Device for conveying substrates through a substrate processing plant

A device for conveying substrates through a substrate treatment device has a base transport belt defining a transport plane and two lateral transport belts positioned at a first spacing above the base transport belt. The two lateral transport belts are laterally spaced at a second spacing to one another. Each one of the two lateral transport belts defines a lateral transport plane. Each one of the lateral transport planes is positioned at a slant to the transport plane of the base transport belt. The two lateral transport belts and the base transport belt have cutouts for receiving vertically poisoned substrates. At least one of the first spacing and the second spacing is changeable. Also, the slant angle between at least one of the lateral transport planes to the transport plane of the base transport belt is changeable.

BACKGROUND OF THE INVENTION
 The invention relates to a device for conveying substrates through a
 substrate processing plant.
 Devices of this kind are known for moving substrates, especially CDs,
 through cooling and drying devices. The substrates are placed into baskets
 moving on a circular path or into slots provided in circular devices. Such
 carousel transporting devices, however, have great dimensions and require
 large size drive devices so that such known devices are cost-intensive.
 Furthermore, loading of such carousel transporting devices with
 substrates, respectively, removal of substrates therefrom, is difficult
 and requires high constructive expenditures.
 For devices of the aforementioned kind it is also known to employ a screw
 conveyor which rotates and moves forward the substrates positioned in the
 conveying path. This has, however, the disadvantage that a relative
 movement between the screw conveyor and the substrates occurs, generating
 friction which causes particles to be rubbed off and thus results in
 contamination.
 From DE 43 41 634 A1, upon which the present invention is based, a device
 for transporting disk-shaped substrates in a substrate treatment device is
 known in which three toothed belts are provided with which the substrates
 can be conveyed through the treatment device. This device, however, is
 designed for only a single substrate shape and size and cannot be adapted
 to different specifications, such as, for example, different substrate
 sizes.
 From U.S. Pat No. 4,947,784 a device for transferring wafers from a first
 wafer securing device (wafer cassette) into a second wafer securing device
 (wafer boat) is known. Such a so-called handling device for wafers is not
 designed for transporting wafers through a treatment device and is not
 suitable for this purpose.
 From DE 195 30 858 C1 a handling device is known in which the wafers are
 transported by suction plates. The handling device of DE 195 29 945 A1
 realizes gripping and securing of flat substrate by an inner gripping
 device, wherein the gripping device engages a hole provided at the
 interior of the substrates, with the gripping device supported at the edge
 of the inner hole.
 It is an object of the invention to improve a device known from DE 43 41
 634 A1 such that an adaptation of the device to different specifications,
 for example, different substrate sizes, is possible in a simple manner.
 SUMMARY OF THE INVENTION
 The aforementioned object is inventively solved by the features of claim 1.
 By providing an adjustable spacing of the lateral transport belts relative
 to one another and/or to the base transport belt, not only an adaption of
 the device to the respective specifications, especially to different
 substrate sizes, but also a readjustment of the spacings required for a
 reliable securing and transporting of the substrates is possible in a
 simple manner.
 A further preferred embodiment of the invention is that the angle between
 the transport planes of the two lateral transport belts and the transport
 plane of the base transport belt can be changed. In this manner, an
 optimal adjustment of the support locations of the substrates transported
 on the transport belts is possible. Furthermore, it is also possible to
 adapt the device with simple means to different substrate shapes or
 substrate sizes, be it round or rectangular shapes. For rectangular
 substrates, the angle between the transport planes of the lateral
 transport belts and the transport plane of the base transport belt is
 preferably 90.degree..
 The invention therefore has the object to provide a device for movement of
 substrates through a substrate treatment device with which a carousel-type
 movement of the substrate on a circular path or substrate wear can be
 avoided and a constructively simple, space-saving, and easily manipulated
 device is possible.
 The aforementioned object is inventively solved by a base transport belt
 and two lateral transport belts which respectively have cutouts for a
 vertical receiving action for the substrates. Due to the inventive
 features, i.e., using three transport belts, a linear movement of the
 substrates results with the advantage that the device is very simple,
 space-saving, and wear-free, and furthermore can be adjusted easily to the
 respective requirements, for example, the size of the substrate.
 According to an especially advantageous embodiment of the invention, the
 cutouts for vertically receiving the substrates are embodied as
 intermediate spaces of teeth at the transport belt provided in the form of
 a toothed belt. Such toothed belts can be manufactured inexpensively.
 For adapting the inventive transport device the spacing of the lateral
 transport belts to the base belt can be changed. By adjusting the lateral
 transport belts to the base belt, an adaptation of the device to different
 substrate sizes is possible in a simple manner.
 In the case of round substrates, such as, for example, CDs or DVDs, it is
 especially advantageous when the transport planes of the two lateral
 transport belts have an angle of greater than 90.degree. to the transport
 plane of the base transport belt. This allows an easy insertion into and
 removal of the substrates from the inventive transport device, whereby
 however the supporting action of the substrates in the transport device is
 safe and secure.
 The transport belts are preferably guided about guide pulleys and drive
 wheels which are embodied especially as gear wheels when the transport
 belts or at least one of the transport belts on the side facing away from
 the transport surface, i.e., its drive side, is embodied as a toothed
 belt. A toothed design of the transport belts on both sides is therefore
 very advantageous.
 Another very advantageous embodiment of the invention resides in that each
 one of the three transport belts is guided in its own transport belt
 device and is driven by its own drive unit. In this manner, the individual
 transport belt devices are individual units so that the arrangement,
 adaptation, and alignment of the transport belts to different substrates
 is possible.
 It is very advantageous to provide the drive units of the three transport
 belts such that they operate synchronously to one another. This results
 not only in a uniform drive velocity for all three transport belts, but
 also in a synchronous alignment of the cutouts for receiving the
 substrates. Instead of such a synchronous control, it is also possible to
 provide the drives of the three transport devices, respectively, the three
 transport belts with a common gear box, for example, a play-free gear box,
 in order to ensure a synchronous movement of three drive belts,
 respectively, their cutouts for receiving the substrates. The gear box can
 also be driven by a drive common to all three transport belts.
 The transport belts or at least parts of the transport belts which are in
 contact with the substrates, are preferably comprised of a special
 material that prevents contamination, such as Teflon, or a material which
 is not sensitive to contamination, respectively, can be easily cleaned.
 Loading and/or unloading of the inventive transport device, respectively,
 the three transport belts with substrates, is preferably carried out with
 suction grippers and/or inner grippers, which engage the edge of the inner
 hole of, for example, CDs. Such gripping devices are simple and prevent
 the subsequent contamination of the substrates after the treatment
 process.
 The inventive transporting device is especially advantageous in connection
 with substrate drying devices or cooling devices which are used especially
 in the production of CDs.
 The term substrate is to include all disk-shaped treatment objects, i.e.,
 not only CDs, including audio CDs, ROM-CDs, so called recordable CDs
 (CDRs), digital video disks (DVDs) etc., but also masks for producing
 semiconductor components, display units etc.

DESCRIPTION OF THE PREFERRED EMBODIMENTS
 As is shown in the figures, the inventive device comprises a first
 transport belt device 1 with a base transport belt 2, a second transport
 belt device 3, comprising a lateral transport belt 4, and a third
 transport belt device 5, having a lateral transport belt 6. The transport
 belts 2, 4, 6 have cutouts, respectively, intermediate spaces between
 teeth of a toothed belt for receiving the substrates 7. Such cutouts or
 intermediate spaces are provided in all three transport belts. As can be
 seen especially in FIGS. 1 and 4, the drive of the transport belts 2, 4, 6
 is realized by a common drive unit 8 which is driven by drive belt 9 and a
 gearbox 10 for synchronously moving the three transport belts 2, 4, 6.
 In the represented embodiment of the inventive conveying device for drying
 the substrates, a blower 11 is provided which extends over a large portion
 of the length of the movement direction with which air, either heated by
 the blower 11 or already heated air coming from the exterior, is
 continuously blown onto the transport belts 2, 4, 6 or onto the stepwise
 transported substrates 7. The depleted drying air is guided away from the
 drying housing to the outlet openings 11, 12.
 The invention has been explained with the aid of a preferred embodiment.
 However, to a person skilled in the art numerous deviations and designs
 are obvious without departing from the gist of the invention. For example,
 the transport belt devices 1, 3, 5 can be embodied independent of one
 another so that they can be changed in their position relative to one
 another in order to be used for transporting different substrates 7. In
 the represented embodiment, the substrate 7 is round and the lateral
 transport belts 4, 6 have an angle to the transport belt 2 which is
 greater than 90.degree. so that the substrate 7 is secured safely at three
 locations at the lower half of the substrate disk. For larger round
 substrates 7, the lateral transport belt devices 3, 5 are simply moved
 farther outwardly and, optionally, the angle of the lateral transport belt
 devices relative to the base belt 2 is changed in order to ensure a
 support action of the substrates as optimal as possible. In the case of
 square or rectangular substrates, the lateral transport belt devices are
 arranged or pivoted such that the lateral belts 4, 6 extend
 perpendicularly to the transport plane of the base transport belt 2.
 The present invention is, of course, in no way restricted to the specific
 disclosure of the specification and drawings, but also encompasses any
 modifications within the scope of the appended claims.