JP2002535681A - Deflection device - Google Patents

Abstract

A deflector having an elongated shape is fixed to a base support structure at one of its ends and moves the other of its ends in a first direction in response to a first electrical signal from a control network. I do. The arm assembly may include at least one piezoelectric crystal having a characteristic that responds to the first signal, performs deflection, and oscillates in response to a sudden change in the amplitude of the first signal. The deflection device is particularly adapted for use as a probe for testing an electrical circuit having a plurality of contact points coated with an insulating material. The probe tip may be located near the second end of the device so that deflection of the crystal imparts kinetic energy to the tip through the insulating material to provide electrical contact with one of the contact points. A second signal can then be introduced at the probe tip to test the electrical circuit. A pair of piezoelectric crystals spaced by a conductive material can provide capacitance to the control network forming the first signal and inhibit oscillation of the crystals.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001] Technical Field The present invention generally relates to a deflection device, in particular, to the use of a piezoelectric crystal in the probe to perform a test of the electric circuit be covered with an oxide type insulating material.

[0002] To maintain the quality in the production of the background art electric circuit, the prior use or sale, it is always desirable to perform the function test and parametric tests of the circuit. this is,
The increasing use of photographic processing in the manufacture of integrated circuits and the associated electrical contacts has become increasingly difficult. Here, the integrated circuit contacts, typically made of aluminum, on a wafer of silicon substrate material are very small and closely spaced.
In fact, the points on the circuit that are typically touched to perform various tests are often less than 2 mm in size. To double the problem associated with providing electrical contact with such points, the aluminum material at the point of contact is oxidized and provided with an insulating coating. It is desirable to penetrate the oxide coating to provide a specific point of contact and sufficient electrical contact.

[0003] Prior art probes are typically held stationary while moving the integrated circuit chip to provide electrical contact between a particular one of the contact points and the tip of the probe. The relative movement between the probe tip and the contact point is slow, and the test equipment will rely on a relatively constant force, eg, 10 grams, to penetrate the oxide coating and provide contact with the contact point. In some cases, a 10 gram force was sufficient to penetrate the oxide coating, but the same 10 gram force was ultimately applied to the point of contact and the test could cut or harm the point. May be affected. For this reason, reprobing of a particular integrated circuit was not recommended. Some probes have tips that move across the oxide coating to facilitate penetration of the coating. This movement also had an adverse effect on the integrated circuit, as it created scratches at certain points of contact.

[0004] It is therefore very desirable to have a new and improved probe which is relatively inexpensive and which breaks through the thick oxide coating and exerts enough force to dissipate the oxide coating from the exposed electrical contacts. desirable.

DISCLOSURE OF THE INVENTION According to the present invention, a probe for testing an electric circuit includes a deflection device which has an elongated shape and is fixed at one end to a support structure. The probe tip is fixed to the other end of the deflection device and is located near a specific contact point of the electric circuit under test. The deflection device moves the probe tip at a relatively high speed in the direction of the contact point in response to the first electrical signal. This causes the deflection device to impart kinetic energy to the probe tip through the oxide coating, providing electrical contact with a particular point of contact. The force of the probe tip on the oxide coating is particularly high compared to the force of the probe tip on the point of contact. This facilitates penetration of the oxide coating by the probe tip, while at the same time greatly reducing static forces on a particular contact point. Thus, the deflection device of the present invention allows testing of an electrical circuit without adversely affecting the point of contact. This is particularly desirable as it allows re-probing of any electrical circuit if desired.

[0006] The deflection device typically comprises at least one piezoelectric crystal having first and second major surfaces and adapted to receive a first signal of a first polarity, the first of the crystals comprising: To provide deflection in the direction of the point of contact. A first signal of the opposite second polarity can deflect the crystal away from the point of contact. In this way, crystals can be coupled in parallel, with both crystals supporting probe reflection from the contact surface and deflection of the contact surface.

[0007] One layer of the conductive material is coated on a wide surface of the crystal, and is electrically separated into a first part for receiving a first signal and a second part for receiving a second signal. The tip can supply energy. The second signal can be provided by an operational amplifier that incorporates a high impedance feedback loop and provides a constant voltage at the probe tip.

[0008] The probe tip responds to sudden changes in the amplitude of the first signal and tends to bounce at certain points of contact. Therefore, it is desirable to shape the first signal so as to avoid sudden changes. In one embodiment of the present invention, a pair of piezoelectric crystals are separated by a conductive material in the deflection device, the crystals providing capacitance to the control network and inhibiting sudden changes in the amplitude of the first signal. This embodiment includes a pair of crystals and is not easily affected by warping.

[0009] These and other features and advantages of the present invention will become more apparent from the description of the preferred embodiment in combination with the accompanying drawings. BEST MODE FOR CARRYING OUT THE INVENTION An apparatus for testing an electrical circuit is generally shown in FIG. The particular electrical circuit under test may be of a type that typically involves an integrated circuit such as chip 13. Chip 13, best shown in FIG. 1 a, typically includes a substrate 15 on which an electrical circuit 17 is etched. The circuit 17 is typically defined by a plurality of lines and conductive material formed in sections or pads, most of which have at least one contact point 19.

To test such a circuit 17, it is desirable to provide electrical contacts at one particular point of contact, such as point 19. Next, energy is supplied to a specific contact point 19, various functional tests and parameter tests are performed, and the characteristics of the circuit 17 are measured. The test is
This can be done with a probe, such as probe 23, which provides an electrical contact at a specific point 19. The various voltages and currents can then be supplied to the circuit 17 by means (not shown) or via the probe 23 and point 19 according to the test procedure.

Providing an electrical contact between the probe 23 and the point 19 naturally becomes particularly difficult when the circuit 17 has a small size. For example, the chip 13 has a small size and is 1 /
Some are 10 square inches. On such a chip 13, the contact point 19 may have a maximum dimension of less than 2 mm. To further complicate the problem associated with providing electrical contacts at point 19, circuit 17 typically includes an aluminum material that oxidizes to form coating 20 on circuit 17. The coating 20 is best shown in FIG. Because the oxide coating 20 has insulating properties, it is desirable to penetrate the coating 20 with a probe 23 to provide sufficient electrical contact with point 19.

The test apparatus 11 generally comprises a base member 21 on which at least one probe such as a probe 23 is mounted. In this regard, the base 21 supports the probe from one of its ends in a cantilevered manner and in a suitable juxtaposition with the electrical contacts 19. Because it may be desirable to perform multiple tests simultaneously, and because any test may involve the use of multiple probes, some of the probes 23 are typically fixed to a single base 21. You.

The probe 23 has a longitudinally elongated shape and is defined by a first end 27 and a second end 29. The first end 27 of the probe 23 is provided with a plurality of oversized holes 31 that can be arranged in parallel with the attached screw holes 33 of the base 21. Multiple screws 34 are oversized holes 3
1 and the fixed relationship between the probe 23 and the base 21 can be maintained. In this way, the probes 23 are juxtaposed such that the second end 29 of the probe 23 extends close to a particular contact point 19 of the circuit 17.

As best seen in FIG. 2, the probe 23 includes a support structure 35, some of which define an oversized hole 31 and a deflection device 37. The deflection device 37 is cantilevered to the support structure 35 and extends to support at least one probe tip in proximity to the associated contact point 19. Probe tip 30 may be a wire or whisker 39 as shown in FIG.

As explained below, the deflection device 37 connects the probe tip 30 to the electrical contact 19.
, And then forcibly and at high speed away from contact 17. In this way, the probe tip 30 forcibly and at high speed impacts the oxide coating 20 covering the electrical contacts 19 with a force sufficient to dissipate the oxide coating from the electrical contacts 19, for the purpose of electrical testing. The probe tip 30 can be mechanically and electrically connected to the electrical contact 19.

The deflecting device 37 has at least one piezoelectric characteristic that deflects in response to an electric signal.
The crystal 41 is included. The crystal 41 can be made relatively thin with a length much larger than the width, and the deflection characteristics can be enhanced along the length. In this way, as shown in FIG. 3, the crystal 41 can have a longitudinally elongated planar shape with a first main surface 43 and a second main surface 45. The signal for deflecting the crystal 41 can be supplied from a deflection signal source 47, on the surface 43 via line 48 and on the surface 4 via line 50.
5 on top. Crystal 41 can be oriented such that a signal from a source 47 that supplies a positive potential to surface 43 with respect to surface 45 deflects crystal 41 to a position 49 off surface 43. A signal from the source 47 indicates the potential of the negative
, The crystal 41 can be deflected to a position 51 off the surface 45. Crystal 41
In this orientation, surface 43 is typically designated with a circled plus sign and surface 45 is typically designated with a circled minus sign.

To enhance the deflection characteristics of crystal 41, it is desirable to apply a signal from source 47 over a substantial area of surfaces 43 and 46. Thus, the deflection device 37
A preferred embodiment includes a thin layer 53 of a metal, such as silver, coated on one of the surfaces 43 and 45. The other of the surfaces 43 and 45 is typically maintained in contact with a structural member 55 that can be formed from any conductive material such as beryllium copper. Next, the signal from the source 47 is sent to the layer 53 and the member 55 to supply energy to the surfaces 43, 45 of the crystal 41.

The crystal 41 can be fixed to the structural member 55 in any suitable way. Deflection device 3
In a preferred method of manufacturing 7, the surface 43 of the crystal 41 is coated with a layer of a solderable material (not shown) such as copper. Next, the layer is soldered to the structural member 55, for example, by induction heating. Similarly, surface 45 is coated with a layer of a solderable material (not shown) such as copper so that surface 45 can be soldered to structural member 53.

The deflection of the crystal 41 is caused by the oxide coating 20 disposed on the contact point 19 as described above.
This is particularly important in the present invention because it imparts kinetic energy to the probe tip 30 for penetrating and removing a portion of the probe tip. In FIG. 4, it can be seen that the probe tip 30 is separated from the contact point 18 by any distance at the deviating position 57, for example a distance of 20 mm at the deviating position. When energy is supplied to the deflection device 37 by a signal from the source 47, the crystal 41 is deflected and the probe tip 30 travels a distance of 20 millimeters in only 50 microseconds. Thus, if the probe tip 30 first contacts the oxide coating 20 at the location 59, it is clear that the tip 30 has a significant speed and thus a high kinetic energy. The kinetic energy is applied to the contact point 19 at the location designated by reference numeral 61 where the probe tip 30 has penetrated the oxide coating 20.
At the first coupling state.

It is clear that the speed of the probe tip 30 at the position 61 is substantially slower than the speed at the position 59. This can be explained by understanding that the oxide coating exerts a force on the probe 30 and slows down the probe tip 30 as the probe tip 30 penetrates the coating 20. Due to the deceleration at position 60, probe tip 30 has minimal kinetic energy. Therefore, the additional force exerted on tip 30 by contact point 19 required to decelerate tip 30 to zero speed is also minimized. Thus, the tip 30 can be brought into mechanical and electrical contact with the point 19 without substantially penetrating or structurally damaging or degrading the point 19. This is particularly advantageous in that it not only preserves the integrity of the circuit 17, but also allows re-probing of the chip 13 if subsequent testing is desired.

If the amplitude of the signal provided by source 47 fluctuates suddenly, crystal 41 oscillates and probe tip 30 bounces over contact point 19. In such a situation, the structural member 5
5 is more useful. Since the member 55 is fixed to the crystal 41 along the longitudinal direction, the member 55 bends with the deflection of the crystal 41 and resists the deflection. The resistance to the bending of the member 55 has a damping effect on the oscillation of the crystal 41.

Preferably, one end of the deflection device 37 is fixed to the support structure 35, and the other end of the device 37 freely supports and deflects the probe tip 30. Although any or all of the layers that make up the laminate can stretch and contact the support structure 35, it is desirable that the stretched layer include the member 55 because the structural member 55 is typically the strongest layer in the laminate. As can be seen in FIG. 2, the structural member 55 extends below the support structure 35,
Holes similar in cross section to 1 can be provided. Next, the screws 34 push the member 55 against the support structure 35 and the support structure 35 against the base 21.

Next, referring to FIGS. 1 to 4, the operation of the test apparatus will be described in more detail. The chip 13 is arranged at the test location 18 on the base 21. 1 like probe 23
Or a plurality of probes are mounted on the base 21 via screws 34, and the probe 30
Are arranged in parallel with the electric contact 19 at the close position. Next, the power supply 47 is connected to the structural member 53 via the conductor 50 and to the structural member 53 via the conductor 48.

Next, by applying a positive charge to the structural member 55, the probe tip 30 is moved to the deviated position. Here, the crystal 41 responds to the electric signal and makes the surface 43 in a tensile state,
With the surface 45 in compression, the structural members 53 and 55 and the probe tip 30 are moved away from the electrical contact 19 and into a deviated position.

Next, after the probe 23 has stopped at the deviated position, a negative charge is applied to the structural member 53, causing the surface 43 to be in a compressed state, the surface 45 to be in a tensile state, and then
And 55 and the probe tip 30 at high speed towards the electrical contacts. Here, a sufficient amount of kinetic energy is imparted to the probe tip 30 so that the probe tip 30 can penetrate and remove a significant portion of the oxide coating 20, and thus the coating 2
Zero is eliminated and removed. The oxide coating 20 exerts an antagonistic force on the probe tip 30 to transmit the kinetic energy in the probe 23 at high speed while the probe tip 30 penetrates. When the probe tip 30 mechanically engages the electrical contact 19,
Such a sufficient amount of kinetic energy is transferred to the coating 20 so that the tip 30 is in mechanical and electrical engagement with the electrical contact 19 without any substantial structural damage to the contact 19.

After the probe 23 establishes electrical contact with the contact 19, various tests can be performed according to conventional test methods. When the test is completed, the negative charge is removed from the probe 23, and the probe 23 comes to a neutral rest position without compression or tension, as shown at 41 in FIG.

From the above description, those skilled in the art will appreciate that the probe tip 30 is forced toward the oxide coating 20 with sufficient force to cause the probe tip 30 to exert a sufficient coating loss impact on the oxide coating. It is understandable that it is propelled at high speed. Disappearing the oxide coating 20 causes the probe tip 30 to come into mechanical and electrical static contact with the electrical contact 19 for testing purposes.

When used in the probe 23, the deflection device 37 supplies kinetic energy to the probe tip 30 to facilitate testing of the electrical circuit. The kinetic energy exerts considerable force on the oxide coating 20 and can penetrate the oxide coating 20. Much of the energy is dissipated in penetrating the oxide coating 20, thus greatly reducing the force on the contact point 19. Thus, the contact point 19 is not adversely affected by contact with the probe tip 30, and re-probing can be performed if necessary. The deflection device 37 can be planarized to supply a desired degree of kinetic energy to the probe tip at the planarized position.

Although the deflection device of the present invention has been disclosed with particular reference to probe 23, many other applications will be apparent to those skilled in the art. Referring now to FIG. 5, another test apparatus 111 constructed in accordance with the present invention is shown. The test apparatus 111 is substantially the same as the test apparatus 11 except that the test apparatus 111 includes the warp prohibition probe 23a. Probe 23a includes elements similar to those described above in connection with probe 232, with such elements indicated by the same reference numerals followed by a lower case "a". Accordingly, the support structure is indicated by reference numeral 35a.

In this embodiment, the structure 35a has a deflection device 37a in the direction of the deflection device 37a.
An arm 65 extending close to a is provided. The arm 65 provides protection means or guards for the deflection device 37a and further provides a reference level for the deflection device 37a to be first aligned with the support structure 35a.

As in the embodiment illustrated in FIG. 2, the deflection device 37a includes a structural member 55a.
, A crystal 41 and a metal layer 53a. Deflection device 37a
In this particular embodiment, a second crystal 67 similar to crystal 41a may be disposed in contact with the structural member on the opposite side of crystal 41a. A thin layer 69 of metal similar to layer 53a can be disposed on the outermost surface of crystal 67, facilitating energy supply to crystal 67. Thus, in the stack forming the deflecting device 37a of this specific example, the crystals 41a and 67 and the metal layers 53a and 69 are symmetrically arranged outward from each surface of the structural member 55a.

As in the previous embodiment of the deflecting device 37, the source 47a includes metal layers 53a and 55a.
When the structural member 55 is a positive electrode with respect to the metal layer 53a, the crystal 41a oriented as described above is deflected to the position 49a. If the second crystal is oriented in the opposite direction, that is, if the side with the plus sign is oriented outward from the structural member 55a, the same potential introduced into the metal layer 53a is sent to the layer 69. Next, even if the crystal 67 is reversed, the polarity of the signal applied to its surface is also reversed, and the crystal 67 deflects in the same direction as the crystal 41a.

The deflecting device 37 a of this embodiment is particularly useful because it resists any warping that may be caused by the deflection of the crystals 41 a and 67. For example, when the deflection device 37a bends from the normal straight position to the position 49a, the crystal 41a is placed in a compressed state and the crystal 67 is placed in a tensile state. Such stresses cancel each other out and inhibit warping of the deflection device 37a.

The support structure 35a is conveniently molded from a suitable material such as plastic. In this molding step, the deflecting device 37a, as shown in FIG.
May be embedded.

Considering the operation of the test device 111 in more detail below, the elongate metal structural element 5
5a is resilient and flexible, is cantilevered at one of its ends, and positions the probe tip 30a at its free end in a travel path extending to the oxide-coated contact 19. Here, when a signal of one polarity is sent to the structural elements 53a, 55a, and 69, the piezoelectric elements 41a and 67 are physically moved, and the structural element 55a is oxidized as shown by the dotted line in FIG. The object-covered contact is bent to a tension state. In this deviated position, the element is under elastic stress and is held in place releasably by the piezoelectric element.

When the signal suddenly changes its polarity, the piezoelectric elements 41 a and 67 physically move in the opposite direction, releasing the structural element 55 a, thereby forcing the structural element 55 a toward the oxide-coated contact 19. Then, the probe tip 30a accelerates, and collides with the oxide coating due to the oxide disappearing impact. The bombardment is sufficient to dissipate the oxide coating, and thus sufficient to mechanically and electrically engage the tip with the contact.

As best seen in FIG. 5, the probe tip 30a can be formed as a blade 71 having a portion defining an elongated hole 73 for receiving the free end of the deflection device 37a. The outer portion of the slot 73 can be extended to contact at least one of the metal layers 53a and 69.

Indeed, a major advantage of the present invention is the superior electrical contacts that provide the probe 23a at a particular contact point 19. However, once contact is made, the probe tip 3
It is desirable to supply energy to Oa and perform various tests on chip 13 and attached electrical circuit 17. A further feature of the present invention relates to the energy supply of the probe tip 30a.

In FIG. 7, the top view of the deflecting device 37 a shows that the metal layer is in the first line by the score line.
This shows that the part 73 and the second part 75 can be separated. A first portion 73 of layer 69 is adapted to receive a signal from source 47a on conductors 48a and 50a and provides deflection of crystal 67 as described above. Score line 71 and crystal 41
And 67 can be cut by an abrasive cutting method such as sandblasting.

The second part 75 of the layer 69 has a shape provided with a conductor 77 extending from the back surface of the deflection device 37 a to the probe tip 30 a. As a result, the conductor 77 on the back of the deflection device 37a
To supply energy to the probe tip 30a. The second portion 75 of the metal layer 69 can also define a second conductor 79 extending from the probe tip 30a to the back of the deflection device 37a. The conductor 79 supplies a voltage corresponding to the voltage at the probe tip 30a on the back of the deflection device 37a. The voltage on conductor 79 can be sent into operational amplifier 80 with a start-up signal. The activation of the probe tip 30a is particularly desirable because the conductor 79 provides a feedback loop that maintains the voltage at the probe tip 30a at a substantially constant level. To get low capacitance at the contacts,
Fine wires may be used. Higher density curved circuits can be used to connect the probe tip to the test equipment and completely isolate the probe drive from the circuit under test.

FIG. 8 shows a bottom view of the deflecting device 37a.
It can be seen that a score line 81 separating the third and second portions 85 is provided in the metal layer 53a. The first part 83 is for receiving a signal from the source 47a on the conductor 48a and deflecting the crystal 41a as described above. Score line 81
To maximize the size of the first portion 83 of the layer 53a, it is desirable to be located close to the probe tip 30a. Score line 81 isolates portion 85 from portion 83 so that the energy supply to probe tip 30 does not interfere with the energy supply to crystal 41a.

The controller 87 that synchronizes the energy supply of the deflection device 37 a with the energy supply of the probe tip 30 a and performs various tests is schematically illustrated in the block diagram of FIG. The operation of controller 87 begins by providing energy to index time circuit 97 and providing a conductor 882 signal. The signal on conductor 88 can be used to move tip 13 to bring specific contact point 19 near probe tip 30a.

The index delay 89 delays the signal to the conductor 88 by a time, such as 50 milliseconds, depending on the time required to index the chip 13. The delayed signal is sent to a conductor 92 that provides an input to a probe stop delay circuit 93. The circuit 93 is fed to a conductor 95 which provides an input to an upper and lower gate 99. The gate 99 may be an OR gate,
The signal on conductor 95 passes through gate 99 and is transmitted to deflection signal source 47a. Conductor 9
The signal of 5 is also sent to the indexing time circuit to prohibit any relative movement between tip 13 and probe tip 30a while probe 23a is in the down position.

The source of the potential 101 supplies voltages of + VP and −VP, and the voltage is applied to the signal source 47a.
Sent to The signals from the upper and lower gates 99 can be used by the signal source 47a to gate the negative reference potential -VP to a plurality of probes, shown schematically at 23. The orientation of the probe 23 is such that, due to the negative reference potential -VP, the deflection device deflects downward to provide electrical contact between the probe tip 30a and a particular contact point 19.

Once contact has been established between the probe tip 30a and the contact point 19, testing of the electrical circuit 17 can begin. Thus, after a delay period corresponding to the time required to deflect the probe 23a to the lower position, the probe down delay 93
03, the test time circuit 105 can be activated. The circuit 105 can supply an output signal to the conductor 107 that can be sent to the signal source 47 via the upper and lower gates. The signal from the gate 99 continues to supply energy to the probe 23a at the negative reference potential -VP, and the probe 23a remains at the lower position. The test time circuit 105 also
According to the test procedure, a signal for starting the test of the electric circuit 17 is supplied to the conductor 109.

The test delay circuit 111 delays the signal on the conductor 109 for a certain period, such as 50 milliseconds, corresponding to the time required for testing the circuit 17. After the delay period, the circuit 111
Is sent on conductor 113 to indicate that the test is complete. The conductor 113 supplies an input to the probe rise delay circuit 115, and the probe rise delay circuit 115
A signal that inhibits the test time circuit 105 can be provided on conductor 117. In a preferred embodiment, the signal on conductor 117 causes the signal on conductor 107 to stop, and signal source 47
a does not receive any more signals from the upper and lower gates 99. Under such circumstances, the signal source 47a can send the positive reference potential + VP to the probe 23a. With the positive reference potential + VP, the deflection device 37a raises the probe tip 30a from the contact point 19 to an upper position.

After a delay period associated with the time used to lift probe tip 30 a, probe rise delay circuit 115 can provide conductor 119 signal. When the probe 23a is in the upper position, a signal to the conductor 119 can be sent to the indexing time circuit 97, which sends a signal to the conductor 88, and the tip 13 moves again with respect to the probe 23a. .

In the controller 86 of the present embodiment, the probe lower and probe rise delay circuits 9
3 and 115 may be circuit numbers 74123 of the type commonly specified in the electronics industry. Similarly, test time and index time circuits 105 and 97 may be circuit numbers 7474 of the type commonly specified in the industry. Similarly, the upper and lower gates 99 may be 7440 circuits, and the test and index delay circuits 111 and 99 may each be 74/23 circuits. The circuits 93, 105, 97, 99, 111 and 89 are sold by many electronic component manufacturers, including Texas Instruments.

As mentioned, the deflection device 37a deflects by a distance corresponding to the amplitude of the activation signal provided by the source 47a. Based on this feature of the invention, the probe 23
a is flattened. For example, the switch 121 is provided with a potential source 101 for sending a planarized potential such as a negative potential -VP / 2 having a smaller amplitude than the negative potential -VP to the source 47a. This reduced negative potential can then provide a smaller deflection of the deflection device 37a during planarization of the probe 23a. Next, the probe tip 30a
It can be adjusted mechanically to a certain reference level. For example, in a preferred embodiment, the probe tip 30a has an oxide coating 20 as shown at 159 illustrated in FIG.
Can be mechanically adjusted to contact the edge of the surface. Then, if the reduced negative reference potential deflects the probe tip 30a to 159, the normal amplitude negative reference potential -VP will give more kinetic energy to penetrate the oxide coating 20 to the probe tip 30a.
a. Further, the amplitude of the planarization potential is changed, and a desired degree of kinetic energy can be supplied at 159. The amplitude obtained by subtracting the planarization potential from the normal reference potential is 1
It corresponds to the kinetic energy at the planarization position such as 59.

As described above, sudden changes in the amplitude of the signal supplied from source 47 a cause deflection device 37 to oscillate and probe tip 30 a to bounce over contact point 19. In some situations, this is undesirable, and it is desirable to form the signal at source 47a so as to inhibit sudden changes in its amplitude. For example, in FIG. 9, the generally square pulse 86 has its edges ramped, and an activation signal such as 150 volts is applied, for example, at -1.
It can be seen that the amplitude does not fluctuate rapidly to a level such as 50 volts.

The deflecting device 37a converts the activation signal supplied by the source 47a into a deflecting device 37a.
Has been found to be particularly useful in that it is shaped to prohibit vibrations. For example, the crystals 41a and 67 of the deflection device 37a are connected in series with the resistor 123,
It has been found that it provides a capacitance that provides an integration network for tilting the sides of a typical square wave signal provided from signal source 47a. In such an embodiment, crystals 41a and 67 can provide a capacitance of 0.05 microfarad and resistor 123 has 200K. Such an integration network can provide a start-up voltage having a waveform as shown in FIG.
Runs in milliseconds or more. In this way, the activation signal as shown in FIG.
It is shaped so as not to include a frequency component corresponding to the fundamental frequency of the deflection device 37a. As a result, the vibration of the deflection device 37a and thus the jump of the probe tip 30a are prohibited.

From the above disclosure, with the minimum structure, the deflecting device can have a characteristic of deflecting in response to both positive and negative potentials. The direction of the deflection device is related to the polarity of the activation signal, and the degree of deflection is related to the amplitude of the activation signal. One embodiment of the deflecting device 37a, which includes a pair of crystals 41a and 67, can inhibit any warping of the deflecting device resulting from supplying energy to the deflecting device.

While the invention has been disclosed with respect to particular embodiments, it will be understood that various modifications are possible and can be contemplated within the true spirit and scope of the appended claims. Accordingly, there is no intention to be limited to the abstract or disclosure provided herein.

[Brief description of the drawings]

FIG. 1 is a top view of an electrical circuit test apparatus including a plurality of probes constructed in accordance with the present invention, showing each probe and an attached probe tip that extends and contacts an integrated circuit chip under test. Show.

FIG. 1a is a top view of the integrated circuit chip shown in FIG.

FIG. 2 is a partial side perspective view of the test apparatus of FIG. 1 taken substantially along line 2-2;
1 shows an embodiment of a probe including a deflection device having one piezoelectric crystal.

FIG. 3 is a three-dimensional view of a piezoelectric crystal showing its deflection characteristics in response to an applied signal.

FIG. 4 is a side perspective view of the probe tip, showing the deflection position of the probe tip with respect to the contact point.

FIG. 5 shows a further embodiment of a probe including a deflection device having a pair of piezoelectric crystals in a side perspective view of another electrical circuit test device constructed in accordance with the present invention.

6 is a three-dimensional view of the deflection device shown in FIG. 5, showing its deflection characteristics in response to an applied signal.

FIG. 7 is a top view of the deflection device of FIG. 5, showing a means for supplying energy to the tip of the probe.

FIG. 8 is a bottom view of the embodiment of the deflection device shown in FIG. 5;

FIG. 9 is a graph showing a current pulse having a desirable configuration for supplying energy to the deflection device of the present invention.

FIG. 10 is a block diagram of a controller for supplying energy to the deflection device of the present invention.

──────────────────────────────────────────────────続 き Continuation of front page (81) Designated country EP (AT, BE, CH, CY, DE, DK, ES, FI, FR, GB, GR, IE, IT, LU, MC, NL, PT, SE ), OA (BF, BJ, CF, CG, CI, CM, GA, GN, GW, ML, MR, NE, SN, TD, TG), AP (GH, GM, KE, LS, MW, SD, SZ, UG, ZW), EA (AM, AZ, BY, KG, KZ, MD, RU, TJ, TM), AL, AM, AT, AU, AZ, BA, BB, BG, BR, BY, CA, CH, CN, CU, CZ, DE, DK, EE, ES, FI, GB, GD, GE, GH, GM, HR, HU, ID, IL, IN, IS, JP, KE , KG, KP, KR, KZ, LC, LK, LR, LS, LT, LU, LV, MD, MG, MK, MN, MW, MX, NO, NZ, PL, PT, RO, RU, SD, SE, SG, SI, SK, SL, TJ, TM, TR, TT, UA, UG, UZ, VN, YU, ZWF Term (reference) 2G003 AA07 AA10 AB01 AG03 AG12 AG20 2G011 AA15 AC06 AC14 AC21 AE03 2G132 AA00 AB01 AF01 AL03 4M106 AD26 BA01 BA14 DD01 DD03 DD12

Claims (8)

[Claims] 1. An electrical test apparatus for enabling testing of an oxide-coated electrical contact, comprising: a cantilever extending at one of its ends, in a direction toward and away from the oxide-coated electrical contact. A moving elongate structural element having first and second surfaces, a free end, and a fixed end; an oxidation of an electrical contact mounted and tested on the free end of the elongate structural element. A probe tip having a perforation shaped to penetrate the object coating; a first piezoelectric crystal overlying the first surface of the elongate structural element and having a piezoelectric property deflected toward an oxide-coated electrical contact; A second piezoelectric crystal superimposed on the second surface of the elongated structural element and having deflecting piezoelectric properties, wherein the elongating structure is configured to deflect at least the first piezoelectric crystal in response to at least one electrical signal. Element for oxide-coated electrical contacts It curved I, whereby the oxide coating with sufficient kinetic energy to penetrate the electrical test device to promote the probe into the oxide coating of the electrical contact. 2. The electrical test of claim 24, wherein the second piezoelectric crystal is arranged to deflect the elongated structural element in a second direction from the oxide-coated electrical contact in response to another electrical signal. apparatus. 3. The electrical test apparatus according to claim 24, wherein the probe tip includes a blade. 4. The apparatus of claim 2, further comprising a signal source coupled to said first piezoelectric crystal.
5. The electrical test apparatus according to 4. 5. The electrical test apparatus according to claim 27, further comprising an elongated conductive plate disposed on the first piezoelectric crystal and coupled to the signal source. 6. An elongated structural element that cantileverly extends at one of its ends and moves in a direction toward and away from the oxide-coated electrical contact, the first and second surfaces and a free end. An elongated structural element having a fixed end; a probe tip mounted on the free end of the elongated structural element and having a perforation shaped to penetrate an oxide coating of an electrical contact to be tested; A first piezoelectric crystal superimposed on the first surface and having a piezoelectric property that deflects toward an oxide-coated electrical contact; and superposed on the second surface of the elongated structural element and having a piezoelectric property for deflection. A method for enabling testing of an oxide-coated electrical contact utilizing an electrical test apparatus having a second piezoelectric crystal, comprising: applying an electrical signal to at least a first piezoelectric crystal, thereby providing at least a first piezoelectric crystal; The piezoelectric crystal is deflected in a first direction, and Bending the elongated structural element toward the oxide-coated electrical contact; hitting the oxide coating of the electrical contact with the probe tip, the probe tip having sufficient kinetic energy to penetrate the oxide coating; And establishing a mechanical and electrical connection of the electrical contacts. 7. Applying an electrical signal to at least the second piezoelectric crystal, thereby:
30. The method of claim 29, further comprising deflecting at least a second piezoelectric crystal in a second direction away from the oxide coated electrical contact to deflect the elongated structural element. 8. The method of claim 30, further comprising providing an electrical signal to the electrical contact via the probe tip after the mechanical and electrical connection between the probe tip and the electrical contact has been established. Method.