JP3754160B2 - Inspection head - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an inspection head used for an electrical characteristic test of a flat inspection object such as an integrated circuit.
[0002]
[Prior art]
An integrated circuit on a semiconductor wafer, an integrated circuit separated from a semiconductor wafer into a chip (IC chip), and an integrated circuit that has been mounted on a chip are subjected to an energization test (electric Characteristic test). This type of test or inspection is generally performed using a test head or inspection head called a probe card, probe boat or the like.
[0003]
As shown in FIGS. 5 and 6, this type of conventional inspection head 70 has a needle presser 76 assembled to a wiring board 74 having an opening 72 in the center, and an electric terminal portion, that is, an electrode pad of an integrated circuit is energized. A plurality of probes 78, 80, 82 connected in a possible state are supported by the needle presser 76 in a cantilever shape with an adhesive 84. In addition, since there are many electrode pads provided in the integrated circuit, as shown in FIG. 5, the probes 78, 80, and 82 are assembled to the substrate 74 in multiple layers (instead of the height position with respect to the substrate).
[0004]
One or more layers of the probes 78 close to the substrate 74 are used as a first power / ground probe connected to one of the power source and ground, and one or more layers of the probes 80 far from the substrate 74 are connected to the power source and ground. Are used as a second power source / grounding probe connected to the other of the two, and each probe 82 in the intermediate layer is used as a signal probe to which a signal is supplied.
[0005]
The substrate 74 includes first and second connection portions 86 and 88 that continuously and coaxially extend around the opening, and a plurality of third spaces spaced circumferentially around the first and second connection portions. The connection portion 90 is provided on the lower surface. The first power / ground probe 78 is soldered to the first connection portion 86, the second power / ground probe 80 is soldered to the second connection portion 88, and the signal probe 82 is connected to the third connection portion 86. Soldered to the connecting portion 90.
[0006]
However, the conventional inspection head 70 has a third probe for the signal probe 82, although the signal probe 82 is disposed between the first and second power / ground probes 78 and 80. The second connecting portion 90 is disposed outside the first and second connecting portions 86 and 88, so that the second power source / grounding probe 80 disposed below the signal probe 82 is connected to the second connecting portion. When soldering to 88, the second power / ground probe 80 must cross the signal probe 82. The same applies to the case where the first and second connection portions 86 and 88 are formed outside the third connection portion 90.
[0007]
As described above, if the power / ground probe and the signal probe are crossed, the characteristic of the measurement signal deteriorates, so that an accurate inspection cannot be performed, and the clear land between adjacent probes decreases. Therefore, the operation of assembling the probe to the needle presser and the connection portion becomes complicated, and there is a possibility that the probes 80 and 82 may come into contact with each other by repeating so-called overdrive that slightly presses the electrode pad of the integrated circuit against the needle tip. These problems are more likely to occur as the number of probes crossing one probe increases as shown in FIG.
[0008]
[Problems to be solved]
An object of the present invention is to enable connection so that a probe in a layer near or far from a substrate and a probe in an intermediate layer do not cross each other.
[0009]
[Solution, action, effect]
The inspection head of the present invention includes a substrate having an opening at the center and a plurality of probes assembled to the substrate in at least three layers. The substrate is disposed between the first connection portion extending continuously around the opening, the second connection portion extending continuously around the first connection portion, and the first and second connection portions. And a plurality of third connecting portions formed at intervals in the direction. Each probe is connected to the first, second or third connection.
[0010]
For example, as a power source / grounding probe, a probe in a layer close to the substrate and a probe in a layer far from the substrate are electrically connected to the first and second connection portions on the inner and outer sides, respectively, and the other probes are used for signals It can be electrically connected to the intermediate second connection portion. Therefore, according to the present invention, it is possible to prevent the probe in the layer close to or far from the substrate from intersecting with the probe in the intermediate layer.
[0011]
Preferably, at least one probe in a layer close to the substrate, a probe in the middle layer and at least one probe in a layer far from the substrate are connected to the inner, middle and outer connections, respectively. In this way, it is not necessary to cross the probe of the layer close to or far from the substrate with the probe of the intermediate layer.
[0012]
Of the probes in the layer close to the substrate, the remaining probes not connected to the first connecting portion are electrically connected to the third connecting portion, and among the probes in the layer far from the substrate, the second connecting portion is connected. The remaining probes that are not connected to are preferably electrically connected to the third connection. In this way, a part of the probes used for signals can be arranged in a layer close to the substrate and a layer far from the substrate, and the probes can be arranged with a high density accordingly.
[0013]
The first or second connecting portion has a pair of coaxially arranged annular portions, and the inner annular portion has a plurality of outward protruding portions protruding outward at intervals in the circumferential direction, The outer annular portion has a plurality of inward projecting portions that project inwardly and between adjacent outward projecting portions at intervals in the circumferential direction, and is connected to the first or second connecting portion. Each probe may be coupled to the protrusion. In this way, a probe in a layer close to the substrate or a probe in a layer far from the substrate can be coupled to the protruding portion by soldering or the like. Therefore, the first or second connecting portion has such a protruding portion. The width dimension of the first or second connecting portion is smaller than that formed by a pair of annular portions that are not.
[0014]
In a preferred embodiment, the first, second and third connecting portions are formed on the surface of the substrate on the probe side. Further, the substrate has a plurality of lands electrically connected to the second connection portion.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
1 to 4, an inspection head 10 is an inspection head called a probe card, a probe boat, or the like, and is used for an electrical characteristic test of a flat inspection object such as an integrated circuit. Used. The device under test may be any of an integrated circuit formed on a semiconductor wafer, an integrated circuit chip that has been cut, and an integrated circuit that has been mounted, or a liquid crystal display panel. However, the inspection head 10 is suitable for inspection of an object to be inspected in which electrode portions, that is, electrode pads, are arranged at high density.
[0016]
The inspection head 10 includes a disk-shaped substrate 12, a needle presser 14 assembled to the substrate 12, and a plurality of layers supported in a cantilevered manner on the needle presser 14 so as to extend in the radial direction of the substrate 12. Of probes 16, 18, and 20. Instead of assembling the needle presser 14 directly to the substrate 12, the needle presser 14 may be assembled indirectly to the substrate 12 via an appropriate means such as a support plate.
[0017]
The substrate 12 can be made of an electrically insulating material such as ceramic or synthetic resin. The substrate 12 has an opening 22 through which the object to be inspected can be seen at the center, and has a downward stepped portion or notch 24 around the opening 22 for receiving the needle presser 14. The opening 22 and the notch 24 have a shape similar to the planar shape of the object to be inspected, and have a substantially rectangular shape in the illustrated example. The opening 22 is a through hole that penetrates the substrate 12 in the thickness direction. The notch 24 is a step formed on the lower surface and the inner surface forming the opening 22, and has approximately the same size as the needle presser 14.
[0018]
The substrate 12 includes a first connection portion 26 that continuously extends around the opening 22, a second connection portion 28 that continuously extends around the first connection portion, and first and second connection portions. 26, 28 and a plurality of third connection portions 30 formed in multiples (double in the illustrated example) at intervals in the circumferential direction, and around the notches 24 at intervals in the circumferential direction. A wiring board having a plurality of wiring portions (not shown) extending in a radial direction. The connection parts 26, 28, 30 and the wiring part are formed of a conductive material.
[0019]
The first, second and third connecting portions 26, 28 and 30 and the wiring portion are part of a wiring pattern formed on the substrate 12 by a printed wiring technique. The substrate 12 has a plurality of terminal portions, that is, lands 32 connected to electric circuits for energization and signal processing at the peripheral portion of the upper surface. The first, second, and third connection portions 26, 28, and 30 are electrically connected to the land 32 by a wiring portion.
[0020]
The first, second and third connecting portions 26, 28 and 30 are formed on the lower surface of the substrate 12. On the other hand, the wiring part is formed on the upper surface or the lower surface of the substrate. However, the substrate 12 may have a multilayer structure having a wiring portion formed in a multilayer on an electrically insulating film-like plate material by a wiring technique at an intermediate portion in the thickness direction. Moreover, the film-like member in which the wiring portion is formed and the film-like member in which the connection portion is formed may be disposed on the upper surface and the lower surface of the substrate, respectively.
[0021]
The needle presser 14 is made of an electrically insulating material such as ceramic in the shape of a square frame, and supports the probes 16, 18, and 20 at portions corresponding to the sides of the square. The opening 34 on the inside of the needle presser 14 is a substantially quadrangle having substantially the same size as the opening 22 of the substrate 12. The lower end portion of the needle presser 14 protrudes downward from the lower surface of the substrate 12.
[0022]
In the illustrated example, the needle presser 14 is attached to the notch 24 of the substrate 12 with an adhesive. However, the needle presser 14 may be detachably attached to the substrate 12 with a plurality of screw members. Further, instead of assembling the needle presser 14 directly to the substrate 12, the needle presser 14 may be indirectly attached to the substrate 12 via an appropriate means such as a reinforcing plate or a mounting plate. Further, a part of the substrate 12 may be used as the needle presser 14.
[0023]
The probes 16, 18, and 20 are formed of conductive metal fine wires having a circular cross section, and are connected to the needle main body supported by the needle presser 14, the distal end side of the needle main body, and the needle main body. It has a needle tip portion bent to the side opposite to the substrate (downward) and a needle rear portion following the rear end side of the needle main portion. Each probe has a tapered portion that becomes narrower from the tip side of the needle main body to the tip of the needle. The lengths of the taper portions of all the probes are substantially the same in the illustrated example, but may be different.
[0024]
The probes 16, 18, and 20 extend in the width direction of the needle presser 14 at intervals in a direction along the corresponding side at a portion corresponding to the square side formed by the needle presser 14 and the opening 34. It is attached to the lower side of the needle presser 14 by an appropriate mounting means 36 such as an electrically insulating adhesive at a portion having the same diameter dimension of the main body. The probes 16, 18, and 20 have a multilayer structure (four layers in the illustrated example) by changing the height position with respect to the substrate 12.
[0025]
In the illustrated example, the probe 16 is located near the substrate 12 (upper layer), the probe 18 is located far from the substrate (lower layer), and the probe 20 is between the probes 16 and 18. Has been placed.
[0026]
In the example shown in the figure, the probe 20 is shown as being arranged in the structure of a plurality of layers (two layers in the example shown) in the middle, but it may be arranged in a structure of one layer. In the illustrated example, the probes 16, 18, and 20 are arranged so that the needle tips are on a virtual straight line, but the needle tips are different in the radial direction of the substrate 12 (that is, zigzag). You may arrange as follows.
[0027]
The first connection portion 26 has a pair of annular portions 38 and 40 arranged coaxially. The outer edge portion of the inner annular portion 38 is formed in a zigzag shape by a plurality of rectangular outward protruding portions 42 protruding outward at intervals in the circumferential direction. On the other hand, the inner edge portion of the outer annular portion 40 is formed in a zigzag shape by a plurality of rectangular inward protruding portions 44 protruding inward at intervals in the circumferential direction. The inward projecting portion 44 projects between the adjacent outward projecting portions 42.
[0028]
Similarly, the second connecting portion 28 has a pair of coaxially arranged annular portions 46 and 48, and the outer edge of the inner annular portion 46 projects outwardly with a spacing in the circumferential direction. The plurality of rectangular outward projections 50 are formed in a zigzag shape, and the inner edge of the outer annular portion 48 has a plurality of rectangular inward projections projecting inward at intervals in the circumferential direction. 52 is a zigzag shape. The inward protruding portion 52 protrudes between the adjacent outward protruding portions 50.
[0029]
The plurality of probes 16 in the upper layer are coupled to the protrusions 42 or 44 of the inner first connection portion 26 by soldering, and the remaining probes 16 in the upper layer are coupled to the third connection portion 30 in the middle by soldering. Has been. The plurality of lower-layer probes 18 are coupled to the protrusions 50 or 52 of the second outer connection portion 28 by soldering, and the remaining lower-layer probes 18 are coupled to the third connection portion by soldering. . The probe 20 is coupled to the third connection portion 30 by soldering.
[0030]
As a result, the probe connected to the first and second connection portions 26 and 28 does not intersect the probe connected to the third connection portion 30, so that the probe is connected to the first and second connection portions 26 and 28. The probe connected to the power supply circuit can be used for power supply and grounding, and the probe connected to the third connection portion 30 can be used for signal connection by connecting to the energization circuit.
[0031]
The inspection head 10 includes a needle presser 14 and a plurality of probes 16, 18, 20 by attaching a predetermined number of probes 16, 18, 20 to a predetermined position of the needle presser 14 using a predetermined jig. Can be manufactured by attaching a needle presser 14 to the substrate 12 and soldering each probe to a predetermined connecting portion.
[0032]
The probes 16, 18, and 20 are attached to the needle presser 14 by appropriate mounting means 36 in a state where all the probes 16, 18, and 20 are maintained in a predetermined arrangement pattern and in a predetermined state by an appropriate jig. it can. The needle presser 14 can be fitted into the notch 24 of the substrate 12 from below and attached to the substrate 12 with an adhesive (or a screw member).
[0033]
The inspection head 10 is assembled to the inspection apparatus so that the probe tips of the probes 16, 18, and 20 are on the side of the object to be inspected. For this reason, in the inspection head 10, the probes 16, 18, and 20 are on the lower side, the upper side, the lateral side, the front side, and the rear side depending on the type of the inspection device to which the substrate is mounted, It is assembled to the inspection device so as to be in any state of horizontal, vertical and diagonal.
[0034]
At the time of inspection, the probe soldered to the first and second connection portions 26 and 28 is connected to the power supply circuit, and the probe soldered to the third connection portion 30 is connected to the energizing circuit. Further, the probe tips of the probes 16, 18, and 20 are slightly pressed against the electrode pads of the device under test by relatively moving the head 10 and the device under test. Due to this overdrive action, the probes 16, 18, and 20 are bowed. As a result, a predetermined needle pressure acts between the needle tips of the probes 16, 18, and 20 and the electrodes of the object to be inspected, and a predetermined amount of slipping or rubbing occurs. By such a rubbing action, the electrically insulating oxide film on the surface of the electrode pad is surely peeled off, and the needle tip and the electrode pad are securely connected electrically.
[0035]
According to the inspection head 10, a plurality of third connection portions 30 spaced in the circumferential direction are formed between the first and second connection portions 26 and 28, and a layer close to the substrate 12 and an intermediate layer are formed. And the far layer probes 16, 20 and 18 are connected to the inner, middle and outer connections 26, 30 and 28, respectively, so that the probe layer 16 or 18 near or far from the substrate 12 is connected to the middle layer. There is no need to cross the probe 20.
[0036]
As a result, the following advantages are produced. That is, first, since the deterioration of the characteristic of the measurement signal due to the presence of the intersecting probes does not occur, an accurate inspection can be performed. Second, since the clearance between adjacent probes does not decrease, the work of assembling the probe to the needle presser and the connection portion is facilitated. Third, even if each probe is repeatedly subjected to an overdrive action, there is no possibility that the probe will come into contact.
[0037]
According to the inspection head 10, the connection portions 26 and 28 each have a pair of annular portions arranged coaxially, and the outward protrusions and the inward protrusions are alternately arranged in the circumferential direction. Since the annular portion is formed and the power source / ground probe is coupled to the protruding portion, compared to the case where the connecting portions 26 and 28 are formed by a pair of annular portions having no such protruding portion, The width dimension of the connection parts 26 and 28 becomes small.
[0038]
In the above embodiment, the upper and lower probes are each arranged in one layer, but the upper and lower probes may be arranged in a multi-layer structure. In this case, instead of connecting one or more probes in the layer closest to the substrate and one or more probes in the layer farthest from the substrate to the inner first connection and the outer second connection, respectively, for example to the substrate One or more probes in the second closest layer and one or more probes in the layer furthest from the substrate may be connected to the inner first connection and the outer second connection, respectively.
[0039]
The present invention is not limited to the above embodiments. For example, instead of using one needle press according to the arrangement pattern of the electrode pads of the object to be inspected, the needle presser is divided into a plurality of needle pressers, and these needle pressers are attached to a common mounting frame as a screw member. You may attach by the appropriate stop means. The cross-sectional shape of the probe can be an arbitrary shape such as a circle or a polygon.
[Brief description of the drawings]
FIG. 1 is a plan view showing an embodiment of an inspection head according to the present invention.
FIG. 2 is an enlarged cross-sectional view taken along line 2-2 in FIG.
3 is an enlarged sectional view of a part of the substrate of the inspection head shown in FIG. 2;
FIG. 4 is an enlarged bottom view of a part of the center side of the substrate.
FIG. 5 is a cross-sectional view similar to FIG. 3, in which a part of a conventional inspection head is enlarged.
6 is a bottom view similar to FIG. 4, in which a part of the center side of the substrate of the conventional inspection head shown in FIG. 5 is enlarged.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Inspection head 12 Substrate 14 Needle presser 16, 18, 20 Probe 22 Substrate opening 24 Substrate notch 26, 28, 30 First, second, third connection 36 Probe mounting means 38, 40, 46, 48 Annular part 42, 44, 50, 52 Protruding part

Claims (2)

  An inspection head for use in an electrical characteristic test of a flat object to be inspected, comprising: a substrate having an opening in the center; and a plurality of probes assembled in at least three layers on the substrate; A first connection for one of the power supply and ground, extending continuously around the opening, and a second connection for the other of the power supply and ground, extending continuously around the first connection And a plurality of third connection portions for signals, which are formed between the first and second connection portions and spaced in the circumferential direction, and are close to the substrate. At least one probe is electrically connected to the first connection portion, and the remaining probes in a layer close to the substrate are connected to one of the first connection portion and the third connection portion. Connected and few layers far from the substrate One probe is electrically connected to the second connection portion, and the remaining probes in the layer far from the substrate are connected to either the second connection portion or the third connection portion. An inspection head, wherein the probe of the intermediate layer is electrically connected to the third connection portion.   The first or second connecting portion has a pair of coaxially arranged annular portions, and the inner annular portion has a plurality of outward projecting portions projecting outward at intervals in the circumferential direction. The outer annular portion has a plurality of inward projecting portions projecting inwardly between the adjacent outward projecting portions at intervals in the circumferential direction, and is connected to the first or second connection portion The inspection head according to claim 1, wherein each probe that is connected is coupled to the protrusion.

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