Patent Description:
An electrical connecting device including probes is used to measure the characteristics of an integrated circuit and the like in a state of not being separated from a wafer. The inspection by use of the electrical connecting device is made such that one ends of the respective probes are brought into contact with pads for measurement of an inspection object, while the other ends of the respective probes are brought into contact with terminals (referred to below as "lands") provided on a wired substrate. The lands are electrically connected to a measurement device such as a tester. A current is caused to flow through the inspection object via the probes so as to inspect the electrical characteristics of the inspection object.

The inspection using the probes needs to ensure the electrical connection of the inspection object and the lands with the probes. This requires the probes to be designed to simultaneously achieve a probe load corresponding to a material used for the pads for measurement and a stroke amount sufficient to avoid an influence by variation in height of the pads for measurement so as to obtain a stable contact resistance between the pads for measurement of the inspection object and the probes. For example, overdrive (OD) is applied so as to strongly press the probes against the inspection object, or the probes are elastically deformed so as to apply a preload to the probes and the lands. Another structure is known in which probes are provided with slit-shaped cuts on side surfaces to form elastically-deformable spring parts (refer to Patent Literature <NUM>). <CIT> relates to inspection probes and probe cards. It discloses subject-matter according to the preamble of claim <NUM>.

The entire length of the probes is inevitably increased if a length of the spring parts, for example, is increased so as to ensure the electrical connection of the inspection object and the lands with the probes. The increase in the entire length of the probes impedes the measurement of the high-frequency characteristics of the inspection object with a high accuracy.

In response to this issue, the present invention provides an electrical connecting device capable of ensuring a stable electrical connection between an inspection object and probes and measuring the high-frequency characteristics of the inspection object with a high accuracy.

An aspect of the present invention provides an electrical connecting device according to claim <NUM>.

The present invention can provide the electrical connecting device capable of ensuring a stable electrical connection between the inspection object and the probe and measuring the high-frequency characteristics of the inspection object with a high accuracy.

Embodiments of the present invention are described below with reference to the drawings. The same or similar elements illustrated in the drawings are denoted below by the same or similar reference numerals. It should be understood that the drawings are illustrated schematically, and the proportions of the length and the thickness of the respective elements in the drawings are not drawn to scale. It should also be understood that the dimensional relationships and proportions between the respective drawings can differ from each other.

An electrical connecting device according to a first embodiment of the present invention includes an insulating probe <NUM> and a conductive probe <NUM> each having a stick-like shape, and a probe head <NUM> that holds the insulating probe <NUM> and the conductive probe <NUM>, as illustrated in <FIG>. The insulating probe <NUM> and the conductive probe <NUM> are also collectively referred to below as "probes". The electrical connecting device illustrated in <FIG> is a vertical operation-type probe card used for measuring the electrical characteristics of an inspection object <NUM>, in which one ends of the respective probes are brought into contact with pads for measurement (not illustrated) of the inspection object <NUM> when measured. <FIG> illustrates a state in which the probes are not in contact with the inspection object <NUM>. The other ends of the probes are in contact with lands <NUM> provided on a printed substrate <NUM>. The lands <NUM> are electrically connected to a measurement device such as a tester (not illustrated), so that the electrical connecting device is used for determining the electrical characteristics of the inspection object <NUM>.

The insulating probe <NUM> includes a tubular barrel <NUM>, a bottom-side plunger <NUM>, and a top-side plunger <NUM>. As indicated by the arrows in <FIG>, a proximal end part of the bottom-side plunger <NUM> is inserted to one end of the barrel <NUM>, and a proximal end part of the top-side plunger <NUM> is inserted to the other end of the barrel <NUM>. The bottom-side plunger <NUM> and the top-side plunger <NUM> are joined with the barrel <NUM> by caulking or an adhesive for example.

The barrel <NUM> is provided with spiral slits penetrating the side surface. The regions provided with the slits serve as spring parts so as to allow the insulating probe <NUM> to flexibly extend and contract in the axial direction. Upon the measurement of the inspection object <NUM>, a tip end part of the insulating probe <NUM> is fixed to the land <NUM>, while the insulating probe <NUM> extends and contracts such that the other tip end part of the insulating probe <NUM> in contact with the inspection object <NUM> moves in the axial direction.

The bottom-side plunger <NUM> and the top-side plunger <NUM> are electrically connected together inside the barrel <NUM>. For example, as illustrated in <FIG>, the proximal end part of the bottom-side plunger <NUM> and the proximal end part of the top-side plunger <NUM> are each formed to have a semicircular notch. The bottom-side plunger <NUM> and the top-side plunger <NUM> slide inside the barrel <NUM> while the flat surfaces of the respective notches are in contact with each other. In other words, the side surfaces of the respective proximal end parts opposed to each other serve as a current path between the bottom-side plunger <NUM> and the top-side plunger <NUM>. The bottom-side plunger <NUM> and the top-side plunger <NUM> are coated with insulating material <NUM> at the parts each opposed to the barrel <NUM> so that the bottom-side plunger <NUM> and the top-side plunger <NUM> are electrically insulated from the barrel <NUM>. For example, the surfaces of the bottom-side plunger <NUM> and the top-side plunger <NUM> are coated with the insulating material <NUM> excluding the parts in contact with the pads for measurement of the inspection object <NUM>, the parts in contact with the lands <NUM>, and the flat surfaces of the notches at the proximal end parts.

<FIG> is a diagram illustrating an electrical configuration of the insulating probe <NUM>. <FIG> indicates a resistor R111 that is an electric resistor corresponding to the tip end part of the bottom-side plunger <NUM>, and a resistor R112 that is an electric resistor corresponding to the proximal end part of the bottom-side plunger <NUM>. <FIG> also indicates a resistor R121 that is an electric resistor corresponding to the tip end part of the top-side plunger <NUM>, and a resistor R122 that is an electric resistor corresponding to the proximal end part of the top-side plunger <NUM>. <FIG> also indicates a resistor R130 that is an electric resistor corresponding to a part of the barrel <NUM> excluding the spring parts, a resistor R131 that is an electric resistor corresponding to the spring part on the bottom side of the barrel <NUM>, and a resistor R132 that is a resistor corresponding to the spring part on the top side of the barrel <NUM>.

A Ag-Pd-Cu material is used for the bottom-side plunger <NUM> and the top-side plunger <NUM>, for example. A Ni material is used for the barrel <NUM>, for example.

The conductive probe <NUM> in the electrical connecting device illustrated in <FIG> has a configuration, for example, in which a proximal end part of a bottom-side plunger <NUM> is inserted to one end of a barrel <NUM>, and a proximal end part of a top-side plunger <NUM> is inserted to the other end of the barrel <NUM>, as illustrated in <FIG>. A tip end part of the bottom-side plunger <NUM> is brought into contact with the pad for measurement of the inspection object <NUM>, and a tip end part of the top-side plunger <NUM> is brought into contact with the land <NUM>. The bottom-side plunger <NUM> and the top-side plunger <NUM> are electrically connected to the barrel <NUM>. The conductive probe <NUM> thus has a conductivity continuously between the one end in contact with the inspection object <NUM> and the other end connected to the land <NUM>. The bottom-side plunger <NUM> and the top-side plunger <NUM> are joined with the barrel <NUM> by caulking or an adhesive, or by spot welding, for example. The barrel <NUM> is provided with spring parts of spiral slits, so as to allow the conductive probe <NUM> to flexibly extend and contract in the axial direction.

<FIG> is a diagram illustrating an electrical configuration of the conductive probe <NUM>. A resistor R211 is an electric resistor corresponding to the tip end part of the bottom-side plunger <NUM>, and a resistor R212 is an electric resistor corresponding to the proximal end part of the bottom-side plunger <NUM>. A resistor R221 is an electric resistor corresponding to the tip end part of the top-side plunger <NUM>, and a resistor R222 is an electric resistor corresponding to the proximal end part of the top-side plunger <NUM>. A resistor R230 is an electric resistor corresponding to a part of the barrel <NUM> excluding the spring parts, a resistor R231 is an electric resistor corresponding to the spring part on the bottom side of the barrel <NUM>, and a resistor R232 is a resistor corresponding to the spring part on the top side of the barrel <NUM>.

The probe head <NUM> includes a plurality of guide plates arranged in the axial direction of the insulating probe <NUM> and the conductive probe <NUM>, and holds the insulating probe <NUM> and the conductive probe <NUM> penetrating through guide holes provided in the respective guide plates. The probe head <NUM> illustrated in <FIG> includes, as the respective guide plates, a bottom guide plate <NUM> arranged on the bottom side located toward the inspection object <NUM>, a top guide plate <NUM> arranged on the top side located toward the printed substrate <NUM>, and a middle guide plate <NUM> interposed between the bottom guide plate <NUM> and the top guide plate <NUM>. The bottom-side plunger <NUM> of the insulating probe <NUM> and the bottom-side plunger <NUM> of the conductive probe <NUM> penetrate through the bottom guide plate <NUM>. The top-side plunger <NUM> of the insulating probe <NUM> and the top-side plunger <NUM> of the conductive probe <NUM> penetrate through the top guide plate <NUM>. The barrel <NUM> of the insulating probe <NUM> and the barrel <NUM> of the conductive probe <NUM> penetrate through the middle guide plate <NUM>. <FIG> illustrates the case in which the middle guide plate <NUM> of the probe head <NUM> includes a first middle guide plate <NUM>, a second middle guide plate <NUM>, and a third middle guide plate <NUM>.

The probe head <NUM> includes a combined guide plate 30A having a structure as illustrated in <FIG> as at least one of the guide plates. The combined guide plate 30A has the structure in which a conductive region <NUM> made of a conductive material and an insulating region <NUM> made of an insulating material are arranged adjacent to each other in a planar view. The conductive material to be used is a metallic material such as copper or stainless steel. The insulating material to be used is a ceramic material, for example. The conductive region <NUM> is manufactured by electroforming or extension processing, guide holes <NUM> is provided by etching or laser processing, for example.

The conductive region <NUM> may be entirely made of the conductive material in the combined guide plate 30A as illustrated in <FIG>, for example. Alternatively, only a part of the combined guide plate 30A in the thickness direction may be provided with the conductive region <NUM> as illustrated in <FIG>.

The insulating probe <NUM> is held by the probe head <NUM> in the state in which the barrel <NUM> of the insulating probe <NUM> penetrates through the conductive region <NUM>. The barrel <NUM> of the insulating probe <NUM> penetrates through the guide hole <NUM> provided in the conductive region <NUM>. The shape of the conductive region <NUM> in a planar view is determined as appropriate, and the conductive region <NUM> is arranged in a region in which the insulating probe <NUM> penetrates through the combined guide plate 30A. The conductive probe <NUM> is held by the probe head <NUM> in the state in which the barrel <NUM> penetrates through the guide hole <NUM> provided in the insulating region <NUM>.

The plural guide plates including the combined guide plate 30A and the insulating guide plate 30B entirely made of the insulating material can be arranged in the axial direction of the probes to form the probe head <NUM>. The combined guide plate 30A may be used as a part of the guide plates included in the probe head <NUM>, and the insulating guide plate 30B may be used as the other guide plates. <FIG> illustrates an example of the probe head <NUM> having a structure in which the combined guide plates 30A and the insulating guide plates 30B are alternately arranged and stacked on one another. The present embodiment may determine as appropriate which guide plate is replaced with the combined guide plate 30A in the plural guide plates. At least one combined guide plate 30A only needs to be used in the guide plates included in the probe head <NUM>. The insulating guide plate 30B is made of a ceramic material, for example.

<FIG> illustrates a case in which the probe head <NUM> including both the combined guide plate 30A and the insulating guide plate 30B holds the insulating probe <NUM> and the conductive probe <NUM>. The combined guide plate 30A is used as the top guide plate <NUM> and as the first middle guide plate <NUM> of the middle guide plates <NUM> closest to the bottom guide plate <NUM>. The insulating guide plate 30B is used as the bottom guide plate <NUM>, the second middle guide plate <NUM>, and the third middle guide plate <NUM>. The combined guide plate 30A may be used for all of the middle guide plates <NUM>.

The insulating probe <NUM> is connected to the pad for measurement to which a high-frequency signal of the inspection object <NUM> is transmitted upon the measurement of the inspection object <NUM>. The conductive region <NUM> is set to a ground potential, so that the barrel <NUM> of the insulating probe <NUM> is connected to the ground potential via the conductive region <NUM>. Since the barrel <NUM> connected to the ground potential is configured to be arranged at the circumference of the bottom-side plunger <NUM> and the top-side plunger <NUM> through which the high-frequency signal is transmitted, the insulating probe <NUM> can stably transmit the high-frequency signal regardless of whether the entire length of the probe is increased, for example. The use of the insulating probe <NUM> for the transmission of the high-frequency signal thus can allow the electrical connecting device as illustrated in <FIG> to be suitably used for the measurement including the high-frequency signal. The frequency of the high-frequency signal transmitted through the insulating probe <NUM> is set to about <NUM> to <NUM>, for example. The conductive probe <NUM> is used for the transmission of the electrical signal other than the high-frequency signal, and is used for setting a ground electrode and a power source electrode of the inspection object <NUM> each to a predetermined potential.

For example, the inner wall surface of the guide hole <NUM> provided in the conductive region <NUM> connected to the ground potential is brought into contact with the outer surface of the barrel <NUM> of the insulating probe <NUM>, so that the barrel <NUM> of the insulating probe <NUM> is connected to the ground potential. The insulating probe <NUM> is caused to be bent when brought into contact with the inspection object <NUM>, so as to bring the outer surface of the barrel <NUM> of the insulating probe <NUM> into contact with the inner wall surface of the guide hole <NUM> of the conductive region <NUM>. For example, the combined guide plate 30A is arranged at a part at which the bent amount of the insulating probe <NUM> is large when brought into contact with the inspection object <NUM> and applied with overdrive.

Various kinds of methods can be employed to set the conductive region <NUM> to the ground potential. For example, <FIG> illustrates a case of including a fixing pin 40A penetrating through the conductive region <NUM> and used for fixing the probe head <NUM> to the printed substrate <NUM> and a fixing pin 40B penetrating through the insulating region <NUM>, in which the fixing pin 40A is used for setting the conductive region <NUM> to the ground potential. In particular, the probe head <NUM> is fixed to the printed substrate <NUM> with the fixing pin 40A so as to bring the conductive fixing pin 40A into contact with the ground electrode of the printed substrate <NUM>. The use of the fixing pin 40A penetrating through the conductive region <NUM> allows the conductive region <NUM> to be connected to the ground potential via the fixing pin 40A. The fixing pin 40A is a screw, for example, so as to accurately ensure the electrical connection between the fixing pin 40A and the conductive region <NUM>. <FIG> also illustrates assembly screws <NUM> used for assembling the respective guide plates to form the probe head <NUM>.

As described above, the electrical connecting device according to the first embodiment of the present invention can stably transmit the high-frequency signal due to the insulating probe <NUM> including the barrel <NUM> connected to the ground potential. The insulating probe <NUM> has the structure that can avoid a decrease in the high-frequency characteristics regardless of whether the entire length of the probes is increased. The electrical connecting device as illustrated in <FIG> thus can ensure a stable connection between the inspection object <NUM> and the probes, and can measure the high-frequency characteristics of the inspection object <NUM> with a high accuracy.

The insulating probe <NUM> of the electrical connecting device according to a modified example of the first embodiment includes a tubular intermediate plunger <NUM> having one end to which the proximal end part of the bottom-side plunger <NUM> is inserted and the other end to which the proximal end part of the top-side plunger <NUM> is inserted, as illustrated in <FIG>. The intermediate plunger <NUM> is made of a conductive material, and is arranged inside the barrel <NUM>.

The bottom-side plunger <NUM> and the top-side plunger <NUM> are electrically connected to each other via the intermediate plunger <NUM>. The intermediate plunger <NUM> thus serves as a current path between the bottom-side plunger <NUM> and the top-side plunger <NUM>. The intermediate plunger <NUM> is made of the same material as the bottom-side plunger <NUM> and the top-side plunger <NUM>. The intermediate plunger <NUM> is manufactured by extension processing or electroforming.

A part of the intermediate plunger <NUM> opposed to the barrel <NUM> is coated with an insulating material. This electrically insulates the bottom-side plunger <NUM> and the top-side plunger <NUM> from the barrel <NUM>.

For example, the proximal end part of the top-side plunger <NUM> is inserted to one end of the intermediate plunger <NUM> on the other side on which the bottom-side plunger <NUM> is fixed to bring the intermediate plunger <NUM> into contact with the top-side plunger <NUM>. The proximal end part of the top-side plunger <NUM> is configured to slide inside the intermediate plunger <NUM>, so as to allow the insulating probe <NUM> in contact with the inspection object <NUM> to extend and contract in the axial direction. Alternatively, the proximal end part of the bottom-side plunger <NUM> is inserted to one end of the intermediate plunger <NUM> on the other side on which the top-side plunger <NUM> is fixed to bring the intermediate plunger <NUM> into contact with the bottom-side plunger <NUM>. Alternatively, a spring or the like may be used so as to allow the intermediate plunger <NUM> to flexibly extend and contract in the axial direction. The fixation of the bottom-side plunger <NUM> and the top-side plunger <NUM> with the intermediate plunger <NUM> may be made by spot welding or caulking.

An electrical connecting device according to a second embodiment of the present invention further includes a conductive probe <NUM> that penetrates through the guide hole <NUM> provided in the conducting region <NUM> of the respective combined guide plates 30A and is brought into contact with a ground electrode Pg of the inspection object <NUM>, as illustrated in <FIG> illustrates the ground electrode Pg indicated by the black dot different from the other pads for measurement indicated by the white dots. The conductive probe <NUM> has the same structure as the conductive probe <NUM> having a conductivity continuously from one end to the other end. The conductive probe <NUM> is set to the ground potential via the land <NUM>. For example, the conductive probe <NUM> is connected to a ground potential region of the printed substrate <NUM> prepared for setting the ground electrode of the inspection object <NUM> to the ground potential. The land <NUM> to which the conductive probe <NUM> is connected may be set to the ground potential in accordance with the setting of the measurement device such as a tester.

The electrical connecting device illustrated in <FIG> differs from the first embodiment in connecting the barrel <NUM> of the insulating probe <NUM> to the ground potential by use of the probe for setting the ground electrode Pg of the inspection object <NUM> to the ground potential. The other configurations are the same as those in the first embodiment.

In the electrical connecting device illustrated in <FIG>, the conductive probe <NUM> in contact with the ground electrode Pg of the inspection object <NUM> is brought into contact with the conductive region <NUM>. For example, the conductive probe <NUM> is caused to be bent upon the measurement of the inspection object <NUM> so as to bring the outer surface of the conductive probe <NUM> into contact with the inner wall surface of the guide hole <NUM> of the conductive region <NUM> of the respective combined guide plates 30A. This causes the barrel <NUM> of the insulating probe <NUM> to be connected to the ground potential via the conductive probe <NUM> and the conductive region <NUM>. The high-frequency signal is thus stably transmitted through the insulating probe <NUM> accordingly.

As described above, the electrical conducting device according to the second embodiment leads the barrel <NUM> of the insulating probe <NUM> to be connected to the ground potential via the conductive probe <NUM>. The electrical conducting device thus can ensure the stable connection between the inspection object <NUM> and the probes, and measure the high-frequency characteristics of the inspection object <NUM> with a high accuracy. The other effects are substantially the same as those in the first embodiment, and overlapping explanations are not repeated below.

While the present invention has been described above with reference to the respective embodiments, it should be understood that the present invention is not intended to be limited to the descriptions and the drawings composing part of this disclosure. Various alternative embodiments, examples, and technical applications within the scope of the claims will be apparent to those skilled in the art according to this disclosure.

For example, the ground electrode of the printed substrate <NUM> and the conductive region <NUM> of the combined guide plate 30A may be directly connected to each other via a wire.

Claim 1:
An electrical connecting device used for measuring an inspection object, the device comprising:
an insulating probe (<NUM>) including a tubular barrel (<NUM>), a bottom-side plunger (<NUM>) having a proximal end part inserted to one end of the barrel (<NUM>), and a top-side plunger (<NUM>) having a proximal end part inserted to another end of the barrel (<NUM>), the bottom-side plunger (<NUM>) and the top-side plunger (<NUM>) being electrically connected to each other inside the barrel (<NUM>), the bottom-side plunger (<NUM>) and the top-side plunger (<NUM>) being electrically insulated from the barrel (<NUM>); and
a probe head (<NUM>) including a combined guide plate (30A) characterized in that
the combined guide plate (<NUM>) has a conductive region (<NUM>) made of a conductive material and an insulating region (<NUM>) made of an insulating material arranged adj acent to each other in a planar view, wherein a side surface of the conductive region (<NUM>) and a side surface of the insulating region (<NUM>) face each other and a top surface of the conductive region (<NUM>) and a top surface of the insulating region (<NUM>) are coplanar, the probe head (<NUM>) holding the insulating probe (<NUM>) in a state in which the barrel (<NUM>) penetrates through the conductive region (<NUM>),
wherein the barrel (<NUM>) of the insulating probe (<NUM>) is connected to a ground potential via the conductive region (<NUM>) when the inspection object is measured.