Electrical test device to test equipment under test and electric testing method

The invention relates to an electrical testing device for testing an electrical test piece, with a printed circuit substrate that is electrically connected via a contact distance Transformer with a test head, wherein the semiconductor substrate is mechanically connected to a first stiffener stiffens and characterized.

An electrical test device of the aforementioned type is known. Its purpose is to create an electrical device under test, such as a wafer electrically. This is a touch contacting, are switched to a testing device through the electrical circuits, testing the device under test to electrical functionality. In this way, functional samples can be distinguished from non-functional test objects. The known electrical test device comprises a semiconductor substrate, which is electrically connected via a contact distance Transformer with a probe. Contact needles of the probe are connected to the contact distance Transformer electrically connected and serve for contacting the DUT. The semiconductor substrate is electrically connected to the aforementioned test device. Since the contact spacings of the specimen are extremely small by increasing high integration density, the checked wiring density between the contact head and the conductor substrate of the contact spacing Transformer is to increase provided which transfers the small contact spacings of the contact needles of the test head to larger contact spacings, the larger contact distances with equal contact intervals correlate the conductor substrate and the semiconductor substrate preferably realized another contact distance increase, which ultimately are the larger this contact spaced contacts of the semiconductor substrate by means of suitable cable connections or the like with the test device in conjunction. As far as is at least one necessary for the electrical connection assembly between the semiconductor substrate and the contact head, sufficient for making contact alignment of the components involved is not always possible, so that the operability of such electrical test equipment is in question. In this context it should be mentioned that the contact head for contact spacing Transformer and the contact distance Transformer to the conductor substrate each is only in electrical contact contact.

The invention therefore has the object of providing an electrical testing device for testing an electrical test piece, which has a high contact reliability and functional safety, so that the examination of an electrical device under test can be performed without error.

This object is achieved with the involvement of the above mentioned features in that at least one substrate by the conductor cross-spacers to the contact distance Transformer is connected mechanically and is held on the first stiffening device with Neigungseinstellmittel. The forces acting on the conductor substrate contact contact forces can take large values ​​in their sum at a high Prüfkontaktdichte. To avoid a mechanical deformation through these contact forces in the semiconductor substrate, the latter is associated with the first reinforcement. To ensure proper electrical touch contacting between contact head and conductor substrate - with the interposition of Kontaktabstandstransformers and possibly further electrical connection means (connectors) - the invention provides that the contact distance Transformer (Space Transformer) is positioned relative to the printed circuit substrate inclination adjustable. To this end, the Neigungseinstellmittel are provided which perform the inclination adjustment of at least one the conductor substrate thoroughgoing, mechanically connected to the contact spacing Transformer spacer. In particular, a tilting element can be provided, which is mechanically connected via at least one, the conductor substrate by cross spacers with the contact spacing Transformer and is held adjustable angle to the first stiffener on Neigungseinstellmittel. therefore reinforcement and tilting element form a brought in through the spacer rigid structure, but with the conductor substrate is between these two parts. Since this is however penetrated by the at least one spacer, performs a tilting movement of the tilting plate through the spacer to a corresponding movement of the Kontaktabstandstransformers without causing the semiconductor substrate changes its position. The at least one spacer interspersed preferably without contact at least one opening of the circuit board. To the tilting element tilt relative to the semiconductor substrate, it is held on Neigungseinstellmittel at the first reinforcement, which in turn is non-displaceably with the conductor substrate in conjunction. Thus, if the tilt element inclined relative to the first stiffening device, this leads to a corresponding tilting movement of Kontaktabstandstransformers (also Space Transformer called) relative to the conductor substrate. Regardless of whether an embodiment of the present invention with or without tilting element, a reference surface at the contact distance Transformer inclination is adjusted relative to a reference surface on the conductor substrate. This contact distance Transformer and circuit substrate can be aligned relative to each other in a desired manner, on the one hand a good contact of the contact pins of the probe to the electrical device under test (wafer) can be realized and on the other hand for a good contact - optionally with the interposition of electrical connection means (connectors) - to the semiconductor substrate is provided.

According to a development of the invention that the spacer passes through the first reinforcement. Thus, the spacer extends to the the conductor substrate side facing away from the first stiffening device, so there may be provided the Neigungseinstellmittel.

According to a development of the invention provides that the semiconductor substrate having first contact surfaces, which are connected via contact means with mating contact surfaces of Kontaktabstandstransformers. In the above-mentioned contact means is the above-mentioned electrical connecting means, which are also called connectors. The contact means are provided with the first contact surfaces of the conductor substrate in abutting contact and also in physical contact with the mating contact surfaces of the Kontaktabstandstransformers.

It is advantageous if the contact means to compensate a caused by tilt adjustment angular misalignment between semiconductor substrate and contact spacing Transformer. Accordingly, the contact means are such flexible that the contact means maintaining the contact in contact with the first contact surfaces of the conductor substrate and the mating contact surfaces of the Kontaktabstandstransformers at an inclination adjustment between the reference surface of the conductor substrate and the reference surface of the Kontaktabstandstransformers.

A development of the invention provides that the contact distance Transformer has second contact surfaces which are in electrical contact with contact pins / contact needles, especially bend needles of the probe. The probe preferably comprises a distance extending guide plates having guide holes, which are penetrated by the needles formed in particular as an articulated contact pins. One ends of the articulated needles come into contact with the second contact pads of the Kontaktabstandstransformers and the other ends of buckling needles are used to physical contact of electrical contacts of the DUT. Accordingly, test device and test specimen are in an electrical test of the test piece moved toward each other to cause the touch contacting the test specimen. Either move test equipment and device under test, or only one of these assemblies. The movement takes place in longitudinal extension of the contact pins of the contact head. Since preferably articulated needles are used as contact pins, these differ widely in terms of their longitudinal extent by a buckling length adaptation on.

A development of the invention provides that the contact elements for the electrical touch contacting the DUT are fixed at the contact distance Transformer. Unlike the above-mentioned embodiment in which the contact spacing Transformer has second contact surfaces which come into touch contacting with contact pins, which in turn are brought into electrical contact contact with the DUT, is provided accordingly that the contact elements serve for contacting the test object, fixed are arranged at the contact distance Transformer. A preferably removable test head is then not available.

It is also advantageous if the contact means are arranged directly and firmly to the contact spacing Transformer in an alternative embodiment. Accordingly, the contact means are therefore associated with the contact spacing Transformer directly and held at this. Alternatively, it is possible that the contact means are elements a separate assembly that is disposed between the semiconductor substrate and the contact distance Transformer.

A development of the invention provides a second stiffener, wherein the first reinforcement means is located on one side of the conductor substrate and the second reinforcement means on the other side of the conductor substrate. Accordingly, the semiconductor substrate on both sides is stiffened by stiffening both devices are mechanically connected to the printed circuit substrate. In particular it can be provided that the two reinforcing devices are sequentially fed clamped by corresponding clamping means and thereby absorb the conductor substrate in particular by clamping and supporting manner between them.

A preferred embodiment of the invention provides preferably that the second reinforcement of the contact spacing Transformer is assigned. In particular, the second reinforcement means to a recording breakthrough, in which the contact spacing Transformer is free of contact at least partially received. This arrangement enables the direct assignment of the second stiffening means for conductor substrate and also effected by the recording breakthrough a close association of Kontaktabstandstransformers the conductor substrate. To effect caused by the tilt element tilting movement of Kontaktabstandstransformers, this must not rest against the second reinforcement. By non-contact recording of Kontaktabstandstransformers in the receiving breakdown of the second stiffener a tilting movement is therefore not hindered.

preferably Neigungseinstellmittel are provided in the form of threaded bolts for the aforementioned tilt adjustment. The threaded screws can be formed as set screws and / or as locking screws. The adjusting screws are used to bring about a corresponding angular position of the tilt element to the first reinforcement and the locking screws are used to fix this angular position. For this purpose, the adjusting screws screwed adjustable in the tilt member, they are supported by their one ends to the first stiffener. The locking screws are screwed into the first stiffening device and lie with their heads on thrilling to the tilting element. The tilt adjustment can be done in other ways. In particular, these screws can be provided where a feeler gauge strip (special film, which is available in very fine gradations thickness) is placed underneath. The special film is preferably made of steel or nickel silver.

The tilting element is preferably designed as a tilting plate. The semiconductor substrate is formed in particular as a circuit board. The first and / or second reinforcement means is / are preferably plate-shaped.

According to a development of the invention that the spacer has a spacer sleeve. This is fixed with one end to the contact spacing Transformer and with its other end to the tilting element.

Preferably alignment means are provided which align the conductor substrate to the Kontaktabstandstranformer sideways to position in this manner, the first contact surfaces of the conductor substrate relative to the mating contact surfaces of the Kontaktabstandstransformers so that the intermediate contact means (connectors) are each mutually associated first contact surfaces with associated can connect opposing contact surfaces electrically properly.

According to a development of the invention can be provided that the Neigungseinstellmittel are arranged on the spacer. These interact with the first reinforcement.

Further, a plurality of spacers are preferably provided, which are spaced from one another.

The invention further relates to a method for electrical testing of an electrical test piece, in particular with use of the above-described test device, with a printed circuit substrate which is electrically connected via a contact distance Transformer with a test head, wherein the semiconductor substrate is mechanically connected to a first reinforcement and stiffened characterized and wherein at least one the semiconductor substrate by cross spacers with the contact distance Transformer is connected mechanically and is held on the first bracing means through Neigungseinstellmittel.

Further advantageous embodiments of the method result from the claims.

The drawings illustrate the invention using an exemplary embodiment, specifically:<dl id="dl0001"><dt>figure 1</dt><dd>a schematic longitudinal section through an electrical testing device for examining an electrical step specimen, the test facility is not fully represented with all its components,</dd><dt>figure 2</dt><dd>a perspective longitudinal section view through the test device of the <figref idrefs="f0001">figure 1</figref>Without representation of a contact head,</dd><dt>figure 3</dt><dd>a perspective view of a contact spacing transformer and a tilting element of the test facility,</dd><dt>figure 4</dt><dd>A perspective view of the arrangement of the <figref idrefs="f0003">figure 3</figref>But from a different angle,</dd><dt>figure 5</dt><dd>a longitudinal sectional view of a portion of the electrical representation of the test apparatus without contact head, </dd><dt>figure 6</dt><dd>a perspective longitudinal section through the region of an electrical testing device according to a further embodiment,</dd><dt>figure 7</dt><dd>a detailed view of the test device of <figref idrefs="f0006">figure 6</figref> and</dd><dt>figure 8</dt><dd>a further detailed view of the test device of <figref idrefs="f0006">figure 6</figref>,</dd></dl>

The <figref idrefs="f0001">figure 1</figref> shows a test device 1 from which not all components are shown. The apparatus 1 has a contact head 2 (also called probe 2), which has in guide bores 3 slidably mounted contact pins 4 which are preferably formed as articulated needles. The contact pins 4 have free ends 5 which can be contacted by contact with contacts of an electrical test piece, not shown. For this purpose, the testing device 1 is lowered on the specimen or the specimen is introduced to the checking device 1 or both parts move towards each other. The other ends 6 of the contact pins 4 are in physical contact to a contact separation transformer 7 which has a support 8 and an electrical Kontaktabstandsumsetzschaltung 9th The support 8 is preferably configured as a metal support. The Kontaktabstandsumsetzschaltung 9 is firmly connected to the ceramic support. 8 The carrier 8 has a receptacle 10 in which the Kontaktabstandsumsetzschaltung 9 is housed sunk. The contact spacing Transformer 7 has on its side facing the contact head 2 side facing reference surface 11 with a small distance to the contact spacing Transformer 7 is a semiconductor substrate 12, in particular in the form of a printed circuit board 13. The circuit board 13 has first contact surfaces 14, which are electrically connected with contacts 15 in surface connection, wherein the first contact surfaces 14 on one side 16 and the surface of contacts 15 on the other side 17 of the conductor substrate 12 are arranged. electrical contact means 18 are arranged between the contact distance Transformer 7 and the conductor substrate 12, having on an insulating substrate 19, electrical contacts 20th On its side facing the head substrate 12 facing surface 21 of the contact distance Transformer 7 has in the region of its Kontaktabstandsumsetzschaltung 9 mating contact surfaces 22, which are electrically connected via the contacts 20 with the first contact surfaces fourteenth The contact distance Transformer 7 has in the region of its Kontaktabstandsumsetzschaltung to 9 second contact surfaces 23, which are electrically connected to the mating contact surfaces 22nd The ends 6 of the contact pins 4 lie at the physical contact against the second contact surfaces 23rd

Seen from not shown specimen results in the following electrical path of the testing device 1, which here for simplicity will be explained in only one of these paths. The other paths correspond to the described path. An existing at the DUT contact occurs when testing the electrical device under test in physical contact with the end 5 of the contact pin 4, the other end 6 into contact Contact is one of the second contact surfaces 23, which is wired within the Kontaktabstandsumsetzschaltung 9 with one of the mating contact surfaces 22, against the one end of one of the contacts 20 is in touching contact with the other end of the contact 20 abuts in abutting contact against one of the first contact surfaces 14, which is wired within the semiconductor substrate 12 with one of the area contacts 15. the surface contact 15, not shown, via an electrical line connected to a testing device. Overall, it is clear that between the test device and DUT electrical Prüfstromwege can be prepared to this to check for proper electrical operation. The contact spacing of the contact pins 4 corresponds to the contact density of the object. The contact spacing Transformer 7 serves to convert this close contact spacing in a less close contact distance. this is the<figref idrefs="f0001">figure 1</figref> can be seen, since there the counter-contact surfaces 22 a greater distance from one another than the second contact surfaces 23 by means of the conductor substrate 12, the contact distance between the first contact surfaces 14 again increased by the contact spacing of the surface contacts 15 is greater than that of the first contact surfaces fourteenth

To the reference surface 11 of Kontaktabstandstransformers 7 to align 12 with respect to their inclination with respect to a reference surface 24 of the conductor substrate, a tilt device 25 is (<figref idrefs="f0002">figure 2</figref>) Is provided. The reference surface 24 of the conductor substrate 12 corresponds to page 16 of this component.

In the <figref idrefs="f0002">figure 2</figref> the arrangement of <figref idrefs="f0001">figure 1</figref> again shown, but wherein the contact head 2 and the contact means 18 are not shown and in the <figref idrefs="f0001">figure 1</figref> downwardly facing area of ​​the test device 1 is now in the <figref idrefs="f0002">figure 2</figref> facing up. From the<figref idrefs="f0002">figure 2</figref> can also be seen that the conductor substrate 12, a first stiffener 26 and a second stiffening means are associated with 27th The first stiffening device 26 is in contact with the side 17 of the semiconductor substrate 12. The second reinforcement 27 is disposed on the side 16 of the conductor substrate 12th Both reinforcing devices 26 and 27 are clamped by clamping means 28 with each other, so that they take up a clamping the conductor substrate 12 between itself and stiffen so far.

The second stiffening device 27 has a receiving breakthrough 29 in which the contact spacing Transformer 7 is accommodated without contact. There he is held by several spacers 30, the openings 31 of the printed circuit substrate 12 pass through without contact and lead to a tilting element 32nd The tilting element 32 is in particular designed as a tilting plate 33rd The Neigeelment 32 is about Neigungseinstellmittel 34 with the first stiffening device 26 tilts in conjunction. The spacers 30 to enforce a non-contact openings 35 of the first stiffener 26th

From the <figref idrefs="f0005">figure 5</figref> the structure of the Neigungseinstellmittel 34 clearly visible. The Neigungseinstellmittel 34 include threaded bolts 36 and 37, wherein the threaded screws 36 are formed as setting screws 38 and the threaded screws 37 as fixing screws. 39 From the<figref idrefs="f0003">figures 3</figref> and <figref idrefs="f0004">4</figref> it is seen that the tilting element 32 with a plurality of spaced apart adjusting screws 38 and set screws 39, wherein each of a set screw 38 and a locking screw are 39 adjacent to each other. In the embodiment of<figref idrefs="f0003">figures 3</figref> and <figref idrefs="f0004">4</figref> the tilting element 32 is designed as a rectangular tilt plate 33, each having projections 40 in the region of its four sides, each of which an adjusting screw 38 and a locking screw are associated. 39

The arrangement is now made such that - according <figref idrefs="f0005">figure 5</figref> - Each of the adjusting screws 38 is screwed adjustable in a threaded bore 41 of the tilting element 32 with its thread and is supported with its one end 42 on an outer side 43 of the first stiffener 26th The associated locking screw 39 is screwed into a threaded hole 44 of the first stiffener 26 and rests with its head 45 exciting on to the tilt element 32nd The locking screw 39 thus pulls the tilt member 32 toward the first stiffening device 26 so that the end 42 of the adjusting screw 38 is pressed against the outside 43 of the first stiffener 26th From all this it is clear that depending on the Herausraglänge, so the screw, the adjusting screws 38, the spacing position of the tilting element 32 can be adjusted to the first stiffener 26th Because several pairs of adjusting screws 38 and set screws 39 are provided, the position of the tilting element 32 with respect to its inclination can be adjusted relative to the first stiffening device 26 by means of Neigungseinstellmittel 34 to a desired position. Since the tilting element is coupled 32 via the spacers 30 rigidly connected to the contact spacing Transformer 7, will change the position, and in particular, the inclination position of Kontaktabstandstransformers 7 in the same manner at an inclination adjustment of the tilt element 32nd It follows that by means of Neigungseinstellmittel 34, the reference surface 11 of the Kontaktabstandstransformers 7 is adjustable relative to the reference surface 24 of the conductor substrate 12th

From the <figref idrefs="f0002 f0003 f0004 f0005">Figures 2 to 5</figref> are further aligning 46 visible in the form of so-called alignment pins 47, which serve the lateral alignment of printed circuit substrate 12 to contact spacing Transformer. 7 This alignment is also called registration and ensures that the first contact surfaces 14 are aligned in the desired way to the mating contact surfaces 22 in the direction of the plane of the circuit board. 13 To this end, pass through the rod-shaped, preferably in cross-section non-circular, in particular in cross-section stadium-shaped aligning means 46, corresponding guide holes 48 in the printed circuit substrate 12 and guide holes 49 in the contact spacing Transformer 7. The alignment means 46 are fixed by means of fastening screws 50 on tilting element 32nd These guide holes 48 and 49 form fits for the pin-shaped aligning means 46. The aligning means 46 through openings 51 but do not touch the first stiffener 26th

It follows that because of the spacers 30, which are preferably configured as spacers, a defined distance between the contact spacing Transformer 7 and the tilting element 32 is guaranteed. The Kontaktabstandsumsetzschaltung 9 is preferably permanently connected to the support 8, preferably glued. In particular, press the four set screws 38 with their ends 42 against the first reinforcement 26, which is also called Backstiffener. Using these four adjustment 38 can therefore be adjusted 26 the distance between the tilting element 32 and the first reinforcement. Since the first stiffening device 26 is fixed to the semiconductor substrate 12 and the tilting element 32 has a fixation for contact spacing Transformer 7, can ultimately with adjusting screws 38, the angle of the reference surface 11 of Kontaktabstandstransformers 7 and the reference surface 24 of the conductor substrate 12 adjusted / Adjust. After such an adjustment of the angle between said reference surfaces 11 and 24 to complete the process by tightening the locking screws. 39 Thus, the mutually aligned reference areas are fixed 11 and 24th

The <figref idrefs="f0006 f0007 f0008">Figures 6 to 8</figref> relate to a further embodiment of a test device. For this further embodiment, the explanations apply to the embodiment of<figref idrefs="f0001 f0002 f0003 f0004 f0005">Figures 1 to 5</figref> is accordingly so received below only on differences. In contrast to the previously described embodiment, the embodiment of the<figref idrefs="f0006 f0007 f0008">Figures 6 to 8</figref> no tilting element. According to the<figref idrefs="f0006">figure 6</figref>Which shows a detail of the testing device 1 according to the further embodiment, wherein the view of the <figref idrefs="f0006">figure 6</figref> rotated about 180 ° from the view of the <figref idrefs="f0002">figure 2</figref> of the other embodiment, can be seen that a plurality of spaced spacer 30 are attached in the form of threaded bolts 60 at the contact distance Transformer 7th The screws 60 have heads 61 which einliegen firmly in shots 62 of Kontaktabstandstransformers 7 by screwing the screws 60 into threaded holes 63 of Kontaktabstandstransformers. 7 The shafts 64 of the threaded bolts 60 extend through with clearance guide holes 48 of the circuit board 12 and engage in record 65 of the first stiffener 26th

According to <figref idrefs="f0007">figure 7</figref> , each receiving 65 an internally threaded, large diameter section 66, an adjoining, smaller diameter and thread-free section 67 and a diameter even smaller and also thread-free section 68th The section 68 has the game on to the shank 64 of the associated screw 60th In the thread of the threaded bolt 60, a nut 69 is screwed, the 'supported with a flange 70 at one stage 71st The stage 71 'is formed between the sections 66 and 67th On the other side of the flange 70 there is a screw ring 71 which has an external thread 72 which is screwed into the female thread of the portion 66th The interior of the screw 71 engages a connector 73 of the nut 69. The ring nut 71 pressed when screwed the nut 69 against the step 71 '.

From all this it is clear that by suitably wide screwing the respective nut 69 to the respective screw 60, the contact distance Transformer 7 can be adjusted relative to the semiconductor substrate 12 with a correspondingly desired inclination, the respective nut position is secured by tightening the corresponding screw rings 71st

Furthermore, the <figref idrefs="f0006">figures 6</figref> and <figref idrefs="f0008">8th</figref> shows that - unlike the embodiment of <figref idrefs="f0001 f0002 f0003 f0004 f0005">Figures 1 to 5</figref> - The Kontaktabstandsumsetzschaltung 9 is not bonded into a receptacle 10, but is inserted into a receptacle 10 of the carrier 8 and held by means of cross-, held by the retaining screws 74 clamping plates 75th The clamping plate 75 overlap the Kontaktabstandsumsetzschaltung 9. In order to maintain a reproducible position of Kontaktabstandsumsetzschaltung 9 within the rectangular or square recess 10, clamping springs 76 are provided at two sides of the receptacle 10, 9 urge the Kontaktabstandsumsetzschaltung accordingly opposite edges 77 of the receptacle 10, whereby highly accurate positioning is ensured.

These foregoing way of positioning the Kontaktabstandsumsetzschaltung 9 can of course also in the embodiment of <figref idrefs="f0001 f0002 f0003 f0004 f0005">Figures 1 to 5</figref> be provided. Of course other hand it is also possible that the embodiment of the<figref idrefs="f0006 f0007 f0008">Figures 6 to 8</figref> a glued Kontaktabstandsumsetzschaltung 9.

The height of the testing device 1 of the embodiment of <figref idrefs="f0006 f0007 f0008">Figures 6 to 8</figref> is less due to the lack reclining plate. Also cheapens this embodiment, since the tilt plate can be omitted.