Abstract:
This disclosure proposes an assembly structure for building probe cards to test square integrated circuit chips. The test probe card assembly structure has one or more wings located at 90° angles to each other upon which probes are laid in a parallel manner for attachment to a probe card. This allows 10 construction of the probe card so that probes touch contacts directly. The probe tips do not touch the contacts at an angle θ, called the fan out angle. The probes also do not differ in their inclination angles β. As a result, the force at which the many probe tips touch the contacts is relatively constant throughout. In addition, the probe tips are less likely to scrub past the surface of the contact onto the insulation surface of the chip and in doing so damage it. The test probe card assembly structure also contains an epoxy groove, which controls epoxy flow so that the position of the probes stays aligned in the correct plane. The epoxy groove also prevents variance in beam length. An alternative embodiment of the present invention can make probe cards for simultaneously testing multiple chips and includes a probe card for testing multiple chips.

Description:
FIELD OF THE INVENTION 
     This invention relates generally to probe cards used to test integrated circuit chips. More particularly, it relates to the assembly structure used to manufacture such probe cards. 
     BACKGROUND OF THE INVENTION 
     In a typical integrated circuit (IC) chip, the input, output, power supply and other terminals of the circuit are formed by metalized contacts, usually deployed along the margins of the circuit pattern. The outline of the chip is often square, and the marginal locations of the contacts depend on the circuit configurations and the available marginal space. In some instances the contacts may lie in a uniform row or rows along the margins. 
     For the purpose of testing any type of integrated circuit patterns, before the application of leads to connect the contacts to other components, various types of test probe cards have been developed. The most commonly used probe card consists of a printed circuit board having a circular opening or port to provide access to contacts on an IC chip. This opening is surrounded by conductive probes connected to terminals on the card which, in turn, are connected to test equipment appropriate to the circuit. The number of probes in the opening determines the maximum capacity of the probe card. 
     Structures used to assemble typical test probe cards consist of a base containing a downward-pointing funnel. A number of probes  22  are laid in a circular manner around the base with the probe tips pointing down towards the center of the funnel, as shown in FIG.  1 A. Due to the curvature of the funnel surface even probes lying next to each other, e.g., probes  22 A and  22 B at a fan out angle θ=0 have different inclination angles β, as indicated in FIG.  1 B. In general, probes at a fan out angle q will also have a different inclination angle β. 
     After probes  22  are adjusted on the funnel plane, a layer of epoxy is laid over them, as shown in FIG.  3 . The epoxy is then hardened by heating and the structure of probes and epoxy is attached to a planar insulation card having a printed circuit and a port. 
     Since the probes are attached to the probe card in a circular manner, they touch contacts  106  located on an IC chip  105  at different fan out angles θ, as illustrated in FIG. 2. A probe located in the center of a row of probes touches a contact located in the center of a row of contacts directly, at 0°. However, a probe located at the end of a row of probes requires a steeper fan out angle θ to reach a contact located at the end of a row of contacts, in the corner of the chip. 
     Since the probes are laid on an inclined assembly structure with the probe tips pointing downwards, as shown in FIG. 1A, they will form an inclination angle θ with the plane of the IC chip. Since the probes are laid on a non-planar surface, the inclination angle of each probe will vary greatly (see FIG.  1 B). In general, probes at the end of the row will have a smaller inclination angle than the probes at the center of the row. The disparity in the inclination angles at which the probes are laid will cause the force between the probe tips and contacts of the IC chip to vary over a wide range. 
     This disparity also causes deformation of the probe tips when they are placed in the holes of the Mylar sheath. The bend angle of the tip changes and alignment of the probe tips suffers. The Mylar may also be dislodged or deformed by the probe tips, which may also cause alignment to suffer. Often if the inclination angles of the probes differ, the probe tips may even pop out of the Mylar holes, again causing problems with tip alignment and planarity. These events may cause differences in the force at which the probe tip touches the contact and prevent uniform scrub length. 
     When the probes touch the contacts on the chip, the probe tips scrub the contact surfaces to remove the oxide film, and thereby establish electrical contact, as shown by scrub mark  100  of FIG.  2 . Disparity in the inclination angles of the probes will cause non-uniform scrub marks. In addition, because of fan out angles, some of the angles at which the probes touch the contacts are quite large (˜25-45°), and the scrubbing motion causes the tips to go beyond the contacts to invade the surface of the chip, as shown by scrub mark  102  of FIG.  2 . These scrub marks damage the functionality of the IC chip by destroying the insulating passivation layer. 
     Since all of the contacts in an IC chip lie in a common plane and must be simultaneously engaged in order to carry out testing, it is essential that all probe tips lie in a plane parallel to the common IC plane. Consequently, a fundamental requirement for a probe card is planarization of the probe tips. After the probes have been adjusted to assume their proper angles, an epoxy is poured over the array of probes so as to embed them at their assigned angles and planes in the epoxy, as illustrated in FIG.  3 . The epoxy is not contained, however, and often flows around the probes, dislodging them. Misalignment of the probes occurs so they are no longer at the correct angles or in the correct plane, as seen in FIG.  4 . Thus a uniform contact force becomes impossible to achieve. 
     Because the epoxy flow is uncontrolled, it may run down the length of the probe, as shown in FIG.  3 . The result is variance in the amount of probe exposed, also called beam length and indicated by reference L. One will thus get some probes with beam lengths L that are shorter or longer than others. The force at which a probe touches a contact on an IC chip depends to a large extent on the beam length and thus uniform beam lengths are crucial. 
     With a view to providing a test probe assembly that has uniform and consistent scrubbing characteristics, the Evans U.S. Pat. No. 4,599,599 discloses a structure in which a circular array of probes, all lying in a horizontal plane, are supported on a mounting ring surrounding a circular port in a card. The probes converge toward the central region of the port below which is the chip to be tested, with the slope angle between each probe tip section and the surface of the chip uniform. Despite the fact that this probe card minimizes the problem of probes aligned on different planes, it still retains the fan out angles for probes touching contacts at the corners of the chip and the resulting scrubbing problem. 
     The Evans U.S. Pat. No. 4,719,417 discloses a structure for a multi-layered test probe assembly, which features two radial arrays of probes to test an exceptionally large number of contacts on an IC chip. It also retains the fan out angles for probes touching contacts at the corners of the chip and the resulting scrubbing problem. 
     Another consideration in the manufacture and use of probe cards is the throughput of the testing step. The testing step often constitutes a bottleneck in the manufacturing process. Increasing the throughput of a probe card would increase the number of chips made and therefore reduce the cost per chip. Throughput can be increased by testing a number of chips simultaneously while the chips are connected in the wafer. 
     OBJECTS AND ADVANTAGES OF THE INVENTION 
     Accordingly, it is a primary object of the present invention to construct an assembly structure for probe cards such that the probes can touch contacts on an integrated circuit chip directly at 0°; i.e. eliminating the fan out angle or making it negligible. This will result in a decrease in the number of contacts and IC chips damaged by scrubbing motions of the probe tips. It is an additional object of the invention to remove variances in the inclination angle β, which will remove the variances in contact force between the many probe tip and contact connections. Removal of the different inclination angles also prevents dislodgment or deformation of the Mylar sheath and the probe tips. It is an additional object of the invention to construct a probe card so that the probes are all located in the same plane by use of an epoxy groove, which prevents the epoxy layer from flowing and thus dislodging the probes after they have been positioned. Preventing the epoxy groove from flowing down the probes also allows control of the beam length, which is crucial for determining the force at which the probe tips touch the contacts of an IC chip. Probes located on a single plane will also remove the resulting variances in force between the many probe tip and contact connections. It is a further object of the present invention to provide these same benefits to a multi-layered probe card constructed in an analogous manner. 
     Another object of the present invention is to provide a probe card capable of testing multiple chips simultaneously and an assembly structure capable of making such probe cards. 
     SUMMARY OF THE INVENTION 
     These objects and advantages are attained by a test probe card assembly structure used to construct probe cards to check integrated circuit chips before terminal leads are applied to the contacts thereof which are deployed on the chip in a common plane. The assembly structure has a base with a block attached to one side. A wing, having a planar face inclined towards the block, is attached to the same side. Two or more wings are attached at 90° angles to each other, depending on the nature of the IC chip and its contacts. The probes are laid on the wing in a parallel manner and at a constant inclination angle. The planar face of the wing has an epoxy groove to insure that the epoxy layer used to hold the probes in place does not flow. Epoxy flowing can disturb the parallel nature and plane of the probes, as well as vary the beam length. The planar face of the wing also has a tape groove to receive double-sided adhesive tape which is used to hold the probes in place, again preserving the parallel nature and plane of the probes. In the preferred embodiment, the wing can consist of two parts. One part is a support block, which has the planar face. The second part is a probe positioning element, which is a removable incline used to secure a sheath for keeping the probe tips in place. The sheath is commonly constructed of Mylar. A probe alignment control element, commonly a ring with at least one raised section, is placed over the epoxy layer to hold it and the probes in place. The probe alignment control element is stopped at a certain position in order to control the thickness of the epoxy layer. this is achieved by guiding members, commonly pins attached perpendicular to the base, in conjunction with recesses on the probe alignment control element. This assembly structure can be used to construct both single and multi-layered test probe cards. 
     The present invention also includes an embodiment which can make probe cards capable of testing multiple chips while the chips are still connected in wafer form. The chips tested are arranged along a diagonal on the wafer and the probes extend in a direction perpendicular to the diagonal. Since the chips are square and arranged in a diagonal fashion, the contact pads along the perimeter lie in a zig zag path. The probes are oriented in a corrugated fashion such that the angle β is the same for each probe, despite the fact that the contact pads lie in a zig zag path. Also, the beam length of the probes is made the same for each probe by making the region where the probe is bonded vary with the same zig zag path as the contact pads. 
    
    
     DESCRIPTION OF THE FIGURES 
     FIG. 1A is an isometric view of a prior art test probe card assembly structure, with the probes aligned in a circular manner. 
     FIG. 1B is an isometric view of a prior art test probe card assembly structure, with the probes having different inclination angles β. 
     FIG. 2 is a top plan view of probes attached in a circular manner to a prior art test probe card testing a square integrated circuit chip at different angles. 
     FIG. 3 is a cross-section of a probe, held in place by an epoxy layer, being mounted on the prior art test probe card assembly structure. 
     FIG. 4 is a cross-section of three probes held in place by an epoxy layer in the prior art method. 
     FIG. 5 is an isometric view of the preferred embodiment of a test probe card assembly structure in accordance with the invention, with probe positioning elements and guiding mechanisms. 
     FIG. 6 is a lower left isometric view of the probe alignment control element with four raised sections and four recesses. 
     FIG. 7A is a cross-section of a probe being mounted on the preferred embodiment of a test probe card assembly structure in accordance with the invention. 
     FIG. 7B is a top plan view of probes being mounted on the preferred embodiment of a test probe card assembly structure in accordance with the invention. 
     FIG. 8 is a cross-section of a probe being mounted using the epoxy groove and probe alignment control element of the preferred embodiment of a test probe card assembly structure in accordance with the invention. 
     FIG. 9 is a cross-section of probes being mounted in a multi-layered manner on the preferred embodiment of a test probe card assembly structure in accordance with the invention. 
     FIG. 10 is an isometric view of the resulting test probe card constructed on the preferred embodiment of a test probe card assembly structure in accordance with the invention. 
     FIG. 11 is a top plan view of probes attached to a test probe card made on the preferred embodiment of a test probe card assembly structure in accordance with the invention testing a square integrated circuit chip at different angles. 
     FIG. 12 is a cross-section of three probes held in place by an epoxy layer on the preferred embodiment of a test probe card assembly structure in accordance with the invention. 
     FIG. 13A is an isometric view of a single-layer probe card with probes located in the same row constructed on the preferred embodiment of a test probe card assembly structure. 
     FIG. 13B is an isometric view of a multi-layered probe card with probes located in two rows constructed on the preferred embodiment of a test probe card assembly structure. 
     FIG. 14 is a top view of a wafer which has finished chips. 
     FIG. 15 shows four chips arranged in a diagonal, which is the preferred arrangement for testing multiple chips. 
     FIG. 16 shows a top view of a multichip tester according to the present invention. 
     FIG. 17 shows a single section from the multichip tester of FIG.  16 . 
     FIG. 18 shows a side view of the single section of FIG.  17 . 
     FIG. 19 shows the probe arrangement for testing three chips simultaneously. 
     FIG. 20 shows a probe positioning structure for making the multichip tester of the present invention. 
     FIG. 21 shows the probe positioning structure with probes attached. 
     FIG. 22 shows the probes and probe positioning structure with an additional layer of epoxy applied. 
     FIG. 23 shows the probes and epoxy layer after separation from the probe positioning structure. 
     FIG. 24 shows the probes and epoxy layer attached to a circuit board to complete the probe card. 
    
    
     DETAILED DESCRIPTION 
     A preferred embodiment of the invention is shown in FIG.  10 . The function of a test probe assembly structure is to allow construction of a test probe card which has probes arranged in a parallel manner and with the same inclination angle so as to touch the contacts of an integrated circuit chip directly, in the absence of fan out angles. Accordingly, the problem of uneven contact forces between probes and contacts and the problem of the probe tip scrubbing across the contact onto the surface of the chip should be minimized. There will also be less chance of dislodging or deforming the Mylar sheath and the probe tips. In addition, the inclusion of an epoxy groove to control epoxy flow should reduce misalignment of probes, as well as variances in beam length of the probes. 
     A base  14  of test probe card assembly structure  10  is simply a piece of material of adequate size and strength to support construction of a test probe card. In practice, a square planar base formed from a rigid material is used. 
     A block  16  attached to a top side  12  of base  14  is used solely to support a sheath  18  for keeping probe tips  15  in place (see FIG.  7 A). Block  16  may actually comprise any shape so long as it can support probe tip sheath  18 . 
     Also attached to top side  12  of base  14  are wings  20 , which may number from one to four. The purpose of wings  20  is to provide a surface on which to place probes  22  in a parallel manner and at a constant inclination angle so that probe tips  15  can touch the contacts of an integrated circuit chip directly, without a fan out angle and without variances in force between probe tips  22  and contacts of the IC chip. 
     Wings  20  can be constructed in two parts: a support structure  21  and a probe positioning structure  24 . Support structure  21  is attached directly to base  14 . It has a planar face which is inclined in the direction of block  16 . The incline should end at the same height and adjacent to block  16 . Probe positioning structure  24  is attached to top side  12  of support structure  20 . It comprises a planar face, theoretically with the same circumference as the planar face of support structure  20 . Probe positioning structure  24  has an epoxy groove  26  of predetermined length and width into which epoxy  28  can be poured (see FIG.  7 A). Groove  26  is a recess which prevents epoxy  28  from flowing and thus causing misalignment of probes  22  and variance in beam length. In addition there is a tape groove  30  of predetermined length and width. Groove  30  is for placement of double-sided adhesive tape  32 , which helps keep probes  22  in place. 
     Square sheath  18 , commonly constructed of Mylar, is placed on top side  12  of block  16  and centered by two protruding pins (not shown). Sheath  18  contains small holes  19  along its perimeter where probe tips  15  will be placed. Mylar sheath  18  thus helps with the positioning of probes  22 . Sheath  18  is not permanently attached to assembly structure  10 . However, it is held in place by two part wing structure  20 , specifically probe positioning structure  24 . The result is that sheath  18  is fastened between support structure  21  and probe positioning structure  24 . Various sheaths may be produced to satisfy the requirements of the probe card being constructed. 
     A probe alignment control element  34 , commonly a ring (see FIG.  6 ), is used to compress epoxy layer  28  poured over probes  22 . It contains at least one raised section  36  which contacts epoxy  28 . In the construction of a probe card to test a square IC chip with contacts along all four sides, there are four raised sections  36 . Section  36  is often ridged to provide better wetting of probe alignment control element  34  to epoxy  28 . Probe alignment control element  34  is placed over epoxy layer  28  with raised section  36  corresponding in position with epoxy groove  26  of probe positioning structure  24 . Probe alignment control element  34  contains at least one recess  38 , such as a small hole, located near raised section  36 , to fit with a guiding member  40 , whose purpose is to help position probe alignment control element  34 . 
     Guiding member  40  is commonly a pin attached perpendicular to top side  12  of base  14  between adjacent wings  20  and near block  16 . Guiding members  40  fit into the recesses of probe alignment control element  34 , thus determining its placement relative to epoxy groove  26  and epoxy  28   a . A stopping member  42  is also commonly a pin attached perpendicular to top side  12  of base  14  between adjacent wings  20  and near block  16 . Stopping members  42  prevent probe alignment control element  34  from compressing epoxy layer  28  too far, thus determining its height relative to epoxy groove  26  and epoxy layer  28 . 
     Test probe assembly structure  10  can be constructed with guiding mechanisms  44 ,  46  to allow movement of wings  20 , guiding members  40 , and stopping members  42  relative to each other. Guiding mechanisms  44 ,  46  are built into top side  12  of base  14  and operate much like slits, in that they allow different components  20 ,  40 ,  42  to be slid along base  14 . However, any type of adjustable mechanism is feasible. Thus, it is possible that several different probe cards could be constructed on a single test probe assembly. 
     Construction of a Single-Layered Probe Card 
     Test probe card assembly structure  10  should be set up according to the specifications of the desired test probe card to be produced. In practice, all four wings  20  and at least two guiding members  40  will be used to construct the typical probe card used to test a square IC chip with contacts located on the perimeter. Suitable Mylar sheath  18  with the appropriate pattern of holes  19  for probe tips  15  is chosen and placed on top side  12  of block  16 . Mylar sheath  18  may be secured in place by the use of two-structure wing  20 , which allows probe positioning structure  24  to be placed over the edges of sheath  18  and fastened. 
     Epoxy  28  is poured into epoxy grooves  26  of wings  20  and allowed to cure for a few minutes. This curing helps prevent epoxy  28  from flowing around probes  22  when they are placed on planar face of wings  20 . Pieces of double-sided adhesive tape  32  are placed in tape grooves  30 . Probes  22  are then placed on wings  20 , over epoxy grooves  26  and tape grooves  30 , in a parallel manner and at a constant inclination angle, with probe tips  15  pointing down the inclines toward block  16 . Probe tips  15  should fit into Mylar sheath  18  which has been placed on block  16 . If all four wings  20  are used, probes  22  will form a square or rectangle, with probe tips  15  in each row positioned essentially parallel to each other and at a constant inclination angle. 
     It is noted that although epoxy is the preferred adhesive material to use in the present invention, many other hard-setting, electrically insulating liquid adhesives can be used. Polyester resins, for example, may be useful in some embodiments of the present invention. 
     Another layer of epoxy  28  is poured over probes  22 , thereby securing them in place. Probe alignment control element  34  is then placed over epoxy  28 , eased into place by guiding members  40  and stopping members  42 . Guiding members  40  and stopping members  42  control the position and height of probe alignment control element  34  so that it compresses epoxy layer  28  according to the specifications of the test probe card being made. Raised sections  36  of probe alignment control element  34  contact epoxy layer  28  to form a secure attachment. Probe alignment control element  34  stays attached to epoxy layer  28  and probes  22 . After epoxy layer  28  is hardened, the probe-epoxy structure is fastened to a planar printed circuit board  48 . 
     Construction of a Multi-Layered Probe Card 
     Construction of a multi-layered test probe card can also be achieved on test probe card assembly structure  10 . Setup of test probe assembly structure  10  for a multi-layered test probe is essentially the same as that for a single-layered test probe. In practice, all four wings  20  and at least two guiding members  40  will be used to construct the typical probe card used to test a square IC chip with contacts located in one or more rows on one side of the chip. Suitable Mylar sheath  50  with the appropriate pattern of holes  19  for probe tips  15  is chosen and placed on top side  12  of a block  16  for accommodating tips  15 . If one is constructing a multi-layered probe card with one row of probes  22  located on two levels, the Mylar sheath  18  will have one row of holes  19  (see FIG.  13 A). If one is constructing a multi-layered probe card with at least two rows of probes  22  located on two levels, there will be at least two rows of holes  19  on Mylar sheath  50  (see FIG.  13 B). Mylar sheath  50  may be secured in place by the use of two-structure wing  20 , which allows probe positioning structure  24  to be placed over the edges of sheath  50  and fastened. 
     The first layer of probes  22  is positioned and secured in much the same manner as described above for the single-layered probe card. However, after epoxy layer  28  is poured over probes  22 , probe alignment control element  34  is not placed on top. Epoxy layer  28  is allowed to cure for a certain amount of time, much like first epoxy layer  28  poured into groove  26 . 
     Spacer elements or another layer of double-sided adhesive tape  52  are then placed over the first layer of probes  22 . Spacer elements or another layer of double-sided adhesive tape  52  are shorter in length than probe positioning structure  24  and do not contain epoxy groove  26 . This is because the second layer of probes  22  will be placed in epoxy layer  28  that was poured over the first layer of probes  22 . Spacer elements or another layer of double-sided adhesive tape  52  are supported by the edges of probe positioning structure  24 . 
     The second layer of probes  22  is placed on spacer elements or another layer of double-sided adhesive tape  52 . Probes  22  are positioned in a parallel manner and in the same plane. Probe tips  15  are positioned in the remaining empty holes  19  of Mylar sheath  50 . Probes  22  are placed on epoxy layer  28  that was poured over the first layer of probes  22 . A third layer of epoxy  28  is then added over the second layer of probes  22  to secure them in place. This third epoxy layer  28  is added over the previous epoxy layers  28 . 
     At this point, it is possible to keep adding probe  22  and epoxy layers  28 , although practical considerations suggest a maximum of layers as defined by the nature of the probe card to be constructed. 
     Probe alignment control element  34  used to construct the single-layered probe card is then placed over the epoxy  28 , eased into place by guiding members  40  and stopping members  42  in the same manner as described previously. Probe alignment control element  34  stays attached to epoxy layer  28  and probes  22 . After epoxy layer  28  is hardened, the multi-layered probe-epoxy structure is fastened to planar printed circuit board  48  just like the single-layered probe. 
     Some example types of probe cards which can be constructed on assembly structure  10  or any analogous structure according to the invention are shown in FIGS. 13A and 13B. FIG. 13A illustrates a straight section of a single-layer probe card. The inclination angles β of all three probes  22  shown are equal. Also, fan out angle θ of probes  22  is approximately zero. These conditions improve planarity and uniformity of contact force between probe tips  15  and circuit pads  106 . This is important because in practice probes  22  frequently require post-production tweaking or bending to ensure planarity. With angles θ and β being constant the amount of tweaking required is minimized. Epoxy  28  is prone to damage during a tweaking session and its life is thus prolonged when the amount of tweaking required is reduced. 
     FIG. 13B shows a straight section of a dual-layered probe card made according to the invention. Once again, angles θ and β are controlled in this card. 
     A Probe Card for Simultaneously Testing Multiple Chips 
     An embodiment of the present invention can make probe cards capable of testing multiple chips simultaneously. FIG. 14 shows a wafer  60  comprising finished chips. The chips to be tested  62  are arranged along a diagonal of the wafer. This is because the contact pads on each chip  62  are distributed along the entire perimeter of each chip. Selecting chips to be tested along a diagonal assures access to every contact pad. If the chips are arranged in a rectangular block  64 , and the contact pads are located around the perimeter of each chip, then probe access to some contact pads is difficult or impossible. 
     FIG. 15 shows a closeup of the four chips  62  along a diagonal. The contact pads  66  on each chip are shown. It can be seen that the contact pads  66  are arranged in two zig zag paths. 
     FIG. 16 shows a top view of a probe card capable of testing multiple chips  62 . The probes  22  are arranged to make contact with the contact pads  66 . The probes  22  are held in place by an epoxy layer  28 . Since the edge  68  of the epoxy layer  28  is a zig zag shape, the beam length (distance from contact pad  66  to epoxy layer edge  68 ) of each probe  22  is identical. 
     FIG. 17 shows a single section of a probe card capable of testing multiple chips. The section shown can only test a single chip  62 , but several sections can be combined in a line to produce a probe card that can test several chips. All the probes  22  are inclined with the same angle β with respect to the surface of the chip  62  being tested. Angle β is typically about 10 degrees. 
     FIG. 18 shows a side view of the section of FIG. 17 without the epoxy layer  28 . Here, the angle β is clearly visible. 
     FIG. 19 shows a perspective view of three sets of probes  22  contacting three chips  62 . The epoxy layer  28  which holds the probes  22  is not shown. It can be seen that the probes  22  are arranged in a corrugated pattern so that β and the beam length are the same for every probe  22  even though the contact pads  66  lie along a zig zag path. Also, the probe tips lie in he same plane. The corrugated pattern is illustrated with a dark line  70 . 
     Refer now to FIG.  20 . The multichip probe of the present invention can be made using a pair of probe positioning structures  24  with each structure having a corrugated top  72  that is also inclined at the angle β. The probe positioning structures  24  are mounted on a base  12  facing each other in a symmetrical fashion. The base  12  is omitted in subsequent figures. The corrugated top  72  is comprised of adjacent opposing surfaces  74 A,  74 B. The corrugation angles ω 1  and ω 2  are determined by the shape of the chips  62  to be tested and the angle β. Angles ω 1 , and ω 2  are selected such that every probe  22  has the same beam length and same orientation with respect to its corresponding contact pad  66 . For square chips, for example, ω 1  and ω 2  will be the same for opposing surfaces  74 A,  74 B of the corrugated surface of the support structure. In the case of testing rectangular chips, ω 1  and ω 2  will be different for the different opposing top surfaces  74 A,  74 B of the corrugated probe positioning structures  24 . More specifically, this results in ω 1  and ω 2  being different angles. 
     The first step in the manufacture of a multichip probe according to the present invention is shown in FIG.  21 . The probes  22  are placed and bonded to the top surface  72  of the corrugated probe positioning structures in the same manner as described for the construction of a single-layered probe card. Specifically, double-sided tape and epoxy are preferably used to secure the probes  22  to the structures  24  and a mylar sheath  18  with small holes is used to align the probe tips  15 . The top surface of the probe positioning structure  24  may have an epoxy groove and tape groove as illustrated in FIGS. 7,  8 , and  9 . Only three of the four sections of the support structures of FIG. 21 are provided with probes in order to more clearly illustrate the process. 
     Next (FIG.  22 ), an additional layer of epoxy  28 B is applied on top of the probes  22  to rigidly hold them with respect to one another. The alignment control element  34  (not shown) can be used to maintain the alignment between the two sides of probes  22 . The use of the alignment control element  34  in the manufacture of a multichip probe card is the same as described for the single-layered probe card of FIG.  10 . The contacting surface of the alignment control element  34  may need to be corrugated so that it contacts all the probes  22 . 
     The probes  22  and epoxy layer  28  are then separated from the probe positioning structures  24 . FIG. 23 shows the probes  22  and epoxy layer  28  after separation. It can be seen that the probes  22  define a corrugated plane. The corrugated plane defined by the probes  22  is the same as the top surface  72  of the probe positioning structures  24 . The alignment control element  34  is used to hold the two sides of probes fixed with respect to one another. Alternatively, rigid metal connectors  78  can be used to hold the two sides fixed with respect to one another. 
     The probes  22  and epoxy layer  28  structure of FIG. 23 is then inverted (flipped over) and bonded to a printed circuit board  48  to produce the probe card shown in FIG.  24 . The probe tips  15  thus point upwards in FIG.  24 . Extra epoxy is applied to further secure the alignment of the probes  22 . Alternatively, any thin, rigid plate can be used in place of a printed circuit board. Electrical connections can be made to the probe ends  76  which extend through the epoxy layer  28 . 
     It is noted that the probes  22  used in the present invention do not necessarily need to have a bent tip section  15 . In other words, the probes  22  may comprise sraight wires. Using straight wire probes may, of course, require a different angle β. 
     It will be clear to one skilled in the art that the above embodiment may be altered in many ways without departing from the scope of the invention. For example, different shapes of integrated circuit chips can be accommodated by this invention. If one has an integrated circuit chip in the shape of a triangle with circuits located on the perimeter, a test probe card can be constructed whereby three rows of probes are arranged in a triangular shape. The assembly structure for such a probe card would consist of three wings arranged around a triangular block, with a triangular Mylar sheath. Thus many different shapes of IC chips can be accommodated. 
     It is also noted that many different glues or resins (more generally adhesives) can be used other than epoxy. Whatever material is used in place of epoxy in the present invention must be a electrically insulating material that is hard, resistant to repeated flexing cycles and curable from a liquid state. Epoxy is the preferred material to use in the present invention because it is easy to use, is strong and is non-conductive. 
     In addition, it should be noted that in cases where many probes are placed in a single row, a small fan out angle θ may still exist. However, this angle θ will be essentially negligible. Accordingly, the scope of the invention should be determined by the following claims and their legal equivalents.