JP2004177176A - Probe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To widen a contact area between a probe and an electrode even when a needle tip is advanced by overdrive. <P>SOLUTION: In this probe, a needle tip part has a face directed to a rear side, to an end face of which a cross portion is linear, in a rear side of a tip part. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a probe used for a current test of an object to be inspected such as an integrated circuit substrate and a display substrate.
[0002]
[Prior art]
2. Description of the Related Art Electrical connection devices such as a probe card, a probe unit, and a probe block are used for a current test of a flat object to be inspected such as an integrated circuit or a display substrate. This type of electrical connection device also uses a plurality of needle-type or blade-type probes as contacts that are pressed against electrodes of the device under test.
[0003]
As one of the probes used in this type of electrical connection device, there is a probe using a needle manufactured in a cylindrical shape from a thin metal wire made of tungsten or a tungsten alloy.
[0004]
A conventional probe of this type includes a needle tip whose tip is pressed against an electrode of an object to be inspected, and a needle main body bent backward with respect to the needle tip. Is attached to an attachment such as a needle holder attached to a support such as a wiring board with an adhesive. As shown in FIG. 7, the tip of the probe tip 72 of the probe 70 is a flat surface 74 parallel to the electrode 78 of the device under test 76.
[0005]
The probe 70 having the above-described tip shape is pressed by the electrode 78 with the flat surface 74 in contact with the electrode 78 of the device under test 76 as shown in FIG. As a result, the probe 70 is subjected to a predetermined overdrive.
[0006]
When the overdrive acts on the probe 70, the probe 70 is elastically deformed in an arc shape at a needle main body (not shown). As a result, the tip of the needle tip 72 moves forward with respect to the electrode 78 as shown in FIG. 7B, and scrapes the oxide film present on the surface of the electrode 78.
[0007]
[Problem to be solved]
However, in the conventional probe 70, since the distal end surface of the needle tip 72 is a flat surface 74 and the needle tip 72 has a circular cross-sectional shape, when the tip of the needle tip 72 advances, The flat surface 74 is inclined with respect to the electrode 78. Therefore, the contact between the needle tip 72 and the electrode 78 becomes a point contact at the location 80.
[0008]
When the contact area between the probe 70 and the electrode 78 is small as described above, the pressing force concentrates on the portion 80 having such a small contact area, and as a result, the electrode 78 and the circuit elements and the like below the electrode 78 are destroyed.
[0009]
An object of the present invention is to increase a contact area between a probe and an electrode even when a needle tip advances by overdrive.
[0010]
[Solutions, actions, and effects]
In the probe according to the present invention, the needle tip has a rearward facing surface at which the intersection with the distal end surface is linear, on the rear side of the distal end.
[0011]
When the needle tip advances due to overdrive, the tip end surface of the needle tip is inclined with respect to the electrode of the test object. However, if the rearward surface where the intersection point with the tip surface of the needle tip is linear is present behind the tip of the needle tip, the contact between the probe and the electrode becomes at least linear contact, and the probe The contact area between the electrode and the electrode increases. As a result, the pressing force is dispersed, and damage to the electrode and the circuit element below the electrode is suppressed.
[0012]
The rearward facing surface may include a flat inclined surface that is closer to the rear side as it is closer to the needle main body. By doing so, since no step is formed at the needle tip, there is no place in the needle tip where the mechanical strength changes rapidly, and as a result, the mechanical strength of the needle tip is not impaired. Can be increased.
[0013]
The needle main body may be bent rearward with respect to the needle tip at an angle of 90 to 140 with respect to the needle tip. Furthermore, the cross-sectional shape perpendicular to the axis of the needle tip may be circular except for the region where the rearward facing surface is formed, and the diameter of the needle tip may be smaller at a position closer to the tip.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Referring to FIGS. 1-3, the probe 10 includes a needle 12 made of a conductive metal wire such as tungsten, an alloy thereof, or the like. The needle 12 includes a needle tip 14 and a needle main body 16 which is bent rearward at a predetermined angle θ1 from the upper end of the needle tip 14 and extends rearward.
[0015]
The needle tip portion 14 and the needle main portion 16 both have a circular cross-sectional area perpendicular to their axes 18 and 20. The angle θ1 between the needle tip section 14 and the needle main body section 16 can be 90 ° to 160 °, preferably 90 ° to 140 °. The diameter of the needle tip 14 is smaller toward the front end (needle tip) 22, but the needle main body 16 has substantially the same diameter.
[0016]
The needle tip 14 has a flat tip end 22 and a flat rearward face 24 at the tip end side, which is closer to the needle main body 16 side (upper side). are doing.
[0017]
In the illustrated example, the rearward facing surface 24 is an inclined surface in which the intersection of the needle tip portion 14 with the flat tip 22 is linear. However, the rearward facing surface 24 may be a surface parallel to the axis 18 of the needle tip 14. The angle θ2 of the rearward face 24 with respect to the axis 18 of the needle tip 14 is an angle at which a linear area 26 is formed between the tip 22 and the inclined face 24.
[0018]
The probe 10 is pressed against the electrode 78 in a state in which the flat tip 22 of the probe tip 14 is in contact with the electrode 78 of the device under test 76 so that the two are in contact with each other. As a result, the probe 10 is subjected to a predetermined overdrive.
[0019]
When an overdrive acts as shown by an arrow in FIG. 1, the probe 10 is elastically deformed in an arc shape at the needle main body 16 as shown by a solid line in FIG. Thereby, as shown by the solid line in FIG. 1, the tip end 22 of the needle tip 16 moves forward with respect to the electrode 78 and scrapes the oxide film present on the surface of the electrode 78.
[0020]
However, in the probe 10, the contact between the probe 10 and the electrode 78 is at least a line contact in the region 26 since the rearward facing surface 24 is located behind the distal end of the needle tip 22. The contact area with the electrode 78 increases. As a result, the damage of the electrode 78 and the circuit element thereunder is suppressed.
[0021]
Further, if the rearward surface 24 is formed as an inclined surface that is closer to the rear of the needle main body 16 (upper side) as in the illustrated example, a step is not formed in the needle tip portion 14, so that mechanical There is no point in the needle tip 14 where the strength changes abruptly, and as a result, the contact area with the electrode 78 can be increased without impairing the mechanical strength of the needle tip 14.
[0022]
At least the probe tip 14 has a circular cross-sectional shape having the same diameter in any direction as shown in FIG. 3 except for the region where the rearward facing surface 24 is formed. However, it may have an elliptical or elliptical cross-sectional shape as shown in FIG. The tip 22 of the needle tip 14 is preferably a flat surface, but may be an arc-shaped projecting surface.
[0023]
5 and 6, the electrical connection device 30 is a probe card using a plurality of probes 10 as described above. The electrical connection device 30 includes a disk-shaped wiring board 32 and a needle holder 34 attached to the lower surface of the wiring board 32.
[0024]
The plurality of probes 10 are attached to the lower surface of the needle holder 34 with an electrically insulating adhesive 36 with an adhesive at an angular interval around the central axis of the wiring board 12.
[0025]
The wiring board 32 has an opening 38 in the center that is larger than the integrated circuit to be inspected, and has a plurality of connection lands 40 corresponding to the probes 10 on the lower surface at angular intervals around the opening 38. Further, a plurality of tester lands 42 electrically connected to the tester are provided on the upper surface of the outer peripheral portion.
[0026]
Each tester land 42 corresponds to the probe 10 and is connected to the connection land 40 of the corresponding probe 10 by an internal wiring (not shown).
[0027]
The needle holder 34 is made of an electrically insulating material so as to extend around the opening 38, and is disposed so as to protrude downward into a recess of the wiring board 32 formed around the opening 38, and Adhered to.
[0028]
In the illustrated example, the wiring board 32 functions as a support for supporting the probe 10, the needle holder 34 functions as a mounting tool for mounting the probe 10 on the wiring board 32, and the connection land 40 supports the probe 10. It functions as a connection member that is electrically connected by a conductive adhesive 44 such as solder.
[0029]
The probe 10 has the needle tip 14 at the position of the opening 38 of the wiring board 32 and is attached to the needle holder 34 with the adhesive 36 in a state where the needle main body 16 extends radially outward. At the rear end of the connection land 40 with an adhesive 44.
[0030]
In the electrical connection device 30, the tip of each probe 10 is pressed against the electrode 78 of the device under test 76, similarly to the conventional probe card. Thus, the overdrive acts on each probe 10. The operation of each probe 10 by this is as described above.
[0031]
The present invention is not limited to the above-described embodiment, and can be variously modified without departing from the gist thereof.
[Brief description of the drawings]
FIG. 1 is a diagram showing one embodiment of a main part of a probe according to the present invention.
FIG. 2 is an enlarged perspective view showing a distal end of a probe tip of the probe shown in FIG. 1;
FIG. 3 is an enlarged view showing a tip of a probe tip of the probe shown in FIG. 1;
FIG. 4 is an enlarged view showing a tip of a probe tip of another probe according to the present invention.
FIG. 5 is a bottom view showing an embodiment of an electrical connection device using the probe of FIG. 1;
FIG. 6 is a diagram showing a mounting state of a probe in the electrical connection device shown in FIG. 5;
7A and 7B are diagrams showing a main part of a conventional probe, in which FIG. 7A shows a state in which a needle tip is brought into contact with an electrode of a device to be inspected, and FIG. 7B shows an overdrive applied to the probe. The figure which shows a state, (C) is a perspective view of a principal part.
[Explanation of symbols]
Reference Signs List 10 Probe 12 Needle 14 Needle tip 16 Needle main part 18, 20 Needle tip and axis 22 of needle main part Tip end 24 of needle tip Backward face 26 Linear area 30 Electrical connection device 76 Inspection object 78 Electrode

Claims (4)

The needle tip includes a needle having a needle tip and a needle main body extending rearward from the needle tip. Have a probe. The probe according to claim 1, wherein the rearward facing surface includes a flat inclined surface that is closer to the rear side toward the needle main body portion. The probe according to claim 1, wherein the needle main body is bent rearward with respect to the needle tip at an angle of 90 ° to 140 ° with respect to the needle tip. The cross-sectional shape perpendicular to the axis of the needle tip is circular except for a region where the rearward facing surface is formed, and the diameter of the needle tip is smaller at a position closer to the tip. The probe according to claim 1.

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