JP2013072706A - Cantilever type probe which can be separated from one place - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a probe structure from which an arm part can be easily pulled off, when replacing cantilever type probes having a single arm structure or a double arm structure.SOLUTION: A probe card includes a probe having: a contact 12; and an arm part to one end of which the contact 12 is attached, the other end of which is fixed, and which is composed of plate material. The arm part is fixed by joining the same, via a peeling layer 24, to a pedestal 26 joined to a substrate. The peeling layer 24 has an area smaller than a joint part of the pedestal 26 and the substrate 28. The arm part has a double arm structure including, via a spacer, two arms of a lower arm 16 and an upper arm 22 which has a thickness equal to or larger than that of the lower arm 16. The arm part is joined to the pedestal 26 via the peeling layer 24, and the lower arm 16 is longer than the upper arm 22.

Description

The present invention relates to a probe card for testing electrical characteristics of a semiconductor integrated circuit, and more particularly to a cantilever type probe structure that can be easily replaced when a probe is repaired.

  Due to the high integration of semiconductor integrated circuits, individual elements constituting the circuit are miniaturized, and accordingly, a test apparatus used for characteristic evaluation performed in a manufacturing process also requires a probe having a fine structure.

  A probe card used as a test apparatus for a semiconductor integrated circuit corresponds to a miniaturized structure, and a probe to be used also manufactures a minute structure with high accuracy by a MEMS (Micro Electro Mechanical System) technology.

  The probe is manufactured by depositing a metal material in a plurality of recesses arranged on a base to form a contact, and then, in turn, a pedestal that serves as a probe arm portion and a synthetic resin film fixing portion to the wiring board. Are formed by a photolithography technique, whereby a plurality of fine probes are manufactured at high density (see, for example, Patent Documents 1 and 2).

  Probes manufactured by photolithography technology need to be improved in strength because they are fine. In addition to making the probe arm sufficiently thick, there are structurally two arms for the arm. (See, for example, Patent Documents 3 and 4).

  The probe card is bonded to a wiring pad formed on the board, and if it is damaged or worn out over time, replacement with a new probe is performed. Yes. This probe exchange is also a fine-structure probe exchange, and various methods including the probe structure have been proposed (see, for example, Patent Documents 5 and 6).

JP 2007-285802 A JP 2010-286360 A JP 2010-276426 A JP 2004-156993 A JP 2011-22027 A JP 2010-156632 A

  The cantilever type probe manufactured by the MEMS structure (structure manufactured by the photographic technology as the MEMS technology) is an assembly of minute assembly parts by plating, and replacement when the probe is damaged or worn is damaged. There was a problem that it was difficult to remove the probe.

  In particular, in a cantilever type probe with a MEMS structure, a double-arm structure probe using two plate members for the arm part has a structure in which the upper and lower arms are fixed with spacers at both ends, and two sheets at the same time. It is necessary to remove the arm from the member fixing the arm.

An object of the present invention is to provide a probe structure in which an arm part is easily peeled off from a member fixing an arm when exchanging a cantilever type probe having a single arm structure and a double arm structure.

  The present invention comprises a probe comprising a contact and an arm portion made of a plate member to which the contact is attached at one end and the other end is fixed, and the arm portion is fixed to the substrate. The probe card is bonded to the bonded base through a release layer.

  The release layer has a smaller area than the joint between the base and the substrate.

  The arm portion has a double arm structure including a lower arm through a spacer and an upper arm that is equal to or thicker than the thickness of the lower arm, and is joined to the pedestal via a release layer. The length of the pedestal-side spacer sandwiched between the arm and the lower arm is shorter than the release layer, and the probe card is characterized in that the lower arm is longer than the upper arm.

  The release layer is a conductive metal material, and is a softer material than the arm and pedestal material. For example, the metal material of the release layer is gold, silver, or copper.

  The replacement probe is bonded to the base by forming a release layer by a flip chip mounting method, and the flip chip mounting method is bonded by any one of a solder bonding method, a stud bump bonding method, and an ultrasonic bonding method.

Further, in the flip chip mounting method, a peeling layer with gold plating can be formed on the bonding surface, and bonding can be performed at room temperature by plasma irradiation.

  Since the cantilever type probe probe card of the present invention is provided with a release layer so that the probe can be easily removed when the probe fails, breaks or wears at the tip, it is always at a certain point, That is, the probe can be removed from the peeling layer portion, and repair can be easily performed.

  The release layer has a smaller area than the joint between the pedestal and the substrate, thereby relatively reducing the bonding strength and facilitating peeling.

In addition, in the double arm structure probe in which the arm portion is composed of two plates, the length of the spacer on the pedestal side is made shorter than the joint portion of the pedestal, and the lower arm is made longer than the upper arm. The peeling force is weak in the normal contact direction, and when the force is applied in the opposite direction, the peeling force works strongly, and the probe can be easily separated from the same location.

The figure which shows the cross section of the Example of the cantilever type probe of the double arm structure provided with the peeling layer by this invention. The figure which shows the cross section of the cantilever type probe of the single arm structure provided with the peeling layer by this invention. The external view of the Example of the probe card to which the cantilever type probe by this invention is applied. The figure which shows the cross section of the cantilever type | mold probe of a double arm structure without a peeling layer. The figure which shows the state which the arm part damaged in the cantilever type | mold probe of the double arm structure without a peeling layer shown in FIG. The figure explaining the state at the time of peeling off a probe in the state where the arm part shown in FIG. 5 was damaged. The figure which shows the state which the arm part damaged in the cantilever type | mold probe of the double arm structure provided with the peeling layer by this invention. The figure explaining the state at the time of peeling off a probe in the state where the contact side shown in FIG. 7 was damaged. The figure explaining the state which peels off a probe in the case of a contactor wearing and exchanging in the cantilever type probe of the double arm structure provided with the peeling layer by the present invention. The figure which shows the probe for replacement | exchange.

  The present invention is characterized in that a release layer is provided so that the probe can be peeled off from a certain location when the probe needs to be replaced due to a failure or the like, which will be described below.

  FIG. 1 is a view showing a cross section of an embodiment of a cantilever type probe 10 having a double arm configuration provided with a release layer according to the present invention. At the lower end of the cantilever type probe 10, there is a contact 12 that comes into contact with the electrode of the object to be measured, and is attached to the lower surface of the contact support 14 configured in two stages so as to protrude downward. A lower arm 16 is attached to the upper surface of the contact support 14. Further, on the upper surface of the lower arm 16, a spacer A18 is attached to one end (contactor 12 side), a spacer B20 is attached to the other end, and an upper arm 22 is provided on the upper surfaces of both spacers A, B. It is attached and has a double arm structure made of two plates.

  The upper arm 22 and the pedestal 26 are joined via a release layer 24. Further, the base 26 is joined to the substrate 28.

  In the cantilever type probe 10, the lower arm 16 and the upper arm 22 are mostly damaged and the contact 12 is worn as the case where the exchange is necessary. It is desirable.

  Therefore, when the peeling layer 24 is provided between the upper arm 22 and the base 26 and the lower arm 16 and the upper arm 22 are held and a force for peeling downward is applied in FIG. It is easy to peel off.

  For this reason, the release layer 24 is a conductive metal material, and is softer than other components, for example, gold, silver or copper, and is used as the release layer 24.

  The area of the joint between the upper arm 22 and the pedestal 26 joined via the release layer 24 is smaller than the area of the joint between the pedestal 26 and the substrate 28, so that the substrate 28 and the pedestal 26 are joined structurally. The structure is such that the bonding strength between the base 26 and the upper arm 22 is weaker than the strength.

  In the embodiment of FIG. 1, the pedestal 26 has a stepped shape with different lengths on the substrate 28 side and the release layer 24 side, but may have a trapezoidal shape with different lengths on the substrate 28 side and the release layer 24 side.

  Further, in the cantilever type probe 10 having a double arm configuration, the length of the spacer B20 on the pedestal side is shorter than that of the release layer 24 so that the lower arm 16 is longer than the upper arm. With such a structure, when the contact 12 is pressed against the electrode of the object to be measured in order to perform a normal electrical test, the peeling force on the peeling layer 24 is weakened. In other words, the upper arm 22 exerts a moment with the corner of the pedestal 26 on the contact 12 side as a fulcrum by pressing of the contact 12, but in the lower arm 16, the spacer B 20 on the contact 12 side. A moment with a corner as a fulcrum acts, and the force exerted by the lower arm 16 at this time acts in the direction of pushing the upper arm 22 at the corner of the spacer B20 serving as a fulcrum.

  For this reason, in the release layer 24, pressure is applied from two locations on the contact 12 side and the contact 12 side end of the spacer B 20, and a force difficult to separate from the release layer 24 acts. .

  On the other hand, when peeling the probe from between the upper arm 22 and the pedestal 26, holding both the upper arm 22 and the lower arm 16 and applying a force to the lower side in FIG. Both side arms 16 have a moment with the pedestal side arm end as a fulcrum. For this reason, a peeling force is applied to the release layer 24, and the structure is easy to separate.

  Furthermore, by making the thickness of the upper arm 22 equal to or greater than that of the lower arm 16, the cross-sectional secondary moment of the upper arm is increased, and further effects can be exhibited.

  FIG. 2 is a view showing a cross section of an embodiment of a cantilever type probe 30 having a single arm configuration in which a plate having one arm is used. Also in this case, the arm 15 and the pedestal 26 are joined via the release layer 24 as in the double-arm cantilever type probe shown in FIG. The area of the joint surface between the arm 15 and the pedestal 26 via the release layer 24 is narrower than the area of the joint surface between the pedestal 26 and the substrate 28 to relatively weaken the joint strength. For this reason, the separation layer 24 facilitates separation in terms of structure.

  FIG. 3 is an example of a probe card 32 to which the cantilever type probe 10 or the cantilever type probe 30 according to the present invention is attached, and shows an external appearance. A plurality of cantilever probes shown in FIG. 1 or 2 are mounted on the probe substrate 36, and are incorporated in a probe card substrate 34 having wirings electrically connected to the plurality of cantilever probes.

  An electrical characteristic is tested by bringing a probe contact 12 mounted on a probe card into contact with an electrode of an integrated circuit that is an object to be measured. Usually, the probe card 32 is pressed against the object to be measured with the probe substrate 36 side of the external view shown in FIG. 3 facing downward.

  During electrical measurement, the contact at the tip of the arm moves up and down, so the arm is also bent into an arch shape with the fixed end as a fulcrum, and a probe that cannot be used due to repeated arm damage or contact tip wear occurs. Replacement is required, and the work of separating the probe or arm from the probe card must be performed.

  The present invention is provided with a release layer that facilitates separation of the probe or arm in this case, and in order to explain the effect, first, a case where there is no conventional release layer will be described.

  FIG. 4 shows a cantilever type probe 40 having a double arm configuration and having no release layer. The other structures are structurally similar to FIG. 1 except for the release layer.

  FIG. 5 shows a case where the upper arm 22 and the lower arm 16 of the cantilever type probe 40 having the double arm configuration shown in FIG. 4 are damaged. In FIG. 5, the arrow portions of the upper arm 22 and the lower arm 16 are damaged and removed. Since the replacement is performed with the probe board 36 of the probe card shown in FIG. 3 facing upward, the drawings show the contact 12 facing upward.

  FIG. 6 shows a case where the upper arm 22 and the base 26 of the damaged cantilever type probe shown in FIG. 5 are to be separated. FIG. 6A shows a state in which a force is applied in the direction indicated by the arrows to the tips of the damaged upper arm 22 and lower arm 16. In this case, the bonding strength between the upper arm 22 and the pedestal 26 is strong, and it is difficult to separate from the bonding surface between the upper arm 22 and the pedestal 26. For this reason, as shown in FIG. 6B, only the upper arm 22 and the lower arm 16 are bent, and in a remarkable case, only the arms of the upper arm 22 and the lower arm 16 may be torn.

  Next, a case where there is a release layer will be described.

  FIG. 7 shows a case where the upper arm 22 and the lower arm 16 are damaged at the locations indicated by the arrows in the cantilever type probe 10 having the double arm configuration shown in FIG.

  FIG. 8 shows a case where the upper arm 22 and the pedestal 26 are going to be separated when the arm of the cantilever type probe 10 having a double arm configuration is damaged and disappeared as shown in FIG.

  FIG. 8A shows a state in which a force is applied in the direction indicated by the arrow to the tips of the damaged upper arm 22 and lower arm 16. In this case, since the release layer 24 exists, the bonding strength between the upper arm 22 and the pedestal 26 in the release layer 24 is weak, and the release layer 24 is torn and the upper arm 22 is cut as shown in FIG. And the base 26 can be separated from the joint surface.

  FIG. 9 shows a case where the upper arm 22 and the base 26 are to be separated when the contact 12 of the cantilever type probe 10 having the double arm configuration shown in FIG. 1 cannot be used due to wear.

FIG. 9A shows a state in which force is applied in the direction indicated by the arrows to the tips of the damaged upper arm 22 and lower arm 16.
Also in this case, as described with reference to FIG. 8, since the release layer 24 exists, the bonding strength between the upper arm 22 and the pedestal 26 in the release layer 24 is weak, and the release layer 24 is torn and FIG. ), It can be separated from the joint surface of the upper arm 22 and the base 26.

  As described above, the case where the upper arm 22 and the lower arm 16 are damaged and the contact 12 is worn has been described with respect to the case where the release layer 24 is present. It can be easily separated on the surface of the layer 24.

  FIG. 10 shows a replacement probe 50 having a double arm configuration. The contact 12 includes a contact 12, a contact support 14, a lower arm 16, a spacer A 18, a spacer B 20 and an upper arm 22, and a release layer 24 is formed on a joint surface between the upper arm 22 and the base.

  The release layer 24 is gold plated. This gold plating is electroless plating, and soft gold is plated. This plated layer corresponds to a connecting metal called a bump in flip chip mounting. The replacement probe 50 is mounted on the probe card by directly electrically connecting the peeling layer 24 (plating layer) toward the base. As a joining method, for example, a solder joining method, a stud bump joining method, an ultrasonic joining method, or the like can be applied.

  The replacement probe 50 is bonded by instantaneously heating a fine bonding portion, and there is pulse heat bonding as an example of a specific solder bonding method. A pulse heat unit is used which is composed of a reflow head for applying pressure by pressing the joint and a pulse heat power source for supplying electricity. In the pulse heat unit, electricity is applied to a heater chip (tip) made of metal to generate resistance heat and melt the solder. When the solder is melted, the electricity is stopped and cooled to perform bonding.

  The solder bonding method, the stud bump bonding method, or the ultrasonic bonding method in the flip-chip mounting is applied at a temperature of 150 ° C. to 300 ° C., whereas the room temperature mounting technology in which no temperature is applied is a high-speed atomic beam or high-frequency plasma There is also a method of performing normal temperature bonding by irradiating the metal bonding surface with cleaning to activate the bonding surface. In this case, the pedestal 26 is also plated with gold.

  Flip chip mounting is performed by irradiating a gold-plated bonding surface with high-frequency plasma or the like to activate the bonding surface. After the high-frequency plasma irradiation, impurities on the bonding surface are removed from the gold-plated surface, and the contact surfaces are brought into contact with each other and pressed to perform room temperature bonding.

As mentioned above, although embodiment of this invention was described, this invention includes the appropriate deformation | transformation which does not impair the objective and advantage, Furthermore, the limitation by said embodiment is not received.

10, 30, 40 Cantilever type probe 12 Contact 14 Contact support 15 Arm 16 Lower arm 18 Spacer A
20 Spacer B
22 Upper Arm 24 Peeling Layer 26 Base 28 Substrate 32 Probe Card 34 Probe Card Base 36 Probe Substrate 50 Replacement Probe

Claims (10)

A contact,
An arm portion composed of a plate member to which the contact is attached at one end and the other end is fixed;
Comprising a probe consisting of
The fixing of the arm part is bonded to a pedestal bonded to the substrate via a release layer,
A probe card characterized by
The probe card according to claim 1,
The arm portion has a double arm structure including two arms, a lower arm through a spacer and an upper arm that is equal to or thicker than the thickness of the lower arm,
The spacer is provided at both ends of the lower arm and the upper arm;
A probe card characterized by
The probe card according to claim 2,
Of the spacers sandwiched between the upper arm and the lower arm, the length of the pedestal side spacer is shorter than the release layer, and the lower arm is longer than the upper arm,
A probe card characterized by
The probe card according to any one of claims 1 to 3,
The release layer has a smaller area than the joint between the base and the substrate;
A probe card characterized by
The probe card according to any one of claims 1 to 4,
The release layer is a conductive metal material;
A probe card characterized by
The probe card according to claim 5, wherein
The release layer is a softer material than the material of the arm and the pedestal;
A probe card characterized by
The probe card according to claim 6, wherein
The metal material of the release layer is gold, silver or copper;
A probe card characterized by
The probe card according to any one of claims 1 to 7,
The replacement probe is bonded to the base by forming a release layer by a flip chip mounting method,
A probe card characterized by
The probe card according to claim 8, wherein
The flip chip mounting method is either a solder bonding method, a stud bump bonding method or an ultrasonic bonding method,
A probe card characterized by
The probe card according to claim 8, wherein
The flip chip mounting method is to form a peeling layer with gold plating on the bonding surface and bond at room temperature by plasma irradiation.
A probe card characterized by