DE19962693A1 - Process for assembling electrical components and automatic placement machine for electrical components - Google Patents

Abstract

The invention relates to a method for placing electric components and to a pick-and-place robot for electric components. The aim of the invention is to increase as much as possible the throughput rate of printed boards (16) in an SMD pick-and-place robot (10). To this end, several printed boards (16) are combined to a sub-assembly (30) and are provided jointly with the components in a pick-up station (22). By combining several printed boards it is possible to save some of the steps required for insertion into and withdrawal from the pick-up station (22). The sub-assembly (30) is preferably re-divided into its individual printed boards (16) in order to facilitate an as easy a handling as possible of the printed boards (16) in the subsequent process steps.

Description

The invention relates to a method for populating elek trical components, especially of printed circuit boards, and egg NEN placement machine for electrical components, especially egg SMD placement machine (surface mounted device) for conductors plates.

Such an SMD placement machine enables automatic and quick assembly of electrical components, such as. B. Circuit boards. These are made with electrical components that from simple electronic components to complex ones IC chips are sufficient to build a circuit arrangement pieces.

In the assembly process, a printed circuit board is created using egg nes conveyor belt brought into an assembly area. The lei during assembly, the terplatte rests in the assembly area, where with the help of an assembler becomes. This takes the electrical components from one dimension magazine and brings it to the circuit board for the position provided for each component. After loading the printed circuit board is removed from the assembly area drive. The length of time for the assembly process of a ladder plate is determined by the actual assembly time plus the time it takes to get the PCB in to move the assembly area in and out of it. The The placement process using the SMD placement machine is a routine pro process in which the highest possible placement rate is striven for becomes. The aim is to have one as possible per unit of time to manufacture a large number of circuit board arrangements gene.

The invention has for its object a high placement rate, d. H. to enable a high PCB throughput.

The object is achieved according to the invention by a method ren for equipping electrical components, in particular for assembling printed circuit boards, the components using a Conveyor belt to an assembly area of an automatic placement machine out there and equipped with components, and where several components combined into a component group and who assemble together as a component group in the assembly area the.

So there are several components (circuit boards) in the loading piece area introduced and there within a work process gangs loaded at the same time. Under "at the same time" is here understand that the assembly of these into one component group of combined components without the intermediate process the retraction or extension of a circuit board in the or from the assembly area. The generating or the The assembly of the component group is done by stringing together individual loose components. In particular, these components pushed together.

This idea of grouping several components into one construction subgroup is based on the consideration that an assembly tomato to carry out such a procedure usually is designed for different circuit board sizes. This also means that in a large part of the cases the by the placement machine with a structurally determined placement area is significantly larger than the circuit board to be assembled. At Current placement processes will depend on the placement area because only a single component is retracted, then be pieces and extended again. Here under component is a unified, one-piece component understood, which under Under certain circumstances have several identical circuit arrangements can.  

By grouping several components into one component group according to the new process in which the individual components are loose are summarized, at least some of the hardships are eliminated manoeuvrable entry and exit processes into and out of the loading area piece area. Overall, this results in a reduction the necessary length of time, i.e. an increase in the number of pieces rate.

The amount of time saved depends in particular according to how many components are combined in a component group can be grasped so that the component group is still in the Placement area fits. With today's placement machines is the usual in the case of normally complex printed circuit boards Assembly time in about 30 s, while the entry and exit times each because it takes about 2 s. With the described procedure can therefore with such standard printed circuit boards and each according to the size of the assembly area and the size of the PCB Achieve around 10% time savings without further ado. The Time savings increase with the number of beers at the same time PCB process retracted and populated. This means considering the mass production of printed circuit boards a clear economic advantage over that conventional process, in which only one component in each Placement area is retracted.

The components are preferably already before they are retracted summarized in the assembly area to the component group. This also contributes to time savings, since the components be already introduced as a component group in the assembly area that and the component group there do not correspond to under the time needs to be put together. Before the placement The area is in particular a collection or buffer zone intended.

For simple and safe assembly of the component group is preferably a stop element in the transport route guided the components, for example inserted or inserted  pivots. The stop element prevents a first component from becoming white tertransport, so that a subsequent second component to first unlocks. The components thus become a building subgroup pushed together.

In a preferred embodiment, the construction sub-group a first and a subsequent second sub-band of the conveyor belt provided independently are driven in such a way that - based on the Trans port direction - upstream first subband with higher trans port speed than the subsequent second subband is driven. In particular, the transport speed of the second conveyor belt zero. Because of the different This means that several speeds are pushed together Components achieved in a component group.

The component group is preferably returned after assembly separated into their individual components. This enables in front partial implementation of the method in the best existing systems, since the components for machining processes in Connection to the assembly process again as individual components and thus un compared to a conventional method changed. This applies, for example, to control Quality control facilities unchanged can be maintained.

Another is preferably used to separate the component group Subband following the assembly area with a height transport speed than that in front of it Subband operated. The upstream sub-band is an example as the second sub-band mentioned, which also serves as mines band is called and the transport of the component in the loading part area takes over. The upstream subband is in front preferably, however, an edition following the middle band band to which the further sub-band follows. The parting functionality is therefore completely out of the assembly area outsourced. This has a positive effect on the time required  because the component group as such emerged from the assembly area will drive. It is particularly important to separate the component group special provided that the upstream sub-band completely dig stops. Due to the different transport speeds the individual components pulled apart.

In order to use the Be to achieve the specified placement area the number of components of a component group more advantageous in particular chosen such that the total length of the Component group as close as possible to the length of the assembly area reaches. The achievement of the defined Ge total length preferably monitored by a sensor to detect an interference enable smooth and automatic operation. By the fullest possible utilization of the placement area in addition to saving the entry and exit times a reduction in the time required for the actual loading piece process reached. Because due to the larger number of Components can have a larger number of components Record elements of the same type at the same time. Reduce it the path of the assembler to the individual maga interest rates for the different types of components.

To ensure high positioning accuracy of the components in the Be to achieve pieces, it is preferred that the Position of each individual component of the component group in the loading piece area in particular optically detected.

The process control is used to carry out the process compared to a conventional process control modified so that the component group as a unit is viewed with multiple subunits, the sub units are assigned to the individual components. For the The controller accordingly provides a circuit board Component group represents a single circuit arrangement, the  in mostly identical sub-switching groups of the one divides individual circuit boards.

The task is still solved by a placement machine ten for electrical components, in particular an SMD assembly automat for printed circuit boards, with an assembly area, which the Components can be fed on a conveyor belt, wherein in Transport route of the components a collecting device to the group ren several components to a component group is provided, and the individual components of the component group in the Be piece area can be populated together.

For the placement machines, these are in terms of the procedure Ren mentioned advantages and special embodiments make sense according to transfer. Further preferred configurations of the Automatic placement machines can be found in the subclaims.

Embodiments of the invention are described below the drawing explained in more detail. They each show in schematic shear and roughly simplified representation:

Fig. 1 is a schematic diagram of a placement line,

Fig. 2 is a partial placement area shown with mounter

Fig. 3 shows a section of a placement machine line in the placement area with a placement device and

Fig. 4 shows a section of a placement machine line in the placement area with several placement devices.

In the figures, parts with the same function have the same loading provide traction marks.

According to Fig. 1 has a placement line 2, in particular an SMD line (Surface Mounted Device-line), a transport belt 6 port direction in Trans 4 to each other below a screen printing device 8, a placement machine 10, egg nen furnace 12 and a Nachlöt Device 14 . Components to be assembled, in particular printed circuit boards 16 , are guided continuously via the conveyor belt 6 through the loading line 10 line 2 in the transport direction 4 . In this case, solder paste is applied to the printed circuit boards 16 by means of a screen printing method in the screen printing device 8 . At the screen printing device 8 is followed by a control area 18 , in which a visual inspection is carried out in particular. After passing through the control area 18 , the printed circuit boards 16 arrive in the automatic placement machine 10 . In the embodiment example according to FIG. 1, this has three consecutive placement devices 21 in a placement zone 20, each with a placement area 22 . In Fig. 1, a herkömm Licher placement process is shown in which only one circuit board 16 is arranged in each of the placement areas 22nd

After the circuit board 16 has been assembled in the automatic placement machine 10 , the circuit board 16 is guided through the oven 12 , where the solder paste is heated for good electrical contacting. If necessary, a faulty solder joint can be repaired in the post-soldering device 14 . The Nachlöt-Vorrich device 14 is part of a further control area 18 , within which, in particular, a visual inspection of the now fully populated circuit board 16 is carried out.

The assembly process in the assembly area 22 in one of the assembly devices 21 is described with reference to FIG. 2. In Fig. 2, the novel method is already indicated, according to which two Lei terplatten 16 are combined to form a circuit board or component group 30 . The circuit boards 16 are equipped with a component 24 with electrical components 26 under different types. For this purpose, the assembler 24 picks up the components 26 from a component magazine 28 and presses the respective component 26 into the solder paste at the location provided for the component 26 on the printed circuit boards 16 . The placement device 24 can be moved within the placement area 22 with the aid of a driving mechanism 34 . Its path covers magazine 28 and component group 30 . The placement device 24 is designed to accommodate a number of components 26 at the same time. The placement device 24 usually comprises a so-called turret head 36 . For the trans port of the circuit boards 16 , the conveyor belt 6 according to the illustrated embodiment comprises two spaced apart transport strands 37 on which the printed circuit boards 16 rest.

According to Fig. 3 the circuit boards are transported 16 after leaving the screen printing device 8 from the conveyor 6 to an input area 38, where processing of a Sammelvorrich 40, which is shown in broken lines, are grouped into a group consisting of two circuit boards 16 member group 30. The collecting device 40 extends into the placement device 21 and comprises a stop element 42 . This can be retracted or swiveled into the transport path, so that the circuit boards 16 are stopped by the stop element 42 . When the conveyor belt 6 is running, the circuit boards are pushed together in front of the stop element 42 , and the component group 30 is formed. The collection device 40 further includes a sensor 44, the total length reaching an adjustable Ge G of the assembly 30 monitors and a corresponding signal via a signal line 46 to a process controller (not shown) passes, ge whereupon the conveyor belt 6 stops is. In the present case, the total length G corresponds to the available length L of the assembly area 22 . The length L which is structurally determined by the placement machine 10 is therefore optimally used according to the exemplary embodiment. In the case of smaller circuit boards 16 or also in the case of a larger assembly area 22 , the component group 30 is preferably composed of more than two circuit boards 16 .

Referring to FIG. 3 for the placement area 22 as a further collection device, a second stop member 47 is provided. A component group 30 that is as compact as possible is thus achieved. Under certain circumstances, the component group 30 , which is composed of loosely arranged circuit boards 16 , is pulled apart somewhat when driving into the mounting area 22 .

The assembly area 22 is followed by an output area 48 which at least partially extends into a separating device 50 shown in dashed lines. In this, the printed circuit boards 16 of the component group 30 are separated from one another again, so that they are available as separate units for the further process. For this purpose - as shown in FIG. 3 - a separating element 52 can be provided for this purpose, which can be moved into the transport path between a first and a second subsequent circuit board 16 of a component group 30 and prevents the subsequent circuit board 16 from further transport. The separation of the component group 30 is preferably monitored in the separation device 50 via a further sensor 54 , which is also connected to the process control via a further signal line 56 .

The assembly of the component group 30 in the collecting device 40 and their separation in the separating device 50 is carried out either via the stop element 42 or the separating element 52 or alternatively or in combination with a special control of different sub-belts of the conveyor belt 6 , as will be described below . Before preferably the component group 30 is generated with the aid of the stop element 42 without a special control of the transport speeds of the sub-belts, and the separation with the aid of different transport speeds of the sub-belts without the separating element 52 .

A first sub-band, the so-called input band 58, extends to the end of the input area 38 . The second sub-band, the so-called center band 60 extends over the assembly area 22nd The central belt 60 is followed by a third sub-belt, the so-called output belt 62 , which extends over the output area 48 . This is followed by a fourth sub-belt 64 , which takes over the normal transport function following the placement device 21 . The individual subbands 58-64 can be driven independently of one another with regard to their transport speed. The transitions between the individual subbands 58-64 are indicated in FIG. 3 by vertical lines.

To assemble the component group 30, there is the possibility of operating the input belt 58 at a higher transport speed than the central belt 60 , which in particular is at rest. Conversely, to separate the component group 30, the fourth sub-belt 64 is operated at a higher transport speed than the output belt 62 . For separating in particular the procedure is such that a first conductor plate 16 of the subassembly 30, a piece is pushed far to the fourth sub-band 64, then stopped the release belt 62 and the fourth sub-band is further operated 64 to between the first and second circuit board 16, a desired distance is reached.

A buffer zone for at least one complete component group 30 is formed before and after the placement area 22 for the fastest possible and smooth process flow. The buffer zone is formed by the input area 38 and by the output area 48 . Referring to FIG. 3, the length E is the length L exceeds the input range 38 of the Bestückbereichs 22 (laid over the ultimately, the maximum length of the subassembly 30 fixed), and the length A of the output section 48 matches the Bestückbereichs 22 with the.

The principle of grouping and separating the component group 30 described for FIG. 3 can be applied analogously to the embodiment according to FIG. 4. In contrast to FIG. 3, the loading machine line 2 shown in detail in FIG. 4 has an assembly zone 20 with three assembly devices 21 , each with an assembly region 22 . A component group 30 is arranged in each of the placement devices 21 . Before the assembly zone 20 , the device 40 is arranged and after it the separating device 50 is arranged. In order to ensure the smoothest possible process, each insertion device is assigned an input belt 58 , a middle belt 60 and an output belt 62 .

Claims (17)

1. A method for assembling electrical components ( 16 ), in particular printed circuit boards, in which the components ( 16 ) are fed via a conveyor belt ( 6 ) to an assembly area ( 22 ) of an automatic placement machine ( 10 ) and are equipped with components ( 26 ) there, wherein a plurality of components ( 16 ) are combined to form a subassembly ( 30 ) and are assembled together as a component group ( 30 ) in the assembly area ( 22 ). 2. The method according to claim 1, wherein the components ( 16 ) in front of the placement area ( 22 ) to the component group ( 30 ) are summarized. 3. The method according to claim 1 or 2, in which to put together the component group ( 30 ) a stop element ( 42 ) is guided in the transport path. 4. The method according to any one of the preceding claims, wherein the conveyor belt ( 6 ) has a first sub-belt ( 58 ) and a second sub-belt ( 60 ) following in the transport direction ( 4 ), which are driven independently of one another, where in order to assemble the component group ( 30 ) the first sub-belt ( 58 ) is operated at a higher transport speed than the second transport belt ( 60 ). 5. The method according to any one of the preceding claims, in which the component group ( 30 ) is separated into the individual components ( 16 ) after assembly. 6. The method according to claim 5, wherein a further sub-band ( 64 ) after the assembly area ( 22 ) for separating the component group ( 30 ) is operated at a higher transport speed than a sub-band ( 62 ) preceding it. 7. The method according to any one of the preceding claims, in which the total length (G) of the formed component group ( 30 ) in particular as close as possible to the length (L) of the assembly area ( 22 ), wherein reaching the total length (G) at Forming the component group ( 30 ) is monitored by a sensor ( 44 ). 8. The method according to any one of the preceding claims, wherein the position of each individual component ( 16 ) of the component group ( 30 ) in the assembly area ( 22 ) is detected before the assembly. 9. The method according to any one of the preceding claims, in which, for the assembly process, the component group is regarded as a unit with a plurality of subunits, the subunits being assigned to the individual components ( 16 ). 10. pick and place machine ( 10 ) for electrical components ( 16 ), in particular special SMD pick and place machine for printed circuit boards, with a loading area ( 22 ) to which the components ( 16 ) can be fed via a conveyor belt ( 6 ), the route being the construction parts ( 16 ) a collecting device ( 40 ) for grouping several components into a component group is provided, and the individual components ( 16 ) of the component group ( 30 ) in the loading area ( 22 ) can be fitted together. 11. placement machine ( 10 ) according to claim 10, wherein the collecting device ( 40 ) is arranged in front of the placement area ( 22 ). 12. Placement machine according to claim 11, in which a further collecting device ( 47 ) is arranged in the placement area. 13. placement machine (10) according to claim 11 or 12, wherein the collecting device (22) or the further Sammelvorrich device (47) a stop element (42, 47) comprise, which is movable into the transport path of the conveyor belt (6). 14. placement machine ( 10 ) according to one of claims 10 to 13, wherein the collecting device ( 40 ) comprises a sensor ( 44 ) with which the reaching of a total length (G) of the component group ( 30 ) can be detected when they are put together. 15. placement machine ( 10 ) according to one of claims 10 to 14, wherein the placement area ( 22 ) between an input area ( 38 ) and an output area ( 48 ) is arranged, where the length (E, A) of the input area ( 38 ) and / or the output area ( 48 ) is at least approximately as large as the length (L) of the placement area ( 22 ). 16. placement machine ( 10 ) according to claim 15, in which in the input and / or in the placement and / or in the output area ( 38 , 22 , 44 ) independently driven sub-belts ( 58 , 60 , 62 , 64 ) of the conveyor belt ( 6 ) are arranged one after the other. 17. placement machine ( 10 ) according to any one of claims 10 to 16, wherein a separating device ( 50 ) for separating the component group ( 30 ) in the individual components ( 16 ) is provided after the placement process.