Patent Description:
In an known example, an apparatus for transferring chips from a first position, e.g. in which position the wafer with the matrix of semiconductor circuits is positioned, to at least a second position, e.g. in which position a carrier film with the individual semiconductor circuits are positioned, are composed of one rotatable transfer assembly provided with at least two transfer heads, each transfer head structured for picking up a chip in the first position, and for positioning the chip in the at least second position through rotation of the at least one rotatable transfer assembly using a rotational motor about an axis of rotation. The at least two transfer heads are also driven by at least one rotational transfer head motor for manipulating the semiconductor circuit in each first and at least second position by means of in-and-out radial translational movement.

The use of at least two traditional rotational motors, operated separately from each other, for separately rotating the rotatably driven transfer assembly and the rotatably driven transfer heads has some significant structural and operational drawbacks. A drawback is machine speed loss, due to rotatably driven transfer heads being connected to the same rotational transfer head motor, thus requiring their semiconductor circuit manipulations being performed in time-sequential order, instead of parallel.

Another drawback pertain to quality issues. Due to hardware dimensional tolerances, semiconductor circuit may not be positioned on the correct, intended location (e.g. out of focus of inspection cameras). Quality issues can occur also, due to the relative high impact mass, when more transfer heads are connected to the same rotational transfer head motor, which potentially may cause chip damage. Quality issues can also occur due to friction occurring from the rotation bearings from the rotational motors used, hampering the position control of the transfer heads manipulations. As a solution, each transfer heads could be connected to an individual rotational transfer head motor in order to individual transfer head manipulation control, however this is not possible due to volume constraints of the overall apparatus construction.

Another drawback is possible machine uptime loss, due to significant conversion time, when adapting the chip transferring apparatus from one configuration to another. The chip transferring apparatus has many configurations (e.g. different number of transfer heads, different positions for collecting, inspecting and placing the semiconductor circuit at several, different positions, etc. Furthermore, due to the volume consuming constructions for supporting the rotational motors, servicing such chip transferring apparatus has become burdensome.

Transfer module leading to chip pick and place placement inaccuracies and quality issues. These mechanical inaccuracies arise because each degree of freedom (rotation and radial translation from inside to outside and vice versa) has its own bearing (in our current design 3x rotational lower) and because there are fewer actuators than transfer heads, allowing independent compensation per transfer head via the servo motor is not possible.

Accordingly, it is a goal of the present disclosure to provide an improved apparatus for transferring chips having reduced constructional dimensions incorporating a simpler operating and driving mechanism, allowing the manipulation of semiconductor circuit at higher operating speeds, improved manipulation quality due to reduced impact mass and reduced friction.

The following document is mentioned as being a pertinent prior art illustration:
<CIT> discloses a chip transfer device for transferring chips from a wafer to a placement head of an automatic placement machine.

The following documents are also mentioned as being an additional prior art illustration:.

According to a first example of the disclosure, an apparatus for transferring chips from a first position to at least a second position is proposed, the apparatus comprising at least one rotatable transfer assembly comprising at least two transfer heads, each transfer head structured for picking up a chip in the first position, and for positioning the chip in the at least second position through rotation of the at least one rotatable transfer assembly about an axis of rotation; a transfer assembly actuator for driving the rotatable transfer assembly together with the at least two transfer heads about the axis of rotation; as well as at least a first transfer head actuator structured for actuating at least one transfer head in a radial direction relative to the axis of rotation, the at least first transfer head actuator being mounted to the rotatable transfer assembly actuator and comprising an actuator element coupled to the at least one transfer head, the actuator element structured to be actuated in the direction of the axis of rotation relative to the rotatable transfer assembly actuator.

The actuator element structured to be actuated in the direction of the axis of rotation relative to the rotatable transfer assembly actuator solves the problem of mechanical inaccuracies in the known applications. The complete construction is capable of rotating around the axis of rotation requiring only one rotational motor or actuator, resulting in a simpler construction with a reduced number of moving parts, such as bearings. Overall, this results in an apparatus of limited volumetric dimensions with an improved accuracy as to the manipulation of the individual semiconductor circuits, and limited machine uptime loss and servicing time. With this simplified mechanical construction, each transfer head can be actuated by its own transfer head actuator improving operational flexibility and accuracy per transfer head as this configuration allows accuracy corrections per transfer head / semiconductor circuit. Alternatively, two (or more) transfer heads can be actuated by one transfer head actuator allowing parallel manipulations of semiconductor chips.

In a preferred example, the actuator element is coupled to the at least one transfer head by means of a bar-linkage or cable-linkage mechanism.

Preferable, the at least first transfer head actuator comprises an actuator component mounted to the rotatable transfer assembly actuator, and the actuator element structured to be actuated in the direction of the axis of rotation relative to the actuator component. Herewith, the complete transfer head actuator rotates together with the transfer assembly actuator with a separate component structured to actuate the one or more transfer heads for semiconductor circuit manipulation.

In a preferred example, the at least first transfer head actuator comprises a magnet-coil drive unit for actuating the actuator element in the direction of the axis of rotation relative to the rotatable transfer assembly actuator. Such contact less actuating principle ensures proper mechanical accuracy and instantaneous response times, further increasing overall machine speed.

In particular, in order to further increase instantaneous response times and machine speed, the magnet-coil drive comprises multiple magnet elements mounted to the actuator element surrounding a coil element being mounted to the actuator component. In an alternative embodiment the multiple magnet elements are mounted to the actuator component, whilst the coil element is mounted to the actuator element.

In an example, the at least first transfer head actuator comprises a guiding element interconnecting the actuator element and the actuator component, wherein the guiding element is chosen from the group not limited consisting of a membrane element, a spring element, a ball bearing, an air bearing, etc. Again, such construction improves mechanical accuracy and instantaneous response times, further increasing overall machine speed.

In a further example according to the disclosure, the at least first transfer head actuator further comprises at least one sensing device for sensing a displacement of the actuator element in the direction of the axis of rotation relative to the rotatable transfer assembly actuator. Such sensing allows for an accurate actuating of the corresponding transfer head in the radial direction relative to the axis of rotation thus improving the accuracy of the semiconductor circuit manipulation. As the sensing device is mounted to the transfer head actuator, which in turn is mounted to the rotatable transfer assembly actuator, the displacement change is sensed in the direction of the axis of rotation irrespective of the rotation (direction and/or speed) of the overall construction.

In a example, the sensing device can be embodied as a linear encoder sensing an encoding scale placed on the actuator element, which encoding scale encodes a position along the axis of rotation. The linear encoder is structured to scan the encoding scale in order to convert the encoded position into an analog or digital signal. In order to ensure machine speed and efficient readout, the sensing device is mounted to the actuator component whereas the encoding scale is placed on the actuator element, which is displaced relative to the actuator component in the direction along the axis of rotation.

Due to the simpler, and less volumetric construction of the apparatus according to the disclosure, the number of transfer heads can be increased for example to four, six, eight, sixteen, or even more transfer heads. Accordingly, the construction of the apparatus can be expanded in only the direction of the axis of rotation by mounting a further transfer head actuator to the at least first transfer head actuator seen in the direction of the axis of rotation.

It should be noted, that the improved construction of the apparatus according to the disclosure - having less volumetric dimensions, less mechanical inaccuracies, and less friction between its moving parts - allows for each transfer head being actuated by its own transfer head actuator. On other hand, each transfer head actuator can be structured to actuate two or more transfer heads, depending on the implementation of the chip transfer apparatus.

In an example, the apparatus further implements a wafer-positioning device structured to position a wafer with chips surfaces thereof extending in a first plane in the first position, as well as a lead frame positioning device for positioning a lead frame, or antenna-foils or packaging tapes etc. with a bond surface thereof extending in a second plane at the second position.

In an additional implementation, the apparatus according to the disclosure may comprise a chip surface inspection device extending in a third plane in a third position. For example, said third position can be an intermediate position between the first and second position, seen in the direction of rotation of the rotatable transfer assembly, allowing for visual inspection in the intermediate, third position of a semiconductor circuit picked up by a transfer head in the first position, prior to the placement of the inspected semiconductor circuit by the transfer head in the second position.

In addition, the apparatus according to the disclosure may comprise a chip transfer device extending in a fourth plane in a fourth position, for example for transferring semiconductor circuits to a further processing line.

The disclosure will now be discussed with reference to the drawings, which show in:.

For a proper understanding of the disclosure, in the detailed description below corresponding elements or parts of the disclosure will be denoted with identical reference numerals in the drawings.

<FIG> depict a schematic example of an apparatus for transferring semiconductor circuits from a first position to at least a second position according to the state of the art.

As outlined in the introduction, semiconductor circuits are manufactured on and in a circular plane substrate, also referred to as a wafer, in a matrix having a plurality of rows and columns of such circuits. For separating the plurality of individual semiconductor circuits (hereinafter also to be referred to as "chips" or "dies") from the wafer and arrange them individually on e.g. a carrier film for further handling and transportation, <FIG> depicts a schematic, yet known example of an apparatus for transferring chips from a first position, e.g. in which position the wafer with the matrix of semiconductor circuits is positioned, to at least a second position, e.g. in which position a carrier film with the individual semiconductor circuits are positioned.

The apparatus for transferring chips according to the state of the art is denoted with reference numeral <NUM>. Throughout this specification, the individual semiconductor circuits or chips are denoted with reference numeral <NUM>.

The apparatus <NUM> is composed of a transfer assembly <NUM> which is rotatable driven by means of a rotational motor or transfer assembly actuator <NUM>. The transfer assembly actuator <NUM> is provided with one or more transfer assembly actuator bearings <NUM>' and is capable for rotating the transfer assembly <NUM> around an axis of rotation, which axis of rotation is denoted with reference numeral 11z in <FIG>.

To the transfer assembly <NUM> are mounted preferably at least two transfer heads <NUM> (denoted with 12a-12b). Although the apparatus <NUM> can operate with one transfer head <NUM> mounted to the rotatable transfer assembly <NUM>, it is preferred - for machine speed considerations - to have at least two transfer heads 12a-12b mounted to the transfer assembly <NUM>. Each transfer head <NUM>; 12a-12b is structured for picking up a semiconductor circuit or chip <NUM> in the first position, and for positioning the chip <NUM> in the at least second position through rotation of the rotatable transfer assembly <NUM> by means of the transfer assembly actuator <NUM> around the axis of rotation 11z.

Furthermore, as shown in <FIG>, for a proper manipulation of the semiconductor circuit (chip) <NUM> in each first and second position, e.g. for picking the chip <NUM> up from a wafer positioned in the first position and for placing the chip <NUM> on a carrier film in the second position, each transfer head 12a-12b are likewise driven by a corresponding rotational transfer head motor <NUM> (14a-14b). Each rotational transfer head motor 14a and 14b is provided with a transfer head actuator bearing 14a'-14b' allowing rotation around their individual axis of rotation 14a-z and 14b-z respectively. The axis of rotations 11z, 14a-z and 14b-z are not in a perfect concentric orientation with each other, thus creating mechanical accuracies for the transfer heads 12a-12b. In addition, each rotational transfer head motor 14a and 14b is provided with a connecting mechanism 15a and 15b actuating the transfer head 12a-12b in order to pick up a semiconductor circuit or chip <NUM> in the first position, and to position or place the chip <NUM> in the second position.

In this known configuration, rotational motors 14a-14b are implemented for each transfer head 12a-12b. However, in a more common configuration, two or even four rotatably driven transfer heads <NUM> can be connected to the same rotational transfer head actuator <NUM>. Such configuration has some significant structural and operational drawbacks. A main drawback is machine speed loss, when rotatably driven transfer heads being connected to the same rotational transfer head motor, requiring their semiconductor circuit manipulations being performed in time-sequential order, instead of parallel.

Another drawback pertain to quality issues due to friction occurring from the rotation bearings <NUM>', 14a' and 14b' from the rotational actuators or motors used, hampering the position control of the transfer heads manipulations. As a solution, each transfer head <NUM> could be connected to an individual rotational transfer head actuator (motor) <NUM> in order to individual transfer head manipulation control, however this is not possible due to volume constraints of the overall apparatus construction.

<FIG> shows a schematic depiction of a first example of the disclosure, wherein the apparatus for transferring semiconductor circuits or chips <NUM> from a first position to at least a second position is denoted with reference numeral <NUM>. The apparatus <NUM> comprises at least one rotatable transfer assembly <NUM>. To the rotatable transfer assembly <NUM> at least two transfer heads <NUM> (120a-120b) are mounted. Similarly, each transfer head <NUM> (120a-120b) serves for picking up a chip <NUM> in the first position, and for positioning the chip <NUM> in the at least second position through radial displacement relative to the axis of rotation of 110z the rotatable transfer assembly <NUM>. Rotation of the at least one rotatable transfer assembly <NUM> about its axis of rotation 110z ensures that each transfer head <NUM> (120a-120b) is displaced, through rotation, from the first position towards the at least second position.

Rotation of the transfer assembly <NUM> about its axis of rotation 110z is achieved with a transfer assembly actuator <NUM>. According to the disclosure, the transfer assembly actuator <NUM> drives or rotates the rotatable transfer assembly <NUM> together with the at least two transfer heads <NUM> (120a-120b) about one, single axis of rotation 110z. As the complete construction of the apparatus <NUM> according to the disclosure and as depicted in <FIG> is capable of rotating around one axis of rotation 110z with the use of only one rotational motor or actuator <NUM>, a simpler construction is obtained with a significantly reduced number of moving parts, such as only one bearing <NUM>'. Also, mechanical inaccuracies due to eccentric rotational axes as in the known device shown in <FIG> are absent. Overall, this results in an apparatus <NUM> of limited volumetric dimensions with an improved accuracy as to the manipulation of the individual semiconductor circuits, and limited machine uptime loss and servicing time.

Furthermore, at least a first transfer head actuator <NUM> (140a) is used to actuate at least one corresponding transfer head <NUM> (120a) in a radial direction relative to the axis of rotation 110z, as depicted by the arrows R in <FIG>. In this example, two transfer head actuators 140a-140b are used to actuate corresponding transfer heads 120a-120b, each with the assistance of a connecting mechanism 150a-150b, such as a bar-linkage mechanism or a cable mechanism. As shown, the transfer head actuators <NUM> (140a-140b) are mounted to the rotatable transfer assembly actuator <NUM>.

Accordingly, the complete configuration of the apparatus <NUM> according to the disclosure consisting of the transfer assembly <NUM>, the several transfer heads <NUM>, the transfer assembly actuator <NUM> and the transfer head actuators <NUM> are mounted on one single bearing <NUM>' and being capable of rotating entirely about the single axis of rotation 110z. The advantages of such simpler construction are clear. Next to a significantly reduced number of moving parts, also the volumetric dimension of such configuration are limited, and next to an increase of machine speed, chips <NUM> can be manipulated faster and at higher accuracies. Also its simpler construction reduces machine uptime loss and servicing time.

<FIG> depict in more details examples of an apparatus according to the disclosure, denoted with reference numerals <NUM> (<FIG>), <NUM>' (<FIG>) and <NUM>" (<FIG>). In <FIG> chip transfer apparatus <NUM> according to the disclosure is composed of the transfer assembly <NUM>, the transfer assembly actuator <NUM>, several, here eight, transfer heads 120a-<NUM>, and one transfer head actuator 140a. Note, that the number of transfer heads <NUM> is arbitrary and depends on the type of application of the apparatus <NUM>. Accordingly, one, two, four, eight, even sixteen transfer heads <NUM> (in such case indicated with reference numerals 120a-120p) can be mounted to the rotatably transfer assembly <NUM>.

In this example, each transfer head 120a-<NUM> is composed of a transfer head body 121a-<NUM> mounted to the transfer assembly <NUM>, and a transfer head arm 122a-<NUM>, which is movable or hinged connected with the transfer head body 121a-<NUM>. Each transfer head arm 122a-<NUM> carries a pick-up element 123a-<NUM> capable to interact with a chip <NUM> in a known matter. For the sake of simplicity, in <FIG> only the reference numerals 121a-122a-123a of the associate transfer head 120a are shown, it is clear that in the configuration of eight transfer heads <NUM>, the other seven transfer heads 120b-<NUM> likewise comprise corresponding parts 121x-122x-123x (with x representing the relevant suffix letter b till h).

The transfer head arm 122a-<NUM> is connected through a corresponding cable mechanism 150a-<NUM> with the transfer head actuator 140a. Actuation of the cable mechanism 150a-<NUM> (which will be discussed in detail later in this description) allows the transfer head arm 122a-<NUM> to displace relative to the corresponding transfer head body 121a-<NUM>, moving the pick-up element 123a-<NUM> in a radial direction relative to the axis of rotation 110z, e.g. away from and towards the axis 110z, as shown with the arrows R in <FIG>. The radial movement of the pick-up element 123a-<NUM> allows for picking a chip <NUM> up from a wafer positioned in the first position and for placing the chip <NUM> on a carrier film in the second position.

Although all transfer heads 120a-<NUM> can be linked with one and the same transfer head actuator 140a, e.g. as depicted in <FIG>, further transfer head actuators 140b, 140c, 140d, etc. can be implemented. For example, as shown in <FIG>, as the overall construction of the chip transfer apparatus <NUM>' according to the disclosure rotates around one single axis of rotation 110z, at least one further transfer head actuator 140b can be mounted to the first transfer head actuator 140a seen in the direction of the axis of rotation 110z. This allows for the advantageous upscale of the apparatus of the disclosure along its axis of rotation 110z also in terms of machine speed, by expanding the apparatus with additional transfer head actuators <NUM>(a-d) for actuating one or more additional transfer heads 120a-<NUM> mounted to the rotatable transfer assembly <NUM>.

Such example is shown in <FIG>, depicting a chip transfer apparatus <NUM>" according to the disclosure, which rotates around one single axis of rotation 110z, and is provided with four transfer head actuators 140a-140b-140c-140d, each mounted to a previous transfer head actuator seen in the direction of the axis of rotation 110z. The complete arrangement of multiple transfer head actuators is mounted to the rotatable transfer assembly <NUM>.

As clearly shown in <FIG>, the several examples of an apparatus <NUM>-<NUM>'-<NUM>" according to the disclosure exhibit limited volumetric dimensions as only the elongated constructional dimension of the apparatus, seen in the direction of the axis of rotation, changes with the number of transfer head actuators <NUM> mounted to the rotatable transfer assembly <NUM>. Accordingly, this design configuration has less mechanical inaccuracies, and less friction between its moving parts as the overall construction rotates about one single axis of rotation 110z, requiring on single bearing <NUM>' (<FIG>).

This principle of adding additional transfer head actuators <NUM> along the axis of rotation 110z allows for each transfer head <NUM> to be actuated by its own transfer head actuator <NUM>. On other hand, each transfer head actuator <NUM> can be structured to actuate two or more transfer heads <NUM>, depending on the implementation of the chip transfer apparatus <NUM>-<NUM>'-<NUM>". For example, in <FIG>, the eight transfer heads 120a-<NUM> can be actuated together and simultaneously by the single transfer head actuator 140a, whereas in the apparatus <NUM>' of <FIG>, the eight transfer heads 120a-<NUM> can be grouped in two separate sets of four transfer heads each, e.g. one set consisting of transfer heads 120a, 120c, 120e and <NUM> and the other set consisting of transfer heads 120b, 120d, 120f and <NUM>, each set being actuated together and simultaneously by one of the two transfer head actuators 140a and 140b. Likewise, in the apparatus <NUM>" of <FIG>, the eight transfer heads 120a-<NUM> can be grouped in four separate sets of two transfer heads each, e.g. one set consisting of transfer heads 120a and 120e, a second set consisting of transfer heads 120b and 120f, a third set consisting of transfer heads 120c and <NUM>, and the fourth set consisting of transfer heads 120d and <NUM>. Similarly, each set is being actuated together and simultaneously by one of the four transfer head actuators 140a-140d, all actuation/manipulation taking placing through the respective cable mechanisms 150a-<NUM>.

As each transfer head <NUM> can be actuated by its own transfer head actuator <NUM> operational flexibility and accuracy per transfer head can be significantly improved, as such <NUM>-on-<NUM> configuration allows accuracy corrections per transfer head <NUM> / semiconductor circuit <NUM>. Alternatively, two (or more) transfer heads can be actuated by one transfer head actuator allowing parallel manipulations of semiconductor chips.

<FIG> show in more detail the functionality of a transfer head actuator <NUM>. In the <FIG> the transfer head actuator is denoted with reference numeral 140a. However, if more than one transfer head actuator <NUM> is used as depicted for example in <FIG> and <FIG>, subsequent letter suffixes are applied for the first and any further transfer head actuator <NUM>. Accordingly, as stated above, in an example each transfer head 120x can be actuated by its own transfer head actuator 140x (with x representing the relevant suffix letter a till h or even more such as a till p). The transfer head actuator <NUM> (a-h) can have a more or less cylindrical configuration, having a reduced impact mass, and balanced inertia during rotation about the axis of rotation 110z. Each transfer head actuator <NUM> (ah) has an actuator element <NUM> (a-h), which is coupled to at least one transfer head <NUM> (ah) through a corresponding connecting mechanism <NUM> (a-h). The actuator element <NUM> (ah) is structured to be actuated in the direction of the axis of rotation 110z relative to the rotatable transfer assembly actuator <NUM>. With the movement of the actuated actuator element <NUM> (a-h) in the direction of the axis of rotation 110z relative to the rotatable transfer assembly actuator <NUM> the problem of mechanical inaccuracies in the known applications is solved.

In particular, the use of a connecting mechanism <NUM> (a-h), such as a bar-linkage mechanism or a cable mechanism, interconnecting the actuator element <NUM> (a-h) with at least one transfer head <NUM> (a-h) provides a sturdy and reliable actuation mechanism due to the absence of any friction and mechanical play. This actuation mechanism thus improves the mechanical accuracy of the manipulation of the semiconductor circuits <NUM>.

As further shown in <FIG>, reference numeral <NUM> (a-h) denotes an actuator component as a further part of the associated transfer head actuator <NUM> (a-h). The actuator component <NUM> (a-h) is fixedly mounted to the rotatable transfer assembly actuator <NUM>. In a non-limiting example, the actuator component <NUM> (a-h) can be formed as a ring shaped base element <NUM>-<NUM> (a-h) provided with several extension parts <NUM>-<NUM> (ah) evenly distributed along the circumference of ring shaped base element <NUM>-<NUM> (a-h) and extending in the direction of the axis of rotation 110z. The extension parts <NUM>-<NUM> (a-h) are to be mounted in a fixed manner to the rotatable transfer assembly actuator <NUM>.

The actuator element <NUM> (a-h) is also structured as a ring shaped element having several openings <NUM>-<NUM> (a-h) also evenly distributed along its circumference. Each extension parts <NUM>-<NUM> (a-h) is accommodated in a corresponding openings <NUM>-<NUM> (a-h), allowing a contactless movement of the actuator element <NUM> (a-h) in the direction of the axis of rotation 110z relative to the actuator component <NUM> (a-h).

Similarly, when looking at <FIG> and <FIG> showing multiple transfer head actuators 140a-140d mounted in line with each other along the axis of rotation 110z, the actuator component 141b-141d of at least one further transfer head actuator 140b-140d is mounted to the actuator component 141a-141c of the previous transfer head actuator 140a-140c thus creating one rigid construction further increasing mechanical accuracy with limited moving parts, hence reduced friction.

In an example shown in <FIG> and <FIG>, each transfer head actuator <NUM> (a-h) comprises a magnet-coil drive unit <NUM> (a-h) for actuating the actuator element <NUM> (a-h) in the direction of the axis of rotation 110z relative to the rotatable transfer assembly actuator <NUM> (and the actuator component <NUM> (a-h)). Such contact less actuating principle ensures proper mechanical accuracy and instantaneous response times, further increasing overall machine speed.

In particular, in order to further increase instantaneous response times and machine speed, the magnet-coil drive <NUM> (a-h) comprises multiple magnet elements <NUM> (a-h) mounted at the inner circumference of the ring shaped actuator element <NUM> (a-h) surrounding a coil element <NUM> (a-h) being mounted to the actuator component <NUM> (a-h). In an alternative embodiment the multiple magnet elements <NUM> (a-h) are mounted to the actuator component <NUM> (a-h), whereas the coil element <NUM> (a-h) is mounted to the actuator element <NUM> (a-h).

To ascertain mechanical accuracy and instantaneous response times, when displacing the actuator element <NUM> (a-h) relative to the actuator component <NUM> (a-h) in the direction of the axis of rotation 110z, each transfer head actuator <NUM> (a-h) comprises a guiding element <NUM> (a-h) interconnecting the actuator element <NUM> (a-h) and the actuator component <NUM> (a-h). The guiding element <NUM> (a-h) can be chosen from the group not limited consisting of a membrane element, a spring element, a ball bearing, an air bearing, etc. In the depicted example of <FIG>, the guiding element <NUM> (a-h) is formed as a disc shaped spring element having first mounting points <NUM>-<NUM> (a-h) for mounting / interconnecting with an extension part <NUM>-<NUM> (a-h) of the actuator component <NUM> (a-h) and second mounting points <NUM>-<NUM> (a-h) for mounting / interconnecting with the actuator element <NUM> (a-h). Such construction allows frictionless movements of the several parts without any mechanical play, thus ensuring operational reliability and accuracy.

Accordingly, with the actuator component <NUM> (a-h) being mounted to the transfer assembly actuator <NUM>, the complete transfer head actuator <NUM> (a-h) rotates together with the transfer assembly actuator <NUM> (and the rotatable transfer assembly <NUM> with the several transfer heads <NUM>) about the axis of rotation 110z, whereas the separate actuator component <NUM> (a-h) can be displaced - upon actuation of the magnet-coil drive <NUM> combined with the guiding element <NUM> (a-h) - in the direction of the axis of rotation 110z relative to the rotatable transfer assembly actuator <NUM> (and the rotatable transfer assembly <NUM> with the several transfer heads <NUM>), in order to actuate via the associated cable mechanism <NUM> (a-h) the one or more transfer heads <NUM> (a-h) for semiconductor circuit manipulation.

Upon actuation of the magnet-coil drive <NUM> (a-h) the actuator element <NUM> (a-h) is displaced in the direction of the axis of rotation 110z relative to the actuator component <NUM>, due to the electromagnetic forces generated. The actuator element <NUM> (a-h) is fixedly connected with one end of a corresponding cable mechanism <NUM> (a-h), whereas the other end of the cable mechanism <NUM> (a-h) is fixedly connected with a corresponding transfer head <NUM> (a-h), in particular with the corresponding transfer head arm 122a-<NUM>. The displacement (back and forth along the axis of rotation) of the actuator element <NUM> (a-h) is transferred via the cable mechanism <NUM> (a-h) towards the transfer head arm <NUM> (a-h) and the associated pick-up element <NUM> (a-h) can be displaced in a radial direction relative to the axis of rotation 110z, as depicted by the arrows R in <FIG>, for performing the respective picking up and placing of a chip <NUM>.

In the <FIG> and <FIG>, reference numeral <NUM> (a-d) denotes a sensing device for sensing a displacement of the actuator element <NUM> (a-h) in the direction of the axis of rotation 110z relative to the actuator component <NUM> (a-h) / the rotatable transfer assembly actuator <NUM> / the rotatable transfer assembly <NUM> / the transfer heads <NUM> (a-h). Such sensing allows for an accurate actuating of the corresponding transfer head <NUM> in the radial direction relative to the axis of rotation 110z thus improving the accuracy of the semiconductor circuit manipulation. As the sensing device <NUM> (a-h) is mounted to the transfer head actuator <NUM> (a-h), which in turn is mounted to the rotatable transfer assembly actuator <NUM>, the displacement change is sensed in the direction of the axis of rotation 110z irrespective of the rotation (direction and/or speed) of the overall construction <NUM>-<NUM>'-<NUM>".

For redundancy purposes, further improving mechanical accuracy, each transfer head <NUM> (a-h) can be provided with more than one sensing devices <NUM> (a-h).

Claim 1:
An apparatus for transferring chips (<NUM>-<NUM>'-<NUM>") from a first position to at least a second position, the apparatus comprising:
at least one rotatable transfer assembly (<NUM>) comprising at least two transfer heads (<NUM>(a-h)), each transfer head structured for picking up a chip in the first position, and for positioning the chip in the at least second position through rotation of the at least one rotatable transfer assembly about an axis of rotation (110z);
a transfer assembly actuator (<NUM>) for driving the rotatable transfer assembly together with the at least two transfer heads about the axis of rotation; as well as
at least a first transfer head actuator (<NUM>(a-h)) structured for actuating at least one transfer head in a radial direction relative to the axis of rotation, the at least first transfer head actuator being mounted to the rotatable transfer assembly actuator and comprising an actuator element (<NUM>(a-h)) coupled to the at least one transfer head, the actuator element structured to be actuated in the direction of the axis of rotation relative to the rotatable transfer assembly actuator.