Abstract:
The invention relates to a method and a device for measuring electric components, in particular for the high-frequency measurement of said components. The invention is characterized by the use of contact elements that can be displaced between an initial position and a measuring position. In the latter, the respective contact elements lie against a stop of the component and a measuring contact. Said contact elements are retained in supports including electrically insulated material.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    The present invention relates to a process and device for high frequency measuring electrical components.  
           [0002]    In the manufacture of small electric components, for example so-called “surface mounted devices” (SMDs), it is necessary that the components, or their electric values, be measured, or tested, in so-called “back-end machines”. For such components that are intended for use at high frequencies (GHz range), a special high-frequency measurement is required.  
           [0003]    A measuring device (U.S. Pat. No. 4,047,780) is known in which the contact elements are provided on movable carriers and are formed by springs. For high-frequency measurements, and also for the measurement of components with very small dimensions, in which the connections are located very close together, this type of a device is not suitable.  
           [0004]    A further measuring device (DE 196 10 462) is known in which the measuring contacts are formed by relatively long leaf-spring elements. Each connection of a component is allocated two such measuring contacts, which can be moved toward and away from the connection in the manner of tweezers. This known measuring device is not suitable for high-frequency measurements due to the long length of the measuring contacts. Furthermore, this known construction is problematic with respect to the arrangement of the measuring contacts when measuring components with very small dimensions.  
           [0005]    Finally, a measuring device (IP 063 47 511) is known in which, for the simultaneous contact of several connections, measuring contacts are located on a strip-like contact carrier that can be moved perpendicular to its longitudinal extension to the contacts of the respective component in order to make the contact. The measuring contacts are connected with a measuring circuit via conductors. This known device is not suitable for high-frequency measurements.  
           [0006]    The object of the present invention is to present a process and a measuring device that enables a reliable measurement together with high performance. The device has electrical connections extending from a component housing, whereby during measurement the connections of each component are connected with measuring contacts by means of movable contact elements. The contact elmeents slide or roll at least one measuring contact during movement from a starting position to a measuring position.  
           [0007]    The present invention enables a reliable measurement, especially a high frequency measurement, together with high performance (measured components per time unit), by means of a particularly simple construction. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]    The invention is described in more detail based on a sample embodiment as depicted in the drawings, as follows:  
         [0009]    [0009]FIG. 1 shows a simplified representation in top view of a component to be measured after being punched form the lead frame;  
         [0010]    [0010]FIG. 2 shows a simplified representation in top view of a back-end machine for processing the components of FIG. 1;  
         [0011]    [0011]FIG. 3 shows an enlarged partial representation of a measuring device according to the present invention;  
         [0012]    [0012]FIG. 4 shows the measuring device of FIG. 1 in top view;  
         [0013]    [0013]FIG. 5 and  6  show a partial representation in side view of the measuring device of FIG. 1 in two different working positions;  
         [0014]    [0014]FIG. 7 shows an enlarged representation in top view of a component located in a receptacle or measuring position of the measuring device, together with the lateral measuring contacts;  
         [0015]    [0015]FIG. 8 shows a simplified representation in side view of a measuring station with the measuring device of a facility for processing electric components, for example a back-end machine, for the electric components;  
         [0016]    [0016]FIG. 9 shows an enlarged partial representation in side view of a further possible embodiment of a measuring device according to the present invention;  
         [0017]    [0017]FIG. 10 shows a top view of the PCB or the contact element carrier of the measuring device of FIG. 9, together with a component located in the measuring position;  
         [0018]    [0018]FIG. 11 shows a simplified representation in top view of the measuring device of FIG. 9; and  
         [0019]    [0019]FIG. 12 shows an enlarged partial representation in side view of several disk-like contact element carriers of the measuring device of FIG. 9. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0020]    The drawings show electric components  1  in the form of SMDs with extremely small dimensions. The components  1  are intended for applications in the GHz range and have a 3 dB critical frequency of approximately 10 GHz. The components have a housing  2 , in which the respective semiconductor chip is accommodated and on two opposite longitudinal sides of which the electric connections  3  are located on both sides of a middle plane M, i.e. in the depicted embodiment there is a total of six connections  3 .  
         [0021]    [0021]FIG. 2 shows for the purpose of illustration, a so-called back-end machine  4 , which is used to punch out the individual components  1 , which are arranged in a lead frame  5  in several parallel rows, from this lead frame in a punching station  6 , to which the lead frame  5  is fed, and then to transport the components by means of a first transporter  7  to a second transporter  8 , on which the components are held individually and in a pre-defined orientation, i.e. with their connections  3  perpendicular to the horizontal direction of transport A of the transporter  8  on the lower end of vacuum holders  9 , which are arranged sequentially in the transport direction A of the transporter  8  and are moved in cycles. The components  1 , which are for example, transistors or integrated circuits, etc. are moved by means of the transporter  8  to a measuring station  10 , at which, in particular a high-frequency measurement or test of the high-frequency properties of each component  1  is conducted. Depending on the measuring result, among other things, the components  1  are then either sorted out or classified at stations  11  according to their properties, or sorted and placed in trays, or classified according to their properties at belt stations  12 , or sorted and belted. Such a back-end machine, but not having a high-frequency measuring station, is described, for example, in the PCT application PCT/DE 98/00268 (WO 98/34452).  
         [0022]    In order to achieve high performance for the back-end machine  4 , it is also necessary that the high-frequency measurement of the individual components  1  is performed very quickly with the required high degree of precision. A measuring device that fulfills these conditions, among others, is described in more detail in FIGS.  3 - 7 , where it is generally designated  13 . FIG. 8 shows the measuring station  10  with the measuring device  13 .  
         [0023]    The measuring device  13  includes a printed circuit, board or substrate  14 , which in the depicted embodiment, is oriented horizontally with its surfaces and is located beneath the movement path of the components  1  held on the vacuum holders  9 .  
         [0024]    The substrate  14 , made of electrically flat insulating material, accommodates, among other elements, the electronic measuring circuitry and measuring contacts  15  on both sides of a vertical plane designated VE in FIGS.  3 ,  5 - 7 . In the depicted embodiment, these measuring contacts are made of a rectangular, or stripe like, metal surface on the top of the substrate  14 . The substrate  14  is, for example, a ceramic board, which, using for example the DCB process (direct copper bonding process—U.S. Pat, No. 3,744,120) known to experts and subsequent structuring and surface processing (nickel plating), is provided with the measuring contacts  15 . In the depicted embodiment, the rectangular measuring contacts lie with their longitudinal side perpendicular to the plane VE enclosing the direction of transport A.  
         [0025]    The number and arrangement of the measuring contacts  15  corresponds to the number and arrangement of the connections  3  of the components, in such a manner that whenever a component  1  has reached the measuring device  13 , or the measuring position, located there during the pulsed movement of the transporter  8 , each connection  3  of this component is located directly above a measuring contact  3 . The middle plane M of the respective component  1  lies in the plane VE. The connections  3  extending on both sides from the component  1  lie with their longitudinal side perpendicular to the plane VE.  
         [0026]    In order to create the shortest possible electrical connection path between the respective connection  3  and the corresponding measuring contact  15 , the measuring device  13  is provided with movable contact elements  16 , which in the depicted embodiment, are small rollers made of metal, i.e. of a metal that is suitable for measuring contacts. Due to the skin effect at high frequencies, the contact elements  16  can be made of copper, for example, with surface refinement (e.g. nickel plating).  
         [0027]    The contact elements  16  can rotate freely on a horizontal axis parallel to the direction of transport A and can move in an axis direction perpendicular to the plane VE between a non-activated starting positions not contacting the connections  3  with a larger distance from the plane VE, and a measuring position, in such a manner that the contact elements  16  in the measuring position each contact the blunt end of a contact  3  with a precisely defined force, and likewise, with a precisely defined force contact the corresponding measuring contact  15  and therefore create the electrical connection between the respective connection  3  and the corresponding measuring contact  15  of the measuring circuit board  14 , via two spatially separate contact areas.  
         [0028]    During the movement from the starting position, into the measuring positions, and during the movement after measuring from the measuring position, back into the starting position, each of the contact elements  16  rolls off to its corresponding measuring contact  15 , so that with each new measurement, each contact element  16  contacts the connection  3  and the measuring contact  15  with other surfaces, or contact areas, thus achieving a long useful life for the measuring device  13 , and, in particulars its contact elements  16 , preventing the need for replacement of this measuring device  13 , or its contact elements  16 , for example, due to contamination of the contact elements  16  with tin, which accumulates on the ends of the connections  3  during punching out of the components  1  from the tin-plated lead frame.  
         [0029]    The described manner of producing the electric connection between the connections  3  and the measuring contacts  15 , via the contact elements  16 , has the advantage, for example, that the connection requires a very short path, which is essential for high-frequency measurement, and moreover that the contact on the connections  3  takes place on the front surfaces on the free ends of these connections, which (ends) were just produced by punching out the components  1  from the lead frame  5 . The free ends of the connections  3  form high-quality contact surfaces, in particular not contaminated by oxides, etc., which enables a reliable measurement in a short time. Furthermore, the contact elements  16  can be pressed against the respective connection  3  and against the corresponding measuring contact  15  with a precisely defined force, in order to achieve a reliable contact and measurement.  
         [0030]    In the depicted embodiment, the roller-like or disk-like contact elements  16  are located on the end  17 ′ of a disk-like carrier  17 , which is made of a plastic material suitable for high-frequency applications and is oriented with its surfaces perpendicular to the plane VE. Between the two ends  17 ′, and  17 ′, the carriers  17  are curved convexly on their upper longitudinal side and curved concavely on their bottom longitudinal side.  
         [0031]    For holding the respective contact element  16 , the end  17 ′ of the carrier  17  is provided with a recess  18  on a surface  17 ″′ with a depth equal to, or greater than, the thickness of the respective disk-like contact element  16 . In each recess  18 , there is a pin  19  that lies with its axis perpendicular to the surfaces of the carrier  17 , and on which, the respective measuring element  16  can rotate freely on bearings. Furthermore, as the drawings show, the carriers  17  are each curved in the shape of an arch between their two ends  17 ′ and  17 ″ and otherwise located above the substrate  14  in such a manner that the concave lower longitudinal side of each carrier  17  extending between the ends  17 ′ and  17 ″ faces the top of the substrate  14 .  
         [0032]    The carriers  17  are each provided with notches  21  that partially extend from the convex upper longitudinal side of these carriers and partially from the lower concave longitudinal side. Due to the notches  21  the carriers  17  are elastically deformable in the manner of a clip spring, for example, by pressing on the upper convex longitudinal side, from the unstrained condition with a smaller radius of curvature between the two ends  17 ′ and  17 ″ to a strained condition with a larger radius of curvature and therefore with a larger distance between these two ends  17 ′ and  17 ″.  
         [0033]    The carriers  17  are arranged directly neighbored to each other in stacks  22  on both sides of the plane VE, in the direction of transport A following each other in such a manner that each surface  17 ″′ with a contact element  16  located in the recess  18  there lies adjacent to a surface  17 ″″ of a connecting carrier  17 , so that the contact element  16  in each carrier  17  is secured against falling out by the adjacent carrier  17 . In order to secure all contact elements  16  in this ways the stack  22  has an additional carrier  17  without contact elements  16 .  
         [0034]    The carriers  17  of each stack  22  are fastened to a common bearing  23 , of a carrier  24 , on the end  17 ″ at a distance from the plane VE, in such a manner as to enable the quick exchange of the carriers  17 . The substrate  14  is also fastened to the carrier  24 .  
         [0035]    The carriers  17  of each stack  22  are held between the shanks  25 ′ of a pressure plate with a U-shaped profile that bears with a yoke section  25 ″ connecting the shanks  25 ′ against the concave upper longitudinal side of the carriers  17  of the respective stack  22 . Each pressure plate  25  is connected by means of a side shackle  26  with a tappet  27  that can be moved up and down in a controlled manner, as indicated in FIG. 3 by the double arrow C, so that each downward stroke of the tappet  27  above the pressure plates  25  results in a deformation of the carriers  17  in such a manner that the contact elements  16  move from the starting position to the measuring position, in which they bear against the respective connection  3  and the contact surface  15  with the defined force. With the upward stroke of the tappet  27  the contact elements  16  move back to their starting position (double arrow B).  
         [0036]    Furthermore, on the measuring device  13 , or the measuring position there, there is a lower centering and clamping unit  28  that is spring-mounted on the upper end of a vertical tappet  29 , which can move vertically upwards and downwards by a specified stroke (double arrow D) by means of the driving mechanism of the measuring station  10  accommodating the measuring device.  
         [0037]    The centering and clamping unit  28  forms an open V-shaped receptacle  30  toward the top with two lateral angled centering surfaces  30 ′, which are offset from each other in the direction of transport A and against which, for the purpose of centering, the front sides of the components  1 , or their housings  2  that do not have the connections  3  bear. Furthermore, the centering and clamping unit forms two lower clamping elements  31 , which are offset in relation to the centering surfaces  30 ′ by 90° on the vertical axis and form clamping surfaces  31 ″ on their free ends and angled centering surfaces  31 ″ connecting to the latter, for centering of the component  1  or its housing  2  on the longitudinal sides possessing the connections  3 . The centering surfaces  31 ″ have, for example, a rib-like design so that they work together with the longitudinal sides of the housings  2  possessing the connections  3  only outside of these connections  3 .  
         [0038]    The centering and clamping unit  28 , or its centering element  30 , with the centering surfaces  30 ′ and their clamping elements  31  are, for example, a single functional element. However, it is also generally possible to design the centering and clamping unit  28  of several parts, in particular, in such a manner that a relative vertical movement between the centering unit  30  and the clamping elements  31  is possible  
         [0039]    On the measuring device  13 , there are two upper clamping elements  32 , on both sides of the plane VE, such that each upper clamping element  32  lies opposite a clamping surface  31 , with a clamping surface  32 ′.  
         [0040]    The elements of the centering and clamping unit  28 , and the upper clamping elements  32 , include an electrically insulating material that is suitable for high-frequency applications and is non-wearing, and are made of ceramic, for example, at least in their areas that lie adjacent to the respective component  1  to be measured. The upper clamping elements  32  are fastened to a holder  33 , which in turn is held on the upper end of a vertical tappet  34 , which can move upwards and downwards by a predefined stroke (double arrow E) by means of a driving mechanism.  
         [0041]    The function of the measuring device  13  can therefore be described as follows:  
         [0042]    Whenever a component  1  held on a vacuum holder  9  has reached the measuring position of the measuring device  13 , the following functions are carried out during the following stopped phase of the pulsed transporter  8 :  
         [0043]    First, the centering and clamping unit  28  is moved upward by means of the tappet  29 , so that the component  1  is received by the centering hole  30 , is centered there on the centering surfaces  30 ′ in the axis of the direction of transport A, with the component  1  being held by the vacuum holder  9 . The clamping surfaces  31 ′ bear against the bottom side of all connections  3 . The connections  3  lie in a common plane perpendicular to the plane VE above the plane in which the axes of the disk-like contact elements  16  are located.  
         [0044]    The upper clamping elements  32  are then lowered by the synchronous actuation of the corresponding tappet  34 , whereby the connections  3  are first clamped between the clamping surfaces  31 ′ and  32 ′ and during the further downward movement of the clamping elements  32  and the elastic deformation of the centering and clamping unit  28  the respective component  1  is released from the vacuum holder  9 , now in the position secured between the clamping elements  32  and the centering and clamping unit  28 . The component  1  is lowered so far that the plane of the connections  3  is in the plane in which the axes of all contact elements  16  are located.  
         [0045]    Once this state is achieved, the carriers  17  are deformed by synchronous actuation of the tappet  27  and by lowering of the pressure plates  25  in such a way that the disk-like contact elements  16  are pressed with a pre-defined force against the ends of the connections  3  extending only partially from the lower clamping elements  31  and the upper clamping elements  32  and simultaneously also with a pre-defined force against the corresponding measuring contact  15 .  
         [0046]    The forces with which each contact element  16  is pressed against the connection  3  and against the measuring contact  15  are determined, with a pre-defined stroke of the pressure plate  25 , by the elasticity or spring constant of the carriers  17  and their curvature.  
         [0047]    After conducting the measurement, the described functional elements are moved in the reverse order, i.e. first the pressure plates  25  are moved upward in order to release the connections  3  by the measuring elements  16 . Afterwards, the clamping elements  32  are moved upward, so that with a following spring-mounted centering and clamping unit  28  and the resulting still securely held component  1 , this component is again held with its housing  2  by the vacuum holder  9 . After the final upward movement of the clamping elements  32  and after lowering of the centering and clamping unit  28  the measured component is then further transported in the new movement step of the transporter  8  and a new component  1  arrives at the measuring position of the measuring device  13 .  
         [0048]    The fact that there is a space between the respective component  1  and the vacuum holder  9  during the measurement insures, for example, that the measurement is not falsified by the vacuum holder  9 , especially if this vacuum holder is made of a material that is not suitable for high-frequency applications and/or if foreign matter etc. that could negatively affect the high-frequency measurement has accumulated in the vacuum holder  9 .  
         [0049]    The measuring device  13 , as described above, is part of a measuring station  10  and is located there on the top of a housing  35  of this measuring station. In the housing  35  there is a central slide  36 , in an axis direction perpendicular to the plane VE. The slide  36  has several regulating grooves  37 , into which the drivers or guide elements located on the tappets  27 ,  29  and  34  are inserted. The regulating grooves  37  are designed in such a way as to guarantee that the movements of the functional elements of the measuring device  13  or of the measuring station  10  are carried out in the required sequence. The slide  36  is controlled by the central driving mechanism of the back-end machine. The measuring station  10  can be replaced as an integral unit.  
         [0050]    As described above, the measurement of the component  1  takes place in the depicted embodiment before bending of the connections  3  into the S-shape that is usual for SMD components.  
         [0051]    FIGS.  9 - 12  show, as a further possible embodiment of the invention, a measuring device  13   a . This includes, among other elements, of a PCB or substrate  40 , which is made of a flat insolating material and the surfaces of which are oriented in vertical planes, parallel to the horizontal direction of transport A of the transporter  8 , of which only the vacuum holders  9  are depicted in FIGS.  9 - 12 . The direction of transport A runs perpendicular to the drawing plane of the representation selected for FIG. 9.  
         [0052]    The top of the substrate  40  forms a receptacle  41  that defines the measuring position and into which the respective component  1  can be inserted by means of the vacuum holder  9  in such a manner that the component  1  in the receptacle  41  corresponds exactly to a pre-defined orientation and is arranged perpendicular to the horizontal direction of transport A on both sides of a middle plane M enclosing this direction of transport and extending parallel to the surfaces of the substrate  40 . On both sides of the substrate  40 , there are two holders  42  made of an electrically insulating material, for example of plastic, which have a fork-shaped design in their upper area at  42 ′, both with two parallel fork arms  43  that are at a distance from each other in the direction of transport A and that extend vertically upward starting from their lower area  42 ″. On the lower area  42 ″ each holder  42  is solid, i.e. not fork-shaped and is held on a machine frame that supports the substrate  40 .  
         [0053]    Between the two fork arms  43  of each holder  42 , there are several carriers  47  corresponding to the carrier  17 , which are made of an electrically non-conductive material, preferably of plastic, likewise sheet or plate-shaped in such a manner that the larger surfaces of these carriers  47  are oriented in vertical planes perpendicular to the direction of transport A. In the depicted embodiment, there are three carriers  47  directly neighbored to each other in the manner of a plate packet on each holder  42  between the two arms  43 . Each carrier is secured on its lower end  47 ′ in FIG. 9 against rotating on the corresponding holder  42 , but can be easily replaced, using two pins  48 , the axes of which are parallel to the direction of transport A and which are provided collectively for all carriers  47  of a holder  42  and which extend through congruent holes in the carriers  47  and in the arms  43  of the respective holder  42 . On the upper free end  47 ″, contact elements  49  are held in some carriers  47 , in such a manner that these contact elements  49  can pivot by a defined angle on an axis parallel to the direction of transport A.  
         [0054]    The contact elements  49  in the depicted embodiment are designed with at least two layers. They include of the layer  50  made of an electrically insulating material. This layer forms one surface of each contact element  49 , such that the layer  50  separates and electrically insulates the adjacent contact elements  49 . Furthermore, each contact element  49  includes a layer  51  made of an electrically conductive material, for example of copper. The free surfaces of this layer  51  are provided with an electrically conductive surface made of an anti-corrosive and mechanically stable metal, such as nickel. The layer  51  forms the other respective surface of the plate or disk-shaped contact elements  49 . In the depicted embodiment, the thickness of the layer  50  is considerably smaller than the thickness of the layer  51 . In certain cases, especially also for reducing capacitive influences between adjacent contact elements  49  during high-frequency measurements it may be useful or necessary to increase the distance between the adjacent layers  51  by selecting a thickness of the respective layer  50  that is considerably larger than the thickness of the layer  51 .  
         [0055]    As FIG. 9 further shows, each contact element  49  is shaped so that it is part of a circular disk in a sub-section  49 ′. This sub-section  49 ′ is used to accept each contact element  49  in a graduated circular recess  52  of the respective carrier  47 , in such a manner that the recess  52 , in relation to its imaginary center, encloses the sub-section  49 ′ for a length larger than 180°, but smaller than 270°. In this way, each contact element  49  is held in the recess  52  of the corresponding carrier  47 , but at the same time can pivot on the horizontal axis extending through the imaginary center of the recess  42  and parallel to the direction of transport A. In order to limit the pivot movement, a projection  53  is provided in each recess  52  that engages in a recess  54  of the respective contact element  49 . The width of the recess  54  is larger than the corresponding width of the projection  54 , corresponding to the possible pivot angle of the contact element  49 .  
         [0056]    The recess  52  of each carrier  47  is open on both surfaces of this carrier and also on the side of the carrier  47  facing the substrate  40 , so that each contact element  49  extends from the recess  52  on this open side, with two sub-sections  49 ″ and  49 ″′, of which the sub-section  49 ″ during the measurement of the component  1  forms the contact area working together with the respective connection  3  of the component and the sub-section  49 ″′ forms the contact area that bears against the respective measuring contact  55  on the substrate  40  during the measurement. On the sub-sections the conductive layer  51  extends somewhat beyond the layer  50 .  
         [0057]    The measuring contacts  55 , which are located on both surfaces of the substrate  40 , are connected with the electronic measuring circuitry  57  by means of circuit board conductors  56 , which are likewise located on the substrate  40  in the direct vicinity of the measuring area formed by the contact elements  49 , between the substrate  40  and the carriers  47  with the contact elements  49  located on both sides of this substrate. This ensures short electrical paths, which enables a high-frequency measurement of the components  1 .  
         [0058]    Furthermore, as shown in particular in FIG. 9, each carrier  47  is provided with a plurality of notches  58  in its area  47 ″′ between the two ends  47 ′ and  47 ″, which (notches) are positioned horizontally with their longitudinal sides in such a way that the carriers  47  in the section  47 ″′ have a meandering course, which causes the disk-shaped carriers  47  to have an elastic design despite their perpendicular orientation to the direction of transport A, such that the free ends  47 ′ in the plane of their surfaces can be pivoted elastically on an imaginary axis parallel to the direction of transport A from a starting position, in which the respective contact element  49  is at a distance both from the connection  3  of a component  1  inserted into the receptacle  41  and from the measuring contact  55 , into a measuring position (double arrow B), in which the sub-sections  49 ″ or  49 ″′ bear against a connection  3  or against a measuring contact  55 , thus establishing an electric connection between a connection  3  of the component  1  and a measuring contact  55 .  
         [0059]    In order for the carriers  47 , or their contact elements  49 , to pivot from the starting position into the measuring position, the carriers  47  each form an angled or control surface  49  in their middle section  47 ″′ on the outer edge facing away from the substrate  40  in such a manner that the distance of this angled surface  49  from the middle plane M increases toward the free end  47 ″. This (control surface) is formed on each carrier  47  between two notches  58 . Rollers  60  act on the control surfaces  49  and can be moved by a pre-defined stroke vertically upwards and downwards parallel to the middle plane M (corresponding to the double arrow F) by a driving mechanism of a machine accommodating the measuring device  13   a , e.g. a back-end machine. With each upward movement of the rollers  60 , the corresponding carriers  47  or their contact elements  49  are pivoted from the starting position into the measuring position, against the inherent elasticity of the carriers  47 .  
         [0060]    Since the control surfaces  49  are located between two notches  58  that are open toward the control surface  49  and an additional notch  48  is provided opposite of each control surface  49 , the individual contact elements  49  can bear elastically against the respective connection  3  and the corresponding contact surface  55 , so that a reliable contact of all contact elements is ensured even in case of tolerances for example in the connections  3  of the components  1 .  
         [0061]    The function of the measuring device  13   a  can be described as follows:  
         [0062]    Whenever a component  1  held on a vacuum holder  9  has reached the measuring position of the measuring device  13   a  formed by the receptacle  41 , the following functions are carried out during the subsequent stopped phase of the pulsed transporter  8 :  
         [0063]    First, the component  1  held on the vacuum holder  9  is inserted into the receptacle  41  by lowering the vacuum holder  9 , which causes it to be centered. The component  1  is then held between the bottom of the receptacle  41  and the respective vacuum holder  9  by clamping.  
         [0064]    Afterwards, the contact elements  49  are pivoted by an upward movement of the rollers  60  from the starting position into the measuring position, in which these contact elements create the electrical connection between a connection  3  and a measuring contact  55 , so that the measurement can be conducted.  
         [0065]    The relatively solid design of the contact elements  49  prevents negative influences on the high-frequency measurement, such as skin effect, partial inductivities, etc.  
         [0066]    The above description assumed that one contact element  49 , which works together with a measuring contact  55 , is provided for each connection  3 . However, a preferable embodiment could also provide for two contact elements  49  for each connection  3 , preferably with a separate carrier  47  for each contact element. Each contact element  49  is then allocated a separate measuring contact  55  on the substrate  40 , so that the electronic measuring circuitry  47 , by means of a contact element  49  allocated to a connection  3 , can also determine the contact or transition resistance for the respective connection  3 , enabling for example the automatic calibration of the measurement.  
         [0067]    The invention was described above based on a sample embodiment. Of course, numerous modifications and variations are possible without abandoning the basic inventive idea of the invention.  
         [0068]    For example, it was assumed above in connection with FIGS.  1 - 8  that the individual carriers  17  are actuated by a pressure plate  25  acting on the surface of these carriers between the ends  17 ′ and  17 ″ in order to move the contact elements  16  forward and backward. Generally, it is also possible to move the contact elements  16  forward and backward by having the carriers  17 , the top side of which bears against a fixed stop, e.g. against a non-movable pressure plate, move forward and backward at their ends  17 ″ in the direction of the plane VE, as indicated in FIG. 3 by the double arrow B′, by means of corresponding controlled movements of the bearing  23 . Of course, it is also possible to combine the two drive types.  
         [0069]    In place of the disk-shaped contact elements  16  other contact elements are conceivable, such as contact elements that slide on the measuring contacts  15 , for example.  
       Reference Number List  
       [0070]    [0070] 1  component  
         [0071]    [0071] 2  component housing  
         [0072]    [0072] 3  connection  
         [0073]    [0073] 4  back-end machine  
         [0074]    [0074] 5  lead frame  
         [0075]    [0075] 6  punching station  
         [0076]    [0076] 7 ,  8  transporter  
         [0077]    [0077] 9  vacuum holder  
         [0078]    [0078] 10  measuring station  
         [0079]    [0079] 11  sorting station  
         [0080]    [0080] 12  belt station  
         [0081]    [0081] 13 ,  13   a  measuring device  
         [0082]    [0082] 14  substrate with measuring contacts of the measuring circuit  
         [0083]    [0083] 15  measuring contact  
         [0084]    [0084] 16  movable contact element  
         [0085]    [0085] 17  contact element carrier  
         [0086]    [0086] 17 ′,  17 ″ end  
         [0087]    [0087] 17 ″′,  17 ″″ surface  
         [0088]    [0088] 18  recess  
         [0089]    [0089] 19  pin  
         [0090]    [0090] 21  notch  
         [0091]    [0091] 22  stack  
         [0092]    [0092] 23  bearing  
         [0093]    [0093] 24  carrier  
         [0094]    [0094] 25  pressure plate  
         [0095]    [0095] 25 ′ shank  
         [0096]    [0096] 25 ″ yoke element  
         [0097]    [0097] 26  extension (shackle)  
         [0098]    [0098] 27  tappet  
         [0099]    [0099] 28  centering and clamping unit  
         [0100]    [0100] 29  tappet  
         [0101]    [0101] 30  centering element  
         [0102]    [0102] 30 ′ centering surface  
         [0103]    [0103] 31  clamping element  
         [0104]    [0104] 31 ′ clamping surface  
         [0105]    [0105] 31 ″ centering surface  
         [0106]    [0106] 32  clamping element  
         [0107]    [0107] 32 ′ clamping surface  
         [0108]    [0108] 33  holder  
         [0109]    [0109] 34  tappet  
         [0110]    [0110] 35  housing  
         [0111]    [0111] 36  regulating slide  
         [0112]    [0112] 37  regulating groove  
         [0113]    [0113] 40  substrate with measuring contacts of the measuring circuit  
         [0114]    [0114] 41  retainer  
         [0115]    [0115] 42  holder  
         [0116]    [0116] 42 ′,  42 ″ section  
         [0117]    [0117] 43  fork arm  
         [0118]    [0118] 47  carrier  
         [0119]    [0119] 47 ′,  47 ″,  47 ″′ section  
         [0120]    [0120] 48  pin  
         [0121]    [0121] 49  contact element  
         [0122]    [0122] 49 ′,  49 ″,  49 ″′ sub-section  
         [0123]    [0123] 50 ,  51  layer  
         [0124]    [0124] 52  recess  
         [0125]    [0125] 53  projection  
         [0126]    [0126] 54  recess  
         [0127]    [0127] 55  measuring contact  
         [0128]    [0128] 56  circuit board conductor  
         [0129]    [0129] 57  electronic measuring component  
         [0130]    [0130] 58  notch  
         [0131]    [0131] 59  angled or control surface  
         [0132]    [0132] 60  roll  
         [0133]    A direction of transport  
         [0134]    B, C, D, E, F direction of movement or swiveling  
         [0135]    M middle plane  
         [0136]    VE vertical plane