper conveyor belt and PCBA electronic module to enter and exit, as well as a through hole for the lower conveyor belt to pass through, is provided on the side wall of the cooling bin away from the drying bin.

[0011] As a preferred solution, a lower partition is respectively provided in the preheating bin and the drying bin, and the lower partition is located between the upper conveyor belt and the lower conveyor belt. The lower partition closes the preheating bin or the drying bin above the lower conveyor belt to reduce heat loss in the preheating bin and the drying bin.

[0012] The present invention further aims to solve the technical problem of providing a potting glue potting method for PCBA electronic module sealing, so as to solve the technical problem that it is difficult to balance the curing speed and the exhaust effect during the potting glue curing process.

[0013] In order to solve the above technical problems, the technical solution adopted by the present invention is: a potting method for potting glue used for PCBA electronic module sealing, comprising the following specific steps: a. Preheat the potting compound and the PCBA electronic module to be potted to a certain temperature to improve the fluidity of the potting compound, which helps the potting compound to completely wrap the electronic components in the PCBA electronic module after potting, and also helps to discharge bubbles and reduce the generation of bubbles; b. Exhaust the potting compound at room temperature. At this time, the potting compound has better fluidity and exhaust performance, and a large number of bubbles can escape; c. After completing step b, place the encapsulated PCBA electronic module in a high temperature environment to accelerate the curing speed of the encapsulation glue and complete the final curing process.

[0014] As a preferred solution, when performing step b and step c, a hair dryer is used to blow hot air on the surface of the potting glue, and the hot air flow is used to stir the surface of the potting glue to eliminate bubbles remaining on the surface of the potting glue.

[0015] As a preferred solution, the preheating temperature is 40-45°C, the normal temperature is 20-30°C, and the high temperature is 50-80°C.

[0016] The beneficial effect of the present invention is that the present invention uses a preheating chamber to preheat the potting glue and the PCBA electronic module to be potted, thereby improving the fluidity of the potting glue after potting, ensuring that the potting glue can completely wrap the various electronic components of the PCBA electronic module, and at the same time, due to good fluidity, the potting glue can effectively discharge the gas generated during the potting process, and in the normal temperature environment between the preheating chamber and the drying chamber, the PCBA electronic module after potting slowly cools down, while the potting glue continues to discharge gas, and finally enters the drying chamber, and uses high temperature to quickly solidify the potting glue to shorten the potting glue curing speed, and finally achieves the technical effect of improving the potting exhaust effect and the potting speed of the PCBA electronic module. Effectively solve the technical problem that it is difficult to take into account both the curing speed and the exhaust effect during the potting glue curing process. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The specific embodiments of the present invention are further described in detail below with reference to the accompanying drawings, wherein: Figure 1 It is a structural schematic diagram of a potting glue potting device used for PCBA electronic module sealing as described in Example 1; Figure 1 In: 1. Belt conveyor; 2. Preheating chamber; 3. Drying chamber; 4. PCBA electronic module; 5. Material port; 6. Through hole; 7. Upper partition; 8. Storage chamber; 9. Glue outlet; 10. Glue injection pump; 11. Glue injection tube; 12. Detector; 13. Electric heating rod; 14. Baffle; 15. Blower; 16. Cooling chamber; 17. Lower partition; 18. Controller. DETAILED DESCRIPTION

[0018] The specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. Example 1

[0019] like Figure 1The potting glue potting device used for PCBA electronic module sealing shown in the figure comprises a belt conveyor 1 and a preheating bin 2 and a drying bin 3 arranged in sequence along the conveying direction of the belt conveyor 1. The two opposite side walls of the preheating bin 2 are respectively provided with a material port 5 for the upper conveyor belt and the PCBA electronic module 4 to enter and exit, and a through hole 6 for the lower conveyor belt to pass through. An upper partition 7 located above the upper conveyor belt is arranged in the preheating bin 2. The upper partition 7 isolates the upper part of the preheating bin 2 into a storage chamber 8, and the storage chamber 8 is used to store the potting glue. The upper partition 7 is provided with an electric heating rod inside, which is used to heat the preheating bin 2, increase the temperature inside the preheating bin 2, and preheat the potting glue at the same time. The upper partition 7 is provided with a glue outlet 9, and the glue outlet 9 is connected to a glue injection pump 10. The outlet of the glue injection pump 10 is connected to a glue injection tube 11 extending downward. A detector 12 for detecting the PCBA electronic module 4 is provided on the downstream side of the glue injection tube 11. The detector 12 is preferably a beam laser sensor, and a reflective optical sensor or other types of sensors can also be used. When the upper conveyor belt conveys the PCBA electronic module 4 to the bottom of the glue injection tube 11, the detector 12 just detects the PCBA electronic module 4; the two opposite side walls of the drying bin 3 are also provided with a material port 5 for the upper conveyor belt and the PCBA electronic module 4 to enter and exit, and a through hole 6 for the lower conveyor belt to pass through. A plurality of electric heating rods 13 are also provided in the drying bin 3, and the preheating bin 2 and the drying bin 3 are arranged separately.

[0020] In this embodiment, a baffle 14 is preferably provided above the upper conveyor belt between the preheating chamber 2 and the drying chamber 3, and the baffle 14 is used to block the dust layer to prevent the potting glue in the PCBA electronic module 4 from being contaminated by the dust layer.

[0021] In the present embodiment, two hair dryers 15 are preferably arranged above the upper conveyor belt between the preheating chamber 2 and the drying chamber 3. Any hair dryer 15 blows obliquely downward along the conveying direction of the conveyor belt, and the inclination directions of the two adjacent hair dryers 15 are opposite. The hair dryer 15 is located above the conveying path of the PCBA electronic module 4 and blows the surface of the potting glue on the passing PCBA electronic module 4. The hair dryer 15 can adjust the wind force and temperature as needed, and the wind force is based on the standard of being able to blow the bubbles on the surface of the potting glue.

[0022] In this embodiment, four blowers 15 are also arranged above the upper conveyor belt in the drying chamber 3. Any blower 15 blows obliquely downward along the conveying direction of the conveyor belt, and the oblique directions of two adjacent blowers 15 are opposite. The blowers 15 are located above the conveying path of the PCBA electronic module 4 and blow the surface of the potting glue on the passing PCBA electronic module 4. The blower 15 can adjust the wind force and temperature as needed, and the wind force is based on the standard of being able to blow the bubbles on the surface of the potting glue.

[0023] In order to avoid shrinkage and cracking caused by a sudden drop in the temperature of the potting glue, the present embodiment preferably has a cooling bin 16 connected to the downstream side of the drying bin 3. The cooling bin 16 shares a side wall with the drying bin 3. The side wall of the cooling bin 16 away from the drying bin 3 is provided with a material port 5 for the upper conveyor belt and the PCBA electronic module 4 to enter and exit, and a through hole 6 for the lower conveyor belt to pass through.

[0024] A lower partition 17 is respectively provided in the preheating bin 2 and the drying bin 3. The lower partition 17 is located between the upper conveyor belt and the lower conveyor belt. The lower partition 17 closes the preheating bin 2 or the drying bin 3 above the lower conveyor belt to reduce heat loss in the preheating bin 2 and the drying bin 3.

[0025] The belt conveyor 1, the glue injection pump 10, and the detector 12 described in this embodiment are electrically connected to a controller 18 and controlled by the controller 18. When the detector 12 detects the PCBA electronic module 4, it sends a signal to the controller 18. After receiving the signal, the controller 18 pauses the belt conveyor 1, so that the PCBA electronic module 4 located below the glue injection tube 11 stops moving. Then, the controller 18 controls the glue injection pump 10 to start and inject the potting glue into the PCBA electronic module 4. After the injection is completed, the belt conveyor 1 is resumed. The glue injection pump 10 preferably has a flow detection type to feedback the potting glue injection amount. If the flow detection is not used, the potting glue injection amount can also be controlled by setting the operating time of the glue injection pump 10. The control of the injection amount belongs to conventional technical means and will not be described in detail here. The controller 18 is a conventional single-chip microcomputer or industrial computer.

[0026] The working process of the present invention is: Figure 1 As shown, the user first starts the potting glue potting device. After starting, the electric heating rods 13 in the preheating chamber 2 and the drying chamber 3 begin to heat. The electric heating rods 13 in the preheating chamber 2 heat the potting glue in the storage cavity 8 and the cavity below the upper partition 7 through the upper partition 7 at the same time. The electric heating rods 13 in the drying chamber 3 heat the internal space of the drying chamber 3. After the temperatures in the preheating chamber 2 and the drying chamber 3 reach the target temperature, the belt conveyor 1 is started. The user places the PCBA electronic modules 4 to be potted at intervals at the upstream end of the belt conveyor 1. The belt conveyor 1 conveys the PCBA electronic modules 4 to the upstream end of the belt conveyor 1. 4 is transported downstream, the PCBA electronic module 4 first enters the preheating chamber 2 and is preheated in the preheating chamber 2. When the PCBA electronic module 4 moves to be opposite to the detector 12, the detector 12 detects the PCBA electronic module 4, and the belt conveyor 1 suspends transportation. At this time, the PCBA electronic module 4 detected by the detector 12 is just located under the glue injection pipe 11, and the controller 18 controls the glue injection pump 10 to start and inject the potting glue into the PCBA electronic module 4. After the injection is completed, the belt conveyor 1 is restarted, and the PCBA electronic modules 4 are potted one by one in this way.

[0027] As the PCBA electronic module 4 that has completed potting continues to move downstream, since the potting glue and the PCBA electronic module 4 are both preheated, the potting glue has good fluidity and can quickly discharge the gas in the potting glue, thereby improving the exhaust effect. Before the PCBA electronic module 4 enters the drying bin 3, it is in the exhaust stage. After the PCBA electronic module 4 enters the drying bin 3, it is baked at high temperature, and the potting glue is quickly solidified. After the PCBA electronic module 4 leaves the drying bin 3, it cools to room temperature, thereby completing the potting process.

[0028] When the PCBA electronic module 4 is located in the area between the preheating chamber 2 and the drying chamber 3, the potting glue still maintains good fluidity. At this time, the blower 15 is used to blow the surface of the potting glue in the PCBA electronic module 4 to burst the bubbles on the surface of the glue and eliminate the pits on the surface of the glue.

[0029] After the PCBA electronic module 4 enters the drying chamber 3, the blower 15 is still used to blow the surface of the potting glue in the PCBA electronic module 4 to eliminate bubbles on the surface of the glue as much as possible before the potting glue is cured.

[0030] After the PCBA electronic module 4 is dried, it enters the cooling chamber 16. The cooling chamber 16 is connected to the drying chamber 3, so its internal temperature is slightly higher than room temperature. The PCBA electronic module 4 can be slowly cooled in the cooling chamber 16, and then leave the cooling chamber 16 and cool down to room temperature. This can prevent the solidified potting glue from shrinking and separating from the electronic components or cracking the potting glue. Example 2

[0031] refer to Figure 1 A potting method for sealing a PCBA electronic module using a potting glue comprises the following specific steps: a. Preheat the potting glue and the PCBA electronic module 4 to be potted to a certain temperature, so as to improve the fluidity of the potting glue, which helps the potting glue to completely wrap the electronic components in the PCBA electronic module 4 after potting, and also helps to discharge bubbles and reduce the generation of bubbles.

[0032] b. Exhaust the potting compound at room temperature. At this time, the potting compound has better fluidity and exhaust performance, and a large number of bubbles can escape.

[0033] c. After completing step b, the potted PCBA electronic module 4 is placed in a high temperature environment to accelerate the curing speed of the potting glue and complete the curing process.

[0034] In this embodiment, when performing step b and step c, a hair dryer 15 is used to blow hot air on the surface of the potting glue, and the hot air flow is used to stir the surface of the potting glue to eliminate bubbles remaining on the surface of the potting glue.

[0035] The preheating temperature described in this embodiment is 40-45°C, the normal temperature is 20-30°C, and the high temperature is 50-80°C.

[0036] The above embodiments are only illustrative of the principles and effects of the invention, as well as some embodiments of its application, and are not intended to limit the invention. It should be pointed out that a person skilled in the art can make several modifications and improvements without departing from the inventive concept of the invention, and all of these belong to the protection scope of the invention.

Claims

1. A potting glue potting device used for PCBA electronic module sealing, characterized in that: It includes a belt conveyor and a preheating bin and a drying bin arranged in sequence along the conveying direction of the belt conveyor. The two opposite side walls of the preheating bin are respectively provided with material ports for the upper conveyor belt and PCBA electronic modules to enter and exit, and a through hole for the lower conveyor belt to pass through. An upper partition located above the upper conveyor belt is arranged in the preheating bin. The upper partition isolates the upper part of the preheating bin into a storage cavity. The storage cavity is used to store potting glue. An electric heating rod is arranged inside the upper partition for heating the preheating bin, increasing the temperature in the preheating bin, and preheating the potting glue at the same time. A glue outlet is arranged on the upper partition, and a glue injection pump is connected to the glue outlet. The outlet of the glue injection pump is connected to a glue injection pipe extending downward. A detector for detecting PCBA electronic modules is arranged on the downstream side of the glue injection pipe. When the upper conveyor belt transfers the PCB When the A electronic module is transported to the bottom of the glue injection tube, the detector just detects the PCBA electronic module; the two opposite side walls of the drying bin are also respectively provided with material ports for the upper conveyor belt and the PCBA electronic module to enter and exit, and through holes for the lower conveyor belt to pass through; a plurality of electric heating rods are also arranged in the drying bin; the preheating bin and the drying bin are arranged separately; the belt conveyor and the glue injection pump are respectively electrically connected to a controller and controlled by the controller; the detector is electrically connected to the controller; when the detector detects the PCBA electronic module, it sends a signal to the controller; after receiving the signal, the controller pauses the belt conveyor, so that the PCBA electronic module located below the glue injection tube stops moving; then, the controller controls the glue injection pump to start, and injects sealing glue into the PCBA electronic module; after the injection is completed, the belt conveyor is resumed.

2. The potting glue potting device according to claim 1, characterized in that: A baffle is provided above the upper conveyor belt between the preheating bin and the drying bin, and the baffle is used to block the ash layer to prevent the potting glue in the PCBA electronic module from being contaminated by the ash layer.

3. The potting glue potting device according to claim 1, characterized in that: The detector is a through-beam laser sensor.

4. The potting glue potting device according to claim 1, characterized in that: At least two blowers are also arranged above the upper conveyor belt between the preheating chamber and the drying chamber. Any blower blows obliquely downward along the conveying direction of the conveyor belt, and the inclination directions of two adjacent blowers are opposite. The blower is located above the conveying path of the PCBA electronic module and blows the surface of the potting glue on the passing PCBA electronic module.

5. The potting glue potting device according to claim 1, characterized in that: At least two blowers are arranged above the upper conveyor belt in the drying bin, and any blower blows obliquely downward along the conveying direction of the conveyor belt, and the inclination directions of two adjacent blowers are opposite. The blower is located above the conveying path of the PCBA electronic module and blows the surface of the potting glue on the passing PCBA electronic module.

6. The potting glue potting device according to claim 1, characterized in that: A cooling bin is connected to the downstream side of the drying bin, and the cooling bin shares a side wall with the drying bin. A material port for the upper conveyor belt and PCBA electronic module to enter and exit, and a through hole for the lower conveyor belt to pass through are provided on the side wall of the cooling bin away from the drying bin.

7. The potting glue potting device according to claim 1, characterized in that: A lower partition is respectively provided in the preheating bin and the drying bin, and the lower partition is located between the upper conveyor belt and the lower conveyor belt. The lower partition seals the preheating bin or the drying bin above the lower conveyor belt to reduce heat loss in the preheating bin and the drying bin.

8. A potting glue potting method for PCBA electronic module sealing, characterized in that: The specific steps include: a. Preheat the potting compound and the PCBA electronic module to be potted to a certain temperature to improve the fluidity of the potting compound, which helps the potting compound to completely wrap the electronic components in the PCBA electronic module after potting, and also helps to discharge bubbles and reduce the generation of bubbles; b. Exhaust the potting compound at room temperature. At this time, the potting compound has better fluidity and exhaust performance, and a large number of bubbles can escape; c. After completing step b, place the encapsulated PCBA electronic module in a high temperature environment to accelerate the curing speed of the encapsulation glue and complete the final curing process.

9. The potting method according to claim 8, characterized in that: When performing step b and step c, a hair dryer is used to blow hot air on the surface of the potting glue, and the hot air flow is used to stir the surface of the potting glue to eliminate bubbles remaining on the surface of the potting glue.

10. The potting method according to claim 8, characterized in that: The preheating temperature is 40-45℃, the normal temperature is 20-30℃, and the high temperature is 50-80℃.

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