Patent Application
20080089762
The invention relates to a wafer table for preparing electrical components of a wafer, which can be placed on a rotary disk of the wafer table, with the rotary disk being able to be finely displaced parallel to the wafer plane in discrete steps, such that the components arrive at a stationary pick-up position, to which at least one stationary auxiliary facility is assigned.
A wafer table of this type is known from EP 0971390 A for instance. According to this, an assembly head can be moved in a linear fashion parallel to a substrate between two fixed locations, said substrate being guided on a clocked tape transport. Next to the conveyor belt is the wafer table having an x-y-displaceable cross carriage, on which wafer table components are prepared in a wafer parallel to the substrate. One component can thereby be captured in each instance at the stationary pick-up position by the assembly head, moved by way of the laterally displaceable substrate and placed hereupon. As the wafer table only features a restricted x-y displacement section, it is not possible to bring all components of the wafer to the pick-up location of the assembly head. The wafer rests on a rotary disk of the cross carriage and can be rotated through 90° or 180°, in order also to pick up the remaining components.
The object underlying the invention is to create a simpler wafer table with a reduced installation width.
This object is achieved by the invention in accordance with claim 1. In the case of the wafer table according to the invention, the fine rotary drive supersedes one of the x-y linear axes of the cross carriage, with a simple rotary bearing and rotary drive instead of a linear guide and linear drive. Only one stationary linear guide remains for the carriage. Such a simple guide provides for greater positioning accuracy than a more complex cross guide with overlapping movements. The rotary movement doe not require any additional movement space. The rotary disk is only moved in a linear fashion. The wafer table can thus be designed with a smaller installation width, thereby increasing its possibilities for use when equipping printed circuit boards for instance. The rotation of the wafer does change the angular position of the respective component. This can be corrected in that a subsequent gripper tool, e.g. of an assembly head, carries out a corresponding counter rotation.
Advantageous developments of the invention are characterized in claims 2 to 6.
The development according to claim 2 allows the angular position of the distancing needles to be adjusted to that of the component to be picked up in each instance.
The flip facility according to claim 3 allows the component, configured as a flip chip for instance, to be moved into a transfer position, in which it can be taken by an assembly head in an orientation which is appropriate for assembly.
With the assembly device according to claim 4, the installation width of the wafer table is reduced considerably.
The camera according to claim 5 allows the precise position, particularly the angular position, of the component at the gripper of the assembly head to be determined and correspondingly corrected.
The development according to claim 6 is enabled by means of the narrow construction of the wafer table such that additional components from other reserve stores, e.g. from component belts can be prepared by means of belt conveyors.
The invention is described in further detail below with reference to an exemplary embodiment illustrated in the drawing, in which;
The central region of the supporting wall 8 is provided with a through hole 9, through which a transport section 10 for the substrates 1 is guided in a perpendicular manner. The entire device is designed to be a mirror-symmetrical on both sides of the supporting wall 8, with the carrier 5 projecting on both sides, the positioning arms 6 and the assembly head 3. Accordingly, the substrates 1 can be temporarily fixed on the transport section 10 at assembly sites on both sides of the supporting wall 8, as shown.
Sites for a wafer table 21 as well as for narrow component feeds 15 arranged next to one another are arranged upstream of the assembly sites next to the transport section. These sites comprise a series of pick-up sites 23, at which the components 2 fed from coils for instance can be removed by means of the assembly head 3, which then transports these components 2 to their mounting positions on the substrate 1.
A maximum access range 24 of the assembly head 3 marked by the dashed line covers the assembly region of the substrate 1 and the pick-up region of the components 2 with the pick-up sites 23. The wafer table 21 is arranged directly adjacent to some of the component feeds 15 and is provided with a rotary disk 26, upon which a wafer 25 which is parallel to the substrate is arranged. The rotary disk 26 is provided with a rotary axis which is perpendicular to the wafer 25 and is coupled to a rotary drive (not shown), which enables the rotary disk 26 to be rotated in small angular steps. The rotary disk 26 is supported on a carriage 20 which can be moved in a stationary linear guide 11, said carriage 20 being able to be finely displaced by means of a linear drive (not shown).
The combination of the linear and angular coordinates of the carriage 20 and of the rotary disk 26 enables each of the components 2 to be moved to a stationary pick-up position, which is defined by the position of a stationary ejector 28, which is arranged below the wafer 25. This is provided with distancing needles 27 which can be lifted and point upwards, said distancing needles lifting the components 2 away from a carrier film of the wafer. The distancing needles 27 are supported at a rotor 29 of the ejector 28, the angle of said rotor 29 being able to be finely adjusted, and can thus be rotated into an angular position appropriate for the component 2.
A revolver-type flip facility 16 with suction grippers 17 for the lifted components 2 is located on the wafer table 21 above the ejector 28. The suction grippers 17 are rotated upward and turned with the suctioned components 2 by gradual rotation about a horizontal axis. In this transfer position, the components 2 are captured by the grippers 7 of the assembly head 3. This latter moves over a camera 19 held in the frame, said camera measuring the precise position of the components 2. The grippers 7 can be rotated about their longitudinal axis by means of a second rotary drive and can rotate the suctioned components 2 into the assembly position provided.
The horizontal displacement direction of the carriage 20 is oriented perpendicular to the transport section 10 of the substrate 1. The wafer table 21 thus requires a minimal installation width, thereby allowing sites to be obtained for further feed facilities 15.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2005 003 454.3 | Jan 2005 | DE | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/EP06/50058 | 1/5/2006 | WO | 11/13/2007 |
