DE4408124C2 - Method and device for producing an arrangement of at least one electronic component (IC) and a wound coil - Google Patents

Description

The present invention relates to a method according to the preamble of claim 1.

Furthermore concerns the Invention an apparatus for performing this Procedure.

When making coil assemblies the above mentioned type occur particularly in connection the winding wire ends with the pads of one Chips manufacturing problems because the application ren of the ends of the very fine, usually only we a few hundredths of a millimeter of wire on the Pads for subsequent connection with this proves to be very complex. To the difficult Pick up the winding wire ends after completing a Avoiding coil winding is in the PCT patent application WO 91/16718 A1 beaten, the winding wire ends not immediately to connect with the pads of an IC but as a carrier for the IC a circuit board use that with versus the actual IC pads significantly enlarged pad Chen is provided. The one from a wire leader Coil winding machine is picked up winding wire coming from an already wound coil over the first pad of the circuit board wegge  leads, then until the required Number of turns around a winding carrier and then over the second pad of the White circuit board to the next coil winding led. To connect the winding wire to the Pads will now be soldered or welded run after which the winding wire in the area severed the connection points thus formed can be. For fixing the circuit board to the Coil becomes an adhesive bond between an iso portion of the circuit board and the coil hen. Finally, this can be done from the printed circuit board te and the coil arrangement formed on both sides plastic layers, for example to form a machine readable credit card.

Although the procedure described above ren the manufacture of such coil assemblies in Comparison to the previously known methods essential Lich simplified, since an inclusion of the winding wire tendency to connect to the pads falls. However, the known method has two we significant disadvantages.

In the known method for connecting the IC's with the winding wire ends is its previous arrangement on a printed circuit board is necessary in order to do this the enlarged pads for the "indirect" Connection of the winding wire ends with the connecting surfaces chen to create the IC’s. In addition to a raised part leaufwand this results in an increased ferti effort for the coil arrangement.

The known method creates a coil arrangement created in which the coil in a Teilbe rich on the pads of the printed scarf device is arranged. As a result, the total  measurements of the coil arrangement adversely affected, because the circuit board both in the thickness direction " contributes "as well as an increase in the overall length as the total width of the coil arrangement wearing. This leads to a relatively large volume End product, what the use of the Spu arrangement, for example to create a credit card, restricted.

DE 43 07 064 A1 describes a method for producing position of a coil arrangement according to the Oberbe handle of claim 1 described. With this The winding wire process is used to form Winding wire end areas in holding devices ge hold the stationary outside of the changing table are ordered. The connection of the winding wires range with the pads one on the wic Celtic component is made in two by the actual coil winding process un broken connections.

Another method is from the DE 42 20 194 A1 known. With this Procedure must be severed the end areas of the coil separately respectively.

The object of the present invention is to achieve reasons, a method and a device create the or the manufacture of a Spu lenanordnung with reduced manufacturing costs fully automatic possible.

This task is accomplished by a procedure with the Merk paint the claim 1 solved, the associated device is given with the features of claim 7.

According to the inventive method in other words a for example as a component in an IC Receiving device stationary on a changing table positioned. Starting from a starting position is a led out of a wire guide free winding wire end from a wire gripper over the receiving device, a wire distance adjustment device and a first holding device a wire guide channel with two channel edges in performed a stop position. When setting the wic keldrahtendes in the first holding device cutting the winding wire so that the winding wire led out of the wire guide now is held only in the first holding device. The changing table is then rotated opposite the wire guide, with a between the first holding device and a winding circumference  the winding die of trained winding wire start area at the first channel edge and the Dre hung until the desired winding number on the circumference of the winding matrix is enough. If the rotation continues the changing table after reaching the desired win number of applications will be extracted from the wire guide led, running end of the winding wire to the two ten channel edge, which is opposite the first Ka nalrand is increased. Finally it lukes end of the winding wire if continued the rotary movement to a second holding device and is subsequently severed. For preparation a connection of the winding wire start area or of the end of the winding wire with the connection surfaces of the component, these are based on their the channel edges created using the Wire spacing adjustment device in overlap area be rich with the pads of the component moves.

The method according to the invention enables the manufacture position of a coil arrangement in which the winding wire end, here the winding wire start area and the end of the winding wire, directly with the An end faces of an electronic component ver can be bound. Contrary to that from WO 91/16718 A1 known methods, the formation of Winding wire areas that are used to connect to the An serve end faces of the electronic component, inside the wound coil. Here, the Holding devices together with the distance adjustment device and the component receiving device, which are all arranged within the winding matrix for correct alignment of the winding wire at the beginning or end of the winding wire the pads so that the connection follow  can be carried out. Both the wrap wire start area as well as the winding wire end the coil arrangement becomes rich until completion tion in the associated holding device held so that the connection of the pads can be done simultaneously with the winding wire.

The definition of the end of the winding wire in the second holding device by means of the rotary movement of the changing table makes an exact angular position tion unnecessary, the z. B. according to DE 42 20 194 A1 is about the wrap wire translationally into the holding device thread. Instead, the winding wire is under off use of the rotational movement of the changing table, so to speak captured when the changing table rotates. This makes the operating function of the second hal especially safe.

It proves to be advantageous if at least the first holding device by the wire gripper acti fourth, because this ensures that the Wire clamping is always done at the right time, namely when the wire gripper through the holding device is passed through.

The winding is preferably severed wire triggered by the function of the Haltein direction. This makes a separate actuation device for cutting the winding wire unnecessary.

It is particularly advantageous if the above written procedures of the wire guide and the wire gripper can be moved synchronously because of the common movement even a common one direction for movement control is necessary.  

If the wire guide and the wire gripper are on one Translation axis are moved and the wire gripper after reaching the desired number of turns before cutting the winding wire back into his Starting position for picking up the running wire which is moved back is a continuous forth position of coil arrangements according to the aforementioned Procedure possible.

To form the coverage areas, the Wire start area and the wire end area of Control elements of the distance setting device against in width the distance between the pads of the Corresponding component, with its central axis aligned coaxially to the central axis of the component te anchor devices are brought. Through the Anchor devices is the one for the following Connection correct distance between the wrap wire start area and the winding wire end area precisely defined reproducibly.

A device for performing the fiction The method has the features of claim 7 on.

The device has essential parts a changing table with a Winding matrix, a first and a second holder direction for holding a winding wire start or of a winding wire end with a wire guide channel a distance setting device for the formation of Coverage areas between the start of the winding wire or the winding wire end and the pads of the Component, separators, a Rotationsan drive device for driving the changing table and and a translational drive for moving wire guide and wire gripper.  

The changing table also has a holder Measuring device for positioning the building elements so that this with its type end faces so relative to the distance setting device can be arranged, which at Actuation of the distance setting device about coverage areas between the pads and adjust the winding wire. Both the establishment for positioning the component, as also the distance adjustment device and the holding device facilities with the separation devices themselves on the changing table and inside the changing table circumference of the winding die.

On the one hand, this results in an overall particular ders compact structure of the device with a partial concentration in the center point realm of the changing table so that the associated low inertia a particularly fast one Control of the changing table during the winding process leaves. On the other hand, the arrangement of the Hal and the separating devices inside area of the winding die ensures that no such a large wire waste arises, as it does for outside the winding matrix or the winding table arranged holding devices is the case.

The above device enables due to the advantageous combination and relative arrangement of their Individual elements carry out the above ge described, inventive method with all its advantages.

To form the coverage areas between the Wire start area and a first pad of the component and the wire end area and one second pad of the component has the  Distance adjustment device control elements that the wire start area or the wire end area against the width of the distance between the pads corresponding to the component, with its central axis aligned coaxially to the central axis of the component te anchor devices can be brought.

The first holding device can be particularly advantageous be designed such that they are Wire guide is activated. Here, the stop function so that the Halteinrich device is provided with a clamping element that under Overcoming an elastic restoring force by the wire gripper is deflected and after execution wire grab from the wire guide Running end of the winding wire jams.

The second holding device is special preferred embodiment with a clamp direction provided to generate a clamp kung while overcoming an elastic reset force through the winding wire across the changing table ne can be operated. Such a holding device allows the winding wire end to be defined empire, as already in connection with the inventions described method by means of a Swiveling movement of the changing table, in which the on the Holding device passed winding wire quasi is captured by this.

In a further advantageous embodiment the distance adjustment device, which is used for training of coverage areas between the winding wire and the pads of the component for a subsequent connection serves, by pair each assigned to each other, in the wire guide direction each on one side of the positioning fixture for  realizes the component arranged control elements, the taking the winding wire against the stop facilities are movable. Here are through the anchor device defines stop surfaces, that are spaced apart from each other Distance between the connection surfaces of the component corresponds.

The actuators can be found in the edges of the wire guide channel be arranged so that they from the Back of the changing table can be actuated. This enables the actuating elements to be actuated Lich, without hereby the free accessibility of the Component, i.e. free access to the connection surfaces, for example to carry out the connection of the An end faces with the winding wire, limited is.

Below is a preferred variant of the inventions method according to the invention with reference to the drawings explained. Show it:

Figure 1 shows an embodiment of an apparatus for performing the method according to the invention with a first and a second holding device.

Fig. 2 shows the illustrated in Fig. 1 Halteein second direction in a sectional view of the Wickelti ULTRASONIC according to section line II-II in Fig. 1.

Fig. 1 shows a winding device 10 for the produc- tion of a coil arrangement with a coil 11 and a chip 12th The coil 11 has a winding wire start region 13 and a winding wire end region 14 , which are each to be connected to a connection surface 60 or 61 of the chip 12 .

The coil 11 shown in FIG. 1 has only a win 15 to simplify the illustration and to simplify the following discussion of a possible variant of the method according to the invention. In fact, depending on the dimensioning of a tion are wound on this on a changing table 16 of the device 10 Wickelvor arranged winding matrix 17 any number of turns.

Fig. 2 shows in a sectional view of the wrapping table 17, disposed thereon, here flat-shaped winding matrix 17, which is opposite a changing platform 18 hubverlagerbar is arranged. As indicated by the illustration in FIG. 2, the winding of the coil 11 on the winding matrix 17 can be carried out not only under the direct location of the winding matrix 17 but also with an arrangement of a coil core 19 formed here in an annular manner. Thus, the Vorrich device shown in FIGS . 1 and 2 is suitable both for the production of coreless air coils and for the production of core-provided coils.

To move the winding wire relative to the winding table 16 , a wire guide device 20 is seen before, which has a wire guide 21 and a wire gripper 22 , which are not shown here in detail. The wire guide 21 can be designed in a manner known per se as a capillary and the wire gripper 22 as a tweezer-like wire gripper device. The wire guide 21 and the wire gripper 22 are connected to one another via a coupling device 23 shown schematically here and are thus moved synchronously with one another. The wire guide 21 and the wire gripper 22 are movable on a translation axis 24 ge relative to the changing table 16 and can perform a lifting movement compared to the changing table 16 .

The changing table 16 is provided with a rotational drive device, not shown, combined with a rotation angle control device and can be rotated in the direction of arrow 62 .

As is apparent from a comparison of FIGS. 1 and 2, the winding matrix 17 or a Trä ger is provided for receiving a winding matrix having an extend in the longitudinal direction over the wrapping table 17 the wire guide channel 25. The wire guide channel 25 has two channel heights or channel banks 26 , 27 of different heights. The channel edges are formed continuously in the illustrated embodiment; can, however, also be realized by discrete, spaced-apart wire feeders, such as pins. Through the wire guide channel, the winding die 17 or the carrier for receiving the winding die in a lin ken and a right winding area 28 , 29 under divides. The left winding area 28 is in turn divided into a first receiving area 30 for receiving a first holding device 31 and a second receiving area 32 for receiving a second holding device 33 .

The right winding area 29 is continuously formed and opposite the first holding device 31 arranged in the channel edge 27 on a Hal teanschlag 34 which cooperates with the holding device 31 .

The holding device 31 is arranged of the receiving portion 30 in a recess 35 and includes a rotatably mounted to a pivot 36 Schwenkhe bel 37 which is supported via a compression spring 38 at egg nem edge 39 of the recess 35 under bias from. To secure the position of the compression spring 38 , its ends are placed on guide pins 40 , 41 . The holding stop 34 arranged opposite the recess 35 consists of a hard metal plate inserted into the channel edge 27 . In the area of the hard metal plate 34 , the channel edge 27 is provided with a swivel recess 42 , which enables a swivel lever end 43 to be swiveled into the channel edge 27 against the hard metal plate 34 . The swivel lever loin 43 is provided with a stop surface 44 which is formed parallel to the surface of the hard metal plate 34 and has a cutting tip 45 at the extreme end which, when the contact surface 44 rests on the hard metal plate 34 in a cutting radius 46 of the swivel recess 42 in the transition region to the hard metal plate 34 comes to rest.

The holding device 33 has a holding plate 48 arranged on a pin 47 , which is provided with a clamping surface 63 running ver inclined to the surface of the receiving area 32 (see also FIG. 2). The pin 47 is passed through the winding die 27 or the carrier for receiving the winding die and inserted into the changing table platform 18 . On the pin 47 , a compression spring 50 is received in a lifting gap 49 between the winding die 16 and the winding platform 18 . After beard to the holding plate 48 is located on the receiving area 32 on a ver with a cutting edge 51 provided separator 52nd

In the upper region of the wire guide channel 25 shown in FIG. 1 there is a receiving device 53 ( not shown in detail) for the receiving chip 12 in position . Above and below the receiving device 53 there is a stop device 64 or 65 , which can optionally be lowered into the channel base 54 . Each stop device 64 , 65 interacts with a pair of adjusting elements 55 , 56 and 57 , 58 to form a spacer adjusting device 59 . The adjusting elements 55 , 56 , 57 , 58 are accommodated in the channel edges 26 and 27 , respectively.

To form the example in FIG. 1 Darge set coil 11, the wire guide 20 with the wire guide 21 and the wire gripper 22, from one arranged above the changing table 16 position in which the wire gripper 22 is in its initial position just above the wire guide channel 25 moved on the translation axis 24 through the wire guide channel 25 until the wire gripper the position shown in Fig. 1 position below the wire guide channel 25 he reaches. In this position, the wire guide 21 is , as shown in Fig. 1, above the wire guide channel 25th

When the wire gripper 22 is moved through the wire guide channel 25 with the picked-up free end of the winding wire, it presses the pivot lever 37 of the first holding device 31 against the action of the compression spring 38 into an open position. After the wire gripper 22 has passed the holding device 31 , the pivot lever 37 is pivoted back by the restoring force of the compression spring 38 into the clamping position shown in FIG. 1. The winding wire is received between the contact surface 44 of the swivel lever end 43 and the hard metal plate 34 and severed when the cutting tip 45 of the swivel lever end 43 is swiveled into the cutting radius 46 of the swivel recess 42 . The end of the winding wire is thus held in the holding device 31 . The changing table 17 is then rotated in the direction of arrow 62 by approximately 180 °, the starting area 13 of the winding wire resting against the channel edge 27 in the manner shown in FIG. 1. As a result of the different heights of the channel edges 26 , 27 or the winding areas 29 and 30 , the winding wire slides over the receiving area 29 when the 180 ° rotational position is reached and lies against the raised channel edge 26 . In this rotational position, the wire gripper 22 is moved back into its starting position above the wire guide channel 25 , the running end of the winding wire moving out of the wire guide 21 . Subsequently, the wire gripper takes on the running end of the wire guide 21 led winding end and holds it.

Starting from the 180 ° rotation position, the winding table 16 is rotated further by approximately 90 ° in a 270 ° rotation position in the direction of arrow 62 , so that the running end of the winding wire is pushed between the clamping surface 63 of the holding device 33 and the surface of the receiving area 32 and is held clamped in the holding device 33 . When the 270 ° rotational position is reached, the winding wire is cut off at the cutting edge 51 of the cutting device 52 . The position of the holding device 33 with respect to the axis of rotation of the changing table 16 is determined such that when the winding wire is clamped in the holding device, essentially no wire extension results. In contrast, the position of the device 52 Tenn is selected such that the winding wire under increased tension on the cutting edge 51 of the separator 52 is applied at the appropriate rotational position of the changing table sixteenth

In this position, the winding wire with its winding wire start area 13 and the winding wire end area 14 is held in the holding devices 31 and 34 and separated from the wire guide device 20 , in which the winding wire is held by the wire gripper 22 .

Subsequently, activation of the distance adjusting device 59 leads to the formation of overdec tion areas between the winding wire beginning area 13 or the winding wire end area 14 and the connection area 60 or the connection area 61 of the chip 12 . For this purpose, the actuating elements 55 , 56 , 57 , 58 are driven against the respectively assigned stop devices 64 , 65 , taking the winding wire starting area 13 or the winding wire end area 14 with them . In this position, the connec tion between the winding wire areas 13 , 14 and the pads 60 , 61 , for example in Ther mokompressionsverfahren, take place.

Finally, the holding devices 31 , 33 are released and the finished coil arrangement with the coil 11 and the chip 12 connected to it can be removed from the changing table 16 .

To release the holding device 31 , for example, a not shown, with a Keilflä surface provided pin can be used, which is similar to the pin 47 shown in Fig. 2 in the Wic celtic platform 18 used. The wedge surface of the pin can be with a corresponding wedge surface on the underside of the pivot lever 37 zusammenwir ken, so that at a lowering movement of the trize Wickelma against the wrapping platform 18 is carried out 17 a forced opening of the pivot lever 37th

The release of the holding device 33 takes place, as is clear from Fig. 2, by lowering the winding die 17 relative to the changing table platform 18 , whereby the clamping force of the compression spring 50 is overcome and that in the clamping gap between the clamping surface 63 of the holding plate 48 and the surface of the Recording area 32 held winding wire is released.

The removal of the coil arrangement from the changing table 16 also takes place as a result of the above-described lowering of the winding matrix, which causes the coil 17 to be repelled by the winding matrix 17 . Below the component 12 , a fixed in the winding platform 18 , not shown here, a mandrel can be provided, which at the same time causes an ejection of the component 12 from the receiving device. Alternatively, extendable mandrels can also be provided in the winding platform 18 , which are distributed over the circumference of the coil or arranged below the component in order to repel it from the winding platform.

In the illustrated embodiment, the winding device is the component within the coil and arranged in the coil plane or parallel to it. In addition, however, it is also possible to build element in the coil plane or parallel to it and outside to be placed half the coil. Then there is also Wire guide channel with the associated equipment gene, such as component receiving device, distance setting device and holding devices with orderly separators, arranged outside.

Another option is the wire guide channel with the associated facilities the outer surface of a cylindrical winding unit  Stuff and the winding die for training the Spu le to be arranged on an end face. This will the formation of a coil arrangement possible at which is the component in a plane perpendicular to Coil level is located.

Claims (12)

1. A method for producing an arrangement of at least one electronic component, such as an integrated circuit (IC), and at least one coil wound from winding wire (coil arrangement), the winding wire end areas of which are connected to connection surfaces of the component, the component being fixed in place in a receiving device is po sitioned on a changing table which rotates to produce a coil winding opposite a wire guide, characterized in that

• - First, a wire gripper ( 22 ) movable relative to the changing table ( 17 ), guided out of a wire guide ( 21 ), the end of the winding wire runs from an initial position via the receiving device ( 53 ), a wire distance adjusting device ( 59 ) and subsequently a first holding device ( 31 ) leads through a wire guide channel ( 25 ) with two channel edges ( 26 , 27 ) into a holding position, where the winding wire in the first holding device ( 31 ) is held and severed;
• - Subsequently, the rotation of the changing table ( 17 ) with respect to the wire guide ( 21 ) it follows, wherein a first device ( 31 ) and a winding circumference of a winding matrix ( 16 ) formed between the first holding device ( 16 ) first winding wire start area ( 13 ) on the first channel edge ( 27 ) applies and the rotation is continued until the desired number of turns on the winding circumference of the winding die ( 16 ) is reached;
• - Continued the rotation of the winding table ( 16 ) after reaching the desired number of turns, the lead out of the wire guide ( 21 ), running Wickeldrah ends up on the second, compared to the first channel edge increased channel edge ( 27 );
• - The wire gripper ( 22 ) which from the wire guide ( 21 ) to the winding die ( 16 ) leads running end of the winding wire and the running end of the winding wire rests on continuation of the rotation to a second holding device ( 33 ) and forms the second end of the winding wire ( 14 ) is cut after the following; and
• - The winding wire start area ( 13 ) and the winding wire end area ( 14 ) by means of the wire spacing adjustment device ( 59 ) are brought into overlap with the connection surfaces ( 60 , 61 ) of the component ( 12 ) for subsequent connection to the connection surfaces.

2. The method according to claim 1, characterized in that at least the first holding device ( 33 ) is activated by the wire gripper ( 22 ). 3. The method according to any one of the preceding claims, characterized in that the cutting of the winding wire from solved by the function of the holding device ( 31 ). 4. The method according to any one of the preceding claims, characterized in that the wire guide ( 21 ) and the wire gripper ( 22 ) are moved synchronously. 5. The method according to claim 4, characterized in that the wire guide ( 21 ) and the wire gripper ( 22 ) are moved on a translation axis ( 24 ) and the wire gripper ( 22 ) after reaching the desired number of turns before separating the winding wire back into his Is moved from the starting position to record the current wire end. 6. The method according to any one of the preceding claims, characterized in that for forming the overlap areas between the wire start area ( 13 ) and a first connection surface ( 61 ) of the component such as the wire end region ( 14 ) and a second connection surface ( 60 ) of the component ( 12 ) the wire start area ( 13 ) and the wire end area ( 14 ) of adjusting elements ( 55 to 58 ) of the distance adjusting device ( 59 ) in the receiving area of the component ( 12 ) against the width of the distance between the connection surfaces ( 60 , 61 ) of the component ( 12 ) corresponding, with their central axis coaxial to the central axis of the component aligned stop devices ( 64 , 65 ) are brought. 7. A device for producing an arrangement of at least one electronic component, such as an integrated circuit (IC), and at least one coil wound from winding wire (coil arrangement) according to one of claims 1 to 6, characterized in that

• a) a changing table ( 16 ) is provided with a receiving device ( 53 ) arranged within the winding circumference of a winding matrix ( 16 ) for positioning the component ( 12 );
• b) on the changing table ( 16 ) a first holding device ( 31 ) for holding a wic keldrahtbegsbereich ( 13 ) and a second holding device ( 33 ) for holding a winding wire end portion ( 14 ) within the winding circumference of the winding die arranged on the changing table ( 16 ) ( 17 ) are provided;
• c) on the changing table ( 17 ), the winding circumference of the winding die-cutting wire guide channel with two channel edges of different heights ( 26 , 27 ) is provided, in which the receiving device ( 53 ) is arranged;
• d) a wire gripper ( 22 ) and a wire guide ( 21 ) are provided, the Drahtgrei fer for guiding the end of the wire guide ( 21 ) led out through the wire guide channel ( 25 );
• e) the holding devices ( 31 , 33 ) separating devices ( 45 , 46 ) are assigned;
• f) the changing table ( 16 ) is provided with a rotary drive device for executing a winding movement around the winding matrix ( 17 ); and
• g) the wire guide ( 21 ) and the wire gripper ( 22 ) are provided with a translational drive device for forming the winding wire starting area ( 13 ) and the winding wire end area ( 14 ).

8. The device according to claim 7, characterized in that to form overlap areas between the rule's winding wire area ( 13 ) and a first connection surface ( 60 ) of the component ( 12 ) and the winding wire end region ( 14 ) and a second connection surface ( 61 ) of the construction elements ( 12 ) of the winding wire start area ( 13 ) and the winding wire end area ( 14 ) of adjusting elements ( 55 to 58 ) of a spacer adjusting device ( 59 ) in the receiving area ( 53 ) of the component ( 12 ) against the width corresponding to the spacing of the connection surfaces, with their The center axis of the stop devices ( 64 , 65 ) aligned coaxially to the center axis of the component can be moved. 9. The device according to claim 7 or 8, characterized in that at least the first holding device ( 31 ) is designed such that it is activated by the wire gripper ( 22 ). 10. The device according to claim 7 or 8, characterized in that the second holding device ( 33 ) is provided with a clamping device ( 48 , 50 ) which is operable to generate a clamping effect while overcoming an elastic restoring force by the wik wire wire transversely to the changing table level. 11. The device according to any one of claims 7 to 10, characterized in that the distance adjusting device ( 59 ) each have paired actuating elements ( 55 , 56 ; 57 , 58 ) which wire to achieve the coverage areas between the winding and the connection surfaces ( 60 , 61 ) with the winding wire against stop devices ( 64 , 65 ) are movable, the striking surfaces of which are at a distance from one another which corresponds to the distance between the connecting surfaces ( 60 , 61 ) of the component ( 12 ). 12. The apparatus according to claim 11, characterized in that the adjusting elements ( 55 , 56 ; 57 , 58 ) in the edges ( 26 , 27 ) of the wire guide channel ( 25 ) are arranged and can be actuated from the rear of the Wic keltischs ( 16 ) .