CN113543514B

CN113543514B - Reflow furnace

Info

Publication number: CN113543514B
Application number: CN202010296614.4A
Authority: CN
Inventors: 王振
Original assignee: Kunshan Dafile Electronic Products Co ltd
Current assignee: Kunshan Dafile Electronic Products Co ltd
Priority date: 2020-04-15
Filing date: 2020-04-15
Publication date: 2022-09-23
Anticipated expiration: 2040-04-15
Also published as: CN113543514A

Abstract

The invention relates to a reflow furnace, which comprises a reflow furnace box body, wherein a heating chamber is arranged on one side of the lower part in the reflow furnace box body, a cooling chamber is arranged on the other side of the lower part in the reflow furnace box body, a conveying chamber is arranged on the upper part in the reflow furnace box body, a PCB carrier jacking device and a heating part are arranged in the heating chamber, a PCB carrier is arranged on the jacking end of the PCB carrier jacking device, a PCB is arranged in the PCB carrier, a PCB carrier lifting device and a cooling part are arranged in the cooling chamber, a pushing power cylinder is arranged in the conveying chamber, the heating part heats the PCB to a preset temperature, and the cooling part cools the PCB to the preset temperature. The invention adopts the scheme of the reflow oven box body with the separated heating chamber and the cooling chamber to respectively carry out heating and cooling treatment in the reflow soldering processing process of the PCB, and has the characteristics of high efficiency and energy saving.

Description

Reflow furnace

Technical Field

The invention relates to a reflow oven, in particular to a high-efficiency and energy-saving reflow oven, and belongs to the field of reflow ovens.

Background

The surface mounting technology is the most popular technology in the electronic assembly industry at present, and is a circuit assembly technology which installs surface assembly components without leads or with short leads on the surface of a printed circuit board and performs welding assembly through reflow soldering. The reflow furnace is necessary equipment for reflow soldering, and has the functions of melting solder paste attached to the PCB by passing the PCB after the placement of the components through high temperature, completing circuit connection, and cooling to normal temperature, namely, the working process of the reflow furnace comprises a high-temperature heating stage and a low-temperature cooling stage. In general, the existing scheme is that a furnace is heated to a preset temperature value, and after the PCB completes circuit connection, a refrigeration medium is input into the furnace to achieve the purpose of cooling. The scheme needs a rear cold source to neutralize a front heat source, and then the next round of production and processing is restarted, namely the heat source is input again to increase the temperature, the cold source is input again to reduce the temperature, the waste heat generated by the upper wheel wastes the cold source of the upper wheel, the heat source is input again to increase the temperature of the lower wheel, and the energy consumption is huge.

Disclosure of Invention

The invention discloses a novel scheme, which adopts a scheme of a reflow oven box body with a separated heating chamber and a cooling chamber to respectively carry out heating and cooling treatment in the reflow soldering process of a PCB (printed circuit board), and solves the problems of low processing efficiency and huge energy consumption of the existing similar scheme.

The invention relates to a reflow oven, which comprises a reflow oven box body, wherein a heating chamber is arranged on one side of the lower part in the reflow oven box body, a cooling chamber is arranged on the other side of the lower part in the reflow oven box body, a conveying chamber is arranged on the upper part in the reflow oven box body, a PCB carrier jacking device and a heating component are arranged in the heating chamber, a PCB carrier is arranged on the jacking end of the PCB carrier jacking device, a PCB carrier lifting device and a cooling component are arranged in the PCB carrier, a pushing power cylinder is arranged in the conveying chamber, the heating component heats the PCB to a preset temperature, the PCB carrier jacking device pushes the PCB carrier out of an automatic door A opened from the top of the heating chamber and enters the conveying chamber, the bearing end of the PCB carrier lifting device is lifted into the conveying chamber from an automatic door B opened from the top of the cooling chamber, the pushing power cylinder pushes the PCB carrier on the jacking end of the PCB carrier lifting device to the bearing end of the PCB carrier lifting device, the lifting end of the PCB carrier lifting device returns to the heating chamber, the automatic door A is closed, the bearing end of the PCB carrier lifting device returns to the cooling chamber, the automatic door B is closed, and the cooling component cools the PCB to a preset temperature.

Further, be equipped with sealed sliding door A on the reflow oven box of one side of the heating chamber of this scheme, inlay on the sealed sliding door A and be equipped with transparent observation window A, operating personnel observes the condition in the heating chamber through transparent observation window A, is equipped with sealed sliding door B on the reflow oven box of one side of cooling chamber, inlays on the sealed sliding door B and is equipped with transparent observation window B, and operating personnel observes the condition in the cooling chamber through transparent observation window B.

Further, be equipped with the soaking fan in the heating chamber of this scheme, the soaking fan promotes the abundant thermally equivalent of PCB board in the PCB board carrier, is equipped with cooling fan in the cooling chamber, and cooling fan promotes the quick cooling of PCB board in the PCB board carrier.

Further, automatically-controlled door A of this scheme includes door plant A, and guide rail groove A on the one end embedding heating chamber inside wall of door plant A forms sliding connection, and door plant A's the other end forms screw thread transmission with screw rod A and is connected, and screw rod A's one end is connected with the motor A transmission of establishing on the outside reflow oven box of heating chamber, and motor A opens or seals the opening at heating chamber top through screw rod A drive door plant A along guide rail groove A reciprocating motion.

The automatic door B comprises a door plate B, a guide rail groove B in the inner side wall of the cooling chamber is embedded into one end of the door plate B to form sliding connection, the other end of the door plate B is in threaded transmission connection with a screw rod B, one end of the screw rod B is in transmission connection with a motor B arranged on a reflow oven box body outside the cooling chamber, and the motor B drives the door plate B to open or close an opening in the top of the cooling chamber along the guide rail groove B in a reciprocating motion mode through the screw rod B.

Furthermore, the PCB board carrier of this scheme includes the carrier base plate, is equipped with the PCB board mounting groove on the loading end of carrier base plate, is equipped with a plurality of elastic positioning baffles in the PCB board mounting groove, and one side of elastic positioning baffle is passed through the spring and is connected with the inside wall of PCB board mounting groove, and the opposite side of elastic positioning baffle will establish the PCB board clamp of PCB board mounting groove central authorities and fix a position.

Further, the reflow oven of this scheme still includes automatic control system, automatic control system includes the PLC controller, PCB board utensil jacking device control circuit, automatically-controlled door A control circuit, PCB board utensil elevating gear control circuit, automatically-controlled door B control circuit, propelling movement power cylinder control circuit, the PLC controller judges according to the temperature value of establishing the temperature sensor feedback in the heating chamber, when reaching preset heating temperature, automatically-controlled door A control circuit, automatically-controlled door A is opened to automatically-controlled door B control circuit, automatically-controlled door B, PCB board utensil jacking device control circuit control PCB board utensil jacking device is ejecting the automatically-controlled door A that PCB board carrier was opened from the heating chamber top and gets into the transfer chamber, PCB board utensil elevating gear control circuit control PCB board utensil elevating gear's bearing end rises into the transfer chamber from automatically-controlled door B that the cooling chamber top was opened, propelling movement power cylinder control circuit control propelling movement power cylinder is with PCB board utensil on the jacking end of PCB board utensil jacking device to propelling movement to PCB board utensil on the jacking end of PCB board utensil elevating gear On the bearing end of the PCB board carrier lifting device, the PCB board carrier lifting device control circuit controls the PCB board carrier lifting device to reset, and the automatic door A control circuit and the automatic door B control circuit close the automatic door A and the automatic door B.

Furthermore, the automatic control system of the scheme further comprises a box nitrogen charging control circuit, and the box nitrogen charging control circuit controls the opening and closing state of an external nitrogen source device for supplying nitrogen to the interior of the reflow oven according to the comparison result of the oxygen concentration value fed back by the oxygen detector arranged in the reflow oven and the preset value.

The reflow oven adopts the scheme of the reflow oven box body with the separated heating chamber and cooling chamber to respectively carry out heating and cooling treatment in the reflow soldering processing process of the PCB, and has the characteristics of high efficiency and energy saving.

Drawings

FIG. 1 is a schematic view of a first operating condition of an example reflow oven.

FIG. 2 is a schematic view of the second operating condition of an example reflow oven.

FIG. 3 is a schematic view of the third operating condition of an example reflow oven.

FIG. 4 is a schematic view of an example reflow oven operating condition four.

Fig. 5 is a schematic view of a PCB carrier.

Fig. 6 is a schematic diagram of one of the mounting states of the units of the PCB board carrier.

Wherein, 100 is a heating chamber, 110 is a PCB board carrier lifting device, 120 is a heating part, 130 is a sealing sliding door a, 140 is a soaking fan, 151 is a door panel a, 152 is a guide rail groove a, 153 is a screw rod a, 154 is a motor a, 200 is a cooling chamber, 210 is a PCB board carrier lifting device, 220 is a cooling part, 230 is a sealing sliding door B, 240 is a cooling fan, 251 is a door panel B, 252 is a guide rail groove B, 253 is a screw rod B, 254 is a motor B, 300 is a transfer chamber, 310 is a pushing power cylinder, 400 is a PCB board carrier, 410 is a carrier substrate, 420 is a PCB board mounting groove, and 430 is an elastic positioning baffle.

Detailed Description

As shown in figures 1-4, the reflow oven of the present invention comprises a reflow oven body, a heating chamber is disposed on one side of the lower portion in the reflow oven body, a cooling chamber is disposed on the other side of the lower portion in the reflow oven body, a transfer chamber is disposed on the upper portion in the reflow oven body, a PCB carrier lifting device and a heating component are disposed in the heating chamber, a PCB carrier is disposed on the lifting end of the PCB carrier lifting device, a PCB carrier lifting device and a cooling component are disposed in the cooling chamber, a pushing power cylinder is disposed in the transfer chamber, the heating component heats the PCB to a predetermined temperature, the PCB carrier lifting device pushes the PCB carrier out of an automatic door A opened at the top of the heating chamber into the transfer chamber, a bearing end of the PCB carrier lifting device is lifted into the transfer chamber from an automatic door B opened at the top of the cooling chamber, the pushing power cylinder pushes the PCB carrier on the lifting end of the PCB carrier lifting device to a bearing end of the PCB carrier lifting device, the lifting end of the PCB carrier lifting device returns to the heating chamber, the automatic door A is closed, the bearing end of the PCB carrier lifting device returns to the cooling chamber, the automatic door B is closed, and the cooling component cools the PCB to a preset temperature.

In the scheme, the scheme of the reflow oven box body with the separated heating chamber and the cooling chamber is adopted in the reflow soldering processing process of the PCB to carry out heating and cooling treatment respectively, as shown in figure 1, a carrier for bearing the PCB is arranged on a supporting plate (jacking end) of a jacking device, a heating part starts to heat until the temperature in the heating chamber reaches a preset value, and at the moment, solder paste on the PCB starts to melt to form good conductive connection. And opening an automatic door A at the top of the heating chamber, jacking the PCB plate carrier by the jacking device into the conveying chamber, as shown in fig. 2, simultaneously opening an automatic door B at the top of the cooling chamber, lifting the bearing end of the lifting device into the conveying chamber, and pushing the PCB plate carrier on the supporting plate of the jacking device and the PCB plate by a pushing power cylinder in the conveying chamber onto the bearing end of the lifting device by the pushing power cylinder, as shown in fig. 3. And finally, the jacking device and the lifting device are descended and reset, the automatic door A and the automatic door B are closed, the excessive loss of heat in the heating chamber is avoided, and the PCB entering the cooling chamber completes the cooling process. The scheme adopts independent heating and cooling spaces, avoids cold and heat neutralization, reduces cooling time, saves energy consumed by heating and cooling, realizes closed automatic transfer in the process of transferring the PCB from the heating chamber to the cooling chamber, and greatly improves processing efficiency.

In order to facilitate taking and placing, the real-time observation and monitoring of the machining process are realized, as shown in fig. 1, a sealing sliding door A is arranged on the reflow oven box body on one side of the heating chamber, a transparent observation window A is embedded in the sealing sliding door A, an operator observes the conditions in the heating chamber through the transparent observation window A, a sealing sliding door B is arranged on the reflow oven box body on one side of the cooling chamber, a transparent observation window B is embedded in the sealing sliding door B, and the operator observes the conditions in the cooling chamber through the transparent observation window B.

In order to satisfy the requirement of heat evenly distributed in the heating chamber, improve processingquality, improve the cooling efficiency of cooling chamber simultaneously, as shown in fig. 1, be equipped with the soaking fan in the heating chamber of this scheme, the soaking fan promotes the abundant thermally equivalent of PCB board in the PCB board carrier, is equipped with cooling fan in the cooling chamber, and cooling fan promotes the PCB board rapid cooling in the PCB board carrier.

In order to realize the function of the automatic door, as shown in fig. 1, the automatic door a of the scheme comprises a door plate a, one end of the door plate a is embedded into a guide rail groove a on the inner side wall of a heating chamber to form sliding connection, the other end of the door plate a is in threaded transmission connection with a screw rod a, one end of the screw rod a is in transmission connection with a motor a arranged on a reflow oven box body outside the heating chamber, and the motor a drives the door plate a to move back and forth along the guide rail groove a to open or close an opening at the top of the heating chamber. Similarly, the automatic door B comprises a door plate B, one end of the door plate B is embedded into a guide rail groove B on the inner side wall of the cooling chamber to form sliding connection, the other end of the door plate B is in threaded transmission connection with a screw B, one end of the screw B is in transmission connection with a motor B arranged on a reflow oven box body outside the cooling chamber, and the motor B drives the door plate B to move back and forth along the guide rail groove B through the screw B to open or close an opening in the top of the cooling chamber.

In order to realize the function of PCB board carrier, and satisfy the requirement that the adaptation has the PCB board of unidimensional to lay, improve the suitability of carrier, as shown in fig. 5, 6, the PCB board carrier of this scheme includes the carrier base plate, be equipped with the PCB board mounting groove on the loading end of carrier base plate, be equipped with a plurality of elastic positioning baffles in the PCB board mounting groove, one side of elastic positioning baffle is passed through the spring and is connected with the inside wall of PCB board mounting groove, the opposite side of elastic positioning baffle will establish the PCB board clamping position of central authorities in the PCB board mounting groove.

In order to realize the automatic control of the equipment and further improve the processing efficiency, the reflow oven of the scheme also comprises an automatic control system, the automatic control system comprises a PLC controller, a PCB board carrier jacking device control circuit, an automatic door A control circuit, a PCB board carrier lifting device control circuit, an automatic door B control circuit and a pushing power cylinder control circuit, the PLC controller judges according to the temperature value fed back by a temperature sensor arranged in a heating chamber, when the preset heating temperature is reached, the automatic door A control circuit and the automatic door B control circuit open the automatic door A and the automatic door B, the PCB board carrier jacking device control circuit controls the PCB board carrier jacking device to push the PCB board carrier out of the automatic door A opened from the top of the heating chamber and enter a conveying chamber, the PCB board carrier lifting device control circuit controls the bearing end of the PCB board carrier lifting device to lift into the conveying chamber from the automatic door B opened from the top of the cooling chamber, the pushing power cylinder control circuit controls the pushing power cylinder to push the PCB board tool on the jacking end of the PCB board tool jacking device to the bearing end of the PCB board tool lifting device, the PCB board tool jacking device control circuit controls the PCB board tool jacking device to reset, the PCB board tool lifting device control circuit controls the PCB board tool lifting device to reset, the automatic door A control circuit, the automatic door B control circuit closes the automatic door A and the automatic door B.

Based on above scheme, in order to guarantee the anaerobic environment of components and parts in reflow soldering processing, avoid simultaneously filling nitrogen extravagant, the automatic control system of this scheme still includes that the box fills nitrogen control circuit, and the box fills nitrogen control circuit controls the on-off state to the outside nitrogen gas source equipment of supplying nitrogen in the reflow oven box according to the oxygen concentration numerical value of establishing the oxygen detector feedback in the reflow oven box and the result of numerical value comparison of predetermineeing. For example, the fed back oxygen concentration is higher than a preset value, the nitrogen charging is started, the fed back oxygen concentration is lower than the preset value, the nitrogen charging is closed, namely, the oxygen concentration in the box body of the reflow oven is dynamically controlled, and the processing quality is ensured.

The systems, devices, modules, etc. disclosed in this application may be implemented in any conventional or customary manner known in the art, unless otherwise indicated.

The reflow oven of the present invention is not limited to the disclosure of the specific embodiments, the technical solutions presented in the examples can be extended based on the understanding of the skilled in the art, and the simple alternatives made by the skilled in the art according to the present invention in combination with the common general knowledge also belong to the scope of the present invention.

Claims

1. The reflow furnace is characterized by comprising a reflow furnace box body, wherein a heating chamber is arranged on one side of the lower part in the reflow furnace box body, a cooling chamber is arranged on the other side of the lower part in the reflow furnace box body, a conveying chamber is arranged on the upper part in the reflow furnace box body, a PCB carrier jacking device and a heating part are arranged in the heating chamber, a PCB carrier is arranged on the jacking end of the PCB carrier jacking device, a PCB carrier is arranged in the PCB carrier, a PCB carrier lifting device and a cooling part are arranged in the cooling chamber, a pushing power cylinder is arranged in the conveying chamber, the heating part heats the PCB to a preset temperature, the PCB carrier jacking device pushes the PCB carrier out of an automatic door A opened at the top of the heating chamber to enter the conveying chamber, and the bearing end of the PCB carrier lifting device is lifted into the conveying chamber from an automatic door B opened at the top of the cooling chamber, the pushing power cylinder pushes the PCB carrier on the jacking end of the PCB carrier jacking device to the bearing end of the PCB carrier lifting device, the jacking end of the PCB carrier jacking device retreats to the heating chamber, the automatic door A is closed, the bearing end of the PCB carrier lifting device retreats to the cooling chamber, the automatic door B is closed, and the cooling part cools the PCB to a preset temperature;

the automatic door A comprises a door plate A, one end of the door plate A is embedded into a guide rail groove A on the inner side wall of the heating chamber to form sliding connection, the other end of the door plate A forms threaded transmission connection with a screw rod A, one end of the screw rod A is in transmission connection with a motor A arranged on the reflow oven body outside the heating chamber, the motor A drives the door plate A to reciprocate along the guide rail groove A through the screw rod A to open or close an opening in the top of the heating chamber,

automatic door B includes door plant B, the one end embedding of door plant B guide rail groove B on the cooling chamber inside wall forms sliding connection, door plant B's the other end and screw rod B form screw transmission and are connected, screw rod B's one end with establish the cooling chamber is outside motor B transmission on the reflow oven box is connected, motor B passes through screw rod B drive door plant B is followed guide rail groove B reciprocating motion opens or seals the opening at cooling chamber top.

2. The reflow oven of claim 1, wherein a sealing sliding door A is arranged on the reflow oven body on one side of the heating chamber, a transparent observation window A is embedded in the sealing sliding door A, an operator observes the conditions in the heating chamber through the transparent observation window A, a sealing sliding door B is arranged on the reflow oven body on one side of the cooling chamber, a transparent observation window B is embedded in the sealing sliding door B, and the operator observes the conditions in the cooling chamber through the transparent observation window B.

3. The reflow oven of claim 1, wherein a soaking fan is disposed in the heating chamber, the soaking fan promotes the PCB in the PCB carrier to be heated sufficiently uniformly, and a cooling fan is disposed in the cooling chamber, the cooling fan promotes the PCB in the PCB carrier to be cooled rapidly.

4. The reflow oven of claim 1, wherein the PCB carrier comprises a carrier substrate, a PCB receiving slot is formed in a carrying surface of the carrier substrate, a plurality of elastic positioning baffles are arranged in the PCB receiving slot, one side of each elastic positioning baffle is connected with the inner side wall of the PCB receiving slot through a spring, and the other side of each elastic positioning baffle clamps and positions the PCB arranged in the center of the PCB receiving slot.

5. The reflow oven of claim 1, further comprising an automatic control system, wherein the automatic control system comprises a PLC controller, a PCB board carrier jacking device control circuit, an automatic door a control circuit, a PCB board carrier lifting device control circuit, an automatic door B control circuit, and a pushing power cylinder control circuit, the PLC controller performs determination according to a temperature value fed back by a temperature sensor disposed in the heating chamber, when a preset heating temperature is reached, the automatic door a control circuit and the automatic door B control circuit open the automatic door a and the automatic door B, the PCB board carrier jacking device control circuit controls the PCB board carrier jacking device to eject a PCB board carrier from the automatic door a opened at the top of the heating chamber into the transfer chamber, and the PCB board carrier lifting device control circuit controls the carrying end of the PCB board carrier lifting device to lift into the PCB board carrier from the automatic door B opened at the top of the cooling chamber The transfer chamber, propelling movement power cylinder control circuit control the propelling movement power cylinder will PCB board carrier propelling movement on PCB board carrier jacking device's the jacking end extremely PCB board carrier elevating gear bears and serves, PCB board carrier jacking device control circuit control PCB board carrier jacking device resetting, PCB board carrier elevating gear control circuit control PCB board carrier elevating gear resetting, automatically-controlled door A control circuit, automatically-controlled door B control circuit close automatically-controlled door A, automatically-controlled door B.

6. The reflow oven of claim 5, wherein the automatic control system further comprises a box nitrogen filling control circuit, and the box nitrogen filling control circuit controls the on-off state of an external nitrogen source device supplying nitrogen to the reflow oven box body according to the comparison result between the oxygen concentration value fed back by an oxygen detector arranged in the reflow oven box body and a preset value.