FR2590439A1 - IMPROVED TEST PIN ASSEMBLY FOR BOARD OR PRINTED CIRCUIT BOARD CONTROLLER - Google Patents

Abstract

APPARATUS FOR TESTING THE ELECTRICAL INTEGRITY OF A CARD OR WAFER 12 OF PRINTED CIRCUITS, COMPRISING A PLURALITY OF 16 NODES ACCESSIBLE TO PREDETERMINED LOCATIONS ON ITS LOWER SURFACE, SUCH APPARATUS COMPRISING MEANS OF SUPPORTING THE PLAQUE , A SUPPORT PLATE 28 MOUNTED IN PARALLEL WITH THE PRINTED CIRCUIT PLATE TESTED ON THE SAME SIDE AS THE ACCESSIBLE NODES OF THIS LAST, A PLURALITY OF TEST PIN 30 CARRIED BY THE SUPPORT PLATE FOR THE SITES ACCOMMODATING THE SITES. ACCESSIBLE NODES, THE TEST PINS INCLUDING CONTACT PORTIONS ON ONE SIDE OF THE SUPPORT PLATE FOR THE CONTACT OF THE NODES AND ACTUATION PORTIONS ON THE OTHER SIDE OF THE SUPPORT PLATE TO CAUSE THE MOVEMENT OF THE CONTACT PORTIONS IN AN ACTUATED POSITION FOR THE CONTACT OF THE NODES WHEN THE ACTUATION PORTIONS ARE MOVED EES, AND AN ACTUATION PLATE 56 PARALLEL TO THE SUPPORT PLATES AND INCLUDING MOVEMENT PORTIONS ALIGNED WITH THE SELECTED ACTUATION PORTIONS CORRESPONDING TO THE PREDETERMINED LOCATIONS OF THE PRINTED CIRCUIT PLATE SUBJECTED TO THE ESSENCES FOR THE PLACES TO REPLACEMENT KNOTS AT PREDETERMINED LOCATIONS OF THE PRINTED CIRCUIT BOARD TESTED.

Description

Set of advanced test pins - 'for

  their cards or printed circuit boards.

  The present invention relates to an apparatus for testing printed circuit boards or boards.

  Tests are often carried out on plates.

  printed circuit boards fitted with their components to detect their electrical integrity, to do this we use test pins mounted on a spring and supported vertically under the circuit board

  printed material under test, in a position

  both to be in contact with the nodes exposed on the

  lower surface of the wafer subjected to the tests.

  For example, US patent NO. 4,132,948 describes the world

  tage of test pins in an unloaded printed circuit board, having a configuration of

  holes identical to that of the plate subjected to the

  know so the test pins self align

  matically on the nodes brought into contact. When the circuit board controller must be

  used to test platelets with a con-

  different nodal representation, the support plate of

  test pins is replaced by a plate

  both of the test pins corresponding to the position

  nodal of the new design of brake pads

cooked prints.

  It has been discovered that test pins can be used more effectively in a controller

  circuit boards, and modifications

  in the design of the circuit boards

  award winning trials can be more easily

  provided by providing a pin holder plate

  test ches and a parallel actuation plate.

  The test pin support plate has a plurality of test pins which are mounted at positions corresponding to the possible locations of the nodes accessible on a plate under test and can be moved independently to the actuated position to come into contact on the nodes of the wafer subjected to the tests. The action plate

  presents displacement portions capable of ac-

  the respective test pins and corresponding

  tooth at the actual locations of the nodes of the specific wafer to be tested so that only the test pins, which correspond to the actual locations of the

  nodes of the wafer under test, are displaced

  in the actuated position. The floor controller

  printed circuit boards can then be changed when switching from testing a wafer type to

  another by simply replacing the action plate-

  ment; it is therefore not necessary to design the relatively expensive test pins to meet a specific configuration of printed circuit boards.

  In preferred embodiments, the plac-

  this support and the actuation plate are mounted

  horizontally. The wafer submitted to the tests

  is lowered into position; the moving portions

  ment on the actuation plate consist of

  cards which project upwards from the plate-

  and have portions under the contact plate

  operating in such a way as to conduct electricity to the

  components of the controller circuit; the support plate is pivotally mounted to allow

  the actuation plate mounted below to be fa-

  clement removed; guide pins on the plate

  actuation pins are used for alignment

precision of the insert.

  In a preferred embodiment, each bro-

  The test che includes a housing which is fixed in the support plate, a pair of rods extending from the opposite ends of the housing and a spring

  compression, sit- between wings, sliding in the lo-

  Ue.naent in the ccn.dU! On not loaded. In another sode of ae; sisatîion e p refr each 'oce dess compzend - zi lcie! aeent qui e. nO-t sliding way dens Mon tU} lA s' s d5> nd1 - 2 ', y U "UE -', X-- '; p35"' U: St ePn 2rt e de iges -e- rint dI - , _ r-. 1 ..; '_..._ s-_ ODDses duÉ

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  L ::, 'b-o _]' es esK t;! _ U i _- _ ri ._- e -a O P_ te

.i_; u of 1 .. _! -

  n t C d- oi- a _-ad -. 'oz 3 ibri-eveent describe los desins dar. are you! ' 1, t e. r t _ e ri z t - io a p pa S- pOé u r e, s zmS Ea 2 ee! i LICe s -_ e z1 eOslO 'La -gur-e' -is a schneatic sectional view -,., - ó, - * '; 1rCUatS pr, * ur ,, s according to' i.nenin La f: Lu re and a schaiatic street in section

  vertical i 'seems like Lbroches of tests of apDa-

rei sei n i -igure.

  La.ure - 3 -it a view of etz-Iity of a spring

  of the pin sssion figure 2.

  Figure 4 is a side view of a portion of the rs-e-r according to Fig. 3

  i Figure 5 is only a side view of a bzo-

  displacement cheek and a low spindle!

3C according to Figure 1.

  Figure 6 is a schematic vertical sectional view of a set of test pins

according to the inventory.

  FIG. 7 is a schematic view in vertical section of another variant of a set of test pins ,. shown with a modified support structure

according to the invention.

  FIG. 1. shows the structure of the apparatus 10 intended for testing the electrical integrity of a printed circuit board or board 12 fitted with components 14, some of them comprising conductors passing through holes in the board and which are soldered at nodes 16 to conductive strips printed on the underside of the board 12 Some components 14 are mounted on the surface (either on the top or above, or on the bottom or bottom of the board 12) and electrically connected

  to conductive pads serving as solderless nodes

  tough. Each different circuit board design

  printed baked 12 subjected to the tests, presents a con-

unique figuration of knots 16.

  Starting approximately from the top of the apartment

  similar 10, it has side walls 18

  providing cantilever portions 19 against

  which a membrane plate 22 of 25.40 cm by 25.40 cm (10 "by 10") (phenolic resin plate filled with glass, fire resistant, with a thickness of 66 mm

  (0.187 "), sold under the brand FR4, often

  signed G-10) is loaded by springs 20. The membrane plate 22 has holes with a diameter of 1.77 mm (0.07 ") spaced at 2.54 mm (0.1") centers and a rubber sealing ring 23 (in neoprene with a height of 3.17 mm (1/8 ") and a width of .40 mm (1 inch) around the perimeter of the plate 22

  provides vacuum sealing with the door portion

  overhang 19 and the wafer under test 12. Two pointed guide pins 24 with a thickness of 3.17 mm (1/8 ") extend upward through corresponding holes in the plate subjected to tests 12 for the correct alignment of the latter. Also provided, at selected locations on the surface of the plate 22, various support pads

  rubber (not shown) which are used for

  cheification the holes in the wafer subjected to the

  know 12 or its support to prevent it from sagging

  when vacuuming the region above

under.

  The test pin support plate 28 carries

  as the test pins 30 is pivotally mounted

  aunt on the side wall 24 at the pivot 26.

  The end 29 of the plate 28 is supported by the flange 31. The support plate 28 is produced from

  two phenolic resin wafers loaded with glass

  re, with a thickness of 3.17mm (1/8 ") (same material as the plate 22) spaced from each other by 19.05mm (3/4") to provide a total thickness of 25, 40 mm (1 "). The test pins 30 are mounted in holes 32 in the plate 28 spaced at 2.54 mm (0.1") centers and aligned with the holes in the membrane plate 22. Figure 2 shows that each pin

  30 has a tubular housing 34 in nickel-

  gold-plated silver, with an outside diameter of 1.37 mm (0.054 "). The housings 34 are fitted in a tight fit in test pin sockets 35 with an inside diameter of 1.39 mm (0.055") , which are fixedly mounted in the support plate 28 and have; shoulders 37 spaced 19.05 mm (3/4 ") apart to provide proper spacing and structural support for insert 28. Housing 34 is 37.33 mm (1.470") long and has a first crimp 36

  located 3.30 mm (0.130 ") from its top, a second ser-

  weaving 38 located at 9.65 mm (0.380 ") from its bottom and a boss (not shown) holding it firmly, although in a removable manner, in the socket 35 of the spindle

  of tests. The contact rod 40 and the actuation rod

  ment 42 are slidably mounted in the housing

  ment 34 with a compression spring 44. The rods 40,

  42 are made of heat treated beryllium copper-

  ment, with a gold plating on nickel, present ex-

  pointed hoppers 45, 47 to allow good contact

  electric, thickened portions 46, 48 respectively-

  ment, for cooperation with crimps 36, 38 and cantilevered shoulders 50, 52 which are larger than the diameter of the housing 34. The spring 44 has an unloaded length of 14.47 mm (0.570 " ), and has a winding of piano strings up to 822g / 25.40mm (29 ounces / inch). Figures 3 and 4 are

  appear that the ends 54 of the spring 44 comprise

  try portions of reduced diameter, eccentric; this has the effect that the spring 44 and the thickened portions 46, 48 are loaded elastically, transversely against the interior surface of the housing 34 only when the spring 44 is compressed in order to ensure good

  electric contact. When the spring 44 is not com-

  award winning, rods 40, 42 and spring 44 can slide

be free in housing 34.

  Referring again to Figure 1, the actuating plate 56 with a thickness of 9.52 mm (3/8 ") (made of the same material as the plate 22) carries displacement pins 57 made of copper-beryllium, low pins 58 and alignment pins 59 which are housed in sockets 60 carried by the walls

  side 24 and 62, supported by the housing 92. Cha-

  that displacement spindle 57 has a projection 64

  (figure 5) with a height of 6.35 mm (1/4 "), a diameter

  1.27 mm (0.05 ") meter extending above the board

  quette 56, and each lower spindle 58 has a diameter

  be 1.27 mm (0.05 "), a projection 65 with a height of

  2.03 mm (0.08 "). The upper surfaces of these sail-

  the lees are concave so as to guide and retain the pointed ends 47 of the test pins 30. Each test pin 57 or 58 has a knurled portion

  intermediate 66 with a diameter of 1.72 mm (0.068 "), mon-

  Tight fitting in plate 56, and a 0.63 mm (0.025 ") square wound wire connection

  side extending below the plate 56.

  Mounted below the action plate

  ment 56, there are rows of sockets 70, lower

  laughing in quantity at the test pins 30, supported by the upper ends of the daughter plates 73,

  aligned and adapted to receive and realize a link

  electric sound with the selected terminals 68. The

  68 selected terminals are either integral with the sail-

  lie 64 of a displacement pin 57 is connected by wires 72 to a terminal 68 of a displacement pin

  57. The sockets 70 are electrically connected to the elements

  elements composing the electronic circuit on the plates-

your daughters 73 of the controller.

  In service, an actuation plate 56 includes

  carrying displacement pins 57, mounted in locations corresponding to accessible nodes 16 of

  the wafer submitted to tests 12 is mounted inside

  laughter of the device 10 by sliding its guide pins 59 into the sockets 60 while

  that the support plate 28 is in the vertical position

  wedge raised. The terminals 68 are introduced with zero insertion force into the respective sockets 70

  which are then translated laterally (by a mechanism

  nism not shown) to allow a good electrical connection. The support plate 28 is then rotated to the horizontal position shown in Figure 1 so that its end 29 is supported by the flange 31. As the plate 28 is lowered into position, the actuating rods 42 test pins 30 aligned with displacement pins 57

  are pushed up. As rod 42 runs

  smooth upwards inside the housing 34, it pushes the spring 44 upwards and the contact rod through a hole in the membrane plate 22 as far as

  in the raised position, as shown & fi-

  gure 1. This only requires the force equal to the weight of the

  two rods and spring. The brochure submitted to the

  know 12 is then mounted in position using the guide pins 24 and it rests on the ring 23 and the

  springs 20. A vacuum is then applied to the region if-

  killed under the wafer subjected to the tests 12, thus causing the compression of the ring 23 and the springs 20 and the lowering of the wafer subjected to the tests 12 so that the nodes 16 come into contact on the corresponding contact rods 40 which were raised by compressing the springs 44. Only the

  springs of the test pins which have been raised, li-

  thus mitigating the force which must be applied to react

read the contact.

  The pointed end 45 plunges into the solder or into the contact pad at node 16, making good electrical contact. The reduced diameter ends 54 of the spring 44 cause the lateral elastic loading of the thickened portions 46, 48 making good contact

  electrical through the test pins 30. The

  pointed mites 47 are loaded elastically towards the

  down by the force of the spring and in the same way, rea

  read good electrical contact with the projections 64 of the displacement pins 57. The electrical connection with the elements making up the electronic circuit is made either directly on a socket 70 under a displacement pin 57 or or by means of a wire 72 on the terminal of a low pin 58 housed in a socket 70; The components of the electronic circuit

  of the controller provide test signals to the board

  quette subjected to tests 12 and detect the responses.

  When you want to test a different design

  of wafer 12, the support wafer 28 is put in pi-

  vote relative to a vertical position and the

  actuation plate 56 is replaced by a new

  velle actuation plate 56 comprising displacement pins 57 corresponding to the nodes 16 for the

  new plate 12 subjected to the tests. Of this ma-

  Finally, it is possible to receive different designs.

  circuit board by simply changing the actuator boards 56 and there is

  no need to design test pins 30 re-

  laterally expensive, which are specially adapted to a particular predetermined configuration. Likewise, it is much easier to adapt to the design modifications of the wafer 12 under test by changing the location of the protrusion pins 58 than to change the locations of the test pins and the connections with the component elements. the circuit as

  this is the case with controllers with pin positions

specific test ches.

  Other embodiments of the invention

  fall within the scope of the following claims. By

  example, Figure 6 shows an alternative design of test pins, test pin 74. Its spring 76 has a load of 70.87 g (2.5 ounces) and a force of 153.08 g ( 5.4 ounces) at 2/3 stroke. The test pin socket 78 which is still mounted

  fixedly in the support plate 28, has a dia-

  1.42 mm (0.056 ") inner meter, allowing the housing

  80 with an outer diameter of 1.37mm (0.054 ") of sliding

  be in it. In use, the displacement pins 57 push the housing 80 upwards,

  as well as the rods 40, 42 and the spring 76.

  Figure 7 shows another design variant.

  for the support of the test pins. Here, the plac-

  this support pin 83 for the test pins is produced in a single support plate with a thickness of 12.70 mm (1/2 ") (same material as the plate 22) which has countersunk holes 81, intended to receive the heads 82 of

  84 single-rod standard test pins. The bro-

  ches 84 can slide in the holes 85 through the plate 83. The caps 86 on the lower end

  re pins 84 prevent pins from falling out

  that the support plate 83 is turned over. The insulating socket 90 is used to electrically isolate the test pins 84 and align them with their test pins.

  displacement 57 respectively. During use, the

  seems from test pin 84 is moved up

  using a displacement pin 57.

he

Claims (18)

  1. Apparatus for testing electrical integrity   stick on a printed circuit board or board,   comprising a plurality of nodes accessible to em-   predetermined placement on its lower surface, said apparatus comprising   means for supporting the circuit board   printed circuit boards submitted to the tests, a test pin support plate mounted parallel to the test plate on the same side as the accessible nodes of the latter, a plurality of test pins supported by the support plate in corresponding locations at possible locations for the accessible nodes, each test pin comprising a contact portion on one side of the support plate for bringing a node into contact and an actuation portion on the other side of the support plate connected so   move the contact portion to an action position-   born for bringing the node into contact when the actuation portion is moved, and   an actuation plate parallel to the plate   support rod and comprising displacement portions aligned with selected actuation portions corresponding to the locations of predetermined nodes of the wafer for displacing the test pins which   correspond to the nodes at predetermined locations   born from the wafer submitted to the tests.   2. Apparatus according to claim 1, in the-   which the support plate and the actuation plate are mounted horizontally so that the pins   tests are raised in an operating position   ment, and in which the means for supporting the wafer under test comprise means for lowering the wafer into position so that the nodes come into contact with the test pins selected at predetermined locations.   3. Apparatus according to claim 2, in the-   which displacement portions are pin pins   placement with projections extending upward from the actuation pad.   4. Apparatus according to claim 3, in the-   which displacement pins are electrically conductive   trically and have lower tra-   pouring the actuation plate to achieve electrical communication o10 with the components of the circuit under test.   5. Apparatus according to claim 2, in the-   which the test spindle includes a fixed mounted housing-   a pair of rods in the support plate   stretching from the opposite ends of the housing, one of these rods carrying the actuating portion, the other rod carrying the contact portion, and a compression spring between the two rods, shorter, when   is not compressed that the distance between the rods when   that they are at opposite ends of the housing   and are free to slide in the housing.   6. Apparatus according to claim 5, in the-   which housing is made of metal.   7. Apparatus according to claim 6, in the-   which the compression spring has an end of reduced diameter so as to move transversely a   rod against the housing when the spring is compressed.   8. Apparatus according to claim 2, in the-   which test pin has a housing which is   movably mounted inside the upper plate   port and a spring loaded rod supported in it.   9. Apparatus according to claim 8, in the-   which housing is slidably arranged in a   metal tube fixedly mounted in the upper plate Harbor.   10. Apparatus according to claim 1, in the-   which the test pin support plate is   formed by two pieces of insulating material spaced from each other by a plurality of tubular test pin sockets which surround the test pins and have shoulders which bear against the internal surfaces of the insulating material to provide a structural support.   11. Apparatus according to claim 4, compre-   additionally providing an insulating cellular structure located   between the support plate and the action plate-   nement, the actuating portions and the displacement pins being located in openings of the alveolar structure.   12. Apparatus according to claim 4, in the-   which some of the lower portions are connected directly to the sockets and certain other lower portions are connected by wires to separate the   lower portions directly connected to the sockets.   13. Apparatus according to claim 4, in the-   which displacement pins have depres-   sions in their upper surfaces.   14. Apparatus according to claim 4, in the-   which support plate is pivotally mounted   to provide access to the actuation board if- killed below.   15. Test pin including a housing,   a pair of rods extending from the ends   opposite housing halves, and a compression spring between the two   stems, which is shorter, when it is not com-   award winning, that the distance between the rods when they   located at opposite ends of the housing and can slidably slide into the housing.   16. Test pin according to claim 15,   in which the housing is made of metal.   17. Test pin according to claim 16,   in which the compression spring has an ex-   extremity with reduced diameter so as to move transversely   dirty rod against the housing when the spring is compressed.   18. Apparatus according to claim 14, comprising   additionally guiding pins to allow a-   alignment of the actuation plate on the plate- support for test pins.