CN114713922B

CN114713922B - PCB board preheating device is used in controller production

Info

Publication number: CN114713922B
Application number: CN202210245574.XA
Authority: CN
Inventors: 张鹏; 李恒
Original assignee: Xuzhou Hezhuo Machinery Technology Co ltd
Current assignee: Xuzhou Hezhuo Machinery Technology Co ltd
Priority date: 2022-03-14
Filing date: 2022-03-14
Publication date: 2023-04-07
Anticipated expiration: 2042-03-14
Also published as: CN114713922A

Abstract

The invention relates to the technical field of PCB production equipment, and discloses a PCB preheating device for controller production, which comprises a loading box, heating cavities and a gas heating device, wherein a plurality of groups of heating cavities and loading boxes which are connected in parallel form a preheating cavity, one side of each heating cavity is provided with a gas suction channel, and a gas inlet of each gas suction channel corresponds to the top of the heating cavity. This PCB board preheating device is used in controller production, according to the intensification condition in each region of PCB, adjust the gas flow cross-sectional area in each region, make each regional intensification efficiency carry out the differentiation adjustment, and then make the different regional programming rate of heat-absorbing capacity keep unanimous, reduce the difference in temperature of preheating the in-process, guarantee PCB welding quality, secondly, the PCB board is pressed close to the induction port of suction channel, gas has longer lateral shifting time when flowing through the PCB board, the contact time of steam with the PCB board has been prolonged, improved the thermal utilization ratio, reduce the power consumption of preheating.

Description

PCB board preheating device is used in controller production

Technical Field

The invention relates to the technical field of PCB production equipment, in particular to a PCB preheating device for controller production.

Background

Before electronic components are welded on a PCB, the PCB needs to be preheated, and the preheating aims are three, wherein one purpose is to evaporate a solvent in a welding flux and moisture possibly absorbed by the PCB, so that the phenomenon of tin explosion caused by liquid boiling during welding is avoided. And secondly, the soldering flux provides a proper reaction temperature for an active agent in the soldering flux to remove an oxidation film and other pollutants. Thirdly, the printing part and the components are prevented from being damaged by thermal stress generated by sharp temperature rise during welding.

Preheating PCB through hot-blast is comparatively economy and commonly used method, compare oven and hot plate, hot-blast homogeneity of preheating is better, however, the different positions of PCB board, the electronic components kind, density all have the difference, and the electronic components heat absorption capacity of different materials is different, the volume of coated welding agent is different, therefore, the different positions heat absorption capacity of PCB board has the difference, preheat in the face of the same hot-blast, the programming rate is different, can lead to PCB to produce the difference in temperature in the heating process different positions, produce thermal stress, influence PCB welding quality.

Secondly, when the PCB is heated by hot air, the hot air is vertically blown to the PCB, part of the air passes through the PCB after encountering the PCB, and part of the air reversely leaves the PCB, namely the contact time of the air and the PCB is short, the utilization rate of heat is small, and great waste is generated.

Disclosure of Invention

Aiming at the defects of the background technology, the invention provides the technical scheme of the PCB preheating device for the production of the controller, which is used for adjusting the flow cross section of each area, controlling the gas flow velocity of each area, carrying out differential heating on each position of the PCB, ensuring that the temperature rising speeds of the areas with different heat absorption capacities are kept consistent, reducing the temperature difference of each position, prolonging the contact time of gas flow and the PCB, improving the utilization efficiency of heat energy and solving the problems provided by the background technology.

The invention provides the following technical scheme: the utility model provides a PCB board preheating device is used in controller production, is including loading box, heating chamber and gas heating device, the multiunit parallelly connected the heating chamber constitutes preheating chamber with loading box, every one side of heating chamber all is equipped with the passageway of breathing in, the air inlet of passageway of breathing in corresponds the top in heating chamber, the heating chamber intercommunication has the hot air cavity, the passageway of breathing in intercommunication has the negative pressure chamber, hot air cavity and gas heating device intercommunication, the negative pressure chamber intercommunication has the aspiration pump, every all be equipped with the flow control spare that can change the passageway circulation cross-section of breathing in and detect the temperature measurement spare that the PCB board corresponds regional temperature in the passageway of breathing in, temperature measurement spare and flow control spare all communicate with the controller, the controller is according to the flow control spare action that the height control of the temperature that the temperature measurement spare detected corresponds, adjusts the sectional area size of passageway of breathing in through the action of flow control spare, and then reduces the difference in temperature in each region of each PCB.

Preferably, the flow regulating member is a cylindrical air bag, the air suction channel is composed of two partition plates fixedly connected with the side wall of the flow regulating member, and each flow regulating member is provided with an air inlet valve and an air outlet valve communicated with a contraction air source.

Preferably, the controller triggers the temperature measuring elements to detect the temperature every T time, and arranges the temperature measuring elements from small to large after receiving the temperature of the temperature measuring elements, the air inlet valves of the flow adjusting elements corresponding to the K temperature measuring elements with the lowest control temperature are kept in an open state, the air outlet valves are kept in a closed state, the air inlet valves of other flow adjusting elements are kept in a closed state, and the air outlet valves are kept in an open state.

Preferably, a sucker is arranged at the end part of the flow adjusting piece, and the temperature measuring piece is arranged in the sucker.

Preferably, the flow adjusting part comprises a supporting tube and an airbag body, the supporting tube penetrates through the airbag body, an air inlet tube communicated with the airbag body is arranged in the supporting tube, a negative pressure channel is arranged between the air inlet tube and the supporting tube and communicated with the sucker at the bottom, a communicating opening communicated with the negative pressure channel is arranged on the side wall of the supporting tube, and the communicating opening is communicated with the negative pressure cavity.

Preferably, the temperature measuring part and the sucker are connected with the supporting tube through flexible tubes.

Preferably, the temperature measuring piece and the sucker are detachably connected with the bottom of the supporting tube.

Preferably, the air inlet valve is arranged at the top of the supporting pipe, the supporting pipe is communicated with a high-pressure air cavity, and the air outlet valve is provided with a position, corresponding to the negative pressure cavity, of the side wall of the supporting pipe.

The invention has the following beneficial effects:

1. this PCB board preheating device is used in controller production according to the intensification condition in each region of PCB, adjusts the gas flow cross-sectional area in each region, makes the intensification efficiency in each region carry out the differentiation adjustment, and then makes the regional programming rate that the heat-absorbing capacity is different keep unanimous, reduces the difference in temperature among the preheating process, guarantees PCB welding quality.

2. This PCB board preheating device is used in controller production, the induction port of breathing in passageway is pressed close to the PCB board, and gaseous has longer lateral shifting time when flowing through the PCB board, has prolonged the contact time of steam with the PCB board, has improved the utilization ratio to the heat, reduces the power consumption of preheating.

Drawings

FIG. 1 is a schematic front view of the present invention;

FIG. 2 is a schematic view of a portion of the heating chamber of the present invention, shown partially offset toward the top;

FIG. 3 is a schematic view of the structure of the heating chamber of the present invention;

FIG. 4 is a schematic view of the structure of the air suction passage in the present invention;

FIG. 5 is a schematic view of the flow control member of the present invention;

FIG. 6 is a partial bottom view of the heating chamber of the present invention.

In the figure: 1. loading a cartridge; 2. a heating chamber; 3. an air suction passage; 4. a flow rate adjustment member; 41. supporting a tube; 42. a capsule body; 43. an air inlet pipe; 44. a negative pressure channel; 45. a communication port; 5. a hot air chamber; 6. a negative pressure chamber; 7. a temperature measuring part; 8. a high-pressure air cavity; 9. an intake valve; 10. and an air outlet valve.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1, a PCB board preheating device for controller production comprises a loading box 1 for fixing a PCB board and a lifting heating box, wherein the loading box 1 moves along with a conveyor belt, a plurality of groups of air suction channels 3 are arranged in the heating box, the spaces separated by the air suction channels 3 form a heating cavity 2, the heating cavity 2 is communicated with a hot air cavity 5, the hot air cavity 5 is communicated with a gas heating device, the gas heating device is in the prior art and is not shown in the figure, inlet air enters the hot air cavity 5 after being heated by the gas heating device, referring to fig. 2, an air ventilation network is arranged between the heating cavity 2 and the hot air cavity 5 to ensure that the gas enters the heating cavity 2 relatively uniformly, the air suction channels 3 are communicated with a negative pressure cavity 6, the negative pressure cavity 6 is communicated with an air suction pump, the hot air flow is contacted with the PCB board, part of the hot air flows through the PCB board, most of the air is sucked into the negative pressure cavity 6 by the air suction channels 3, and is discharged by the air suction pump or enters other recycling equipment, referring to fig. 3, the side surfaces of the hot air cavity 5 and the negative pressure cavity 6 are both provided with a communicating cavity, the hot air cavity 5 and the negative pressure cavity 6 are respectively communicated with the gas heating device and the air pump through the communicating cavity, the side wall of the heating box is connected with a lifting structure through a support, the heating box can be an air cylinder, a lifting table and other equipment, after the loading box 1 is in place, the edge of the heating box is controlled to be attached to the edge of the loading box 1, the air suction channel 3 is internally provided with a flow adjusting member 4, the flow cross section of the air suction channel 3 can be changed through the action of the flow adjusting member 4, the air suction channel 3 is also internally provided with a temperature measuring member 7, the temperature measuring member 7 detects the temperature of the corresponding area of the PCB, the temperature measuring member 7 and the flow adjusting member 4 are both connected with a controller, the temperature measuring member 7 transmits the detected temperature to the controller, the controller controls the flow cross section of the air suction channel 3 through the flow adjusting member 4, the sectional area is reduced due to overhigh temperature, otherwise, the flow area is increased, the flow area is large, the air flow is increased, more temperature can drive the low-temperature area, the heating efficiency of the low-temperature area is improved, and the temperature difference of each area of the PCB is reduced.

Referring to fig. 4, the flow adjusting member 4 is a cylindrical air bag, the air intake channel 3 is composed of two partition plates fixedly connected with the side wall of the flow adjusting member 4, each flow adjusting member 4 is provided with an air intake valve 9 and an air outlet valve 10 communicated with a contracted air source, the air intake valve 9 and the air outlet valve 10 are both electromagnetically controlled, when the air intake valve 9 is opened, the flow adjusting member 4 is expanded, so that the gap between the two partition plates of the air intake channel 3 is enlarged, the flow area is enlarged, the air intake channel 3 is connected with the flow adjusting member 4 through an elastic body, and the displacement between the two partition plates is responded through elastic deformation.

The controller triggers the temperature measuring parts 7 to detect the temperature every T time, the temperature measuring parts 7 are arranged from small to large after receiving the temperature of the temperature measuring parts 7, the air inlet valves 9 of the flow adjusting parts 4 corresponding to K temperature measuring parts 7 with the lowest temperature are controlled to be in an open state, the air outlet valves 10 are in a closed state, the air inlet valves 9 of other flow adjusting parts 4 are in a closed state, the air outlet valves 10 are in an open state, K is one third of the total number of the temperature measuring parts 7, when the flow adjusting parts 4 corresponding to the temperature measuring parts 7 with the lowest temperature are in a thickest state, the flow area is large, under the condition that the total amount of air flow is unchanged, the air flow passing through the low temperature is increased, the air flow of other areas is reduced, the heating efficiency of the low temperature area is increased, the heating efficiency of the high temperature area is reduced, and the temperature difference is reduced.

The end part of the flow adjusting part 4 is provided with a sucker, the temperature measuring part 7 is arranged in the sucker, the sucker is made of a heat insulating material, hot air is isolated from the temperature measuring part 7 under the action of the sucker, the temperature detected by the temperature measuring part 7 is the temperature of the PCB, and the measurement precision is improved.

Referring to fig. 5, the flow rate adjusting member 4 includes a supporting tube 41 and a bag body 42, the supporting tube 41 passes through the bag body 42, the bag body 42 is fixedly connected to the air suction channel 3, an air inlet tube 43 connected to the bag body 42 is disposed in the supporting tube 41, an air inlet valve 9 and an air outlet valve 10 are disposed on the air inlet tube 43, a negative pressure channel 44 is disposed between the air inlet tube 43 and the supporting tube 41, the negative pressure channel 44 is connected to the suction cup at the bottom, a communication port 45 connected to the negative pressure channel 44 is disposed on a side wall of the supporting tube 41, the communication port 45 is connected to the negative pressure chamber 6, and the negative pressure in the negative pressure chamber 6 directly acts on the suction cup through the negative pressure channel 44 to enable the suction cup to suck the bottom of the PCB.

The temperature measuring piece 7 and the sucker are connected with the supporting tube 41 through the flexible tube, and the positions of the temperature measuring piece 7 and the sucker can be changed through the stretching and the twisting of the flexible tube so as to bypass welded components and reduce the interference to the components and the sucker.

Wherein, temperature measurement piece 7 and sucking disc can be dismantled with the bottom of stay tube 41 and be connected, when meetting that components and parts arrange comparatively intensive region, can dismantle temperature measurement piece 7 and sucking disc, at this moment, negative pressure channel 44 passes through as the backward flow, has increased the gas flow of this department, and the place that components and parts are comparatively intensive, and the intensification is slower, is favorable to temperature distribution's homogeneity.

Referring to fig. 6 and fig. 1, the air inlet valve 9 is disposed on the top of the support tube 41, the support tube 41 is communicated with the high pressure air chamber 8, the high pressure air chamber 8 is communicated with all the flow adjusting members 4, so as to facilitate air supply and maintenance of the air inlet valve 9, the side wall of the air outlet valve 10, which is provided with the support tube 41, corresponds to the position of the negative pressure chamber 6, and the bladder 42 is rapidly shrunk under the action of negative pressure.

The working principle and the working process of the invention are as follows:

after the loading box 1 is loaded with PCBs and is in place, the heating cavity 2 rises along with the heating box and is tightly attached to the edge of the loading box 1 to form a relatively closed preheating cavity, heating gas enters the heating cavity 2 through the hot gas cavity 5, hot gas in the heating cavity 2 is extracted by negative pressure of the negative pressure cavity 6 through the air suction channel 3, the temperature of the PCBs in the corresponding area is measured according to the temperature measuring piece 7, the size of the flow section of the air suction channel 3 is controlled, the larger the flow section is, more air flows pass through, each area is heated through differentiation, and the temperature of each area is guaranteed to be kept the same.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims

1. The utility model provides a PCB board preheating device is used in controller production, is including loading box (1), heating chamber (2) and gaseous heating device, its characterized in that: the heating chamber (2) that the multiunit is parallelly connected constitutes preheating chamber with loading box (1), every one side of heating chamber (2) all is equipped with breathing in passageway (3), the air inlet of breathing in passageway (3) corresponds the top of heating chamber (2), heating chamber (2) intercommunication has hot air chamber (5), breathing in passageway (3) intercommunication has negative pressure chamber (6), hot air chamber (5) and gas heating device intercommunication, negative pressure chamber (6) intercommunication has the aspiration pump, every all be equipped with flow control spare (4) that can change breathing in passageway (3) circulation cross-section and detect temperature measurement spare (7) that the PCB board corresponds regional temperature in breathing in passageway (3), temperature measurement spare (7) and flow control spare (4) all communicate the controller, the controller is according to the flow control spare (4) action that the height control of temperature that temperature measurement spare (7) detected corresponds, through the action adjustment of flow control spare (4) the sectional area size of breathing in passageway (3), and then reduce each regional air supply of PCB, flow control spare (4) are cylindrical gasbag, the flow control spare (3) are equipped with the suction valve (4) and every intake valve (10) the flow control spare (4) is connected the suction valve (10), the temperature measuring part (7) is arranged in the sucker, the flow adjusting part (4) comprises a supporting tube (41) and a bag body (42), the bag body (42) is penetrated through the supporting tube (41), an air inlet tube (43) communicated with the bag body (42) is arranged in the supporting tube (41), a negative pressure channel (44) is arranged between the air inlet tube (43) and the supporting tube (41), the bottom of the negative pressure channel (44) is communicated with the sucker, a communicating port (45) communicated with the negative pressure channel (44) is arranged on the side wall of the supporting tube (41), and the communicating port (45) is communicated with the negative pressure cavity (6).

2. The preheating device for the PCB used for the production of the controller according to claim 1, wherein: the controller triggers the temperature measuring parts (7) to detect the temperature every T time, the temperature measuring parts (7) are arranged from small to large after receiving the temperature, the air inlet valves (9) of the flow adjusting parts (4) corresponding to K temperature measuring parts (7) with the lowest control temperature value are kept in an open state, K is one third of the total number of the temperature measuring parts (7), the air outlet valves (10) are in a closed state, the air inlet valves (9) of other flow adjusting parts (4) are kept in a closed state, and the air outlet valves (10) are in an open state.

3. The preheating device for the PCB used for the production of the controller according to claim 1, wherein: the temperature measuring piece (7) and the sucker are connected with the supporting tube (41) through a flexible tube.

4. The PCB preheating device for controller production according to claim 3, wherein: the temperature measuring piece (7) and the sucker are detachably connected with the bottom of the supporting tube (41).

5. The PCB preheating device for controller production according to claim 1, wherein: the air inlet valve (9) is arranged at the top of the supporting pipe (41), the supporting pipe (41) is communicated with a high-pressure air cavity (8), and the air outlet valve (10) is arranged at the position, corresponding to the negative pressure cavity (6), of the side wall of the supporting pipe (41).