Adapter for a measurement test probe

A probe adapter for coupling probe tip contacts of a electrical measurement probe to leads of a surface mounted integrated circuit IC device has an insulating housing from which extend first and second flexible electrically conductive leads having a pitch geometry compatible with the leads of the IC device. First and second electrical contacts, respectively coupled to the first and second flexible electrically conductive leads, are disposed in the housing and have a pitch geometry compatible with the probe tip contacts of the electrical measurement probe.

TECHNICAL FIELD
 The present invention is related to probe adapters for measurement test
 probes and more specifically to a probe adapter for measuring electrical
 signals on very fine pitch geometry electronic devices.
 BACKGROUND OF THE INVENTION
 Surface mounted (SMT) integrated circuit devices are fast becoming the
 dominant type of IC packaging in the electronics industry. These devices
 come in a wide variety of package configurations and lead pitch
 geometries. For example, IC packages may be square or rectangular with
 electrical contact or lead counts from 44 to 232 or higher. A variety of
 electrical contact or lead types are also being used. Quad flat pack IC's
 use Gull wing leads or J-leads. Both type of leads extend from the
 perimeter of the IC package with the former type of leads bending down and
 outward from the package while the later bend down and fold under the
 package in a J-shape. The leads are soldered to electrical contact pads
 formed on a circuit board.
 The small pitch geometries of the quad flat pack SMT devices makes these
 devices very difficult to probe using oscilloscope or logic analyzer
 probes. The pitch geometries or lead spacing between lead centers varies
 on these devices. The most commonly used lead spacings for quad flat packs
 are 0.5 mm, 0.65 mm, 0.8 mm, 1 mm, 0.025 inches and 0.019 inches. Work is
 progressing on even smaller pitch geometries in the range of 0.010 inch
 lead spacing. The standards for gap spacing between leads is set out in
 JEDEC Publication No. 95, MO-104 and varies for the various lead spacings.
 For example, the minimum gap spacing standard for an 0.025 inch pitch
 geometry is 0.010 inches and 0.008 inches for a 0.019 inch pitch geometry.
 Using oscilloscope probes on these types of IC packages can cause the
 shorting of adjacent leads of the device.
 U.S. Pat. No. 5,184,065, assigned to the assignees of the present
 invention, describes a twist lock probe tip for use with passive
 measurement probes. The probe tip has a flat flexible body of insulating
 material with an electrical conductor embedded or coated on one or both
 sides of the body. The flexible body has a notch or notches for exposing
 the embedded electrical conductor and/or for engaging a lead of an
 electronic component. The flexible body is inserted between the leads of
 the electronic device and twisted by means of an attached knob or wing
 lever so that the notches engage adjacent leads and the conductor or
 conductors contacts the desired lead or leads. As the pitch geometries of
 electronic devices continue to decrease, the leads on the electronic
 devices become increasing fragile and susceptible to bending and damage.
 Further, the chance for shorting adjacent leads together by bending leads
 increases as the gap between leads decreases. The twist lock probe tip
 design has the potential for deforming the leads of the electronic device
 as the probe tip is twisted into position. Additionally, the probe tip
 becomes increasing fragile as the thickness of the tip is decreased to
 match the decreasing gap size of the leads, especially where the notches
 are added for locking the tip between the leads. Further, the thickness of
 the tip may exceed the leads gaps, especially where electrical conductors
 are formed on opposite sides of the insulating material.
 U.S. Pat. No. 5,387,872, assigned to the assignees of the present
 invention, describes a positioning aid for directly positioning a
 hand-held electrical test probe onto leads of a surface mounted integrated
 circuit device. The positioning aid has a housing made of a polycarbonate
 material with a central bore therethrough for receiving the probing tip of
 the test probe. One end of the housing that is normal to the bore has at
 least four teeth extending therefrom defining slots for engaging the leads
 of the integrated circuit device. The central bore is exposed in the
 central slot for exposing the probing tip therein for providing an
 electrical connection between one of the leads on the integrated circuit
 device and electrical circuitry in the test probe.
 The usefulness of this design is limited by the thickness of the teeth. For
 pitch geometries less than 0.019 inches, the teeth become to fragile for
 practical use due to the thickness of the teeth being so small. Further,
 this design does not lend itself for dual lead probing where adjacent IC
 leads are probed using a single probe. Modifying this design for such a
 use requires some sort of internal transition from the pitch spacing of
 the probe contacts to the pitch spacing of the IC leads. Such a transition
 is considered expensive and increase the manufacturing costs of such a
 device.
 U.S. Pat. No. 5,506,515 describes a high-frequency probe tip assembly for
 low-loss microwave frequency operations. The tip assembly includes a
 semi-rigid coaxial cable that is formed with a semicylindrical recess
 defining a shelf along which an inner finger and outer pair of fingers are
 mounted. Each finger is made of a resilient conductive material, such as
 beryllium copper, so as to form a coplanar transmission line. Cantilevered
 portions of the fingers extend past the end of the cable to form an
 air-dielectric transmission path of uniform and stable characteristics.
 The inner finger is electrically connected to the central conductor of the
 semi-rigid coaxial cable and the outer pair are electrically coupled to
 the shield of the semirigid cable.
 The probe tip is designed as part of a coaxial transmission line for
 probing pads of integrated circuit dies. As such, the fingers of the probe
 tip need to be configured in terms of material composition,
 cross-sectional geometry and spacial orientation to provide a uniform
 deflection characteristic relative to each finger for even wearing of the
 pads and fingers and for stability of transmission characteristics despite
 contact pressure variations. These requirements result in the use of rigid
 conductive material for the fingers. Additionally, the design does not
 require the use of insulating material other than the air gaps between the
 fingers. Further, this design does lend itself for use with standard
 electrical measurement probes, such as used in conjunction with
 oscilloscopes, logic analyzers, and the like.
 What is needed is a probe adapter for electrical measurement probes that
 are used in conjunction with oscilloscopes, logic analyzers, and the like
 for probing closely spaced leads of an electronic device, such as a
 surface mounted integrated circuit IC. The probe adapter should have
 electrically conductive elements that are compatible with the pitch
 geometry of the IC leads and electrical contacts compatible with the pitch
 geometry of the measurement test probe.
 SUMMARY OF THE INVENTION
 Accordingly, an object of the present invention is to provide an adapter
 for probing fine pitch geometry integrated circuit devices.
 An additional object of the present invention is to provide an adapter for
 a measurement test probe having multiple probing leads compatible with the
 pitch geometry of integrated circuit devices.
 A further objective of the present invention is to provide an adapter easy
 to assemble and inexpensive to manufacture.
 The present invention is a probe adapter for coupling probe tip contacts of
 an electrical measurement probe to an electronic device having multiple
 electrical leads directly connected to a substrate with separation between
 the electrical leads defining a pitch geometry. The probe adapter has
 first and second flexible electrically conductive leads extending from a
 first surface of an insulating housing. The leads are preferably formed of
 a flexible dielectric substrate having electrically conductive material
 formed on one surface of the respective substrates. Separation between the
 flexible electrically conductive leads is compatible with the pitch
 geometry of the electrical leads of the electronic device. First and
 second electrical contacts are disposed in a second surface of the housing
 and are respectively coupled to the first and second flexible electrically
 conductive leads. The pitch geometry of the electrical contacts are
 compatible with the probe tip contacts of an electrical measurement probe.
 The probe adapter further includes a first insulating member disposed
 between the first and second flexible electrically conductive leads for
 establishing the separation between the leads compatible with the pitch
 geometry of the electrical leads of the electronic device. A second
 insulating member is disposed between the first and second electrical
 contacts for establishing the pitch geometry compatible with the probe tip
 contacts of the electrical measurement probe.
 The housing preferably has an outer shell and inner insulating member with
 the inner insulating member including the first and second insulating
 members. The outer shell has a bore therethrough defining openings at
 opposing ends of the shell with one opening being sized to receive the
 flexible electrically conductive leads and the other opening being sized
 to receive the electrical contacts. The inner insulating member is
 conformable with the bore for securing the flexible electrically
 conductive leads and the electrical contacts within the housing and has a
 first end disposed between the first and second flexible electrically
 conductive leads for establishing the separation between the leads
 compatible with the pitch geometry of the electrical leads of the
 electronic device. An opposing second end of the inner insulating member
 is disposed between the first and second electrical contacts for
 establishing the pitch geometry compatible with the probe tip contacts of
 the electrical measurement probe.
 The first and second electrical contacts are preferably electrically
 conductive pins extending from the second surface of the housing.
 Alternately, the first and second electrical contacts may be electrically
 conductive sleeves extending into the insulating housing.
 The housing may further have a base and cover with the base having a bottom
 surface and opposing end surfaces defining the first and second surfaces.
 The first end surface includes an opening therein for receiving the
 flexible electrically conductive leads and the second end surface includes
 an opening therein for receiving the electrical contacts. The cover has a
 top surface and opposing side surfaces with the top and side surfaces of
 the cover mating with the bottom and end surfaces of the base. The first
 and second end surface openings may further include a rib or a wedge
 disposed in the respective opening defining slots through which the
 respective first and second flexible electrically conductive leads and the
 first and second electrical contacts extend. The rib or wedge may be
 integral with the base or cover. The wedge may also be movable within a
 slot formed in either the base or the cover for varying the minimum
 spacing between the flexible electrically conductive sleeves. The wedge
 may be moved laterally or laterally and rotatably in the slot.
 Alternately, the first end surface may have slots therein for receiving
 the flexible electrically conductive leads and the second end surface may
 have apertures therein for receiving the electrical contacts.
 The probe adapter of the present invention may also include a plurality of
 flexible electrically conductive leads extending from one end of the
 housing and coupled to corresponding electrical contacts extending from
 the other end of the housing. The flexible electrically conductive leads
 have a pitch geometry compatible with the pitch geometry of the electrical
 leads of an electronic device and the electrical contacts have a pitch
 geometry compatible with the probe tip contacts of a logic analyzer type
 probe. The objects, advantages and novel features of the present invention
 are apparent from the following detailed description when read in
 conjunction with appended claims and attached drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
 Referring to FIG. 1 there is shown a perspective view of the probe adapter
 10 of the present invention. The probe adapter 10 includes flexible
 electrically conductive leads 12 and 14 that extend from one end of an
 insulating housing 16. In the preferred embodiment, the flexible
 electrically conductive leads 12 and 14 extend from the housing in a range
 of about 0.080 inches. Extending from the opposite end of the housing 16
 are electrical contacts 18 and 20, which are coupled to probe tip contacts
 22 and 24 of an electrical measurement probe 26. The probe tip contacts 22
 and 24 may be electrically conductive sleeves that are coupled to
 electrical circuity within the probe 26. Alternately, the probe tip
 contacts 22 and 24 may be probing tips extending from the probe 26 that
 mate with the electrical contact sleeves to be described later. The probe
 tip contacts 22 and 24 may be inputs of a differential measurement test
 probe. Alternately, one probe tip contact may be signal conductor while
 the other is ground conductor.
 Each conductive lead 12, 14 is insulated on one side and has electrically
 conductive material on the other. The electrically conductive material on
 the leads 12 and 14 are preferably disposed in the same direction. The
 conductive leads 12 and 14 are positioned between electrical leads 28 on
 an electronic device 30, such as a quad flat pack integrated circuit, IC,
 having gull wing leads or J-leads. The pitch geometry or lead spacing
 between the leads 28 may range 0.5 mm or about 0.019 inches to 1 mm or
 about 0.04 inches. Current development is underway for IC packages having
 0.25 mm or 0.01 inches lead spacing. The leads 28 of the electronic device
 30 are connected to electrical contact pads 32 formed on a substrate 34,
 such as a circuit board or the like.
 Referring to FIG. 2, there is shown an exploded perspective view of the
 preferred embodiment of the probe adapter 10 of the present invention. The
 flexible electrically conductive leads 12 and 14 are electrically coupled
 to the respective electrical contacts 18 and 20 forming assemblies 40 and
 42. The electrical contacts 18 and 20 have respective flat portions 44 and
 46, as shown in FIGS. 3A and 3B, with tapered fingers 48 extending upward
 on opposite sides of the flat portions 44, 46. Extending from one end of
 the respective flat portions 44, 46 are square pins 50. Leads 12 and 14
 are formed of a flexible dielectric substrate 52, such as polyamide or the
 like, with electrically conductive material 54, such as tin plated copper
 or the like, deposited on one of the flat surfaces of the substrate 52.
 The ends 56 of the leads 12 and 14 are preferably angled for making
 insertion between the leads 28 of the electronic device 30 easier. The
 other ends of the leads 12 and 14 are placed on the respective flat
 portions 44, 46 of the electrical contacts 18 and 20 with the electrically
 conductive material 54 in contact the flat portions 44, 46. The tapered
 finger 48 on the respective electrical contacts 18 and 20 are folded over
 and crimped against the leads 12 and 14 to electrically couple and
 physically secure the leads 12 and 14 to contacts 18 and 20. Alternately,
 the leads 12 and 14 may be electrically coupled and secured to the
 contacts 18 and 20 using electrically conductive adhesive, solder, rivets,
 or any other securing means that provides good electrical contact and a
 strong physical connection between the leads 12 and 14 and the contacts 18
 and 20. With such alternative securing means it may not be necessary to
 have the tapered fingers 48 on the flat portions 44, 46 of the electrical
 contacts 18 and 20. Further, the square pins 50 may be replaced with
 conductive sleeves 58, shown in FIG. 3C, which extend over at least part
 of the flat portion 44, 46 of the electrical contacts 18 and 20. One
 possible configuration for the sleeve type electrical contact is to have
 one end of the sleeves 58 being physically connected to the end of the
 flat portions 44, 46 and the sleeves 58 folded back over the flat portions
 44, 46 at the connection. The flexible electrically conductive leads 12 or
 14 are placed between the flat portions 44, 46 and the sleeves 58 and the
 tapered fingers 48 are crimped against the sleeves 58 securing the lead 12
 or 14 between the flat portions 44, 46 and the sleeves 58.
 The insulating housing 16 includes an outer shell 60 having a bore 62
 therethrough for receiving assemblies 40 and 42. The outer shell 60 and
 the bore 62 are tapered to produce an opening 64 on one surface 66 of the
 outer shell 60 from which the flexible electrically conductive leads 12
 and 14 extend. The opening 64 establishes the maximum separation between
 the leads 12 and 14. The opposing surface 68 of the outer shell 60 has an
 opening 70 in which the electrical contacts 18 and 20 are disposed.
 Opening 70 establishes the maximum separation between the contacts 18 and
 20. An inner insulating member 72 is disposed within the bore 62 between
 the assemblies 40 and 42. The inner insulating member 72 is tapered to
 conform to the taper of the bore 62. The inner insulating member 72
 secures the flexible electrically conductive lead and electrical contact
 assemblies 40 and 42 and establishes the minimum separation or pitch
 geometry between the leads 12 and 14 and the contacts 18 and 20. In the
 preferred embodiment, the spacing between flexible lead 12 and 14 centers
 extending from the insulating housing 60 is in the range of about 0.0225
 inches producing a gap between the leads 12 and 14 of 0.0145 inches. This
 allows probing of the leads 28 of IC devices 30 having either 0.019 inch
 center or 0.025 inch centers in that the flexible leads may be bent to
 conform to the particular lead spacing. This is a particular advantage of
 using the flexible electrically conductive lead design. Further, the
 present invention allows the minimum spacing between the flexible
 electrically conductive leads 12 and 14 to be decreased as the lead
 spacing or pitch geometry of IC devices 30 decrease as for example in IC
 devices having 0.010 pitch geometry. This flexibility in lead spacing also
 carries over to the spacing of the electrical contacts 18 and 20. As lead
 spacing on IC devices decreases, it may be necessary to decrease the size
 of the measurement test probe for performing measurements on these
 devices. The probe adapter 10 of the present invention may be easily
 configured for smaller probe designs.
 With continued reference to FIGS. 3A and 3B, the overall length of the each
 assembly 40 and 42 is in the range of about 0.778 inches with the overall
 length of the flexible electrically conductive leads 12 and 14 being in
 the range of about 0.520 inches and the electrical contacts 18 and 20
 being in the range of about 0.475 inches. The width of the leads 12 and 14
 is in the range of about 0.050 inches and the thickness, including the
 electrically conductive material 54, is in the range of 0.004 to 0.010
 inches with the preferred thickness being about 0.008 inches. The
 thickness of the electrically conductive material is in the range of about
 0.001 to 0.003 inches. An example of the flexible dielectric substrate 52
 having electrically conductive material 54 deposited on one of the
 surfaces is flexible flat conductor cable, manufactured and sold by Amp,
 Inc., Harrisburg, Pa. under Part No. 88586-9. Another example of the
 flexible dielectric substrate 52 is a polyamide substrate having copper
 electrically conductive material deposited on one side as may be provided
 by Merix, Corp., Forest Grove, Oreg. One end 56 of the electrical leads is
 angled, preferably in a range of about 45.degree..
 The flat portion 44, 46 of the respective electrical contacts 18 and 20 has
 a length in the range of 0.250 inches, a width in the range of 0.072
 inches, and a thickness in the range of 0.0099 inches. The height of the
 tapered fingers 48 before they are folded over is in the range of about
 0.090 inches. The overall thickness of the electrical contacts 18 and 20
 after the tapered fingers 48 are crimped is in the range of about 0.037
 inches. The square pin 50 extending from the flat portion 44, 46 has an
 overall length in the range of 0.225 inches and width and height
 dimensions in the range of 0.025 inches. The electrical contacts are made
 of a phosphor bronze alloy with a 0.000015 thick underplating of nickel.
 Localized areas, such as on the square pins 50, are plated with a 0.000015
 layer of gold and the rest of the contact is plated with a 0.000100 layer
 of tin-lead. The above described electrical contact is manufactured and
 sold by AMP, Inc. Harrisburg, Pa. under Part No. 88976-2. Other types of
 electrical contacts having similar dimensions may be used in implementing
 this invention.
 Referring to the respective horizontal and vertical cross-sectional views
 of the outer shell 60 in FIGS. 4A and 4B, the outer shell 60 has an
 overall length in the range of about 0.400 inches with a width at wide end
 or opening 70 in the range of about 0.260 inches tapering to a width in
 the range of about 0.053 inches at the narrow end or opening 64. The
 height of the housing at the wide end is in the range of about 0.166
 inches tapering to a height in the range of about 0.072 inches at the
 narrow or lead end 64. The width and height of the bore 62 at the wide end
 of the outer shell 60 are respectively in the ranges of about 0.140 inches
 and about 0.100 inches. The bore 62 tapers to lead end 64 of the outer
 shell 60 and has a width in the range of about 0.0305 inches and a height
 in the range of about 0.050 inches. In the preferred embodiment, the bore
 62 has a rectangular section 80 having a length in the range of about
 0.250 inches transitioning into a tapered section 82 having a length in
 the range of about 0.150 inches.
 The inner insulating member 72 is conformable with the bore 62 for securing
 the assemblies 40 and 42 within the housing. The inner insulating member
 72 has an overall length in the range of about 0.400 inches with a
 rectangular portion 84 having a length in the range of about 0.250 inches
 and a tapered portion 86 having a length in the range of about 0.150
 inches. The rectangular portion 84 has a width in the range of about 0.100
 inches and a height in the range of about 0.100 inches. The tapered
 portion 86 tapers from the 0.100 inch width and height dimensions at one
 end to a width in the range of about 0.0145 inches and a height in the
 range of about 0.050 inches at the other end 88.
 The outer shell 60 and the inner insulating member 72 are preferably
 injected molded parts made of ABS plastic or similar type of insulating
 material, Alternately, the outer shell 60 and inner insulating member may
 be made of a polycarbonate material.
 One or both of the inner side walls 90 and 92, adjacent to the bore 62, may
 include notches or grooves for receiving the crimped fingers 48 of the
 electrical contacts 18 and 20. Alternately, notches and grooves may be
 formed in one or both side surfaces 94 and 96 of the inner insulating
 member 72 for receiving the crimped fingers 48. As shown in FIG. 2, the
 crimped fingers 48 of assemblies 40 and 42 are disposed in the same
 direction. In this configuration, one inner sidewall 90 of the shell and
 one of the inner surfaces 96 of the insulating member 72 will have the
 notches or grooves. In a configuration where the assemblies 40 and 42 are
 formed with the crimped fingers 48 disposed outwardly, the notches or
 grooved would be formed in the both of the inner sidewalls 90 and 92 of
 the shell 60. In a configuration where the assemblies 40 and 42 are formed
 with the crimped fingers 48 facing each other, the notches or grooves
 would be formed in both inner surfaces 94 and 96 of the insulating member
 72. In the configuration where the square pins 50 are replaced with
 sleeves 58, grooves may be formed in either or both the inner sidewalls 90
 and 92 of the shell 60 and the side surfaces 94 and 96 of the insulating
 member 72 for receiving the sleeve contact.
 The probe adapter 10 is assembled by inserting the assemblies 40 and 42
 into the bore 62 in the outer shell 60 with the angled ends 56 of the
 flexible electrically conductive leads 12 and 14 extending out of the
 opening 64 on the surface 66 of the outer shell 60. The inner insulating
 member 72 is inserted into the bore 62 at the opening 70 on the opposing
 surface 68 of the shell 60 with the inner insulating member 72 being
 disposed between the assemblies 40 and 42. The tapered end 88 of the inner
 insulating member 72 extends to the opening 64 in the outer shell 60 and
 the opposing other end 98 of the inner insulating member 72 extends to the
 opening 70 in the shell 60. The inner insulating member 72 conforms to the
 dimensions of the bore 62 in height and the bore 62 and the assemblies 40
 and 42 in width for securing the flexible electrically conductive leads 12
 and 14 and the electrical contacts 18 and 20 of assemblies 40 and 42 in
 the housing. The assemblies 40 and 42 are captured between the side
 surfaces 94 and 96 of inner insulating member 72 and the inner sidewalls
 90 and 92 of the outer shell 60. The inner insulating member 72 may be
 secured in the outer shell 60 by any number of alternative methods. For
 example, the insulating member 72 may be secured within the bore 62 by
 frictional force, gluing, sonic welding, or tabs and notches in the shell
 60 and insulating member 72 for snap fitting the parts together.
 Referring to FIG. 5A, the is shown an alternative housing 16 for the probe
 adapter 10. The housing 16 includes a base 100 and cover 102. The base 100
 has a bottom surface 104 and opposing end surfaces 106 and 108. End
 surface 106 has an opening 110 therein for receiving the flexible
 electrically conductive leads 12 and 14 of assemblies 40 and 42. The end
 surface 108 has an opening 112 for receiving the electrical contacts 18
 and 20 of assemblies 40 and 42. The cover 102 has a top surface 114 and
 opposing side surfaces 116 and 118. The top surface 114 and side surfaces
 116 and 118 of the cover 102 mate with the end surfaces 106 and 108 and
 the bottom surface 104 of the base 100. The overall dimensions of the
 alternative housing conform to the dimensions of the previously described
 housing formed of the outer shell 60 and inner insulating member 72.
 Specifically, the width of the opening 110 is in the range of 0.0305
 inches and the height is in the range of 0.050 inches. The opening 112 may
 vary depending on the configuration. For example, the cover 102 may
 include a rib 120 extending from the end of the cover having approximately
 0.025 inches square notches formed in the lower corners. The width of the
 upper portion of the rib 120 is approximately 0.125 inches. The width of
 the opening 112 would be the same approximate 0.125 inch width of the
 upper portion of the rib 120. The height of the opening would be in the
 range of about 0.0705 inches, which would center the electrical contacts
 18 and 20 in the end surface of the housing. The height of the rib 120
 would be in the range of about 0.0955 inches, which when combined with the
 height of the opening produces a overall height in the range of 0.166
 inches matching that of the previously described housing. This
 configuration for the opening 112 and the rib 120 establishes a center to
 center spacing between the electrical contacts of 0.100 inches.
 FIG. 6 shows an alterative spacing configuration 122 for the flexible
 electrically conductive leads 12 and 14 and the electrical contacts 18 and
 20 usable in the housing shown in FIG. 5. The flexible electrically
 conductive leads 12 and 14 and the electrical contacts 18 and 20 for
 assemblies 40 and 42 are the same as previous described. An insulating
 member 124 is disposed between the leads 12 and 14 that establishes a lead
 spacing compatible with the electrical leads 28 of the IC 30. As
 previously described, the preferred width of insulating member 124 is in
 the range of about 0.0145 inches producing a center to center spacing
 between the leads 12 and 14 of about 0.0225 inches. The electrical
 contacts 18 and 20 are disposed in another insulating member 126 having
 rectangular apertures 128 and 130 formed therein for receiving the
 contacts 18 and 20. The distance between the centers of the apertures 128
 and 130 is 0.100 inches for establishing the proper spacing between the
 contacts 18 and 20. The overall length and width of the insulating member
 126 may vary depending on the size of the opening 112 in the base 100 of
 the housing 16. A representative length would be in the range of about
 0.160 inches and a width would be in the range of about 0.100 inches.
 The alternative spacing arrangement 122 is usable with the housing 16 shown
 in FIG. 5A. The insulating member 126 is secured in the opening 112 using
 an adhesive or other appropriate fastening means, such as snap fit. The
 flexible electrically conductive leads 12 and 14 extend from the opening
 110 with the insulating member 124 providing the minimum spacing between
 leads 12 and 14. Additional ribs or the like, not shown in FIG. 5A, may be
 included in the base 104 for guiding the flexible contacts 12 and 14
 within the housing and to prevent the leads 12 and 14 from extending too
 far out of the opening 110.
 FIGS. 5A and 5B also shows modifications to the housing 16 which may be
 used with a modified alternative spacing arrangement 122. In FIG. 5A, the
 housing has a rib 131 extending down from the cover 102 into the opening
 110. The rib 131 has a width that defines the minimum separation between
 leads 12 and 14. The rib 131 replaces the insulating member 124 in the
 spacing arrangement 122. FIG. 5B also show an approximate triangular wedge
 132 formed on the base 100 at the opening 110. The triangular wedge 132
 tapers from the base of the triangle to the apex which has width defining
 the minimum spacing between leads 12 and 14. The triangular wedge 132
 replaces the insulating member 124 in the alternative spacing arrangement
 122. With any of these arrangements it is possible to switch the position
 of the elements, such as the rib 131, wedge 132, the opening 112 and the
 like from the base 100 to the cover 102. For example, the wedge insulating
 member 132 may be disposed from the cover 102. Further, a 133 slot having
 detents therein may be formed in the cover that receives a rod 135
 attached to the wedge 132. The wedge 132 may then be moved into and out of
 the opening 110 to increase or decrease the minimum spacing between the
 leads 12 and 14. A further configuration is to have the wedge 132
 rotatable within the housing 16 about the rod. The corners of the wedge
 132 could have different thicknesses defining different minimum
 separations between leads 12 and 14. The wedge 132 is moved away from the
 opening 112 using the rod 135 attached to the wedge 132 disposed in the
 slot 133 in the cover 102. The wedge 132 is rotated to bring the selected
 corner into alignment with the opening 112. The wedge 132 is moved back
 into alignment with the opening 112 bringing the selected apex of the
 wedge 132 into the opening 112.
 FIG. 7 shows a further modification to the base 100 usable in housing 16.
 Like elements of the base in FIGS. 5A and 5B are the same in FIG. 7. The
 base 100 has a bottom surface 104 and opposing end surfaces 106 and 108.
 End surface 106 has an opening 110 therein for receiving the flexible
 electrically conductive leads 12 and 14 of assemblies 40 and 42. The end
 surface 108 has rectangular apertures 134 and 136 for receiving the
 electrical contacts 18 and 20 of assemblies 40 and 42. The alternative
 spacing arrangement 122 can be modified where the insulating member 126 is
 replaced with the end surface 108 having the apertures 134 and 136. The
 square pins 50 are inserted through the apertures 134 and 136 and the
 leads 12 and 14 with the insulating member 124 are inserted through
 opening 110. Even in this configuration, the insulating member may be
 replaced with the rib 130 or wedge 132 shown in FIGS. 5A and 5B.
 Referring to FIG. 8, there is shown a further modification of the probe
 adapter 10 of the present invention. The modified probe adapter 200 is
 usable for logic analyzer applications where signals are simultaneously
 taken off of a number of leads 28 on the electronic device 30. A plurality
 of flexible electrically conductive leads 202, similar to leads 12 and 14,
 extend from one end of housing 204. Extending from the opposite end of the
 housing 204 are a plurality of electrical contacts 206 that are
 respectively coupled to corresponding leads 202 in a manner previously
 described for assemblies 40 and 42. The housing 204 may be formed in a
 manner previously described for the dual lead adapter 10. The electrical
 contacts 206 may be plugged into sockets inputs of a high-speed, low
 profile logic analyzer probe described in U.S. Pat. No. 5,223,787,
 assigned to the assignees of the present invention. The logic analyzer
 probes may be individually placed on the electrical contacts 206 or the
 probes may be ganged together as described in the '787 patent.
 The overall length of the outer flexible electrically conductive leads 202
 will be longer than the leads 202 in the center due to the tapering of the
 housing 204 from the approximate 0.100 center pitch geometry for the
 electrical contacts 206 compatible with the pitch geometry of the logic
 analyzer probes to the approximate 0.0225 pitch geometry compatible with
 the pitch geometry of the leads 28 of the electronic device 30. The
 housing 204 may include a base and cover similar to the base and cover 104
 and 102 with opening 208 and 210 for respectively receiving the leads 202
 and the contacts 206. The base 102 may include ribs extending from the
 openings 208 and 210 defining channels for receiving the assemblies 40, 42
 made of the flexible electrically conductive leads 202 and the electrical
 contacts 206. The ribs at the opening 208 have a thickness defining the
 minimum separation between the leads 202. The ribs at opening 208 may be
 used to define the lead spacing of the electrical contacts 206. The
 alternative spacing arrangement shown in FIG. 6 may also be used in the
 probe adapter of FIG. 8. Additional insulating members 124 are provided
 between the adjacent leads 202 and the insulating member 126 has
 additional apertures 128, 130 therein for receiving the electrical
 contacts 206. The housing 204 would have a configuration similar to that
 of the housing in FIG. 5.
 The probe adapter 10 has been shown and described with flexible
 electrically conductive leads 12 and 14 extending from one surface of a
 housing 16 and electrical contacts 18 and 20 extending from a second and
 opposing surface. The present invention is not limited to this sole
 configuration and other configuration are possible within the scope of the
 accompanying claims. For example, the leads 12 and 14 may extend in a
 direction that is not parallel with the contacts 18 and 20. The leads 12
 and 14 or the contacts 18 and 20 may be angled and extend from the top or
 bottom of the housing 16. In such a configuration, the connection between
 the leads 12 and 14 and the contacts 18 and 20 would be modified to the
 configuration.
 A probe adapter 10 has been described for use with a measurement test probe
 having a first and second flexible electrically conductive leads 12 and 14
 extending from a first surface 66 of an insulating housing 16 and having a
 separation between the leads 12 and 14 compatible with the pitch geometry
 of electrical leads 28 of an electronic device 30. First and second
 electrical contacts 18 and 20 are disposed in a second surface 68 of the
 housing 16 and are respectively coupled to the leads 12 and 14 with the
 contacts 18 and 20 having a pitch geometry compatible with probe tip
 contacts 22 and 24 of the measurement test probe 26. A number of
 configurations for the housing 16 and shown and described including an
 outer shell 60 and insulating member 72 and a base 100 and cover 102
 arrangement. A number of configurations for the insulating member 72 are
 shown and described including an insulating wedge conformable with a bore
 62 in the outer shell 60, respective insulating members 124 and 126
 secured between the leads 12 and 14 and the electrical contacts 18 and 20,
 a rib 131 or wedge 132 formed on the base 100 or cover 102, and apertures
 formed through the surface 112 of the base 100. The wedge 132 may be
 attached to a rod 135 disposed through a slot 133 in the cover 102
 permitting longitudinal or rotational movement of the wedge 132 for
 varying the minimum separation between the leads 12 and 14. The probe
 adapter 10 may also be configured with a plurality of flexible
 electrically conductive leads 202 and electrical contacts 206 for use in
 logic analyzer probing applications. These and other aspects of the
 present invention are set forth in the appended claims.