Manipulator, docking method therefor and data carrier usable in the method

Abstract

A manipulator (1) comprises a holder (11) for a test head (17) that can be moved in multiple degrees of freedom between a standby position and a docking position on a docking connection (23) of a peripheral device (20) in order to carry out measurements on semiconductor components in the peripheral device (20). The holder (11) carries a data reading device, which is configured to read data relating to the peripheral device (20) in an intermediate position assumed by the holder (11) on the way from the standby position to the docking position, and a navigation unit (28) is configured to control the docking position on the basis of the read data.

Description

[0001] Manipulator, docking method therefor and data carrier usable in the method

[0002] The present invention relates to a manipulator for docking a test head to a peripheral device, a docking method that can be carried out with the manipulator and a data carrier for use in the docking method.

[0003] Probes are used in the semiconductor industry to perform functional tests on semiconductor components during various stages of their production. To do this, the probe must be docked to a port on a peripheral device containing the semiconductor components to be tested, and which typically previously underwent a step in the manufacturing process whose result is to be determined using the probe.

[0004] To perform such a test on a large number of integrated circuits or their precursors produced on a common substrate, a large number of probe contacts and leads connected to probe contacts are required. The power released during a test process requires effective cooling, for which the required cooling medium is also usually supplied and removed via the probe. The mass of such a probe is therefore considerable, and the number of leads connected to it also makes the probe difficult to move.

[0005] It is therefore common practice to use a manipulator, such as that described in US 2006 / 0177298 A1, to move a test head between a rest position assumed when not in use and a docking position on a peripheral device. This known manipulator comprises a base and a holder that is movable relative to the base in three translational and two rotational degrees of freedom and on which the test head is pivotally suspended in a third rotational degree of freedom.

[0006] In a typical application, the manipulator, with the probe's connection surface essentially oriented horizontally, is pushed beneath the underside of the peripheral device where the connector to be docked is located. Because the probe and manipulator obstruct the view of the connector, it is difficult to position the manipulator beneath the peripheral device in such a way that simply lifting the probe is sufficient for docking.

[0007] To compensate for inaccuracies in placement, the test head and the peripheral device can be equipped with complementary centering pins and receptacles that engage when the test head is lifted, thereby increasingly determining the position of the test head relative to the connector until both finally align with the accuracy required to perform the test procedure. However, if the manipulator is positioned so inaccurately that the centering pins and receptacles miss each other when lifted, serious damage to the test head or the peripheral device can result.

[0008] From US2024 / 0036586 Al an autonomously navigating robot is known which uses an imaging sensor such as a camera or LIDAR to generate a map of its surroundings and to orient itself in this environment.

[0009] KR 20210125107 A discloses a system in which, for calibrating a robot intended to manipulate substrates in a substrate processing chamber, a camera is temporarily mounted on the substrate processing chamber. The calibration enables the robot to precisely manipulate substrates after the camera has been removed.

[0010] The object of the present invention is to provide a method and means for carrying it out which enable a quick and safe docking of a test head to a connection of a peripheral device.

[0011] According to one aspect of the invention, the object is achieved in that, in a manipulator with a holder for a test head which is movable in several degrees of freedom between a standby position and a docking position on a docking connection of a peripheral device in order to carry out measurements on semiconductor components in the peripheral device, the holder carries a data reading device which is set up to read data of the peripheral device in an intermediate position which the holder assumes on the way from the standby position to the docking position, and a navigation unit is set up to control the docking position based on the read data.

[0012] To enable fast and safe docking, it is therefore sufficient to place the manipulator in an intermediate position where the data can be read, in order to be able to automatically control the docking position from there.

[0013] The read data may include directions that the navigation unit can follow to reach the docking position.

[0014] According to a preferred embodiment, the data reading device is an imaging sensor, in particular a camera, and is oriented to detect a surface spaced apart from a connection surface of the test head. This opposite surface is, when the test head is in the intermediate position, typically a surface of the peripheral device adjacent to its connection and to which a data carrier to be read by the data reading device is attached.

[0015] In order to ensure a reliable and reproducible reading of the data, at least one light source for supplying the light required for a reading can be integrated with the imaging sensor in a structural unit.

[0016] In order to make it easier for the navigation unit to find the docking position starting from the intermediate position, the manipulator can further comprise an environmental sensor for detecting a reference feature of the peripheral device, wherein the navigation unit is configured to draw a conclusion about a path to be covered from the intermediate position in the direction of the docking position from a detected position of the reference feature and the read data.

[0017] Preferably, the environmental sensor is identical to the imaging sensor; in particular, one and the same camera can perform the functions of both the environmental sensor and the imaging sensor.

[0018] Since the orientation of the manipulator with respect to the peripheral device can vary before docking, the direction of a path that the test head must travel from the intermediate position to the docking position can only be uniquely described in a coordinate system related to the peripheral device. So that the navigation unit can find the correct direction in a coordinate system related to the manipulator or the test head, it should be set up to determine a rotation required for the transition from the intermediate position to the docking position from the orientation of the reference feature in an image from the imaging sensor. A distance to be traveled, however, can be determined from the read data.

[0019] If the imaging sensor is movable with the holder, preferably mounted on the holder, any deformation of the manipulator under the load of the probe and / or play when the navigation unit controls the movement of the holder will also affect the position of the imaging sensor and hence the position of the reference feature in an image generated by the sensor; therefore, no special corrective measures need to be taken to compensate for the effects of the deformation or play during docking.

[0020] In particular, in order to be able to effectively compensate for a play in a degree of freedom of rotation of the holder, the camera should be arranged at a location on the holder that is remote from an axis of rotation, such as at the free end of an arm carrying the test head.

[0021] If the path from the intermediate position to the docking position is short enough so that the reference feature is still within the detection range of the imaging sensor in the docking position, the navigation unit can be configured to derive a target position of the reference feature in an image from the imaging sensor from the read data and to steer the holder into the docking position by aligning the position of the reference feature in an image from the imaging sensor with the target position. Since the navigation unit receives continuous feedback on deviations between the actual and target positions in this way, precise control of the target position is possible using simple means.

[0022] The reference feature is expediently also the carrier of the data to be read by the data reading device. For example, the reference feature can be an RFID label that is glued to the peripheral device or attached in some other suitable way, which can be read by a transponder of the manipulator acting as a data reading device, and which is visible to a camera of the manipulator acting as an environmental sensor. According to a preferred embodiment, the reference feature is a flat object, such as a sign or a sticker, with a first main surface that is designed to rest on a surface of the peripheral device, and a second surface that bears an electro-optically readable code. A laser scanner can be provided for reading the code; preferably, the same camera is used for this purpose as for detecting the reference feature.

[0023] According to a second aspect of the invention, the object is achieved by a method for docking a test head to a peripheral device with the aid of a holder which is movable in several degrees of freedom and on which the test head is held, comprising the steps of: a) attaching a data carrier to a peripheral device, the data carrier encoding data which allows a conclusion to be drawn about a path (D) to be covered from an intermediate position of the holder, in which a data reading device carried by the holder is able to read the data from the data carrier, in the direction of a docking position for the test head on the peripheral device; b) moving the holder from a rest position into the intermediate position and reading the data; c) controlling the holder with the test head into the docking position on the basis of the read data. The data carrier can be identical to the reference feature.

[0024] Step c ) preferably comprises

[0025] Creating an image of the reference feature;

[0026] Determining a target position of the reference feature in the image based on the read data, and controlling the holder such that the position of the reference feature in the image matches the target position.

[0027] Based on the data read, a decision can be made as to whether automatic docking is possible. Step c) is only performed if it has been decided that docking is possible. If it has been decided that docking is not possible, an error message can be generated instead to alert a user that docking must be performed manually, assuming the test head is even physically compatible with the peripheral device's connector.

[0028] The data read in step b) can directly contain a description of the path to be traveled to the docking position. This is particularly useful if the reference feature is not identical to the data carrier and has a fixed spatial relationship to the connection, which can be measured and encoded in the data carrier during its manufacture.

[0029] According to a preferred alternative, the data read in step b) contain a unique identifier of the peripheral device to which the data carrier is attached. If the navigation unit of the manipulator receives this identifier from the data reading device and does not find a correspondence with stored identifiers, this leads to an error message as described above. If docking is then carried out manually, it can be provided that the navigation unit records the path covered during manual docking or the position of the reference feature in the camera image after docking and stores it in connection with the read identifier. If the manipulator is to be docked to the same peripheral device again and the identifier is read again, the navigation unit finds the corresponding stored entry and can use this to carry out docking automatically.

[0030] It is also conceivable that the identifier does not uniquely identify a single peripheral device, but merely a device type. If it is ensured that the data storage device is attached in the same location on all devices of this type, it makes no difference to the navigation unit's control of the connection whether the identifier identifies peripheral devices or device types.

[0031] If the data carrier is attached to the same position on all devices of the same type, the data on the data carrier may, instead of a type identifier, contain information describing the path to be covered from the intermediate position to the docking position.

[0032] Further features and advantages of the invention will become apparent from the following description of exemplary embodiments with reference to the accompanying figures. They show:

[0033] Fig. 1 is a perspective view of a manipulator;

[0034] Fig. 2 is a perspective view of a peripheral device; Fig. 3 is a side view of the manipulator in an intermediate position of the docking process, in front of the peripheral device;

[0035] Fig. 4 is a block diagram of the manipulator control system;

[0036] Fig. 5 shows an exemplary image generated by the manipulator’s camera;

[0037] Fig. 6 is a flowchart of an operating method of the controller according to a first embodiment of the invention;

[0038] Fig. 7 shows an exemplary image of the camera according to a second embodiment of the invention; and

[0039] Fig. 8 is a flowchart according to the second embodiment.

[0040] Fig. 1 shows a perspective view of a manipulator 1. The manipulator 1 has a base plate 2 with several rollers 3 that allow manual movement of the manipulator 1, for example, from a standby position to an intermediate position, and feet 4 that can be moved toward the floor to lift the rollers 3 off the floor and fix the base plate 2 relative to the floor.

[0041] A first carriage 5 is movable on the base plate in the x-direction of a coordinate system related to the base plate 2. The rails guiding the movement are covered by bellows 6. The carriage 5 carries a carriage 7 which is movable in the y-direction, and this in turn carries a column 9 which is rotatable about an axis 8 oriented in the z-direction, i.e. vertical axis, and has a carriage 10 which is adjustable in the z-direction. A U-shaped holder 11 for a test head 17 is mounted on the carriage 10 so that it can pivot about a horizontal axis 12. Two arms 13, 14 of the holder 11 carry holders 16 which can pivot about a further horizontal axis 15 and between which the test head 17, shown here in a separate position and schematically as a cuboid, can be mounted.

[0042] At the distal end of the arm 13, a camera 18 is mounted with a viewing direction perpendicular to the plane of the axes 12, 15.

[0043] An exposed cover glass on top of the camera 18 is shown in a detailed magnification.

[0044] Located beneath the center of the cover glass is an objective lens 35 of the camera 18; light sources 36, such as LEDs, are distributed around it. The annular arrangement of the light sources 36 around the objective lens 35 ensures illumination of the field of view of the camera 18 that is essentially free of cast shadows, so that local brightness differences in the images provided by the camera 18 can be clearly attributed to differences in the albedo of an illuminated surface.

[0045] If the light sources 36 are narrowband emitting LEDs, the cover glass can be a color filter that transmits the emission wavelength of the LEDs. By not significantly attenuating the emission of the LEDs but suppressing ambient light whose wavelength does not match the emission wavelength of the LEDs, the sensitivity of the camera 18 to ambient light can be reduced.

[0046] As a further measure to improve tolerance to ambient light, it can be provided that the camera is only sensitive during a shutter opening time and the light sources are operated in pulsed mode and synchronized with the shutter opening time in order to provide a higher light output in each light flash than would be possible in continuous operation. Fig. 2 shows a view obliquely from below of a peripheral device 20 in which the test head 17 is to be used. A connection 23 for the test head 17 is formed on the exposed underside 22 of a process chamber 21 of the peripheral device 20. A frame 24, which surrounds a feedthrough opening 25 of the connection 23, carries a plurality of centering pins 26, which are provided to engage in receptacles 19 of the test head 17 during a docking process.

[0047] A reference feature 27 in the form of a sign or sticker is arranged on the underside 22 outside the frame 24. In order to enable automatic docking when the manipulator 1 has been pushed under the process chamber 21 such that the test head 17 is approximately opposite the frame 24, as shown in Fig. 3, the reference feature 27 must be in the field of view of the camera 18. In order for this to be the case with sufficient reliability, the field of view of the camera 18 in the plane of the underside 22 in the x and y directions should each have an edge length of not less than 10 cm, and better still, of at least 20 cm.

[0048] In order to ensure easy recognition of the reference feature 27 by the camera 18 and reliable evaluation of data encoded in it, the surface of the reference feature preferably has only two discrete albedo values. By preferably making a part of the surface retroreflective, it reflects the light of the light sources 36 essentially only in the direction of the front lens 35 and thereby achieves a significantly higher albedo than the surface areas surrounding the reference feature 27 and thus makes it easier to identify the reference feature 27 in the images from the camera 18. Other parts of the surface can be dark in color and thus have a significantly lower albedo than the area surrounding the reference feature 27. In particular, the reference feature 27 can comprise a retroreflective film onto which dark structures are printed locally or which is locally removed in order to form surface areas with the low albedo.

[0049] Fig. 4 shows a block diagram of the control of the manipulator 1. A navigation unit 28 is connected to the camera 18 in order to receive images generated by the latter and to control motors 29 for translating the holder 11 in the x, y and z directions and for rotating it at least about the vertical axis 8 with the aid of information extracted from these images. The navigation unit 28 can be built into the manipulator 1 or control it externally. Force sensors 30 can be provided on the receptacles 19 in order to detect forces exerted by the centering pins 26 and optionally by the frame 24, which forces are used by the navigation unit 28 to control motors 29 assigned to the axes 12 and 15.

[0050] Navigation data for various peripheral devices are stored in a memory 31.

[0051] A user interface 32 may be provided to enable commands to control the motors 29 to be entered manually.

[0052] Fig. 5 shows an example of an image as it could be recorded by the camera 18 after the manipulator 1 has been pushed by hand under the process chamber 21 of the peripheral device 20. A section of the underside 22 with part of the frame 24 and the reference feature 27 can be seen. The reference feature 27 comprises, on the one hand, data and, on the other hand, an orientation mark, shown here as letters and a type of crosshair. Both can be replaced or supplemented by a barcode or QR code. After the manipulator 1 has been placed in the intermediate position (SO), the navigation unit 28 is activated in order to control automatic docking of the test head 17 to the connection 23. The operating method then carried out by the control unit is shown in Fig. 6. In a first step S 1 , the navigation unit 28 reads in the current image from the camera 18.If the image evaluation in step S2 reveals that no reference feature can be found in the image, the process aborts with an error message S3, which alerts the user that manipulator 1 must be positioned more precisely. Once this is done, the process can be restarted.

[0053] If a reference feature is present in the image, the navigation unit 28 extracts the data contained therein in step S4.

[0054] According to a first embodiment of the method, the data contain a unique identifier of the peripheral device 20. In step S5, the navigation unit 28 checks whether a data record linked to this identifier is contained in the navigation data of the memory 31.

[0055] If so, then in step S 6 it determines from this data set a target position and orientation of the reference feature 27 , shown in Fig . 5 with dashed lines and spaced from the real reference feature 27 by a path D , and controls the motors assigned to the translation in the x and y directions and the rotation about the axis 8 ( S 7 ) and, if necessary, reads new images from the camera 18 until a satisfactory correspondence between the position and orientation of the reference feature 27 visible in the current image of the camera 18 with the target position and orientation is determined in S 8 . In particular, the navigation unit 28 can calculate a correction of the position of the holder 11 in the x and y directions and the orientation about the axis 8 from the offset between the target and actual position and orientation of the reference feature 27 determined in an image, make the calculated corrections and then generate another image.

[0056] If the actual position and orientation of the reference feature 27 correspond with the target values ​​with satisfactory accuracy, then the test head 17 is in such a position under the connection 23 - referred to here as the engagement position - that when the holder 11 is lifted (S 9) the centering pins 26 reliably engage in the receptacles of the test head 17 and the latter comes to rest exactly on the frame 24.

[0057] If no data record linked to the identifier is found in step S5, the method can also abort with an error message. Preferably, however, and as shown in Fig. 6, the user is instead shown a message (S10) that no navigation data is available for this peripheral device 20 and that docking to the connection 23 must therefore be controlled manually. If the user then carries out such control via the user interface 32, the navigation unit 28 records in step S11 the position and orientation that the reference feature 27 has in the image taken by the camera 18 immediately before the test head begins to be raised, and links this in the navigation data in the memory 31 with the identifier determined in step S4.The test head 17 is docked by the manually controlled lifting; when the manipulator 1 is later brought into the intermediate position again on the same peripheral device 20, the navigation data are available in the memory 31, on the basis of which the navigation unit 28 can automatically carry out the docking with the steps S 6 - S 9.

[0058] In order to make an existing peripheral device suitable for use within the scope of the invention, it is sufficient to attach the reference feature 27 to this device in such a way that it can be seen by the camera 18 when the measuring head 17 is in the engaged position. As a result, the position of the reference feature 27 on the peripheral device is only roughly defined, and the reference feature 27 can be placed quickly, e.g. in the form of a sticker, without the use of tools or measuring instruments. Apart from the identifier, the reference feature does not need to contain any further data, since the path D corresponding to the identifier is learned individually by the navigation unit 28 of each individual peripheral device on which the manipulator 1 is used.

[0059] According to a second embodiment of the invention, the reference feature 27 is placed on the peripheral device 20 in exact spatial relationship to its connection 23, e.g. as shown in Fig. 7, with the aid of a gauge 33 (highlighted by hatching in the figure) which is placed against a corner of the frame 24 and which, through its shape, here for example through free edges 34, defines a desired position at which the reference feature 27 is to be attached to the underside 22. Since the position of the reference feature 27 relative to the connection 23 is thus clearly defined, the desired position of the reference feature 27 in the camera image does not have to be learned in each individual case, but can be determined before the reference feature 27 is attached and noted on the reference feature 27 in machine-readable form.

[0060] The working method of the navigation unit 28 according to this embodiment is shown in Fig. 8. In steps S0-S4 it is identical to that of Fig. 6. In step S5' the navigation unit 28 rotates the measuring head 17 about the axis 8 in order to adjust the orientation of the real reference feature 27, as it appears in the images of the camera 18, to the desired orientation. In order to prevent the reference feature 27 from leaving the field of view of the camera 18, corrective movements of the carriages 5, 7 in the x and y directions may be necessary.After the orientation has been adjusted, it is sufficient to move the holder 11 in the x and y directions so that the reference feature 27 in the camera images comes to lie at a position defined in the data noted on the reference feature 27 (S 6 '); when this has happened, the engagement position is reached, from which the measuring head 17 can be lifted in step S7 ' and docked onto the connection 23.

[0061] According to one variant, the navigation unit 18, based on the angle α by which the test head 17 was rotated in step S5', determines a transformation between the axes x, y of the coordinate system related to the base plate 2 and axes of a coordinate system defined on the reference feature 27, e.g., as directions of the axes of the crosshairs, in which the path D is noted on the reference feature 27. As a result, the navigation unit 18 is able to convert the path D into distances to be traveled by the test head 17 in the x and y directions and, by controlling a translation over these distances, to bring the measuring head 17 into the engagement position, even if the reference feature 27 is no longer in the field of view of the camera 18 in the engagement position. P43990DE00

[0062] List of reference symbols

[0063] 1 manipulator

[0064] 2 base plate

[0065] 3 rolls

[0066] 4 feet

[0067] 5 sleds

[0068] 6 bellows

[0069] 7 sleds

[0070] 8 axis

[0071] 9th pillar

[0072] 10 sleds

[0073] 11 holders

[0074] 12 Axis

[0075] 13 arms

[0076] 14 arms

[0077] 15 Axis

[0078] 16th version

[0079] 17 test heads

[0080] 18 Camera

[0081] 19 recording

[0082] 20 Peripheral device

[0083] 21 Trial Chamber

[0084] 22 Bottom

[0085] 23 Connection

[0086] 24 frames

[0087] 25 Feed-through opening

[0088] 26 centering pin

[0089] 27 Reference feature

[0090] 28 Navigation unit

[0091] 29 Engine

[0092] 30 force sensor

[0093] 31 storage

[0094] 32 User interface

[0095] 33 Teaching

[0096] 34 rand

[0097] 35 lens

[0098] 36 light source

Claims

Patent claims 1. Manipulator (1) with a holder (11) for a test head (17), which is movable in several degrees of freedom between a standby position and a docking position on a docking connection (23) of a peripheral device (20) in order to carry out measurements on semiconductor components in the peripheral device (20), characterized in that the holder (11) carries a data reading device which is set up to read data of the peripheral device (20) in an intermediate position which the holder (11) assumes on the way from the standby position to the docking position, and a navigation unit (28) is set up to control the docking position on the basis of the read data.

2. Manipulator according to claim 1, wherein the data reading device is an imaging sensor (18), in particular a camera (18), and is aligned to detect a surface (22) located at a distance from a connection surface of the test head (17), wherein optionally the imaging sensor (18) is integrated with a light source in a structural unit.

3. Manipulator according to claim 1 or 2, further comprising an environmental sensor for detecting a reference feature (27) of the peripheral device (20), wherein the navigation unit (28) is configured to draw a conclusion about a path (D) to be covered from the intermediate position in the direction of the docking position from a detected position of the reference feature (27) and the read data.

4. Manipulator according to claim 3, as far as dependent on claim 2, in which the environmental sensor is the imaging sensor (18).

5. Manipulator according to claim 4, wherein the navigation unit (28) is configured to determine from the orientation of the reference feature (27) in an image of the imaging sensor (18) a rotation required for the transition from the intermediate position to the docking position and optionally from the read data a distance to be covered for the transition.

6. Manipulator according to claim 4 or 5, wherein the imaging sensor (18) is movable with the holder (11) and optionally the navigation unit (28) is configured to derive a desired position of the reference feature (27) in an image of the imaging sensor (18) from the read data and to control the holder (11) into the docking position by bringing the position of the reference feature (27) in an image of the imaging sensor (18) into line with the desired position.

7. Manipulator according to one of claims 3 to 6, wherein the reference feature (27) is a carrier of the data to be read by the data reading device.

8. Manipulator according to one of the preceding claims, in which the navigation unit (28) is set up to decide (S2, S5) on the basis of the read data whether it is able to control docking, and optionally to only approach the docking position (S6-S8) after it has been decided that docking is possible, and / or to generate an error message (S3, S10) if it has been decided that it is not able to control docking.

9. Method for docking a test head (17) to a peripheral device (20) by means of a holder movable in several degrees of freedom (11) on which the test head (17) is held, comprising the steps of: a) attaching a data carrier (27) to a peripheral device (20), the data carrier (27) encoding data which allows a conclusion to be drawn about a path (D) to be covered from an intermediate position of the holder (11), in which a data reading device (18) carried by the holder (11) is able to read the data from the data carrier (27), in the direction of a docking position for the test head (17) on the peripheral device (20); b) moving the holder from a rest position into the intermediate position (S0) and reading (S1) the data; c) controlling the holder (11) with the test head (17) into the docking position on the basis of the read data (S4-S9; S4, S5'-S7').

10. The method according to claim 9, wherein the data carrier (27) is the reference feature (27).

11. The method according to claim 9 or 10, wherein step c) generating (Sl) an image of the reference me r kma 1 s (27); Determining a target position of the reference feature in the image based on the read data, and Controlling (S4-S9) the holder (11) such that the position of the reference feature (27) in the image coincides with the target position.

12. Method according to one of claims 9 to 11, comprising the step d) Deciding (S2, S5) whether docking is possible based on the read data, whereby step c) is only carried out (S6 — S9) if it has been decided that docking is possible and / or an error message is generated (S3; S10, S11) if it has been decided that docking is not possible.

13. The method according to one of claims 9 to 12, wherein the data read in step b) contain a unique identifier of the peripheral device and the path to be covered from the intermediate position to the docking position is determined on the basis of a memory entry assigned to the identifier (S4), or the reference feature (27) is attached to a location on the peripheral device that is predetermined for a type of peripheral device, the data read in step b) contain a unique identifier of the type of peripheral device and the path to be covered from the intermediate position to the docking position is determined on the basis of a memory entry assigned to the identifier, or the reference feature (27) is attached to a location on the peripheral device that is predetermined for a type of peripheral device, the data read in step b) contain parameters of a path to be covered from the intermediate position to the docking position.

14. A data carrier (27) for attachment to a peripheral device (20) in a method according to any one of claims 9-12, which encodes data which allows a conclusion to be drawn about a data read-out device (18) carried by the holder (11) from an intermediate position of the holder (11) in which a data reading device (18) carried by the holder (11) is capable of reading the data from the To read the data carrier (27), allow the path (D) to be covered in the direction of a docking position for the test head (17) on the peripheral device (20).

15. Data carrier according to claim 14, in the form of a flat object with a first main surface which is designed to bear against a surface of the peripheral device, and a second surface on which the data is encoded in electro-optically readable form, wherein optionally the coding comprises light and dark surface areas and further optionally the light surface areas are retro-reflective.

Images