DE102019102633B3 - Process for placing components on a workpiece, placement machine - Google Patents

Abstract

The correct feeding of empty component tapes into a waste channel is monitored for errors in an automatic placement machine. Preferably, the machine's PCB camera is used to optically determine the supply and optically visible signs are provided near the waste channel to reference the tape position. If it is determined that the tape is not properly fed into the channel, further pickup of components from that tape is prevented.

Description

This invention relates to a method for placing components on a workpiece and an automatic placement machine for placing components on a workpiece.

Background and state of the art

Currently, SMT / SMD pick and place machines are supplied with components that are housed in component belts for subsequent assembly by a placement head on workpieces, the filled belts being made available to the machine in corresponding modular feeders that are received in corresponding feeder docks in the machine. The component straps are narrow (on the order of cm) and flexible, typically made of plastic or paper material. The tapes comprise a plurality of compartments or pockets along their length, each compartment containing a component. The compartments are covered with masking tape that must be removed to gain access to the components in the compartments at a receiving portion of the feeder. The feeders are used to feed the belt to the machine step by step while the components are being emptied from the compartments.

With this type of system, the empty component belt must be disposed of as soon as the components have been emptied from their compartments. Usually, the empty component tapes are fed to corresponding “empty tape channels” or channels within the machine. The empty band channel, which can be funnel-shaped, connects directly to an outlet opening on the front of the feeder. The empty tapes or blank tapes are first introduced into the channels by advancing the tapes forward and then downward at an angle of approximately 90 degrees to the horizontal. At the distal end of the channel, a cutting device is attached, which cuts the empty tape as required, for example at regular intervals or after using a certain tape length.

US 2018/0 242 485 A1 discloses an automatic placement machine with a plurality of feeder docks for accommodating one feeder each for component belts. Inside a housing of the pick-and-place machine there is an inclined shaft pointing downwards, in which cut, empty component belts can be transferred down onto a conveyor belt, which ensures that the corresponding belt waste is disposed of.

Also US 2017/0 347 502 A1 and US 2003/0 183 347 A1 each disclose an automatic placement machine with a shaft, via which cut, empty component tapes can be disposed of as belt waste for disposal.

When a single feeder is removed from the (loading) machines described above, a long section of tape protrudes from the front of the feeder. If the same belt conveyor is now reinserted into the machine, the operator must cut the empty belt to a certain length so that it can run back into the empty belt channel.

The problem with such systems is that if the tape is not properly inserted into the blank tape channel, the blank tape may reach the processing area of the machine and then cause placement errors. For example, if the tape does not enter the blank tape channel, the blank tape may be conveyed over the top of the channel or even form a tape loop if the tape hangs on the leading edge of the channel and then bends upward. The placement head or its suction nozzles can collide with the blank tape and thus affect the placement. In this case the machine has to be stopped and the error has to be remedied, or in the worst case the assembly head or the suction nozzles have to be replaced. Another possible problem arises when the belt advances further and then reaches the workpiece. This can lead to components that have already been assembled being moved from their correct position. Unfortunately, there can be several reasons for incorrect tape insertion. B. that the operator may not be cutting the tape to the correct length or that the tape is mistakenly positioned incorrectly.

The present invention seeks to alleviate these problems in a reliable and inexpensive manner.

In accordance with the present invention, this goal is achieved by sensing the presence and location of a loose tape and preventing the loose tape from adversely affecting the assembly.

Summary of the invention

1. i) Bereitstellen eines Bestückungsautomaten, wobei der Bestückungsautomat Folgendes umfasst: einen Zubringerabschnitt, der bei Verwendung zur Aufnahme einer oder mehrerer Zubringer an jeweiligen Zubringerdocks angepasst ist, wobei jeder Zubringer betreibbar ist, um dem Bestückungsautomaten ein jeweiliges Band entlang eines jeweiligen Bandweges zuzuführen, wobei das genannte Band eine Vielzahl von Fächern enthält, die entlang des Bands angeordnet sind, wobei jedes Fach mit einer Komponente vorbeladen ist, eine Komponentenaufnahmeanordnung, die zum Aufnehmen von Komponenten von den Bandfächern an einem Aufnahmeabschnitt betreibbar ist, der entlang des Bandweges bereitgestellt ist, eine Bestückungsanordnung zum Bestücken von aufgenommenen Komponenten auf ein Werkstück, und mindestens einen Leerband Kanal an einem distalen Ende des Bandwegs, angepasst, um ein Band nach der Aufnahme von Komponenten von diesem Band zu empfangen;
2. ii) Anschließen von mindestens einem Zubringer mit einem entsprechenden Zubringerdock am Zubringerabschnitt, wobei der Zubringer mit einem Band ausgestattet ist, das mit Komponenten in Fächern davon beladen ist,
3. iii) Betreiben des angeschlossenen Zubringers, um dessen Band entlang des Bandwegs zu fördern,
4. iv) Aufnehmen von mindestens einer Komponente vom Förderband am Aufnahmeabschnitt mit der Komponentenaufnahmeanordnung,
5. v) Verwenden eines Sensors, um automatisch zu bestimmen, ob das Förderband dem Leerband Kanal falsch zugeführt wird, und
6. vi) wenn festgestellt wird, dass das Förderband dem Leerband Kanal falsch zugeführt wird, Verhindern eines weiteren Aufnehmens von Komponenten von diesem Band durch die Komponentenaufnahmeanordnung.

According to a first aspect of the present invention, a method for placing components on a workpiece is provided, comprising the steps:

1. i) Providing an automatic placement machine, the automatic placement machine comprising: a feeder section which, when used for receiving one or more Feeder is adapted to respective feeder docks, each feeder being operable to feed the assembly machine with a respective belt along a respective belt path, said belt containing a plurality of compartments arranged along the belt, each compartment being preloaded with a component , a component receiving arrangement, which is operable for receiving components from the tape compartments on a receiving section which is provided along the tape path, a mounting arrangement for mounting picked components on a workpiece, and at least one empty tape channel adapted at a distal end of the tape path, to receive a band after recording components from that band;
2. ii) connecting at least one feeder with a corresponding feeder dock to the feeder section, the feeder being equipped with a belt which is loaded with components in compartments thereof,
3. iii) operating the connected feeder to convey its belt along the belt path,
4. iv) picking up at least one component from the conveyor belt at the pick-up section with the component pick-up arrangement,
5. v) using a sensor to automatically determine whether the conveyor belt is incorrectly fed to the empty belt channel, and
6. vi) if it is determined that the conveyor belt is incorrectly fed into the empty belt channel, preventing further pick-up of components from this belt by the component receiving arrangement.

According to a second aspect of the present invention, there is provided an automatic pick and place machine for placing components on a workpiece, comprising: a feeder section which, when used to receive one or more feeders, is adapted to respective feeder docks, each feeder being operable to provide a respective one to the pick and place machine Feeding tape along a respective tape path, said tape containing a plurality of compartments arranged along the tape, each compartment being preloaded with a component; a component receiving assembly operable to receive components from the tape compartments at a receiving portion provided along the tape path; a mounting arrangement for mounting picked components on a workpiece; at least one blank tape channel at a distal end of the tape path adapted to receive a tape from the tape path; and a sensor that is operable to automatically determine the presence of a tape in the vicinity of the blank tape channel.

Further specific aspects and features of the present invention are set out in the appended claims.

Figure list

• 1 schematisch einen Bestückungsautomaten gemäß der vorliegenden Erfindung in Schrägprojektion zeigt; und
• 2 schematisch eine vergrößerte Ansicht eines Teils des Zubringerbschnitts des Bestückungsautomaten von 1 zeigt, wenn mit einer Vielzahl von Zubringern ausgestattet.

The invention will now be described with reference to the accompanying drawings (not to scale), in which:

• 1 schematically shows an automatic placement machine according to the present invention in oblique projection; and
• 2nd schematically shows an enlarged view of part of the feeder section of the pick and place machine of FIG 1 shows when equipped with a variety of feeders.

Detailed description of the preferred embodiments of the invention

A pick and place machine 1 according to an embodiment of the present invention is schematically in 1 shown. The pick and place machine 1 is through a frame 2nd that defines the various mechanisms within the pick and place machine 1 supported. The placement process of placing picked components on a workpiece takes place inside the pick and place machine 1 using an assembly arrangement instead. This includes an assembly head 3rd on a portal spanning the interior 4th is mounted. The portal is for this type of machine 4th as shown, movable between the front and back of the interior while the placement head 3rd along the length of the portal 4th is mobile, d. h, between the left and right sides as shown. In this way, the assembly head 3rd can be moved to any side position within the interior. On the assembly head 3rd is a suction nozzle 5 provided for lifting and lowering against the placement head 3rd is operable to move towards and away from a workpiece inside the machine (not shown). The suction nozzles 5 is connected to a vacuum or vacuum source (not shown) so that a component (not shown) is selectively under vacuum to the suction nozzles 5 can be clamped. With this type of pick and place machine 1 the placement assembly may simultaneously be a component pickup assembly operable to pick up components from the tape compartments at a pickup section provided along a tape path, as described in more detail below is described. In other words, the assembly head 3rd with the suction nozzles 5 can be operated to remove one component from a band compartment ( 17th , please refer 2nd ) and then place the recorded component on a workpiece.

It should be noted that there are many different configurations of pick and place machines that can be used in accordance with the present invention. For example, placement heads may include a plurality of suction or suction nozzles, placement heads may be provided in a rotating configuration, a separate pickup assembly could receive components and route them to a placement head, etc., as is known to those skilled in the art.

As is well known in the art, the pick and place machine 1 be equipped with various inspection devices such as optical detectors or cameras to determine the position of a workpiece within the pick and place machine 1 capture (sometimes referred to as a "PCB camera"). and / or to detect the position of components placed on the workpiece relative to the workpiece. In the in 1 The machine shown is the placement head 3rd with such an optical camera 6 fitted. Other cameras can be found elsewhere in the machine 1 be provided.

The pick and place machine 1 is provided with a feeder section that has a plurality of feeder docks 7 each feeder dock 7 is adapted to a single feeder ( 10th , please refer 2nd ) in a modular way. A second feeder section (not shown) can be on the opposite side of the pick and place machine 1 be provided. So that the correct feeder from an operator into the intended feeder dock 7 can be introduced is near the feeder docks 7 a lane marker 8th provided with reference to 2nd is described in more detail below. Between the feeder docks 7 and the bout marker 8th there is an empty channel 14 , an opening which is arranged to receive empty tapes or empty tapes from the or each feeder for subsequent disposal. In alternative machines, there can be separate channels for each feeder.

A control processor 9 is on the pick and place machine 1 for controlling the pick and place operations provided and connected to the or each camera to receive signals therefrom. The control processor 9 may include, for example, a computer, a tablet, or the like.

2nd shows schematically an enlarged view of part of the feeder section of the pick and place machine 1 when equipped with several (here four) feeders 10th that are in the feeder docks " 1 "," 2 "," 4th " and " 6 “Fit in, like the one on the track display 8th specified track numbers 15 displayed.

Every feeder 10th is operable to a respective band 11 , 12 the placement machine step by step along a respective belt path 1 feed. The belt path includes a receiving portion (not shown), typically on an upper surface of the feeder 10th is arranged where it can be accessed by the component receiving assembly, as is known in the art. The ribbon 11 , 12 is advanced in the feeder by a motor assembly (not shown) that feeds the belt 11 , 12 by engaging a variety of drive holes 13 drives which are arranged along the belt. In 2nd are the tapes 11 , 12 shown that from their respective feeders 10th emerge after their components from the local band compartments 17th were recorded at the recording section to in the blank channel 14 to be fed. As shown, however, while the tapes 11 the empty channel 14 correctly fed the tape 12 of the feeder 10th in position " 4th “Incorrectly fed and thus has the empty band channel 14 misses and instead extends over the bout marker 8th out and inside the pick and place machine 1 . It can be seen that when feeding this tape 12 is continued in an uncontrolled manner, this could disrupt the assembly process and / or the workpiece or its components that have already been assembled.

The lane marker 8th is with optically visible reference marks 16 provided, in this case crossing, with a reference mark 16 at each end of each track position. It is in 2nd to see that the tape 12 both reference marks 16 in the track position " 4th “At least partially covered. The reference marks 16 and the track numbers 15 are both optically visible characters that can therefore be detected by an optical sensor such as a camera.

In alternative embodiments, other machine-readable marks may be used instead of reference marks 16 be used.

An exemplary methodology of the present invention will now be described.

First, an operator (optionally a robot system can be used) loads the feeders into the correct feeder docks of an automatic placement machine as required. Ideally, all free ends of the empty tapes are fed to the empty tape channel. However, it is possible that there is an incorrect feed, which can lead to the component tape missing the entrance to the empty tape channel.

Then an assembly process can begin in which components can be picked up from the various feeder belts as required under the control of the control processor and placed on a workpiece. During placement, each belt is carried along its belt path by the feeder.

A sensor is used to automatically determine whether the conveyor belt is mis-fed into the empty belt channel. The sensor used can advantageously be an already existing optical camera in the machine, for example a PCB camera or a component camera. This has the advantage that no additional sensor equipment has to be attached to the automatic placement machine, which reduces costs and complexity. Alternatively, a dedicated sensor can be used. The camera checks the lane display 8th to confirm that all reference marks are visible, thus showing correctly fed tapes. If at least one reference mark is covered, an incorrectly fed tape is displayed. The identity (ie, the track position) of the tape can be confirmed, for example, by optically detecting the track numbers near the hidden reference marks or by using knowledge of the camera position when the hidden reference marks are detected. Display signals from the camera are forwarded to the control processor, which prevents further pick-up of components from the identified tape by the component pick-up arrangement, at least until an operator can solve the problem, for example. It will be appreciated that when a tape is stopped picking up, the tape will no longer advance and thus cannot move into an area that may adversely affect the loading.

This acquisition step is preferably repeated for each band after a predetermined number of components have been picked up from that band by the component containment assembly, which is controlled by the control processor.

Reference symbol list

1 -

Pick and place machine

2 -

frame

3 -

Assembly head

4 -

portal

5 -

Suction nozzles

6 -

PCB camera

7 -

Feeder docks

8th -

Lane display

9 -

Control processor

10 -

Feeder

11 -

Tape (correctly fed)

12 -

Tape (incorrectly fed)

13 -

Drive hole

14 -

Blank tape channel

15 -

Track number

16 -

Reference mark

17 -

Tape compartment

Claims (14)

A method for placing components on a workpiece, comprising the steps of: i) providing an automatic placement machine, the automatic placement machine comprising: a feeder section which, when used to accommodate one or more feeders, is adapted to respective feeder docks, each feeder being operable, to feed the assembly machine a respective tape along a respective tape path, said tape containing a plurality of compartments arranged along the tape, each compartment being preloaded with a component, a component receiving arrangement for receiving components from the tape compartments a pickup section is operable provided along the tape path, a pick and place assembly for picking up picked components onto a workpiece, and at least one blank tape channel at a distal end of the tape path adapted to pick up a tape after picking up components from d to receive this band; ii) connecting at least one feeder with a corresponding feeder dock to the feeder section, the feeder being equipped with a belt loaded with components in compartments thereof, iii) operating the connected feeder to convey its belt along the belt path, iv) Picking up at least one component from the conveyor belt at the receiving section with the component receiving arrangement, v) using a sensor to automatically determine whether the conveyor belt is incorrectly fed to the empty belt channel, and vi) if it is determined that the conveyor belt is incorrectly fed into the empty belt channel, preventing further pick-up of components from this belt by the component receiving arrangement. The procedure after Claim 1 , wherein the pick and place machine comprises an optical detector and step v) comprises operating the optical detector to determine whether the conveyor belt is incorrectly fed to the empty belt channel. The procedure after Claim 2 , wherein the placement machine has optically visible characters in the vicinity of the blank channel, and wherein step v) comprises determining whether the characters are visible to the optical detector. The procedure according to one of the Claims 2 to 3rd , wherein the optical detector comprises a workpiece camera, which is operable to detect the position of a workpiece within the pick and place machine. The procedure according to one of the Claims 2 to 4th , wherein the optical detector has a camera that is operable to detect the position of components arranged on the workpiece relative to the workpiece. The procedure according to one of the Claims 1 to 5 wherein step v) is repeated for the or each conveyor belt after a predetermined number of components have been picked up from the conveyor belt by the component receiving assembly. The procedure according to one of the Claims 1 to 6 , wherein the pick and place machine has a control processor which can be operated to control the component receiving arrangement. The procedure after Claim 7 wherein the control processor is operable in step vi) to prevent the component take-up assembly from picking up components from the incorrectly fed tape. The procedure according to one of the Claims 7 or 8th , in which the control processor is adapted to receive signals from the sensor which indicate the feed of the conveyor belt to the empty belt channel. An automatic placement machine for placing components on a workpiece, comprising: a feeder section adapted to accommodate one or more feeders on respective feeder docks, each feeder being operable to feed a respective ribbon to the pick and place machine along a respective ribbon path, said ribbon containing a plurality of compartments running along the ribbon are arranged, each compartment being preloaded with a component; a component receiving assembly operable to receive components from the tape compartments at a receiving portion provided along the tape path; a mounting arrangement for mounting picked components on a workpiece; at least one blank tape channel at a distal end of the tape path adapted to receive a tape from the tape path; and a sensor that is operable to automatically determine the presence of a band near the empty band channel. The pick and place machine after Claim 10 , wherein the sensor comprises a workpiece camera, which is operable to detect the position of a workpiece within the pick and place machine. The pick and place machine according to one of the Claims 10 and 11 , wherein the sensor comprises a workpiece camera, which is operable to detect the position of components arranged on the workpiece relative to the workpiece. The pick and place machine according to one of the Claims 10 to 12 , comprising optically visible signs in the vicinity of each empty band channel, the optically visible signs for the respective empty band channels being clearly identifiable. The pick and place machine according to one of the Claims 10 to 13 comprising a control processor adapted to receive signals from the sensor indicative of the presence of a tape in the vicinity of the blank tape channel and operable to control the component containment assembly.

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