EP3651929A1

EP3651929A1 - Soldering device, soldering system and method

Info

Publication number: EP3651929A1
Application number: EP18735574.8A
Authority: EP
Inventors: Meinrad Eckert; Stefan Voelker
Original assignee: Ersa GmbH
Current assignee: Ersa GmbH
Priority date: 2017-07-11
Filing date: 2018-07-02
Publication date: 2020-05-20
Also published as: CN110869155B; US20200156168A1; DE102017115548A1; DE102017115548B4; WO2019011686A1; CN110869155A

Abstract

The invention relates to a soldering device for removing solder pearls and/or solder balls from the lower face of a printed circuit board, in particular a soldering device for a soldering system for a selective wave soldering process, comprising a brush device for removing solder pearls and/or solder balls from the lower face of a printed circuit board. The brush device has a brush which can be driven about a drive axis and which is designed to remove the solder pearls and/or solder balls, wherein a moving device is provided, said brush device being arranged on the moving device such that the brush device can be moved relative to the printed circuit board in the direction of an X, Y, and Z axis.

Description

Title: Soldering device, soldering and process

description

The invention relates to a soldering device for removing solder balls and / or solder balls from a lower side of a printed circuit board, in particular a soldering device for a soldering system for selective wave soldering, with a

Bürsteinrichtung for removing solder balls and / or

Lotkugeln from the underside of the circuit board, wherein the Bürsteinrichtung one driven about a drive axis

Brush has, which is designed for removing the solder balls and / or solder balls.

When soldering assemblies, especially when soldering power strips and other comparable components, which can be inserted through a printed circuit board and soldered to the bottom of the circuit board, on the underside of the circuit board small solder balls or

Adhere solder balls, which can lead to failures over the life of the circuit board, for example. When the solder balls or solder balls peel off over time. By detached solder balls or solder balls can

Short circuits occur which lead to a failure of the

can lead electronic assemblies.

Therefore, the removal of the solder balls or solder balls from the bottom of the circuit board is desirable.

Devices of the type mentioned are therefore already known from the prior art. In this case, solder balls or solder balls with a rotating cylindrical

Brush roller, which has bristles on its lateral surface, removed from an underside of a circuit board, while the circuit board is driven in the machine direction by a system, for example. By a soldering for selective wave soldering, so that the circuit board is moved relative to the fixed brush roller. With such brush rollers, however, no targeted removal of solder balls and solder balls is possible because always the entire

Bottom of the circuit board with the lateral surface of the

Brush roller comes into contact, so that the entire

Is brushed down the bottom of the circuit board.

Moreover, it is known from the prior art to remove solder balls and solder balls at an underside of a printed circuit board only at the points at which also soldered has been. The components along the soldered paths from the bottom of the circuit board with a

Hand brush brushed off. In this case, the brush is used only in soldered areas, so that not the entire bottom of the circuit board must be brushed. However, it has been found in this manual brushing disadvantageous that the abzubürstende underside must face a worker for the brushing step, so that the entire circuit board must be rotated by 180 °. However, it can not be ruled out that brushed or removed solder balls or solder balls in cracks and gaps of the components or in cracks and

Columns between components and circuit board can remain. Such remaining in cracks and columns

Solder beads and solder balls can also lead to failures in the course of the life of the circuit board, for example. When the solder balls or solder balls over time

peel off. By detached solder balls or solder balls can cause short circuits, resulting in failure of the

electronic assemblies can led.

The invention is therefore based on the object, a

Possibility to provide a simple, safe and automated removal of solder balls and / or

Solder balls from a bottom of a circuit board

allows.

This object is achieved by a soldering device with the

Characteristics of claim 1 solved. Such

Soldering device is characterized in that a Moving device is provided, the

Bürsteinrichtung on the shuttle so

is arranged to be relative to the circuit board in

Direction of an X, Y and Z axis, in particular

automated, movable. An X, Y and Z axis are axes of an axis system, as is commonly used in machine tools, in which all axes are arranged orthogonal to one another.

Advantageously, the X- and Y-axis are arranged parallel to the circuit board, so that a method of

Bürsteinrichtung in through the X and Y axis

spanned X-Y plane leads to a relative displacement of Bürsteinrichtung to the circuit board, wherein a distance in the direction of the Z-axis remains unchanged. This distance in the direction of the Z-axis can then by a

Brush direction method to be changed in the Z-axis direction.

According to a first advantageous embodiment of

Soldering device is provided that the traversing device is a portal system.

It is conceivable that the gantry system has at least one X-axis drive, which is used to move the

Brushing along the X-axis is formed, wherein the gantry system has at least one Y-axis drive, which is designed for movement of the Bürsteinrichtung along the Y-axis and wherein the gantry system has at least one Z-axis drive, which is used to move the

Bürsteinrichtung along the Z-axis is formed. there For example, it is conceivable that the axis drives are arranged to be movable towards each other, so that a

Method of Y-axis drive leads to a displacement of the X-axis drive and arranged on the X-axis drive Z-axis drive in the direction of the Y-axis, wherein a

Moving the X-axis drive leads to a displacement of the X-axis drive arranged Z-axis drive in the Z-axis direction. Advantageously, the axis drives as

Linear drives, in particular as chain drives,

Spindle drives, ball screws, roller screw drives Linear direct drives, hydraulic cylinders and / or

Pneumatic cylinders are formed.

According to a further advantageous embodiment of the

Soldering device is provided that the traversing device is a manipulator of a robot. It is conceivable that the Bürsteinrichtung at a free end of a

Robot arm of an industrial robot is arranged.

Another particularly advantageous embodiment of

Soldering device is characterized in that the

Brushing a brush drive, which is designed to generate an oscillating rotational movement of the brush. The generation of an oscillating

Rotational motion has proven to be particularly effective for the removal of the solder bumps and / or solder balls from the underside of the circuit board. It is conceivable that the brush drive as an electric or pneumatic drive is trained. The drive is advantageously designed such that the brush is oscillating

Performs rotational movements with a frequency of about 50 Hz to about 400 Hz, preferably at a frequency of about 250 Hz. According to a particularly advantageous

Further development, the drive is designed such that it oscillates at a voltage of 24 volts 14000

Movements per minute (this corresponds to approximately 230 Hz) performs, the oscillation speed through

Control of the voltage between 0 and 24 volts is adjustable. However, it is also conceivable that the drive the

Brush does not oscillate drives, but the brush in a rotational movement in the clockwise direction or opposite offset.

To make a destruction of on the

Printed circuit board arranged electronic components

To prevent it, it has proven to be advantageous if the Bürsteinrichtung for the derivation of

electrostatic discharges is formed. Thus, occurring electrostatic discharges on the

Bürsteinrichtung be derived without causing it

Destruction of components due to electrostatic discharges comes.

It is particularly preferred when the brush

having electrically conductive bristles. It is conceivable that the bristles made of a so-called ESD plastic (electrostatic discharge plastic) are. However, it is also conceivable that the brush comprises bristles of electrically conductive carbon.

In order to enable a safe dissipation of electrostatic discharges, it has proved to be advantageous

proven when the brush is electrically connected to a ground terminal of the soldering device.

According to a further advantageous embodiment of the

Soldering device is provided that the brush a

Having orthogonal to the drive axis arranged brushing surface, wherein the brushing surface is circular or annular. Advantageously, the brush is cylindrically shaped, i. the bristles of the brush extend cylindrically in the direction of the drive axis. To ensure a reliable removal of solder bumps and / or even in small structures

To allow solder balls on the underside of the circuit board, it has proven to be advantageous if the brush has a brush diameter in the range of about 1 mm to about 40 mm, preferably in the range of about 6 mm to about 20 mm.

Furthermore, it is advantageous if a

Winkelverstelleinrichtung is provided, the

Adjustment of a machining angle of the Bürsteinrichtung is formed in the range of about 0 ° to about 20 ° to the Z-axis. An angle of rotation is understood to mean an angle between the drive axis of the brushing direction and the Z axis of the travel device. By adjusting the machining angle, the brush surface depending on the space conditions on the underside of the circuit board are positioned relative to the circuit board or to the inserted through the circuit board contact pins, so that a particularly reliable removal of solder balls and / or solder balls can be made possible.

In order to enable an adjustment of the machining angle automatically, it is conceivable that the

Angle adjustment at least one electric servomotor comprises. However, it is also conceivable that the angle adjustment is done manually.

A further advantageous embodiment of the soldering device provides that a collecting container is provided, which is designed for collecting solder balls and / or solder balls removed from the underside of the printed circuit board. Advantageously, the collecting container is cup-shaped and concentric with the drive axis of the

Brush direction arranged. Thus, a flying around of the removed by the Bürsteinrichtung solder balls and / or solder balls can be prevented by using the collection container. In addition, can simultaneously

prevents remote solder balls and / or

For example, lead solder balls to contamination in the working space of a soldering system for selective wave soldering. To one

To be able to prevent ejection of already collected solder balls and / or solder balls, it is conceivable that the collecting container is not motion-coupled with the brush. It is particularly preferred if a

Suction device is provided, which is designed to generate a negative pressure in the collecting container. Thus, remote solder balls and / or solder balls under

Use of the suction device are sucked and thus be safely collected by means of the collecting container.

The above-mentioned object is further achieved by a soldering system for selective wave soldering, comprising a

Soldering device according to at least one of claims 1 to 14.

The object mentioned at the outset is furthermore achieved by a method for removing solder balls and / or solder balls from a lower side of a printed circuit board,

in particular by a method for operating a

Soldering system according to claim 15, wherein solder beads and / or

Solder balls are removed from the underside of the circuit board with a brush that has an oscillating

Performs rotational movement, wherein the brush relative to

Printed circuit board is automatically moved in the direction of the X, Y and / or Z axis.

Further details and advantageous developments are apparent from the following description, with reference to which an embodiment of the invention is described and explained in detail.

Show it: Figure 1 is a schematic side view of a

Bürsteinrichtung a inventive

Soldering device for removing solder balls and / or solder balls from an underside of a

Printed circuit board; and

Figure 2 is a schematic side view of a

Soldering device according to the invention for removal

Lot beads and / or solder balls of one

Bottom of a circuit board

1 shows a brushing device 10 of a soldering device 12 according to the invention shown in FIG. 2 for removing solder balls and / or solder balls from a lower side of a printed circuit board 14 shown in FIG. 2 in a schematic side view. FIG. 2 shows a schematic

Side view of the soldering device 12 according to the invention. In FIG. 2, above the soldering device 12, the printed circuit board 14 is shown, through which from a top side 16 a

electronic component 18 is inserted with its contact pins 20 and which is soldered from a bottom 22 of the circuit board 14 with this, for example. By selective wave soldering in a soldering system, not shown in the figures for selective wave soldering.

On the underside 22 of the printed circuit board 14 adhere in the region of the contact pins 20 small solder balls and / or solder balls 24, which have been generated by a solder wave in the selective wave soldering. These so-called solder balls and / or solder balls 24 are undesirable and can in the course of Life of the circuit board 14 lead to failure of the circuit board 14 and the component 18, if they peel off over time. Detached solder balls and / or solder balls 24 can lead to short circuits, which can lead to destruction of an electronic component 18.

The soldering device 12 is a total for removing the

Lot beads and / or solder balls 24 from the bottom 22 of the circuit board 14 and can be designed in particular to be installed in a soldering system, not shown in the figures for selective wave soldering.

The soldering device 12 has the one shown in FIG

Brushing direction 10 on. The brushing device 10 in turn has a brush 28 that can be driven about a drive axis 26 and that is designed to remove the solder balls and / or solder balls 24. The brushing device 10 has a brush drive 30, which is designed to generate an oscillating rotational movement of the brush 28 about the drive axis 26. The brush drive 30 is designed as an electric drive, the brush 28 oscillating during operation

Performs rotational movements with a frequency of about 50 Hz to about 400 Hz, preferably at a frequency of about 250 Hz. Advantageously, the brush drive 30 is designed such that it performs at a voltage of 24 volts 14000 oscillating movements per minute (this corresponds to approximately 230 Hz), wherein the Oscillation speed is adjustable by regulating the voltage between 0 and 24 volts.

The brush 28 has an orthogonal to the drive axis 26 arranged brushing surface 32 which is circular (see Figure 1). The brush 28 is cylindrical

formed, i. the bristles 34 of the brush 28 extend cylindrically in the direction of the drive axis 26. In FIGS. 1 and 2, the bristles 34 are shown only schematically. The brush 28 has a brush diameter 36 in the range of about 1 mm to about 40 mm, preferably in the

Range of about 6 mm to about 20 mm, so that even in small structures and crowded conditions on the

Bottom 22 of the circuit board 14 a reliable

Removal of solder balls and / or solder balls 24 can be made possible.

To make a destruction of on the

To be able to prevent printed circuit board 14 arranged electronic components 18, the Bürsteinrichtung 10 for

Derivative of electrostatic discharges formed. Thus occurring electrostatic discharges can be dissipated via the brushing device 10, without the destruction of components 18 due to the electrostatic discharges.

In this case, the brush 28 on electrically conductive bristles 34, which consists of a so-called ESD plastic

(electrostatic discharge plastic) or made of electrically conductive carbon or this at least include. The brush 28 and its bristles 34 are connected to a ground terminal of the soldering device 12 and a

Ground terminal of a not shown in the figures

Soldering system for selective wave soldering electrically connected.

Concentric with the drive axis 26, a collecting container 38 is provided, which for collecting the remote from the bottom 22 of the circuit board 14 solder balls and / or

Lotkugeln 24 is formed. The collecting container 38 is cup-shaped and surrounds the brush 28 in

Circumferential direction, i. orthogonal to the drive axis 26 at least partially, so that a flying around of the means of the Bürsteinrichtung 10 remote solder balls and / or

Solder balls 24 can be prevented by using the collecting container 38. In addition, it can be prevented at the same time that removed solder balls and / or

Solder balls 24 lead to contamination eg. In the working space of a soldering for selective wave soldering. To one

To be able to prevent ejection of already collected solder balls and / or solder balls 24, it is also conceivable that the collecting container 38 is not coupled in motion with the brush 28. It is conceivable that the collecting container 38 is arranged on a hollow shaft which is connected to the drive 30, wherein a drive shaft 28 driving the drive shaft may be guided through the hollow shaft.

It is conceivable that a suction device 37 is provided, which is designed to generate a negative pressure in the collecting container 38. The suction device 37 can thereby For example, include a vacuum pump and be connected to the collecting container 38 by means of a hose 39. Thus, remote solder balls and / or solder balls 24 can be sucked off using the suction device 37 and thus be safely collected by means of the collecting container 38.

As can be clearly seen in Figure 2, is the

Bürsteinrichtung 10 arranged on a trained as a portal system traversing device 40 such that it is relative to the circuit board in the direction of an X, Y and Z-axis 42, 44, 46 movable. The X-axis is by the

Double arrow 42, wherein the Y-axis is indicated by the double arrow 44 and wherein the Z-axis is indicated by the double arrow 46. An X, Y and Z axis 42, 44, 46 means axes of an axis system, as is commonly used in machine tools and in which all axes are arranged orthogonal to one another. Advantageously, the X and Y axes 42, 44 are parallel to the printed circuit board 14

arranged so that a method of the Bürsteinrichtung 10 in the spanned by the X and Y axis 42, 44 XY plane leads to a relative displacement of the brushing direction 10 to the circuit board 14, wherein a distance in the direction of the Z-axis 46 unchanged remains. This distance in the direction of the Z-axis 46 can then be changed by a method of brushing direction 10 in the direction of the Z-axis 46. The portal system 40 includes two Y-axis drives 48, an X-axis drive 50, and a Z-axis drive 52. The X-axis drive 50 is configured to move the brushing direction 10 along the X-axis 42. The Y-axis drives 48 are for moving the Bürsteinrichtung 10 along the Y-

Axis 44 is formed. Further, the Z-axis drive 52 is configured to move the brushing direction 10 along the Z-axis 46. The trained as linear actuators

Axle drives 48, 50, 52 are so mutually

movably arranged that a method of Y-

Axial drives 48 leads to a displacement of the X-axis drive 50 and arranged on the X-axis drive 50 Z-axis drive 52 in the direction of the Y-axis 44, wherein a method of the X-axis drive 50 to a displacement of the arranged on the X-axis drive 50 Z -Axis drive 52 in the direction of the X-axis 42 leads.

By using a portal system 40, it is conceivable to install the device 12 in an existing soldering system for selective wave soldering with a separate portal system 40. However, it is also conceivable that

Bürsteinrichtung 10 in a soldering for selective

Equip wave soldering, which has two separately movable solder pot, wherein instead of a second solder pot, the Bürsteinrichtung 10 is provided.

To the brush 28 even in confined spaces on the bottom 22 of the circuit board 14 relative to

To be able to position the printed circuit board 14 or to the contact pins 20 inserted through the printed circuit board 14 and thus to enable a reliable removal of solder balls and / or solder balls 24 is a

Angle adjustment 54 with an electric

Actuator provided for the adjustment of a

Machining angle of the Bürsteinrichtung 10 in the range of about 0 ° to about 20 ° to the Z-axis 46 in the direction of

Double arrow 56 is formed. Under a

Machining angle is an angle between the

Drive axle 26 of the Bürsteinrichtung 10 and the Z-axis of the shuttle 40 understood.

In operation, the brush 28 of the brushing 10 is automated, for example. CNC controlled by means of

Portal system 40 along the contact pins 20 so that solder balls and / or solder balls 24 can be removed from the bottom 22 of the circuit board 14.

Overall, a possibility can be realized with the soldering device 12, with which a simple, safe and automated removal of solder balls and / or solder balls 24 from a bottom 22 of a printed circuit board 14 can be made possible.

Claims

claims

1. Soldering device (12) for removing solder balls

and / or solder balls (24) from a lower side (22) of a printed circuit board (14), in particular soldering device (12) for a selective wave soldering machine, with a brushing device (10) for removing the solder balls and / or solder balls (24) from the Underside (22) of the printed circuit board (14), wherein the Bürsteinrichtung (10) has a driven about a drive axis (26)

Brush (28) which is designed for removing the solder balls and / or solder balls (24), characterized in that a traversing device (40) is provided, wherein the Bürsteinrichtung (10) on the traversing device (40) is arranged such that it is movable relative to the printed circuit board (14) in the direction of an X, Y and Z axis (42, 44, 46).

2. soldering apparatus (12) according to claim 1, wherein the

Moving device (40) is a portal system.

3. soldering device (12) according to claim 2, wherein the

Gantry system (40) comprising at least one X-axis drive (50) adapted to move the brushing direction (10) along the X-axis (42), the gantry system (40) comprising at least one Y-axis drive (48) for movement of the brushing direction (10) along the Y-axis (44) is formed and wherein the portal system (40) at least one Z- Axis drive (52) for moving the Bürsteinrichtung (10) along the Z-axis (46)

is trained.

4. soldering apparatus (12) according to claim 3, wherein the

Axle drives (48, 50, 52) as linear drives, in particular as chain drives, spindle drives, ball screw drives, roller screw drives

Linear direct drives, hydraulic cylinders and / or pneumatic cylinders are formed.

5. soldering device (12) according to claim 1, wherein the

Traversing device (40) is a manipulator of a robot.

6. soldering device (12) according to at least one of

previous claims, wherein the Bürsteinrichtung (10) comprises a brush drive (30) which is adapted to generate an oscillating rotational movement of the brush (28).

7. soldering device (12) according to at least one of

previous claims, wherein the Bürsteinrichtung (10) is designed for discharging electrostatic discharges.

8. soldering device (12) according to at least one of

previous claims, wherein the brush (28) comprises electrically conductive bristles (34).

9. soldering device (12) at least one of the preceding claims, wherein the brush (28) with a Ground terminal of the soldering device (12) is electrically connected.

10. soldering device (12) according to at least one of

previous claims, wherein the brush (28) arranged orthogonal to the drive axis (26)

Brushing surface (32), wherein the brushing surface (32) is circular or annular.

11. soldering device (12) according to at least one of

previous claims, wherein a

Angle adjusting device (54) is provided, which for adjusting a machining angle of

Bürsteinrichtung (10) is formed in the range of about 0 ° to about 20 ° to the Z-axis (46).

12. Soldering device (12) according to claim 11, wherein the

Angle adjusting device (54) comprises at least one electric servomotor.

13. soldering device (12) according to at least one of

previous claims, wherein a collecting container (38) is provided, which for collecting from the underside (22) of the printed circuit board (14) removed

Lot beads and / or solder balls (24) is formed.

14. soldering device (12) according to claim 13, wherein a

Suction device is provided, which is designed to generate a negative pressure in the collecting container. A soldering system for selective wave soldering, comprising a soldering device (12) according to at least one of the preceding claims.

Method for removing solder balls and / or

Lotkugeln (24) from a bottom (22) of a

Printed circuit board (14), in particular method for

Operating a soldering system according to claim 15, wherein solder balls and / or solder balls (24) are removed from the underside of the printed circuit board (14) with a brush (28) which performs an oscillating rotational movement, wherein the brush (28) relative to

Printed circuit board (14) is moved automatically in the direction of the X, Y and / or Z axis.