Soldering device, in particular reflow soldering device, having a fan unit arranged laterally adjacent to a process channel

Abstract

A soldering device (10) for continuously soldering printed circuit boards along a conveying direction (18), in particular a reflow soldering device, is disclosed, comprising a process channel (16) comprising a preheating zone (20), a soldering zone (22) and a cooling zone (24), a base body (60) and a cover, which can be shifted between a closed position and an open position, wherein a nozzle plate, a fan unit with a fan motor, an air channel for conveying process gas, a filter element and / or a cooling element are arranged in the base body, characterized in that at least one fan unit is arranged in or on the base body laterally adjacent to the process channel in the conveying direction, and the air channel is arranged and configured so that during operation of the at least one fan unit, process gas is blown into the process channel, the process gas is guided through the filter element arranged in the filter area after passing through the process channel, and the filtered process gas is sucked in by the at least one fan unit.

Description

Technical Field

[0001] The invention relates to a soldering device, in particular a reflow soldering device, for continuously soldering printed circuit boards along a conveying direction, having a process channel including a preheating zone, a soldering zone and a cooling zone, having a base body and a cover, which can be shifted between a closed position and an open position, wherein a nozzle plate, a fan unit, an air channel for conveying process gas, a filter element and / or a cooling element are arranged in the base body. Background Art

[0002] Reflow soldering equipment is used to solder so-called SMD components (surface mounted devices) to the surface of a printed circuit board using solder paste. In particular, a solder paste of a mixture of solder metal particles, flux and paste components is applied or printed on the surface of the printed circuit board for reflow soldering. The components to be soldered are then placed in the solder paste. In the reflow soldering process, the soldering material (i.e., the assembly consisting of the printed circuit board, solder paste and the components to be soldered) is preheated in a preheating zone along a process channel, and the material is heated to a temperature above the melting point of the solder paste in the soldering zone. This causes the solder paste to melt and form a solder joint. In the cooling zone (if available), the material is cooled until the molten solder solidifies before it is removed from the reflow soldering equipment.

[0003] Soldering devices for continuous soldering of printed circuit boards are known from DE 10 2019 128 780 A1, DE 10 2019 125 981 A1 and DE 10 2005 055283 A1, further soldering devices are known from EP 3 096 915 B1, CN 201167453Y and EP 1023 136 B1.

[0004] In reflow soldering equipment, the process channel is usually formed by two channel halves (i.e., an upper channel half and a lower channel half). The lower channel half is arranged in or on the substrate, and the upper channel half is arranged in or on the cover. In or on the process channel, or in or on the substrate, and in or on the cover, other structural elements (such as nozzle plates, fan units, air channels for conveying process gases, filter elements and / or cooling elements) are usually arranged. In short, the desired temperature distribution is provided in the process channel along the conveying direction, wherein the process gas is blown into the process channel, taken out of the channel, cooled, cleaned and sent back to the process channel, especially in the cooling zone.

[0005] From the applicant's machines named HotFlow 3 or HotFlow 4, it is known to arrange a fan unit on the base body vertically below the process channel and to blow the process gas from the fan unit vertically upwards through the nozzle plate into the process channel. In this case, it has been found that condensate formed in the cooling zone collects on the fan units and contaminates them, resulting in a non-negligible amount of maintenance. Summary of the invention

[0006] The object of the invention is to provide a welding device for which, in particular, the cooling zone is advantageously designed such that contamination is avoided.

[0007] This object is achieved by a welding device having the features of solution 1. Therefore, it is provided in particular that at least one fan unit is arranged in or on the base body laterally adjacent to the process channel in the conveying direction, and the air channel is arranged and configured such that during operation of the at least one fan unit, process gas is blown into the process channel, the process gas is guided through the filter element after passing through the process channel, and the filtered process gas is sucked in by the at least one fan unit.

[0008] The advantage of arranging at least one fan unit laterally adjacent to the process channel in the conveying direction rather than vertically below the process channel is that the overall height of the welding equipment is reduced, the process channel can be arranged correspondingly lower, and the fan unit can be easily accessed for repair and maintenance. In addition, since the heat generated by the fan unit can be dissipated laterally adjacent to the process channel, the heat generated by the fan unit can be better dissipated. This improves the cooling of the fan motors and increases their service life. However, a closed air circuit can be provided that is approximately transverse to the conveying direction.

[0009] Advantageously, at least one fan unit is arranged not only laterally adjacent to the process channel but also in a plane below the process channel, and the air channel is arranged and configured such that during operation of the at least one fan unit, the process gas is blown by the at least one fan unit laterally below the process channel and there deflected vertically upwards into the process channel. Specifically, since preferably a plurality of fan units are arranged on the one hand laterally adjacent to the process channel and on the other hand below the process channel, the air can be directed approximately along a straight line in a plane into the region below the process channel.

[0010] In addition, it is advantageous that at least one fan unit comprises a fan motor, a rotor shaft and a fan impeller arranged on the rotor shaft, wherein the rotor shaft is arranged transversely to the conveying direction and in a manner extending in the vertical direction, and is laterally spaced apart from the process channel, wherein the fan motor is arranged vertically above the fan impeller. This design has the advantage that pollutants do not accumulate in the fan motor. Even if pollutants or condensate accumulate or accumulate on the fan impeller or the rotor shaft, they do not enter the fan motor. Since the fan motor is arranged vertically above the fan impeller, pollutants and condensate are deposited below the fan impeller due to gravity, especially when the fan unit is closed. This saves maintenance costs, reduces the wear of the fan motor, and extends the service life of the fan unit.

[0011] Furthermore, it is advantageous to arrange at least one fan unit and form the fan impeller so that the process gas is sucked in axially and blown radially at the air inlet region facing away from the fan motor. Thus, the process gas is sucked in vertically from below and discharged laterally in the horizontal direction.

[0012] Preferably, a plurality of fan units are provided for the targeted movement of the process gas in the substrate, wherein at least one shielding plate is provided axially below the air inlet area, the shielding plate shielding the air inlet area of ​​at least one fan unit from the filter area. This ensures that the process gas does not flow directly from the filter element to the fan unit, but is deflected via the corresponding shielding plate.

[0013] Furthermore, it is advantageous if a guide channel is provided laterally adjacent to the at least one fan unit in the conveying direction at the height of the fan impeller and below the process channel, so that the process gas from the at least one fan unit is first blown laterally downwards into the process channel and then guided vertically upwards into the process channel. During operation of the at least one fan unit, the process gas is thereby blown into the process channel in the cooling zone, so that the welding material is blown from below.

[0014] It is also advantageous to arrange a plurality of fan units one after another along a line parallel to the conveying direction, the rotor axes of the fan units extending parallel to each other. This arrangement can be used to produce an air circuit extending along the conveying direction, wherein the main direction of the air flow is transverse to the conveying direction.

[0015] Furthermore, it is conceivable that the cover can be pivoted about the cover axis between a closed position and an open position, and that at least one fan unit is arranged between the cover axis and the process channel in a lateral direction extending transversely to the conveying direction, so that at least one fan unit is arranged on a side of the process channel close to the cover axis. This has the advantage that when the cover is opened and working in the process channel, the at least one fan unit does not hinder the operator. Thus, when the cover is open, the provision of at least one and preferably a plurality of fan units does not interfere with access to the process channel.

[0016] Furthermore, it is advantageous to arrange the air channel and the cooling element, in particular in the form of a heat exchanger, so that before the process gas is blown into the process channel, the process gas passes through the cooling element and then enters the process channel through the nozzle plate. When passing through the cooling element, the process gas can be further cooled. By arranging the nozzle plate, a relatively uniform and ideal laminar flow can be provided in the process channel.

[0017] Furthermore, it is advantageous, in particular, to arrange the air channel and the cooling device in the cooling zone such that the process gas is guided along the cooling device including the cooling plate after passing through the process channel and before passing through the filter element. This ensures that moisture and steam absorbed by the process gas when passing through the cooling plate can condense on the cooling plate before the process gas is guided through the filter element.

[0018] It is also advantageous if the cooling plate extends along a cooling plane which extends obliquely to the horizontal and has a drip tray in its vertical lower region. This allows liquid condensed on the cooling plate to be collected in the drip tray along the inclined surface of the cooling plate. Furthermore, the drip tray is transparent, in particular so that it is possible to visually check whether and how much condensate is present in the drip tray. Further, preferably, the drip tray is arranged detachably so that the drip tray can be emptied in a simple manner.

[0019] Furthermore, it is advantageous if the filter element in the cooling zone extends along a filter plane extending obliquely to the horizontal. The oblique arrangement of the filter plane allows increasing its surface area compared to a horizontal arrangement, thereby increasing the filtering capacity. In addition, the moisture collected in the filter element can drip better. The filter element can include a filter grid and a filter fleece arranged in or on the filter grid.

[0020] It is particularly advantageous if the cooling plane and the filtering plane enclose an acute angle, which results in optimized air guidance and an overall optimized cooling and filtering result for the process gas.

[0021] Furthermore, it can be provided that the air channel is formed and arranged in such a way that the process gas is discharged vertically downward from the process channel via the insertion channel on a side facing away from the at least one fan unit and is deflected toward the cooling plate.

[0022] Furthermore, it is advantageous to provide a drawer in the base body in the cooling zone, which can be pulled out in a pull-out direction extending transversely to the conveying direction and has a bottom, a front wall and a rear side, which can be formed in particular by a rear wall or can include a rear wall, wherein an air channel for guiding the process gas, at least one filter element and at least one cooling device are provided in the drawer. By providing a drawer that can be pulled out transversely to the conveying direction and in particular vertically, at least one replaceable filter element and a cooling device provided in the drawer can thus be easily accessible. Since the steam contained in the process gas condenses on the cooling device, it is particularly advantageous to collect the condensate in the drawer and finally remove it by opening the drawer if necessary. Further, it is advantageous to provide a drawer in order to visually check and / or replace the filter element. It is relatively easy to replace the filter element when the drawer is open. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Further details and advantageous embodiments of the invention can be found in the following description, by which exemplary embodiments of the invention are described and explained.

[0024] Figure 1 shows a side view of a reflow soldering apparatus viewed from the front at an angle, with the cover closed;

[0025] Figure 2 Shown according to Figure 1 A front view of a reflow soldering apparatus with a cover hood open and a cover flap open;

[0026] Figure 3 Shows the view from the front at a certain angle Figure 1 A reflow soldering apparatus wherein the cover is open and the cover flap is open;

[0027] Figure 4 Shows the view from the rear at an angle Figure 1 A reflow soldering apparatus wherein the cover is open and the cover flap is open;

[0028] Figure 5 Shows no coating according to Figure 1 A cross section of a cooling zone of a reflow soldering apparatus with a drawer closed;

[0029] Figure 6 Shown according to Figure 1 Cross section of a reflow soldering apparatus with the drawer opened;

[0030] Figure 7 The diagram of the individual parts shows the Figure 6 and Figure 7 A cross section of a base body of a reflow soldering device having a drawer;

[0031] Figure 8 Shown according to Figure 6 and Figure 7 Drawers for reflow soldering equipment; and

[0032] Fig. 9 Shown according to Figure 8 Longitudinal section of a drawer. DETAILED DESCRIPTION

[0033] Figure 1 A reflow soldering device 10 for continuously soldering materials for soldering is shown. The reflow soldering device 10 has an inlet 12 and an outlet 14, wherein the soldering material to be soldered enters the reflow soldering device 10 via the inlet 12 and is discharged from the reflow soldering device 10 via the outlet 14. The soldering material is transported along a transport direction 18 through the reflow soldering device 10. Figure 1 The process channel 16 is shown. In the process channel 16, a preheating zone 20, a welding zone 22 and a cooling zone 24 are arranged.

[0034] As from Figure 1 and Figure 2 As can be seen in FIG. 1 , a communication unit 36 ​​having a display and an input device is provided, via which communication unit a communication with a machine control system of the reflow soldering device 10 can be established.

[0035] The soldering material (i.e., the printed circuit board provided with solder paste and equipped with electronic components) is initially heated to a temperature below the melting temperature of the solder paste in the preheating zone 20. In the soldering zone 22, the printed circuit board is heated to a process temperature above the melting point of the solder paste for a specified period of time so that the solder paste melts in the soldering zone to solder the electronic components to the printed circuit board. In the cooling zone 24, the soldering material is cooled so that the liquid solder solidifies before the soldering material is removed at the outlet 14 of the reflow soldering apparatus 10.

[0036] A conveyor system 34 is provided in the reflow soldering system 10 for conveying the printed circuit boards along a conveying direction 18 .

[0037] As from Figure 2 As can be seen in the figure, the reflow soldering device 10 has a cover 25 with two cover flaps 26, 28. The cover 25 can be swung open about a cover axis 32 extending parallel to the conveying direction 18. Swinging open the cover 25 provides access to the interior of the process tunnel 16 and the conveyor system 34 for visual inspection, maintenance, cleaning, setting, replacement and repair as required.

[0038] As from Figure 2As can be further seen in the figure, the hood flaps 26, 28 can be swung open about a flap axis 38 extending parallel to the hood axis 32. By swinging open the hood flaps 26, 28, the hood space 30 located above the process channel and thus above the upper channel half becomes accessible by the arrangement of the fan modules, the heating elements and the air ducts. The flap axis 38 is arranged above the hood axis 32 both when the cover hood 25 is open and when the cover hood 25 is closed.

[0039] The welding device 10 has two longitudinal sides 42 and 44 and two narrow sides 46 and 48. Figure 2 It can be easily seen in FIG. 3 that the hood axis 32 is located in the region of a rear longitudinal side 44 . In contrast, the flap axis 38 is located in the region of the front longitudinal side 42 or is closer to the front longitudinal side 42 than to the rear longitudinal side 44 .

[0040] exist Figure 3 In the embodiment of the present invention, the cover 25 on the one hand and the cover flaps 26, 28 on the other hand are open, and in particular the open process channel 16 can be seen. The process channel 16 is formed by two channel halves, namely an upper channel half and a lower channel half. The lower channel half with the lower nozzle plate 118 is arranged in or on the base body 60, while the upper channel half with the upper nozzle plate 40 is arranged in or on the cover 25. The upper channel half and the upper nozzle plate 40 as well as other components located in the cover space 30 are arranged on the cover 25 so that they also swing open when the cover 25 is opened and the process channel 16 is released.

[0041] As from Figures 2 to 4 As is clear from the figure, this arrangement ensures that when the cover 25 is open, the process channel 16 is accessible from the front longitudinal side 42, and the upper cover space 30 covered by the cover flaps 26, 28 is accessible from the other rear longitudinal side 44. In addition, this has the advantage that when the cover 25 is open and thus when the process channel 16 is exposed, the gas flowing out of the process channel 16 does not flow into the upper cover space 30 covered by the cover flaps 26, 28. Further, on the one hand, multiple operators can simultaneously inspect or maintain the process channel 16 and independently inspect or maintain the cover space 30 covered by the cover flaps 26, 28.

[0042] As from Figure 4 and Figure 5As can be seen in FIG. 1 , a plurality of fan units 50 with fan motors 51 are located above the upper channel half in the hood space 30 covered by the hood flaps 26, 28 and are arranged to generate the provided air flow in the process channel 16. The fan units 50 in the preheating zone 20 and the process zone 22 can additionally have heating elements in order to provide a predetermined temperature. By means of the fan units 50 or their fan motors 51, the appropriately heated and cooled process gas is introduced from above through the nozzle plate 40 into the process channel 16 and then sucked in again via the longitudinal sides of the process channel 16.

[0043] Thus, if the cover 25 is opened, in particular the process channel 16 and the conveying system arranged therein are accessible. If the cover flaps 26, 28 are open, in particular the fan unit 50 in which its heating element (if any) is arranged and the air ducts also arranged therein are accessible.

[0044] exist Figure 1 In their closed position shown, the two cover flaps 26, 28 have a horizontal portion 52, which is located close to the flap axis 38 and extends generally in the horizontal direction. This horizontal portion 52 is adjacent to an inclined portion 56, which is away from the flap axis 38 and forms an obtuse angle 52 with the horizontal portion 52. Figure 4 As is particularly clear from the figure, the handle 58 for opening the two cover flaps 26, 28 is arranged on the inclined portion. The obtuse angle 54 can be particularly Figure 2 Clearly seen in.

[0045] The base 60 stands on the bottom plate via feet 62. The feet 62 are arranged on a lower frame 64. In addition, a drive unit 66 is provided for electrically opening and closing the cover 25, which is supported on the lower frame 64 at one end and on the cover 25 at the other end. Figure 5 It is also clear that the cover 25 comprises gate-shaped frame legs 68, each having a first support portion 70 directed towards the cover axis 32 and a second support portion 72 directed towards the respective drive unit 66. Between each of the two support portions 72 a central portion 74 is provided.

[0046] As according to Figure 5 As can be seen in the cross-sectional view of the cooling zone 24 of FIG. 1 , a plurality of fan units 100 arranged one behind the other in the conveying direction 18 are arranged in the base body 60 laterally adjacent to the process channel 16 in the conveying direction 18 and in a plane below the conveying channel 18, wherein in each case, according to Figure 5 and Figure 6 Only one fan unit 100 can be seen in the cross-sectional view of FIG. The fan unit 100 corresponds to the fan unit 50 in structure, and as shown in FIG. Figure 5 and Figure 6As can be seen in FIG. 1 , it is located laterally between the hood axis 32 and the process channel 16 .

[0047] The fan units 100 each have a fan motor 102, a rotor shaft 104 driven by the fan motor 102, and a fan impeller 106 disposed on the rotor shaft 104. The respective fan impeller 106 is a radial fan impeller having a radial rotation direction. Figure 5 The process gas 108 is sucked in axially from below from the gas inlet region 109 and the process gas 110 is blown away radially. Figure 5 As is clear from the figure, the respective rotor shaft 104 is spaced apart from the process channel 16 laterally in the horizontal direction by a dimension 112. The respective rotor shaft 104 extends in the vertical direction. The arrangement enables the respective fan motor 102 to be located vertically above the respective fan impeller 106.

[0048] During operation of the fan unit 100, the process gas 110 is blown into a substantially horizontally extending guide channel 114, which extends adjacent to the fan impeller 106 in a transverse direction extending transversely to the conveying direction 18, first laterally immediately adjacent and then vertically below the process channel 16. The process gas is then blown vertically upwards through the guide channel 114, through a cooling element in the form of a heat exchanger 116, in which the process gas is further cooled, and from below through a lower nozzle plate 118 into the process channel 16. Thus, the weld material to be cooled is blown from below in the cooling zone 24.

[0049] At the welding material arranged in the process channel 14, the blown process gas 120 is directed to the front longitudinal side 42. There, the process gas 124 enters the insertion channel 122 and is directed vertically downward. In the region 123, the insertion channel 122 arranged on the base body 60 merges into the input channel 125 arranged in the drawer 126. The drawer 126 is located in Figure 5 Shown as closed, Figure 6 Also, the drawer 126 is shown as open. Figure 8 and Fig. 9 The drawer 126 is accessible from the front side 42 of the base 60. Figure 3 The illustrated base body 60 has an openable door disposed on its front side, behind which a drawer 126 is disposed.

[0050] The drawer 126 has a rear side in the form of a bottom 128, a front wall 130 and a rear wall 132. The drawer 126 also has an upper edge 133, which is formed to extend horizontally. The inlet channel 125 guides the process gas in the region of the bottom 128 towards a cooling device 136 formed as a cooling plate 134.

[0051] In particular, from Figure 5 and Figure 6As can be seen in FIG. 1 , the cooling plate 134 extends obliquely to the upper edge 133 or the horizontal line 137 and is inclined forward and downward, i.e., toward the front longitudinal side 42 or toward the front wall 130 of the drawer 126. A removable drip tray 138 is arranged on the bottom 128 of the drawer 126 in the region of the front wall 130. Condensate condensed on the cooling plate 134 collects in the drip tray 138. In the present embodiment, the cooling plate 134 is cooled by ambient air. However, it is conceivable to arrange an active cooling element, such as a heat exchanger or an electrically powered cooling element, in the region of the cooling plate 134 in order to achieve a higher cooling capacity.

[0052] In particular, the removable and drainable drip tray 138 is formed to be translucent, so that the filling level of the drip tray 138 can be visually checked.

[0053] The inlet channel 125 opens into the filter area 140 on the side facing away from the front wall 130 and facing the rear wall 132. The filter element 142 is arranged in the filter area 140. Figure 5 and Figure 6 As can be seen in the drawing, for example, a filter element 142 with a filter grid having a filter fleece can be provided, extending obliquely to the horizontal line 137 and formed to be inclined downwardly toward the rear wall 132. The filter element 142 is then located on a diagonal line of the drawer 126. In general, the plane in which the cooling plate 134 is located encloses an acute angle 144 with the plane formed by the filter element 142.

[0054] The drawer 126 has a cover plate 146 in the rear area above the filter element 142. Figure 5 As can be seen in the figure, the baffle 146 is arranged between the air inlet region 109 of the fan impeller 106 and the filter element 142, and thus shields the air inlet region 109 of the fan impeller 106. In particular, the baffle 146 shields the region of the filter element 142 close to the bottom 128 of the drawer 126. Therefore, the provision of the baffle 146 means that not the entire upper side of the drawer 126 is open, but rather only the region not covered by the baffle 146 is open. This produces an advantageous air deflection and a more uniform passage of the process gas through the filter element 142.

[0055] In order to guide the process gas passing through the filter element 142 to the air intake region of the corresponding fan unit 100 , a guide plate 148 is arranged on the base body 60 .

[0056] exist Figure 5 and Figure 6, the drawer 126 is shown in a slightly vertically lowered state. To raise the drawer 126, a lowering mechanism 150 with a lever transmission is used, which can be operated via a manually operated lever 152, with which the drawer 126 can be adjusted between the lowered position and the raised position. In particular, it is conceivable that the lowering mechanism 150 and the drawer 126 are arranged behind a door, which is arranged on the front side of the base body 60, so that the lowering mechanism 150 and the drawer 126 are accessible after the door is opened. After the drawer 126 has been lowered, it can be pulled out in a horizontally extending pull-out direction 154 transversely to the conveying direction 18, as shown in FIG. Figure 6 To this end, Figure 6 A horizontal guide 156 in the form of a rail for the drawer 126 is shown.

[0057] Of course, it is also conceivable that the lowering mechanism 150 is automatically operated, for example electrically or pneumatically.

[0058] A collecting tray 155 is arranged in the base body 60 below the drawer 126 , which serves to collect dripping condensate or fallen contaminants when the drawer 126 is open.

[0059] Figure 7 Three fan receptacles 158 are shown for receiving fan units 100 (not shown here). The fan receptacles 158 are arranged laterally adjacent to the process channel 16 and horizontally spaced apart relative to the process channel 16, so that the fan units 100 inserted into the fan receptacles 158 are arranged along a line extending parallel to the conveying direction 18. The rotor axes 104 of these fan units 100 are then arranged to extend parallel to each other.

[0060] The fan units 100 arranged in three fan receptacles 158 provide a total of three air circuits extending transversely to the process direction 118, wherein the drawers 126 are arranged in three fan receptacles 158. Figure 8 and Fig. 9 The three compartments 160 shown here are adjacent to each other in the extension direction 154. Adjacent compartments 160 are separated by compartment walls 162. Each compartment 160 in the drawer 126 has its own inlet channel 125, its own filter element 142 and its own baffle 146. Thus, a total of three separate air circuits are provided in the drawer 126, each of which is provided by a fan unit 100 arranged in a corresponding fan receptacle 158.

[0061] Figure 7The illustration in FIG. 1 again clearly shows the corresponding circuits of the process gas. A total of three air circuits are provided, which extend approximately transversely to the conveying direction 18 . The air circuits provided by the corresponding fan units 100 are such that the process gas 110 is initially blown laterally into a guide channel 114 below the process channel via the corresponding fan units 100 and deflected upwards. The process gas then passes through a heat exchanger 116 before entering the process channel 16 via a nozzle plate 118 . The welding material then flows from below and is cooled, preferably over the entire length of the cooling zone 24 . The process gas is taken from the process channel via an insertion duct 122 arranged on the front side, which leads to a corresponding inlet channel 125 of a drawer 126 . The process gas then flows along the bottom 128 or the cooling plate 134 into the corresponding filter area 140 . The condensate contained in the process gas condenses on the cooling plate 134 and collects in a drip tray 138 , which can preferably be emptied without opening the drawer 126 . The process gas then flows through the respective filter element 142, is deflected at the lower side of the respective baffle plate 146, and is further guided on the upper side of the respective baffle plate 146 towards the respective fan unit 100. Overall, this ensures that all process gas flowing back into the process channel passes through the filter element 142 and is thereby cleaned.

[0062] As from Figure 8 and Fig. 9 As can be seen in FIG. 1 , the respective shielding plates 146 extend from the rear wall 132 toward the front wall 130 such that they cover approximately half of the filter element 142. Figure 8 and Fig. 9 In the embodiment, the filter element 142 is composed of Figure 8 The wire mesh shown is formed in which a filter fleece (not shown further) is placed which can be replaced in a simple manner.

Claims

1. A welding device (10) for continuously welding printed circuit boards along a conveying direction (18), The welding device (10) has a process channel (16) including a preheating zone (20), a welding zone (22) and a cooling zone (24). The welding device (10) comprises a base body (60) and a cover (25). The cover (25) is displaceable between a closed position and an open position. in, A nozzle plate (118), a fan unit (100) with a fan motor (102), air channels (114, 122) for conveying process gas, a filter element (142) and / or a cooling element are arranged in the base body (60). The invention is characterized in that at least one fan unit (100) is arranged in or on the base body (60) laterally adjacent to the process channel (16) in the conveying direction (18), and the at least one fan unit (100) is also arranged below the process channel (16). The at least one fan unit (100) comprises a fan motor (102), a rotor shaft (104), and a fan impeller (106) arranged on the rotor shaft (104), wherein the rotor shaft (104) is arranged in a manner extending in a vertical direction so as to be laterally adjacent to the process channel (16), wherein the fan motor (102) is arranged vertically above the fan impeller (106), wherein the air channel (114) is arranged and configured such that during operation of the at least one fan unit (100), process gas is blown laterally downward into the process channel (16) and deflected there vertically upward into the process channel (16), wherein after passing through the process channel (16), the process gas is guided through a filter element (142) arranged in a filter area (140), wherein the filtered process gas is sucked in by the at least one fan unit (100), wherein a plurality of fan units (100) are provided for the targeted movement of the process gas in the substrate (60), Wherein, at least one shielding plate (146) is arranged axially below the air intake area (109), and the shielding plate (146) shields the air intake area (109) of at least one fan unit (100) from the filter area (140).

2. The welding device (10) according to claim 1, wherein: The at least one fan unit (100) is arranged and the fan impeller (106) is formed so that the process gas is sucked in axially from an air intake area (109) located below the fan motor (102) and facing away from the fan motor (102) and is blown in radial direction.

3. The welding device (10) according to claim 1, wherein: A guide channel is arranged laterally adjacent to the at least one fan unit (100) in the conveying direction (18) at the height of the fan impeller (106) and below the process channel (16), so that the process gas from the at least one fan unit (100) is blown laterally from below the process channel (16) and then guided vertically upward into the process channel (16).

4. The welding device (10) according to claim 1, wherein: A plurality of fan units (100) are arranged one behind the other parallel to the conveying direction (18), wherein the rotor shafts (104) of the fan units (100) are arranged to extend parallel to one another.

5. The welding device (10) according to claim 1, wherein: During operation of the at least one fan unit (100), process gas is blown into the process channel (16) so that welding material is blown from below.

6. The welding device (10) according to claim 1, wherein: The cover (25) is pivotable about a cover axis (32) between the closed position and the open position, and the at least one fan unit (100) is arranged between the cover axis (32) and the process channel (16) in a lateral direction extending transversely to the conveying direction (18).

7. The welding device (10) according to claim 1, wherein: The air channel (114) and the heat exchanger (116) are arranged so that the process gas passes through the heat exchanger (116) before being blown into the process channel (16) and then enters the process channel (16) through a nozzle plate (118).

8. The welding device (10) according to claim 1, wherein: The air channels (122, 125) and the cooling device (136) are arranged such that the process gas is guided along the cooling device (136) comprising a cooling plate (134) after passing through the process channel (16) and before passing through the filter element (142).

9. The welding device (10) according to claim 8, wherein: The cooling plate (134) extends along a cooling plane which extends obliquely to the horizontal (137) and has a drip tray (138) in its vertical lower region.

10. The welding device (10) according to claim 9, characterized in that The filter element (142) extends along a filter plane that extends obliquely to the horizontal line (137).

11. The welding device (10) according to claim 10, wherein: The cooling plane and the filtering plane form an acute angle (144).

12. The welding device (10) according to claim 1, wherein: The air channel (122) is formed and arranged in such a way that the process gas is discharged vertically downward from the process channel (16) via an insertion channel (195) on a side facing away from the at least one fan unit (100).

13. The welding device (10) according to claim 1, wherein: A drawer (126) is arranged in the base body (60), the drawer (126) being able to be pulled out along a pull-out direction (154) extending transversely to the conveying direction (18) and having a bottom (128), a front wall (130) and a rear side (132), wherein an air channel (125) for guiding the process gas, at least one filter element (142) and at least one cooling element are arranged in the drawer (126).

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