JP6373011B2 - Probe card - Google Patents

Description

  The present invention relates to a probe card.

  The probe card includes a substrate that is electrically connected to the tester device by a signal line or the like, and a needle called a probe that is connected to the substrate and contacts a pad of an LSI chip that is an object to be measured. As types of probe cards, a cantilever type probe card and a vertical type probe card are known.

  Cantilever type probe card is configured as a cantilever with one end of the needle fixed on the outer peripheral side of the board, this needle extending obliquely toward the center of the board, and bent obliquely toward the pad It has a simple structure. For example, Patent Document 1 discloses a cantilever type probe card provided with a probe whose needle diameter becomes narrower toward the distal end side.

  Patent Document 2 discloses a cantilever type probe card in which the tip of a needle penetrates a guide hole provided in a guide plate that regulates the direction in which the needle moves. The guide hole has a long hole shape.

  Further, Patent Document 3 discloses a cantilever type probe card provided with a probe that penetrates through a through hole of a guide sheet and is brought into contact with the tip of a needle pressed against a pad. The through hole of the guide sheet has an inverted conical shape in which the hole area decreases from the upper surface to the lower surface.

  Further, the vertical probe card is attached with a needle that descends vertically from the substrate toward the pad to prevent the needle from slipping in contact with the pad. As an example of a vertical probe card, Patent Document 4 discloses a pin having a curved portion and a tip that is electrically in contact with an electrode of a wafer that is a substrate to be inspected, and a plurality of probe needles are fixed by hanging down. A vertical probe card is disclosed that includes an upper guide plate and a lower guide plate having a guide hole through which the probe needle passes.

JP 2001-108708 A JP 2011-99698 A JP-A-7-183341 Japanese Patent Laid-Open No. 11-038044

  As described above, since the needle of the cantilever type probe card extends obliquely toward the center side of the substrate, it strikes obliquely against the surface of the pad. For this reason, when the needle and the pad come into contact, the needle may slip and exceed a predetermined pad area.

  On the other hand, the vertical probe card does not have the above-mentioned concern, but has a complicated structure in which a needle having a flexible curved portion is passed through both the upper guide plate and the lower guide plate. The work man-hours and member costs in the probe card manufacturing process increase.

  An object of the present invention is to provide a probe card that can prevent a needle tip portion from sliding on the surface of a pad when the cantilever structure is adopted while contacting the pad.

  Another object of the present invention is to provide a cantilever type probe card having a simple structure as compared with a vertical type probe card.

A probe card according to the present invention includes a substrate including wiring connected to an external device, and a guide plate disposed in parallel to the substrate on the lower side of the substrate, and a plurality of circular shapes penetrating perpendicularly to the plate surface A guide plate having a through-hole, a connecting member for connecting the substrate and the guide plate, and one end connected to the needle connecting portion on the outer peripheral side of the substrate and passing through the connecting member toward the center side of the substrate and to stretching, then through the needle intermediate fixing portion, and extends further toward the center side of the substrate, and a plurality of needles having a uniform diameter over the entire length of the one end to the other end, the Each needle is fixed at the needle intermediate fixing portion, a beam portion protruding from the end surface on the center side of the needle intermediate fixing portion, and bent from the tip of the beam portion toward the guide plate, Diameter with clearance between holes set to a predetermined value And a needle tip portion whose tip portion passes perpendicularly through the circular through hole, and the size of the diameter of the needle is set based on the shortest pitch between adjacent needle tip portions, The length of the beam portion from the end face to the tip of the beam portion is set according to a target needle pressure value and a diameter of the needle.

  In the probe card according to the present invention, it is preferable that the length of the beam portion is set shorter as the diameter becomes smaller under the target needle pressure value.

  In the probe card according to the present invention, the needle tip portion has a bent portion between a tip portion of the needle tip portion and a tip end of the beam portion, and extends from the tip of the bent portion to the tip portion. It is preferable that the portion in between is parallel to the penetration direction of the circular through hole.

In the probe card according to the present invention, the connection member may be a needle height adjusting member having a preset needle height dimension between the lower surface of the substrate and the tip of the needle tip portion. preferable.

  In the probe card according to the present invention, it is preferable that the needle intermediate fixing portion is provided on the guide plate or the substrate.

  According to the said structure, the front-end | tip part of a needle-tip part passes through the circular through-hole of a guide plate perpendicularly, and contacts a pad. Thereby, since the front-end | tip part of a needle tip part contacts the surface of a pad substantially or indefinitely, slip of a needle tip part can be suppressed.

  Moreover, according to the said structure, the clearance gap dimension between the front-end | tip part of a needle-tip part and a circular through-hole is set to the predetermined value. Thereby, it can suppress that the front-end | tip part of a needle tip part inclines with respect to the surface of a pad at the time of contact with the pad of a needle tip part, and can suppress the slip of a needle tip part.

  Further, according to the above configuration, the two guide plates of the upper guide plate and the lower guide plate are not used unlike the conventional vertical probe card, and the needle tip portion is passed through the through holes of the plurality of guide plates. Since it is not necessary, the number of members can be reduced and manufacturing can be performed more easily.

It is a side view which shows the probe card of embodiment which concerns on this invention. It is the sectional view on the AA line in FIG. It is a figure which shows another structure. It is a figure which shows another structure. It is a figure which shows another structure.

  Embodiments according to the present invention will be described below in detail with reference to the drawings. Also, in the following, corresponding elements in all drawings are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 1 is a side view of the probe card 10. 2 is a cross-sectional view of the probe card 10 taken along the line AA in FIG. In addition, the partial enlarged view of the dotted line B is shown in the lower right of FIG.

  The probe card 10 has a substrate 12, a guide plate 14 disposed in parallel to the substrate 12 on the lower side of the substrate 12, and one end connected to the outer peripheral side of the substrate 12, and extends toward the center of the substrate 12. The needle 16 further extends toward the center of the substrate 12 via the needle intermediate fixing portion 22. The test head 6 electrically connected to the substrate 12 is not a component of the probe card 10 but is attached to a tester device (not shown). In FIG. 1 and FIG. 2, two axes orthogonal to each other in a plane parallel to the surface of the substrate 12 are an X axis and a Y axis, and an axis perpendicular to the surface of the substrate 12 is a Z axis.

  The substrate 12 is a wiring substrate having a circular or square outer shape. The substrate 12 is made of glass epoxy resin or the like. The substrate 12 has an upper surface on which a plurality of electrodes connected to the test head 6 are arranged, and a lower surface to which a plurality of needles 16 are attached.

  The needle connection pad 20 is disposed at a predetermined position on the outer peripheral side of the lower surface of the substrate 12. The needle connection pad 20 is configured using copper or the like. The needle connection pad 20 is electrically connected to the wiring on the upper surface of the substrate 12 through a conductive member (not shown). One end of a plurality of needles 16 is fixed to the needle connection pad 20.

  The guide plate 14 is a plate member having a circular or square outer shape. The guide plate 14 is disposed in parallel to the substrate 12 on the lower side of the substrate 12. The guide plate 14 is made of a highly insulating material, and is made of, for example, ceramic or glass. The guide plate 14 has a plurality of circular through holes 18 penetrating perpendicularly to the plate surface.

Circular holes 18, having a predetermined diameter d _2. The circular through holes 18 are formed side by side along the Y direction at a predetermined pitch p.

  The needle height adjusting member 19 has an annular outer shape and has a function of connecting the guide plate 14 and the substrate 12. The needle height adjusting member 19 is arranged approximately in the middle between the outer peripheral side and the central side of the substrate 12. The needle height adjusting member 19 is configured by using an insulating material such as epoxy resin, ceramic, or glass.

  The height of the needle height adjusting member 19 is set so that the distance between the lower surface of the substrate 12 and the distal end portion 28 of the needle tip portion 26 is set in advance. The needle height adjusting member 19 has a through hole 17 through which the needle 16 passes. The through-hole 17 may be formed in advance for passing the needle 16 or may be a hole formed as a result when the periphery of the needle 16 is hardened with an epoxy resin.

  The needle 16 is a probe that extends toward the center of the substrate 12 and is bent toward the pad of the LSI chip. The needle 16 is made of a material such as tungsten, beryllium copper, or a noble metal alloy.

The needle 16 has a fixed end that is one end connected to the needle connection pad 20 on the outer peripheral side of the substrate 12 and a needle tip portion 26 that is the other end in contact with the pad of the LSI chip. The needle 16 has a uniform diameter d ₁ over the entire length from one end to the other end. The size of the diameter d ₁ is determined based on the shortest pitch p between adjacent needles 16. Here, the uniform diameter d ₁ means that the needle 16 has the same diameter over the entire length from one end to the other end, but the tip of the needle tip portion 26 conforms to the specifications. Those that change shape and diameter are also included.

  The needle 16 is fixed by a needle intermediate fixing portion 22 and has a beam portion 24 protruding from an end surface on the center side of the substrate 12 among the end surfaces of the needle intermediate fixing portion 22. The needle 16 has a needle tip portion 26 formed by bending from the tip of the beam portion 24 toward the guide plate 14 side. The needle tip portion 26 has a tip portion 28 that passes vertically through the circular through hole 18.

Here, in the needle tip portion 26, the length L of the beam portion 24 from the end surface on the center side of the substrate 12 to the tip of the beam portion 24 among the end surfaces of the needle intermediate fixing portion 22 is the target needle pressure value T _P. It is set according to the diameter d _{1 of the} needle 16. Here, when the deflection amount of the beam portion 24 is δ, E is an elastic coefficient, and the needle pressure is P _n , the deflection amount δ is δ = (P _n × L ³ ) / (3 × E × d ₁ ⁴ Xπ / 64). In this equation, it is understood that the needle pressure P _n is inversely proportional to the cube of the length L when the deflection amount δ, the elastic coefficient E, and the diameter d ₁ are constant. That is, if L is lengthened, the needle pressure P _n decreases, and if L is shortened, the needle pressure P _n increases. Then, under the target needle pressure value T _P , the length L of the beam portion 24 is set shorter as the diameter d ₁ becomes thinner.

The needle intermediate fixing portion 22 is configured by using an insulating material such as epoxy resin, ceramic, or glass. The needle intermediate fixing portion 22 is provided so that the needle pressure P _n can be increased by shortening the length L even when the entire length of the needle 16 is increased. The intermediate needle fixing portion 22 is disposed on the center side of the guide plate 14 and fixes the plurality of needles 16. The needle intermediate fixing part 22 may be arranged on the substrate 12 side. Here, the needle intermediate fixing portion 22 and the needle height adjusting member 19 are described as separate members, but it is also possible to form them integrally.

  Next, the operation of the probe card 10 having the above configuration will be described. In the needle 16 of the probe card 10, the distal end portion 28 of the needle tip portion 26 passes vertically through the circular through hole 18 of the guide plate 14 and contacts the pad. As a result, the tip end portion 28 of the needle tip portion 26 comes into contact with the surface of the pad substantially or indefinitely, so that slipping of the needle tip portion 26 when the tip portion 28 contacts the pad can be suppressed. it can.

  Further, according to the probe card 10, the gap dimension between the distal end portion 28 of the needle tip portion 26 and the circular through hole 18 is set to a predetermined value. Thereby, even when a force that tilts the tip end portion 28 of the needle tip portion 26 is applied when the needle tip portion 26 contacts the pad, the movement of the tip portion 28 is stopped by the circular through hole 18. Therefore, it is possible to suppress the needle tip portion 26 from being inclined with respect to the surface of the pad.

  Further, the probe card 10 does not use the two guide plates of the upper guide plate and the lower guide plate, unlike the conventional vertical probe card, and is configured using only one guide plate 14. . Accordingly, since it is not necessary to pass the needle tip portion 26 through the through holes of the plurality of guide plates, the needle tip portion 26 can be manufactured more easily than the conventional vertical probe card, and the number of members can be reduced. .

In the probe card 10, as described above, the length L of the beam portion 24, under the target needle pressure value T _P, is set shorter as the diameter d ₁ becomes thin. Therefore, the needle pressure P _n of the needle 16 is adjusted to the target needle pressure value by adjusting the length L even when the diameter d ₁ is reduced in order to make the pitch p between the adjacent needle tip portions 26 narrow. can be tailored to the T _P.

  Next, a probe card 10a that is a first modification of the probe card 10 will be described. FIG. 3 is a diagram corresponding to the partially enlarged view of the dotted line B in FIG. 1 in the probe card 10a. A difference between the probe card 10 a and the probe card 10 is a bent portion 25. Hereinafter, this difference will be mainly described.

The bent portion 25 is bent so that the angle formed with the beam portion 24 is a predetermined angle θ ₁ and the angle formed with the distal end portion 28 is a predetermined angle θ ₂ . In general, the shorter the length L of the beam portion 24, the higher the needle pressure when the needle 16 comes into contact with the pad. Therefore, it is preferable that the needle 16 bend easily. Since the probe card 10a is bent as described above, there is an advantage that the probe card 10a is easily bent when the needle 16 comes into contact with the pad as compared with the case where the probe card 10a is not bent. Further, it is possible to make the bending easier by making θ ₂ close to 180 ° or by increasing the length of the needle tip portion 26.

  In the probe cards 10 and 10a, the LSI chip pads are described as being arranged in a line along the Y direction. However, the pads may be arranged in a staggered pattern in two lines. FIG. 4 is a diagram showing a probe card 10b in which pads are arranged in a staggered manner in two rows. In the probe cards 10, 10a, and 10b, when the pads arranged in a staggered manner have a narrow pitch, the needles 16 may be attached in two upper and lower stages as shown in FIG. In such a case, the length of the upper needle 16 from the tip of the beam portion 24 to the tip portion 28 is longer than that of the probe cards 10 and 10a. Occurrence can be suppressed. Moreover, in the probe card 10, although the needle | hook 16 was demonstrated as what is arrange | positioned at 2 sides, as FIG. 2 shows, it is not restricted to this example, For example, you may arrange | position at 4 sides. In the probe card 10, the needle 16 has been described as extending linearly as shown in FIG. 2, but it is also possible to use a probe having a bent shape as shown in FIG. 5.

  6 Test head 10, 10a, 10b Probe card, 12 substrate, 14 guide plate, 16 needles, 17 through holes, 18 circular through holes, 19 needle height adjusting member, 20 needle connection pads, 22 needle intermediate fixing part, 24 Beam part, 25 bent part, 26 needle tip part, 28 tip part.

Claims (5)

A substrate including wiring connected to an external device;
A guide plate disposed parallel to the substrate on the lower side of the substrate, the guide plate having a plurality of circular through holes penetrating perpendicularly to the plate surface;
A connection member for connecting the substrate and the guide plate;
One end is connected to the needle connecting portion on the outer peripheral side of the substrate, extends toward the center side of the substrate via the connecting member , then passes through the needle intermediate fixing portion, and further to the center of the substrate A plurality of needles extending toward the side and having a uniform diameter over the entire length from the one end to the other end;
With
Each needle is
A beam portion fixed at the needle intermediate fixing portion and protruding from an end surface on the center side of the needle intermediate fixing portion;
A needle tip that is bent from the distal end of the beam portion toward the guide plate and has a diameter in which a gap between the circular through hole is set to a predetermined value, and the distal end portion passes through the circular through hole vertically. And
Including
The size of the diameter of the needle is set based on the shortest pitch between adjacent needle tips,
The length of the beam part from the end face of the center side to the tip of the beam part is set according to a target needle pressure value and a diameter of the needle. The probe card according to claim 1,
Under the target stylus pressure value, the length of the beam portion is set shorter as the diameter becomes smaller. In the probe card according to claim 1 or 2,
The needle tip portion has a bent portion between a tip end portion of the needle tip portion and a tip end of the beam portion, and a portion between the tip end of the bent portion and the tip end portion penetrates the circular through hole. A probe card characterized by being parallel to the direction. In the probe card according to any one of claims 1 to 3,
The probe card according to claim 1, wherein the connecting member is a needle height adjusting member having a preset needle height dimension between a lower surface of the substrate and a tip end portion of the needle tip portion. In the probe card according to any one of claims 1 to 4,
The probe card, wherein the needle intermediate fixing part is provided on the guide plate or the substrate.

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