Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
  • G01R1/00—Details of instruments or arrangements of the types included in groups G01R5/00 - G01R13/00 and G01R31/00
  • G01R1/02—General constructional details
  • G01R1/06—Measuring leads; Measuring probes
  • G01R1/067—Measuring probes
  • G01R1/073—Multiple probes
  • G01R1/07307—Multiple probes with individual probe elements, e.g. needles, cantilever beams or bump contacts, fixed in relation to each other, e.g. bed of nails fixture or probe card
  • G01R1/07314—Multiple probes with individual probe elements, e.g. needles, cantilever beams or bump contacts, fixed in relation to each other, e.g. bed of nails fixture or probe card the body of the probe being perpendicular to test object, e.g. bed of nails or probe with bump contacts on a rigid support
  • G01R1/07328—Multiple probes with individual probe elements, e.g. needles, cantilever beams or bump contacts, fixed in relation to each other, e.g. bed of nails fixture or probe card the body of the probe being perpendicular to test object, e.g. bed of nails or probe with bump contacts on a rigid support for testing printed circuit boards
  • G01R1/07335—Multiple probes with individual probe elements, e.g. needles, cantilever beams or bump contacts, fixed in relation to each other, e.g. bed of nails fixture or probe card the body of the probe being perpendicular to test object, e.g. bed of nails or probe with bump contacts on a rigid support for testing printed circuit boards for double-sided contacting or for testing boards with surface-mounted devices (SMD's)

Definitions

• This invention is related to an apparatus for testing boards provided with electrically conductive patterns and an adapter intended for such an apparatus according to the preambles of the following independent claims.
• the two contacting arrangements of a known apparatus are intended to be located on two in relation to each other movable parts of the apparatus according to the preamble of claim 1 , said parts also having a set of test contact spots each.
• both apparatus parts, which are movable in relation to each other must have a fairly complex design with a substantial measure of electrical and electronic complication. This tends to make the known apparatus much more expensive.
• the need for arranging separate sets of test contact spots on the two apparatus parts is from this point of view especially contributing.
• a known apparatus arranged according to the preamble of claim 2 is arranged so that the test contact spots are arranged as a relatively close grid in a bed.
• This bed and the grid of test contact spots are arranged with a surface big enough for being able to receive the normally largest prevailing pattern boards.
• the contacting arrangement is arranged so that it connects the test contact spots with the electrically conductive places on the pattern board.
• the aim is thereby to obtain as short communication paths as pos- sible between the conductive places on the pattern board and the test contact spots of the bed.
• the apparatus region, in which pattern boards are intended to be received is arranged in an overlapping relation to a second apparatus region, in which the test contact spots are arranged.
• test contact spots are arranged in a grid with a very large surface, for example comprising 20 000 test contact spots, in order to secure that pattern boards located in the first apparatus region may be brought into contact the test contact spots.
• a typical grid separation i.e. a typical distance between two test contact spots in the grid is 2,54 mm.
• grids with twice the density i.e. for the same apparatus size are 40 000 test contact spots utilised.
• the number of test contact spots effects the total price of the apparatus considerably. Thus, it is desirable to devise a way of reducing the number of test contact spots.
• Prior art has besides the disadvantage that it is very troublesome to arrange detectors in order to determine the mutual position between the contacting arrangement/-s and the pattern board.
• the object of this invention is to develop the apparatus and the adapter respectively according to the preambles of the independent patent claims 1 , 2, 16 and 17 in order to simplify the apparatus, especially when it is formed for testing conductive places located on two opposite sides of the pattern board.
• a further object is to obtain a cheaper embodiment relating to that the number of test contact spots is to be reduced compared to the case where a test contact spot region is substantially as large as the pattern board receiving region.
• a further object is to create the necessary conditions for a suitable location of a detector for detecting any position deviation for the pattern board in relation to one or two contacting arrangements intended for electrical contact therewith.
• the adapter the object is to arrange the same so that the necessary conditions arise for the already mentioned further developments of the apparatus.
• test contact spots are only needed on a base part of the apparatus.
• a further part of the apparatus which up to now has served as press member and as test contact spot carrier, may now completely be released from test contact spots and electrical and electronic couplings and components so that the function of the further apparatus part will be limited to the pure press function, wherein this function may be active or non-active.
• the further apparatus part may in the active case function for pressing down towards the underlying base apparatus part.
• the further apparatus part may in the non- active case function as a counteracting support, against which a movable pattern board supporting arrangement of the base part is pressable from below and upwards.
• the arrangement of the contacting arrangement formed as an adapter according to claim 17 with the first and second contact places located in separate adapter regions implies that the adapter is capable of transmitting test signals via electrical conductive paths from the adapter region where the first contact places for contact with the test contact spots are arranged to the second contact places intended for being brought into conductive contact with the pattern board.
• an electrical connection may thereby be established between the test contact spots and the conductive places on the pattern board independent of that the pattern board is located outside the second region and independent of the number of prevailing conductive places of the pattern board, wherein however the limiting criteria of course is that a sufficient number of test contact spots exists.
• test example with totally about 8 000 test contact spots may be mentioned as an example and it has showed to be just as functionable in reality as a test apparatus according to prior art with totally 32 000 test contact spots (20 000 test contact spots in a lower apparatus part and 12 000 in an upper apparatus part).
• a very good balance relating to arising forces is achieved by that the apparatus is formed according to the following claim 6, namely so that at least two second apparatus regions comprising first con- tact places of the contacting arrangement/adapter are located on each side of the first pattern board receiving region.
• Fig. 1 is a schematical general view illustrating a lower apparatus part of the apparatus according to the invention.
• Fig. 2 is an enlarged view of a detail from fig. 1 , wherein however elucidating additions have been carried out.
• the apparatus according to the invention comprises a lower apparatus part 1 visible in fig. 1 and below in fig. 2 as well as an upper apparatus part 2.
• the lower part 1 has suitably the character of a test table; it has generally a receiver 3 for a pattern board which is to be tested.
• the lower part 1 has some kind of framework 4, by means of which the lower part may be brought to stand on a floor or a table or similar.
• the upper apparatus part 2 may in the example have the character of a counteracting support. This implies that the lower apparatus part 1 is intended to function for pressing the pattern board to be tested upwards, as well as completing equipment, which will be described in more detail in the following, towards the upper apparatus part 2.
• the arrow 42 indicates the movability of the lower apparatus part 1.
• a support arrangement 25 comprised in the lower apparatus part is movable upwards and downwards in relation to the rest of the lower apparatus part 1 by means of a not shown force member, said support arrangement being described in more detail in the following.
• the upper apparatus part 2 has suitably the character of a cap, which could be translationary movable in vertical direction, but which in the example may be formed to describe a pivoting movement.
• the upper apparatus part 2 is in its counteracting position locked in relation to a stationary portion of the lower apparatus part 1 .
• the upper apparatus part must be openable or in some other way be removed for insertion of pattern boards. Even if the movable pressing member is intended to be formed by the lower apparatus part 1 or the support arrangement 25 of the same, it is noted that it is within the scope of the invention to use the upper apparatus part 2 as a movable member for pressing down onto the lower apparatus part 1.
• a pattern board 5 is schematically illustrated in fig. 2. It has first electrically conductive places 7 on a first side 6 and second elec- trically conductive places 9 on a second side 8, which is opposite the first side 6.
• the pattern board 5 has conventional electrically conductive paths 10, not showed openings etc.
• the object is that the pattern board 5 will be provided with or connected to various different electrical or electronic components.
• the conductive places 7, 9 and the conductive paths 10 are suitably produced by means of plating on an insulating ground plate, in addition to which existing openings may also be plated on the opening walls to the extent they are to serving as a conductive connection between both sides of the pattern board.
• the jjattern boards also can be produced according to a multiple layer technique, i.e. that conductive paths, contact places etc. may exist within or countersinked in, respectively the insulating ground plate, which thereby is formed by several suitably plated layers.
• the apparatus comprises an arrangement 1 1 of test contact spots for application of test signals.
• the apparatus comprises further a first contacting arranging 12 for establishing electrical contact between first test contact spots with reference numeral 13 and the first places 7 on the pattern board 5 and a second contacting arrangement 14 for establishing electrical contact between second test contact spots with reference numeral 15 and the second places 9 on the pattern board.
• the two contacting arrangements 12, 14 are provided with electrically conductive contact places 16 and 17 respectively on surfaces 18 and 19 respectively facing substantially in the same direction, considered when the two contacting arrangements are in electrical contact with the pattern board 5, said contact places being in- tended for contact with the test contact spots 13, 15.
• the first and second test contact spots 13, 15 are likewise facing in substantially the same direction, i.e. upwards in fig. 2, in order to during contacting meet these contact places 16, 17.
• the contacting arrangement 12 has electrically conductive second contact places 20 intended for electrical contact with the conduc- tive places 7 of the pattern board 5.
• the second contact places 20 of the contacting arrangement 12 are located in a pattern board receiving first apparatus region 21 , which is separated from a second apparatus region 22, in which the first contact places 16 of the contacting arrangement 12 are arranged.
• the second contacting arrangement 14 has second contact places 23 intended for electrical contact with the second conductive places 9 of the pattern board. These second contact places 23 are arranged in the just mentioned first apparatus region 2T7
• the first contact places 17 of the contacting arrangement 14 are arranged in the second region 22.
• the two regions 21 and 22 are in fig. 2 distinctly illustrated as being completely separated from each other. It should however be pointed out that the regions 21 and 22 may touch upon each other and during circumstances even partly overlap each other.
• the regions 21 and 22 are also illustrated in fig. 1. It is there also illustrated how at least one detector 24 for detecting any possible position deviation between the pattern board 5 and one or both of the contacting arrangements 12, 14 is located in the pattern board receiving first apparatus region 21 and thus outside the second apparatus region 22.
• ap- paratus according to the invention of course may be utilised in a position turned 90° around a substantially horizontal axis, in which case the expressions above/below used in this application of course must be converted to imply a position varying in the hori- zontal plane.
• the detector 24 is arranged below a support arrangement arranged in the first region 21 and having the general reference numeral 25. It is meant for supporting the contacting arrangements 12, 14 and the pattern board from below.
• the support arrangement 25 may be movable upwards for pressing against the upper apparatus part 2, which has already been mentioned.
• the detector 24 is intended to operate with detection signals, which are transmitted upwards and for which the support arrangement 25 is permeable.
• the detector 24 preferably comprises both a signal transmitter and a signal receiver so that the receiver collects signals transmitted from the transmitter and reflected by over-lying material components. The detector 24 utilises such signals, which are better reflected by an electrically conductive material than an electrically insulating material according to a preferred embodiment.
• the support arrangement 25 is suitably formed by an electrically insulating material as a consequence of such an embodiment.
• the reflection collected by the detector 24 will thereby reproduce the electrically conductive places, which are intended to be brought into electrically conductive contact with each other and indicate any sideways deviations between them so that adjustments of the mutual positions of the contacting arrangements 12, 14 and the pattern board 5 may be performed if needed.
• the contacting arrangements 12, 14 comprise first contact places 16, 17 in the regions 22, which has been described by guidance of fig. 2.
• the test contact spots 13, 15 are formed by contact devices 26 and 27, respectively with an elastic non-rigidity.
• the contacting devices 26, 27 may more closely comprise elastically compressible pins 28, the upper ends thereof forming the test contact spots 13 and 15, respectively and the lower ends thereof may in the example abut contact members 29 arranged on the frame of the apparatus, said contact members in turn being connected to a device for transmitting and receiving test signals.
• the support arrangement 25 is elastically non-rigid.
• the support arrangement 25 comprises more closely two mutually movable support parts 30, 31 , the part with reference numeral 30 having the character of carrier and being drivable vertically in relation to the framework 4 of the apparatus, while the part with the reference numeral 31 has the character of a support plate and is arranged to support the contacting arrangements 12, 14 and the pattern board during testing while the support part 31 may be pressed downwards in relation to the part 30 against the effect of springs 32.
• the force needed to overcome the effect of the springs 32 and thus press down the support part 31 is substantially equal to the force needed for pressing the pins 28 together in the regions 22.
• the first test contact spots 13 are formed by the first contact de- vices 26, which are arranged to contact the first contact places 16 of the first contacting arrangement 12.
• the second test contact spots 15 are formed by second contact devices 27, which are arranged to contact the first contact places 17 of the second contacting arrangement 14.
• the second contact devices 27 project through openings 33 provided in the first contacting arrangement 12.
• First and second contact devices 26, 27 and first contact places 16, 17 of both contacting arrangements 12, 14 are arranged in the second apparatus region 22. It is preferred that the first and sec- ond contact devices 26, 27 are uniformly distributed in the " second apparatus region 22. Every second contact device may for example, which is indicated in fig. 1 and 2, be intended to contact the lower of the contacting arrangements while every second contact device could be intended to contact the upper of the contacting ar- rangements.
• the contacting arrangements 12, 14 comprise a plate 34, 35 in the example, which has the first contact places 16, 17 and third contact places 36, 37 as well as conductive paths 38, 39 running be- tween them. It is preferred that the first and third contact places 16, 36 and 17, 37 respectively and the conductive paths 38 and 39 respectively of the plate 34, 35 are formed by plating with an electrically conductive material of an insulated foundation plate.
• the first and second contacting arrangements 12, 14 comprise an adapter 34, 35, having mutually disposed first and third contact places 16, 36 and 17, 37 respectively and a contact part 40 and 41 respectively for establishing contact between the third contact places 36 and 37 respectively of the adapter 34 and 35 respec- tively and the conduct places 7 and 9 respectively in question of the pattern board.
• Said adapter 34, 35 may in the preferred case be formed by the just described plate.
• the contact part 40 and 41 respectively is formed by a conductive fabric or disc. This fabric or disc is suitably formed by an elastical material and arranged with an electrically conductive ability in the thickness direction by comprising electrically conductive components.
• the function of the conductive fabric or disc 40, 41 is such that the fabric or disc 40, 41 will be intimately abutting both the pattern board 5 and the respective adapter 34, 35 during electrically contacting against both of them when the adapters 34, 35 are pressed upwards with the aim of the support arrangement 25, which is movable in the direction of the double arrow 42. It has already been described how the fabric or disc 40, 41 respectively may be included in what earlier was denoted first and second contacting arrangements 12, 14, wherein the fabric or disc forms the second contact places 20 and 23, respectively on its side facing the pattern board 5.
• a ⁇ corre- sponding contact place, here denoted fourth contact place 43 and 44 respectively will as a consequence of the constitution of the fabric or disc 40, 41 arise on the opposite side of the respective fabric or disc, said contact place will in practice contact the earlier mentioned third contact places 36 and 37 respectively.
• the contact places with reference numerals 20, 23, 43 and 44 on the fabric or disc 40, 41 has for the sake of clearness only been illustrated as elevations.
• the fabric or disk 40, 41 is in reality uniformly thick and it may thus serve for electrical connection in the thickness direction in an arbitrary position along the width thereof.
• the contacting arrangements 12, 14 and the pattern board and the apparatus are provided with mutually controlling members in order to at least roughly control the contacting arrangements and the pattern board in relation to each other. It is in the example suggested how the apparatus is provided with a pin-like control member 45 (there are in practice several such members), which have a controlling function in relation to the contacting arrangements 12 and 14 and the pattern board 5 by means of that the latter have openings so that they may be threaded on to the control member 45. These openings are located in a predetermined relation to the different contact places on the adapters 34, 35 and the pattern board 5 so that they will be located mutually adequate and besides so that the adapters 34, 35 will be located in correct place in rela- tion to the contact devices 26, 27.
• the earlier discussed detector 24 will be capable of detecting very small de- viations regarding the mutual position of the adapters 34, 35 and the pattern board 5 and that information regarding such deviations may be able to be utilised for adjusting purposes.
• the actual adjustments are normally within the existing tolerances referring to the control members 45 and the corresponding openings.
• the adapters 34, 35 and the pattern board 5 are intended to be able to be adjusted in a micro-scale during displacement in relation to the control member 45.
• Adapters 34, 35 matching to the pattern board 5 to be testeTJ and to the arrangements 1 1 of test contact spots 13, 15 are initially setup when the apparatus according to the invention is to be used.
• the adapter 34 is thereafter applied and a completed rubber fabric 40 is located on the same.
• the pattern board 5 is thereafter ap- plied and the further rubber fabric 41 is thereafter applied.
• the upper adapter 35 is finally applied.
• the test function may be initiated as soon as the upper apparatus part 2 is being locked with suitable means in an active or "closed" position.
• the support arrangement 25 is thereafter raised so that actual components are pressed against each other.
• Test signals are thereafter applied via the contact devices 26, 27 and these test signals are transmitted to the pattern board 5 via the adapters 34, 35 and the intermediate rubber fabrics 40, 41 and thereafter transmitted back on a suitable path via the rubber fabrics and the adapters so that the conductive ability of existing conductive paths on the pattern board 5 may be tested. Necessary fine adjustment of the position of the adapters and the pattern board may take place before such testing by means of the output signals of the detector 24.
• the third contact places 36, 37 thereof could be provided with elastic, electrically conductive layers in order to obtain a lenient contacting directly against the pattern board 5 without the need for any intermediate fabric or disc 40, 41 .
• the adapter 34, 35 itself not necessary needs to have the character of an insulating plate with applied electrically conductive places and paths respectively.
• the adapters 34, 35 could instead be arranged as box-like units, in the interior of which conduits could run between spots on the outer sides of the box units in order to establish the necessary conductive paths between the outer sides of the adapters.
• certain contact means 40, 41 are desired between the adapter 34, 35 and the pattern board 5, other embodiments than fabrics or discs of conductive embodiments may be considered.
• a contact means for electrical contacting substantially perpendicular to the plane of the adapters and the pattern board could for example be realised by applying a contact member in a suitable carrier, for example in the form of pins, which would be intended for establishing contact between the respective adapter and the pattern board 5.
• a contact member in a suitable carrier, for example in the form of pins, which would be intended for establishing contact between the respective adapter and the pattern board 5.
• One of the ends of these pins would thereby be able to contact one of the adapters while the other end would contact the pattern board 5.
• the pins could suitably be formed elastically compressible in order to obtain a uniform contact also by a great number of pins.
• the contact means it is however always suitable to arrange the contact means so that it operates contacting perpendicularly to the plane in which the con- tact means mainly is arranged if there is a need for such ⁇ certain contact means 40, 41 between the respective adapter and the pattern board 5.
• a further alternative is to divide the contact devices 26, 27 in different homogeneous groups provided at a distance from each other by double adapters 34, 35. Thus, only the contact devices 26 for contacting one 34 of the adapters would exist in a similar group while only contact devices 27 for contacting the second adapter 35 would exist in another similar group.
• the lower adapter 34 would in such an embodiment not necessarily have openings for allowing insertion of the contact devices 27 which are to contact the upper adapter 35, but the adapter 34 could quite simply be arranged completely beside an area situated by the group of contact devices 27.
• the conductive paths of the adapters 34, 35 may be arranged inside the adapters if they are formed by a multiple layer technique when the adapters 34, 35 are arranged in an embodiment similar to a pattern board.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Coupling Device And Connection With Printed Circuit (AREA)
• Testing Of Short-Circuits, Discontinuities, Leakage, Or Incorrect Line Connections (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (1)

Family

ID=26662413

Family Applications (1)

Country Status (3)

Citations (5)

• 1995
  • 1995-11-06 SE SE9503902A patent/SE9503902L/sv unknown
• 1997
  • 1997-03-20 AU AU29836/97A patent/AU2983697A/en not_active Abandoned
  • 1997-03-20 WO PCT/SE1997/000462 patent/WO1998041878A1/en not_active Application Discontinuation

Patent Citations (5)

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