JPH07318587A - Probe card - Google Patents

Abstract

PURPOSE:To provide a probe card where the pressure of a probe needle in cantilever structure in that two rows or more are extended from one side is constant and the deformation of the probe needle between the rows can be suppressed. CONSTITUTION:The title probe card is provided with a plurality of probe needles connected to the printed wiring board of a printed circuit board 12 and a pedestal 14 for holding one end of the probe needles. Each probe needle is brought into contact with a specific electrode pad P of a semiconductor wafer W to perform a specific electrical inspection. First and second supporting parts 21 and 22 for supporting first and second probe needles 151 and 152 at upper and lower parts are provided on the lower surface of the pedestal 14, at the same time two stages of upper and lower supporting parts 21 and 22 are arranged in two rows back and forth in the extension direction of the probe needles, and loose edge lengths l1 and l2 of the first and second probe needles 151 and 152 extended from the two rows of first and second supporting parts 21 and 22 are set equally.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a probe card.

[0002]

2. Description of the Related Art When a large number of IC chips are formed on a semiconductor wafer in a semiconductor process step, individual IC chips of the semiconductor wafer are inspected for electrical characteristics to screen defective products. There is.
A probe device is usually used for this inspection. This probe device is used for individual ICs on a semiconductor wafer.
Each IC chip has basic electrical characteristics by contacting an electrode pad of the chip with a probe needle of a probe card and applying a predetermined voltage from the probe needle to conduct an electrical test such as a continuity test of each IC chip. It is a device that tests whether or not it has a tester.

The above-mentioned probe device has an I
A test head having pin electronics including a sample power source for applying a voltage to the C chip and an input unit for taking the output from the IC chip into the measurement unit, and a probe needle for contacting a predetermined electrode pad on the IC chip. It has a probe card and a connection ring having pogo pins for electrically connecting the test head and the probe needle. Then, such a probe device is provided with a relay substrate such as a linear motherboard or a performance board as required, and the probe card and the tester are electrically connected by these relay substrates. Then, when inspecting the IC chip on the semiconductor wafer, in order to secure the continuity between the probe needle and the electrode pad, the semiconductor wafer is further overdriven, for example, by 100 μm from the contact position between the probe needle and the electrode pad, and each I
The electrical characteristics of the C chip are inspected.

The conventional probe card has, for example, a cantilever structure in which the tips of a plurality of probe needles project obliquely downward from the central opening of the printed circuit board toward the center. In such a cantilever type probe needle, only one row of needle tips protrudes from one side, and the probe needles on both sides simultaneously contact two rows of electrode pads to perform an inspection. However, there is a demand for shortening the inspection time due to an increase in the diameter of semiconductor wafers, and it is necessary to inspect more IC chips at one time. Therefore, even a probe card having a cantilever structure can meet the above-mentioned requirements if two or more rows of probe needles are projected from one side and can be inspected by simultaneously contacting two or more rows of electrode pads on one side.

[0005]

However, in the case of the conventional cantilever type probe card, the upper and lower probe needles are respectively supported even if the probe card has a structure of supporting two rows of probe needles on one side. Since the protruding length from the part to the needle tip is short, the needle pressure on the electrode pad differs between the long needle tip and the short needle tip, with the longer needle needle having a smaller needle pressure and the shorter needle needle having a larger needle pressure. Because,
The long probe needle may not be able to secure the needle pressure necessary for conduction with the electrode, and there is a possibility that an accurate test cannot always be performed.

Further, when the protruding lengths of the needle tips are different as described above, a probe needle with a long protrusion is more likely to be deformed than a short probe needle when caught on the unevenness of an electrode pad or the like, whereby the needle tip is separated from the electrode pad. There has been a problem that the position cannot be accurately inspected due to displacement in the upward direction or the lateral direction. In addition, there is a problem that it is difficult to set the overhanging length of the needle tip and the like under the same conditions.

The present invention has been made in order to solve the above-mentioned problems, and the needle pressure of a probe needle having a cantilever structure protruding from one side in two or more rows is constant, and the difference in deformation of the probe needle between the rows is reduced. The object is to provide a probe card that can be suppressed.

[0008]

A probe card according to the present invention comprises a plurality of probe needles connected to the wiring of a printed circuit board and a pedestal that cantilevers each of these probe needles. In a probe card for performing a predetermined electrical inspection by contacting a predetermined electrode of an inspection object, a plurality of supporting portions for supporting the probe needles at a plurality of upper and lower positions are provided on the lower surface of the pedestal, and a plurality of upper and lower supporting portions are provided. The respective support portions are arranged in a plurality of rows so as to be adjacent to each other in the protruding direction of the probe needles, and the free end lengths of the probe needles protruding from the respective support portions of the plurality of rows are set to be the same.

[0009]

According to the present invention, the tip of the probe needle comes into contact with the electrode of the object to be inspected at the time of inspection, and each probe needle cantilevered by each of the upper and lower support portions of the pedestal is pressed from the object to be inspected. When the electrodes receive stylus pressure in response to the needle pressure, the free end lengths of the upper and lower probe needles projecting from the upper and lower support portions are the same, so that the probe needles in the upper and lower rows are substantially the same with respect to the electrodes. The stylus pressure acts, and it is possible to suppress the difference in deformation between the probe needles in a plurality of rows.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on the embodiments shown in FIGS. The probe device shown in FIG. 1 includes a test head 1 configured to be able to move up and down by a lifting mechanism (not shown), a performance board 2 sequentially arranged in a device body (not shown) below the test head 1, and a performance board 2 of this performance board. A connection ring 4 supported by an insert ring 3 so as to be connected to the connection ring 2, and a probe card 5 of this embodiment arranged below the connection ring 4.

Inside the test head 1, a pin including a power source for a sample for applying a voltage to an IC chip on a semiconductor wafer W as an object to be inspected and an input section for taking an output from the IC chip into a measuring section. The electronics 6 are built in, and the pin electronics 6 are electrically connected to a plurality of electronic component circuits 7 mounted on the performance board 2. These electronic component circuits 7 are
For example, it is configured as various measuring circuits including a matrix relay, a driver circuit, etc., and the connection terminals 8 of the electronic component circuits 7 and the connection ring 4 are provided on the lower surface of the main body of the performance board 2, for example, an epoxy resin substrate 9. For example, they are arranged on four circumferences that are concentric with the substrate 9. In addition, pogo pins 10 corresponding to the connection terminals 8 are formed on the upper surface of the connection ring 4 so as to form concentric circles.
Pogo pins 11 which are arranged on one circumference and which are electrically connected to the respective pogo pins 10 are provided on the lower surface corresponding to the connection terminals of the probe card 5 of the present embodiment described later. As a result, the test head 1 is configured to be electrically connectable to the probe card 5 via the performance board 2 and the connection ring 4.

As shown in FIGS. 2 to 4, the probe card 5 of this embodiment has a printed board 12 formed in a circular shape by an epoxy resin and an elongated shape attached to the upper surface of the printed board 12. The support 13 includes a pedestal 14 directly attached to the lower surface of the support 13 with a heat-resistant thermosetting resin, and a plurality of probe needles 15 fixed and supported by the pedestal 14.

The printed wiring board 1 is mounted on the printed circuit board 12.
6 is formed, and an elongated rectangular opening 1 is formed in the center thereof.
7 are formed. Connection terminals 18 of the printed wiring 16 are provided on the peripheral edge of the opening 17 and the outer peripheral edge of the printed circuit board 12, respectively. The connection terminals 18 on the outer peripheral edge of the printed circuit board 12 are arranged on, for example, four concentric circles as shown in FIG. 2, and are connected to the pogo pins 11 on the lower surface of the connection ring 4 as shown in FIG. ing.

Support 1 for supporting the printed circuit board 12
3 is an elongated rectangular shape made of a highly rigid material having excellent thermal conductivity such as aluminum and copper, and has an opening 17
Is formed so as to cover (see FIGS. 3 and 4). The support 13 has a role of quickly absorbing heat of a pedestal 14 described later and quickly radiating the heat to the outside, and suppressing thermal deformation such as bending of the printed circuit board 12 due to temperature change. Therefore, the support 13 is preferably made of a material having a thermal expansion coefficient as small as possible, and more preferably made of a shape memory alloy.

Further, two rows of through holes 19 are formed in the support 13 in the longitudinal direction, and the heat inside the apparatus main body is radiated to the outside through these through holes 19. It is preferable that all of these through holes 19 are located above the needle tip of the probe needle 15. By providing the through hole 19 at such a position, the heat inside the apparatus main body is externally passed through the through hole 19. Heat is radiated to the probe needle 15, and an ascending air current is generated near the probe needle 15 at this time, so that the temperature rise of the probe needle 15 can be efficiently suppressed. In FIGS. 2 and 4, reference numeral 20 denotes a fastening member such as a bolt for fastening the support 13 to the printed board 12.

The pedestal 14 is made of a heat-resistant material such as ceramics and glass that has an insulating property and a coefficient of thermal expansion as small as possible. Furthermore, this pedestal 14 is
As shown in FIGS. 3 to 5, it is formed to be smaller than the opening 17, and is formed in a size that forms a gap δ between its outer periphery and the edge of the opening 17 when directly attached to the support 13. , And is independent of the printed circuit board 12. Even if the printed circuit board 12 thermally expands, the opening 17 does not come into contact with the pedestal 14 so that the gap δ is not blocked. This pedestal 1
4 and the probe needle 15 have a relationship as shown in FIG.
In FIG. 5, for convenience of explanation, the lower probe needle 15 is described as the first probe needle 151, and the upper probe needle 15 is described as the second probe needle 152.

That is, the probe card 5 of this embodiment is characterized by the relationship between the base 14 and the probe needles 15. On the lower surface of the pedestal 14 of the probe card 5 of the present embodiment, as shown in FIG. 5, first and second upper and lower two-stage first and second probe needles 151 and 152 are supported in a cantilever state at two upper and lower positions, respectively. , Second support portions 21 and 22 are provided, and the support portions 2 in the upper and lower stages are provided.
Nos. 1 and 22 are arranged in two rows one behind the other in the direction in which the probe needles 15 project. And these support parts 2
First and second probe needles 15 supported by 1, 22
Reference numerals 1 and 152 extend inward of the pedestal 14 and obliquely downward. The probe tips of the probe needles 151 and 152 hang down with respect to the electrode pad P, and are in contact with the two rows of electrode pads P on one side substantially perpendicularly. The probe needles 151 and 152 are fixed to the support portions 21 and 22 with a heat-resistant thermosetting resin 23, for example. The thermosetting resin 23 is preferably a resin having excellent heat resistance such as silicone resin. Also, the second probe needle 152 supported by the second support portion 22 is above the first probe needle 151 supported by the first support portion 21, and these two are parallel to each other. Second probe needle 152
Of the first probe needle 151 is extended to the inner side of the pedestal 14 than the tip of the first probe needle 151, and these do not interfere with each other, and there are two rows of IC chips T on one side of the pedestal 14 and four rows of IC chips T on both sides.
(See FIG. 6A) can be inspected at the same time.

Further, the free end length (overhanging length of the first probe needle from the first support portion) l ₁ of the first probe needle 151 protruding from the lower first support portion 21 is equal to the upper second support portion. Free end length of the second probe needle 152 protruding from 22 (length of the second probe needle protruding from the second supporting portion) l
_The bending moment is substantially equal to the probe needles 151 and 152 when the semiconductor wafer W is overdriven on the probe card 5, and as a result, the probe needles 151 and 152 have the same bending moment. Therefore, the stylus pressures applied to the respective electrode pads P are substantially equal. Further, the curved portions 24 and 25 are formed near the bases of the probe needles 151 and 152, and the curved portions 2 and 25 are formed.
Numerals 4 and 25 absorb the expansion and contraction of the printed circuit board 12 due to the temperature change and prevent the probe needles 151 and 152 from being subjected to an excessive force.

The lower first support portion 21 supports both the upper and lower first and second probe needles 151 and 152. That is, the first support portion 21 is the upper second probe needle 15
The lower portion 26 is divided from the pedestal body at a position supporting the second probe needle 1 by the pedestal body and the lower portion 26.
The lower portion 26 is bonded and integrated with the pedestal body by the thermosetting resin 23 so as to sandwich 52. As the first support portion 21, the pedestal body and the lower portion 26 serve as a second support.
In addition to the type in which the probe needle 152 is sandwiched, for example, the first support portion 21 may be provided with a pore penetrating it obliquely, and the second probe needle 152 may be passed through this pore. The former type is preferable in manufacturing.

Now, the alignment mechanism for aligning the semiconductor wafer W with respect to the probe card 5 will be described with reference to FIG. 1 again. A substantially circular stage 27 is provided below the probe card 5 as shown in the figure, and a semiconductor wafer W is held horizontally by a wafer chuck 28 provided on the upper surface of the stage 27. ing. A heating device 29 and a circulation path 30 for a cooling medium are provided as a temperature adjusting mechanism inside the wafer chuck 28, and the heating device 2 is provided as necessary during inspection.
9, the semiconductor wafer W can be heated to, for example, 150 ° C., and the cooling medium flowing through the circulation path 30 can cool the semiconductor wafer W to, for example, −10 ° C.

Further, the stage 27 has a driving mechanism (not shown) for driving the wafer chuck 28 in the horizontal direction, the vertical direction and the θ direction, and when the semiconductor wafer W is aligned, the stage 27 is driven by the driving mechanism. Three
The wafer chuck 28 moves in the X and Y directions on the Nos. 1 and 32, rotates in the θ direction, and further moves up and down. Further, a target plate 33 is attached to the wafer chuck 28, and the target plate 33 and a predetermined IC chip T are detected by the optical image pickup devices 34 and 35 and the capacitance sensor 36 arranged above the target plate 33, The positions of the probe card 5 and the IC chip on the semiconductor wafer W are calculated based on this detection signal. Then, the drive mechanism of the stage 27 is drive-controlled on the basis of this calculation result so that the IC chip to be inspected on the semiconductor wafer W is aligned with the probe card 5.

Next, the operation will be described. For example, 15
When the semiconductor wafer W is electrically inspected at a temperature of 0 ° C., the heating device 29 is operated to heat the semiconductor wafer W, and the temperature is set to 150 ° C., for example, and the temperature is maintained. Then, the target plate 33, the optical imaging device 34,
The stage 27 is driven based on the detection data obtained from the sensor 35 and the capacitance sensor 36, and the semiconductor wafer W is aligned with the probe card 5.

After the alignment is completed, the test head 1 is lowered and the probe card 5 is raised. As a result, the connection terminals 8 on the lower surface of the performance board 2 are electrically connected to the pogo pins 10 on the upper surface of the connection ring 4, and the connection terminals 18 of the probe card 5 are electrically connected to the pogo pins 11 on the lower surface of the connection ring 4. As a result, the pin electronics 6 of the test head 1 and the electronic component circuit 7 of the performance board 2 are electrically connected, and these are electrically connected to the connection terminal 18 of the probe card 5 via the pogo pins 10 and 11 of the connection ring 4. And the pin electronics 6 and the probe needle 15 are brought into a conductive state. Thereafter, the wafer chuck 28 is raised to bring the probe tips of the probe needles 15 into contact with the respective electrodes P of the IC chip T on the semiconductor wafer W, and the wafer chuck 28 is overdriven by a predetermined amount as shown in FIG. The needle 15 and the electrode pad P are brought into a conductive state.

In this state, a predetermined electric signal is transmitted from the test head 1, and the performance board 2 and the connection ring 4 are connected.
When an electric signal is input to the IC chip T via the probe needle 15 and the electrode pad P, an output signal based on this input signal is output from the IC chip T to the pin via the connection ring 4 and the electronic component circuit 7 of the performance board 2. It is taken into the electronics 6 and the IC chip T is electrically inspected. As described above, since the semiconductor wafer W is electrically inspected by the heating device 29 in the wafer chuck 28 at a high temperature of 150 ° C., the IC chip T is electrically inspected with high reliability. be able to.

If the probe card 5 of this embodiment is used, as described above, since it has the probe needles 151 and 152 that contact the electrode pads P in two rows on one side and four rows on both sides as described above, for example, FIG. As shown in (a), the probe needles 151 and 152 can be simultaneously stood on the IC chips T in four rows for inspection. However, in the case of the conventional probe card, for example, as shown in (b) of the same figure, the probe needles can be set only on the two rows of the IC ships T, which is half the size of the present embodiment at a time. Only the number can be inspected.

Moreover, in the probe card 5 of the present embodiment, the free end lengths l ₁ and l _{2 of} the first and second probe needles 151 and 152 protruding from the upper and lower first and second support portions 21 and 22, respectively. Since the lengths are set to the same length (l ₁ = l ₂ ), the probe tips of the probe needles 151 and 152 come into contact with the electrode pads P of the semiconductor wafer W during inspection, and the probe needles are cantilevered by the pedestal 14. Even if 151 and 152 receive a pressing force from the semiconductor wafer W, and stylus pressure acts on the electrode pad P due to the pressing force, the play of the upper and lower probe needles 151 and 152 protruding from the first and second support portions 21 and 22 is prevented. Edge length l
_{Since 1} and l ₂ are equal to each other, the upper and lower probe needles 15
Substantially the same needle pressure acts on the electrode pad P from the needle tips of Nos. 1 and 152, moreover, the difference in deformation between the probe needles 151 and 152 is suppressed, and stable inspection can be performed.

On the other hand, when the inspection is performed at such a high temperature, the probe card 5 is close to the semiconductor wafer W.
The probe card 5 is heated by the heat radiation from the semiconductor wafer W heated during the inspection, and the temperature is raised. As a result, the printed circuit board 12 thermally expands and the printed circuit board 12 bends,
Although warping tends to occur in this case, in the present embodiment, since the printed circuit board 12 is supported by the support body 13, the support body 13 prevents the warp of the printed circuit board 12 from the conventional one.
It can be suppressed to / 5 to 1/3. Therefore, in the case of the conventional probe card, when the printed circuit board is thermally deformed and bent, it takes 2 to 5 minutes to stabilize, and there is a loss time of 2 to 5 minutes for each semiconductor wafer W. In the embodiment, since the flatness of the tip of the probe needle is always maintained, there is no such loss time, and the inspection throughput can be remarkably increased.

Further, since the support 13 is provided with the through hole 19, the heat inside the apparatus main body is radiated to the outside through the through hole 19, and at this time, an ascending air current is generated in the vicinity of the probe needle 15, The temperature rise of the probe needle 15 can be suppressed.
Further, since the pedestal 14 is directly attached to the support 13 having excellent thermal conductivity, the heat of the pedestal 14 and the probe needle 15 heated by the semiconductor wafer W is quickly transmitted to the outside through the support 13. The temperature of the probe needle 15 can be further suppressed by radiating heat.

Since there is a gap δ between the outer periphery of the pedestal 14 and the edge of the opening 17 of the printed circuit board 12, the pedestal 14 is independent of the printed circuit board 12, so that the printed circuit board 1
It is possible to maintain the initial flatness of the probe tip of the probe needle 15 without affecting the pedestal 14 due to the thermal expansion of No. 2. Furthermore,
Since the curved portions 24 and 25 are provided in the vicinity of the base portion of the probe needle 15, even if the curved portions 24 and 25 are pressed by the thermal expansion of the printed circuit board 12, the force at this time can be absorbed.

As described above, according to this embodiment, the first and second supporting portions 21 and 22 which are located above and below the first and second supporting portions 21 and 22, respectively, project.
Since the free end lengths l ₁ and l _{2 of} the second probe needles 151 and 152 are set to the same length (l ₁ = l ₂ ), the probe tips of the probe needles 151 and 152 are set to the semiconductor wafer W during inspection.
Even if the probe needles 151 and 152 cantilevered by the pedestal 14 are pressed from the semiconductor wafer W by contact with the electrode pad P of the above, and the needle pressure acts on the electrode pad P by this, Substantially the same stylus pressure acts on the electrode pad P from the stylus tip of the stylus 151, 152, the difference in deformation between the probe stylus 151, 152 is suppressed, and stable inspection can be performed.

In the above embodiment, the probe card has the probe needle having two rows of needle tips on one side, but the present invention can be applied to a probe card that cantileverly supports three or more rows of probe needles. it can. Further, in the above embodiment, the case where the rectangular opening is provided on the printed circuit board has been described, but the shape of the opening is not limited to the rectangular shape.

[0032]

As described above, according to the present invention, a plurality of stages of supporting portions for supporting the probe needles at a plurality of upper and lower positions are provided on the lower surface of the pedestal, and the supporting portions of the upper and lower stages are provided for each probe needle. The needle pressure of the probe needles protruding from two or more rows from one side is constant because the probe needles protruding from each supporting portion of the plurality of rows are set to have the same free end length by arranging them in a row so as to be adjacent to each other in the protruding direction. Moreover, it is possible to provide a probe card that can suppress the difference in deformation of the probe needles between rows.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a main part of a probe device to which an embodiment of a probe card of the present invention is applied.

FIG. 2 is a plan view showing an upper surface of the probe card of the present embodiment shown in FIG.

3 is a sectional view taken along the line III-III in FIG.

FIG. 4 is a sectional view taken along line IV-IV in FIG.

5 is a cross-sectional view showing an enlarged main part of the probe card shown in FIG.

6 is a plan view showing an arrangement of IC chips that can be inspected at once by a probe card, and FIG. 6A is a diagram showing an arrangement of IC chips when inspecting by the probe card shown in FIG. 2; 8] is a diagram showing an arrangement of IC chips in the case of inspecting with a conventional probe card.

[Explanation of Codes] 5 Probe Card 12 Printed Circuit Board 14 Pedestal 15 Probe Needle 16 Printed Wiring 151 Probe Needle 152 Probe Needle W Semiconductor Wafer (Inspection Object) T IC Chip P Electrode Pad l ₁ Overhanging Length of 1st Probe Needle ( Free end length) l ₂ Overhanging length of the second probe needle (free end length)

Claims (1)

[Claims] 1. A plurality of probe needles connected to wiring of a printed circuit board, and a pedestal that cantilevers each of these probe needles. The probe needles are brought into contact with a predetermined electrode of an object to be inspected to a predetermined position. In the probe card for performing the electrical inspection of the above, a plurality of stages of supporting portions for supporting the probe needles at a plurality of upper and lower positions are provided on the lower surface of the pedestal, and the supporting portions of the plurality of upper and lower stages are provided in the protruding direction of the probe needles. The probe card is characterized in that the probe needles are arranged in a plurality of rows so as to be adjacent to each other, and the free end lengths of the probe needles protruding from the respective support portions of the plurality of rows are set to be the same.