JP3558327B2 - Vertically operated probe card - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a probe card used for measuring various electrical characteristics of a semiconductor integrated circuit such as an LSI chip.
[0002]
[Prior art]
A probe card used to measure various electrical characteristics of a semiconductor integrated circuit such as an LSI chip includes a horizontal type using a horizontal probe called a cantilever type and a vertical type probe called a vertical type. It is roughly divided into the vertical type used. With the recent demand for higher integration, miniaturization, and higher speed of semiconductor integrated circuits, and simultaneous measurement of a plurality of semiconductor integrated circuits, there is an increasing demand for an increase in the number of probes and an increase in the arrangement density of probes. I have.
[0003]
Here, the probe is often made of a material such as tungsten or beryllium copper, but from the viewpoint of wear resistance and cost, 90% or more of tungsten is used. However, this tungsten probe has a problem that the contact resistance is increased by repeating the contact with the electrode many times (thousands of times). This increase in contact resistance can be attributed to a rise in the temperature of the contact portion at the tip of the probe due to the current or friction flowing between the electrode and the electrode when the electrode contacts the electrode. This is caused by adhesion of the aluminum oxide to the contact portion at the tip of the probe. In particular, this problem has become remarkable in a burn-in test in which an LSI chip to be measured is heated to 85 to 150 ° C.
[0004]
As a measure for removing the cause and restoring the contact resistance, when the probe contacts the electrode a predetermined number of times (thousands), the contact portion at the tip of the probe is cleaned with a cleaning sheet. I have.
[0005]
[Problems to be solved by the invention]
However, performing a separate operation of cleaning, even once every several thousand times, is problematic in a measurement test of electrical characteristics of a fully automated LSI chip. There is also a problem that the contact portion at the tip of the probe is worn by cleaning.
[0006]
SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and a micro-probe and a vertically operated probe using the micro-probe which can contribute to a long life without requiring cleaning once every thousands of times as in the related art. The card is intended to be provided.
[0007]
[Means for Solving the Problems]
The vertical actuation type probe according to the present invention is a probe that vertically contacts an electrode of an object to be measured, a substrate on which a wiring pattern to which the probe is connected is formed, and the probe is provided on a lower surface side of the substrate. A probe support member for supporting the probe, the probe having a microprobe perpendicular to the electrode of the object to be measured, and a needle probe whose tip fits into a recess formed in the microprobe. The microprobe has an upper end diameter of 40 to 50 μm , an upper end surface to a contact portion at the lower end is set to 1 mm , and a depth of the concave portion is set to 150 to 200 μm. A first support for supporting the needle-shaped probe, and a second support for supporting the microprobe via an elastic resin applied to the upper surface side, wherein the second support is It has become detachable from the first support portion.
[0008]
Further, the microprobe is formed using a LIGA process.
[0009]
Further, the micro probe is made of a Ni-W alloy or an Fe-W alloy.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a schematic cross-sectional view of a vertical operation type probe card according to an embodiment of the present invention, FIG. 2 is a schematic cross-sectional view of a main part of the vertical operation type probe card according to an embodiment of the present invention, and FIG. FIG. 4 is a schematic cross-sectional view of a main part of a vertical operation type probe card according to an embodiment of the present invention. FIG. 4 is an explanatory view showing a manufacturing process of a micro probe used in the vertical operation type probe card according to the embodiment of the present invention. It is.
[0012]
The vertical operation type probe card according to the embodiment of the present invention includes a substrate on which a probe 100 vertically contacting an electrode 710 of an LSI chip 700 to be measured and a wiring pattern 210 to which the probe 100 is connected are formed. 200, and a probe support member 300 provided on the lower surface side of the substrate 200 and supporting the probe 100. The probe 100 includes a minute probe 110 which vertically contacts an electrode 710 of the LSI chip 700; The probe support member 300 includes a first support portion 310 that supports the needle probe 120, and a needle probe 120 whose tip fits into a concave portion 111 </ b> A formed in the minute probe 110. A second support portion 320 for supporting the micro-probe 110, wherein the second support portion 320 It is detachably attached to the support portion 310.
The substrate 200 is laminated as the number of probes 100 increases, and a wiring pattern 210 is formed in each layer. In FIG. 1, only the uppermost wiring pattern 210 is shown. The outer end 211 of the uppermost wiring pattern 210 is a pogo seat, called a pogo pin, with which a connecting member comes into contact.
The substrate 200 has a through hole 220 corresponding to the arrangement of the electrodes 710 of the LSI chip 700. The through hole 220 is a portion through which a connection portion at the rear end of the needle probe 120 described later penetrates.
[0013]
The probe 100 is composed of two members. That is, they are the needle probe 120 and the micro probe 110. The needle-like probe 120 is made of tungsten, the tip of which is thinner than other parts, like the one used in the conventional vertical operation type probe card. On the other hand, as shown in FIG. 2, the microprobe 110 is formed in a substantially shell shape when viewed from the side, and has a concave portion 111 </ b> A formed on the upper end surface 111. In the microprobe 110, the diameter of the upper end face 111 is set to about 40 to 50 μm, the distance from the upper end face 111 to the contact portion 112 at the lower end is set to about 1 mm, and the depth of the recess 111A is set to about 150 to 200 μm.
[0014]
The micro probe 110 is formed using a LIGA process. Here, the LIGA process is an abbreviation of the German term Lithographie Galvanoformug and Abformung, in which a polymer resist is irradiated with synchrotron radiation to bake a fine component mold, and a metal is embedded in the mold by electroplating. After that, it refers to a method of forming a fine component by dissolving a mold made of a polymer resist.
[0015]
In the vertical operation type probe card according to the embodiment of the present invention, the microprobe 110 formed using the LIGA process is made of a Ni-W alloy or an Fe-W alloy. Conventionally, only soft materials such as Cu, Au, and Ni can be used in the LIGA process. However, recent research has made it possible to use hard materials such as Ni-W alloys or Fe-W alloys.
[0016]
The manufacturing process of the microprobe 110 using the LIGA process is as follows.
[0017]
The manufacturing process of the microprobe 110 is roughly divided into two processes. That is, a process of forming a portion where the recess 111A is not formed (see FIGS. 4A to 4D) and a process of forming a portion where the recess 111A is formed (see FIGS. 4E to 4D). 4 (H)).
[0018]
First, a polymer resist 800 is applied over the substrate 810 (see FIG. 4A). Then, a shape corresponding to the microprobe 110, that is, a concave portion 820 corresponding to a portion where the concave portion 111A of the microprobe 110 is not formed is formed by lithography using synchrotron radiation SR (see FIG. 4C). A synchrotron radiation light absorption pattern 831 is formed on the mask 830 used at this time (see FIG. 4B). That is, only the portion corresponding to the portion where the synchrotron radiation light absorption pattern 831 is not formed is irradiated with the synchrotron radiation light.
[0019]
Next, a Ni-W alloy is deposited by electroplating in the recess 820 formed in the portion irradiated with the synchrotron radiation (see FIG. 4D).
[0020]
During this deposition, for example, nickel sulfate _(NiSO 4 _-6H 2 O), sodium tungstate _(NaWO 4 _-H 2 O), sodium citrate _{(Na 3 C 6 HSO 7 -2H} 2 O), ammonium chloride (NH _The substrate 810 having the polymer resist 800 in which the concave portion 820 is formed is immersed in an aqueous electrolytic solution composed of ₄ Cl) and sodium bromide (NaBr), and electroplating is performed using the substrate 810 as a cathode.
[0021]
Further, a new polymer resist 840 is applied on the polymer resist 810 and the Ni—W alloy (see FIG. 4E). Then, synchrotron radiation is irradiated through the mask 850. In the mask 850, a synchrotron radiation light absorption pattern 851 is formed in a portion other than a portion corresponding to the concave portion 111A of the microprobe 110 and a portion between adjacent microprobes 110 (see FIG. 4F). Therefore, only the portion corresponding to the concave portion 111A of the micro probe 110 is not irradiated with the synchrotron radiation light (see FIG. 4F).
[0022]
When the polymer resist 840 is developed in this state, only a portion corresponding to the periphery of the concave portion 111A of the micro probe 110 is removed (see FIG. 4G). Further, a Ni-W alloy is deposited by using an electroplating method (see FIG. 4H). At the time of this deposition, a substrate 810 having polymer resists 800 and 840 in which recesses 820 are formed in an electrolytic aqueous solution composed of, for example, nickel sulfate, sodium tungstate, sodium citrate, ammonium chloride, and sodium bromide, as described above. And electroplating is performed using the substrate 810 as a cathode.
[0023]
As a result, it was possible to form the substantially bullet-shaped minute probe 110 having the concave portion 111A.
[0024]
The microprobe 110 manufactured in this manner is made of a Ni—W alloy having a high elastic deformation capability with a bending strain of 0.01 or more and not breaking even after complete close contact bending deformation. According to X-ray diffraction measurement, it has been confirmed that this Ni-W alloy has an ultrafine crystalline structure or an amorphous structure, and it has been confirmed that the Ni-W alloy has a high Vickers hardness of 500 DPN or more.
[0025]
On the other hand, the needle probe 120 is fixed with a fixing resin 240 on the lower surface side of the substrate 200. The connection portion, which is the rear end of the needle probe 120, is electrically connected to a wiring pattern 210 formed on the substrate 200 using a lead wire 230.
[0026]
In addition, the probe support member 300 has a first support portion 310 that supports the needle probe 120 and a second support portion 320 that supports the micro probe 110. The first support part 310 is located on a lower surface of the fixing resin 240. Therefore, the first support portion 310 has a through hole 311 through which the rear end portion of the needle probe 120 penetrates. Of course, the through holes 311 are formed corresponding to the arrangement of the electrodes 710 of the LSI chip 700.
[0027]
Further, the second support portion 320 has a through hole 321 formed corresponding to the arrangement of the electrodes 710 of the LSI chip 700. The second support portion 320 is set to a thickness such that the microprobe 110 having a length of about 1 mm penetrates, the upper end surface 111 projects to the upper surface side, and the contact portion 112 projects to the lower surface side. As shown in FIG. 2, the microprobe 110 is attached to the second support 320 via an elastic resin 330 having elasticity. That is, the elastic resin 330 is applied to the upper surface side of the second support 320, and the microprobe 110 is fixed via the elastic resin 330. Therefore, the microprobe 110 is not directly fixed to the second support 320. The upper end surface 111 of the micro probe 110 protrudes from the elastic resin 330.
[0028]
The first support portion 310 and the second support portion 320 thus configured are supported in parallel by a support member 340 hanging down from the lower surface of the substrate 200. At this time, the distance between the first support portion 310 and the second support portion 320 is such that the tip of the needle probe 120 supported by the first support portion 310 is inserted into the concave portion 111A of the micro probe 110 and It is set so as not to contact the bottom surface 111B.
[0029]
Next, measurement of various electrical characteristics of the LSI chip 700 by the vertically operated probe card configured as described above will be described.
[0030]
The LSI chip 700 in the wafer state is sucked on the vacuum suction table 750 located below the vertically operated probe card. In this state, the vacuum suction table 750 is raised to bring the microprobes 110 constituting the probe 100 into contact with the electrodes 710. The vacuum suction table 750 is raised even after the microprobe 110 contacts the electrode 710. This is called overdrive.
[0031]
Then, as shown in FIG. 3, the tip of the needle probe 110 that has entered the concave portion 111A of the micro probe 110 contacts the bottom surface 111B of the concave portion 111A. At this time, the elastic resin 330 supporting the micro-probe 110 is deformed upward, thereby absorbing excessive overdrive. At the same time, the needle probe 120 is also deformed to absorb the overdrive. In this state, signals are exchanged between the LSI chip 700 and a tester (not shown), and the electrical characteristics of the LSI chip 700 are measured.
[0032]
When the measurement is completed, the vacuum suction table 750 is lowered, and the vacuum suction table 750 is moved in the horizontal direction to prepare for the next LSI chip 700 measurement.
[0033]
If the contact resistance of the microprobe 110 is increased by performing a large number of measurements, the microprobe 110 is replaced. However, since the microprobe 110 is made of a Ni-W alloy using a LIGA process, it can withstand at least 50,000 or more contacts. The replacement of the micro probe 110 is performed as follows. First, the second support 320 is removed from the first support 310. The new second support 320 to which the new micro probe 110 is attached is attached to the first support 310. At this time, the tip of the needle probe 120 is surely fitted into the concave portion 111A of the new micro probe 110.
[0034]
In the above-described embodiment, an electrolytic aqueous solution composed of nickel sulfate, sodium tungstate, sodium citrate, ammonium chloride, and sodium bromide is used to precipitate a Ni-W alloy. It may be. By performing the electroplating ammonium iron _(III) and _{(Fe (NH 4) (SO} 4) 2 -12H 2 O) with an aqueous electrolyte solution added to the above aqueous electrolytic solution, can be precipitated Ni-Fe alloy.
[0035]
Also, nickel sulfate, sodium tungstate, sodium molybdate _{(Na 2 MoO 4 -2H 2 O} ) ,, sodium citrate, ammonium chloride, the use of the electrolyte solution of sodium bromide to precipitate a Ni-W-Mo alloy be able to.
[0036]
Also in these cases, it is confirmed that the material has a high elastic deformation capability with a bending strain of 0.01 or more, does not break even after complete close contact bending deformation, and has a high Vickers hardness of 500 DPN or more.
[0037]
【The invention's effect】
The vertical actuation type probe according to the present invention is a probe that vertically contacts an electrode of an object to be measured, a substrate on which a wiring pattern to which the probe is connected is formed, and the probe is provided on a lower surface side of the substrate. A probe support member for supporting the probe, the probe having a microprobe perpendicular to the electrode of the object to be measured, and a needle probe whose tip fits into a recess formed in the microprobe. The microprobe has an upper end diameter of 40 to 50 μm , an upper end surface to a contact portion at the lower end is set to 1 mm , and a depth of the concave portion is set to 150 to 200 μm. A first support for supporting the needle-shaped probe, and a second support for supporting the microprobe via an elastic resin applied to the upper surface side, wherein the second support is It has become detachable from the first support portion. For this reason, even if the micro probe having a long life is worn, the micro probe can be replaced together with the second support portion.
[0038]
Further, since the elastic resin is applied on the upper surface side of the second support portion, it is possible to absorb overdrive by deformation of the elastic resin, and to secure an appropriate contact pressure between the microprobe and the electrode. It becomes possible.
[0039]
Further, since the microprobe is formed using the LIGA process, it is formed with high accuracy.
[0040]
Furthermore, since the microprobe is made of a Ni-W alloy or an Fe-W alloy, it can be hard and does not break, can withstand at least 50,000 or more contacts, and has a long life. It can be a vertically operated probe card.
[Brief description of the drawings]
FIG. 1 is a schematic sectional view of a vertical operation type probe card according to an embodiment of the present invention.
FIG. 2 is a schematic cross-sectional view of a main part of the vertical operation type probe card according to the embodiment of the present invention.
FIG. 3 is a schematic cross-sectional view of a main part of the vertical operation type probe card according to the embodiment of the present invention.
FIG. 4 is an explanatory view showing a manufacturing process of a microprobe used in the vertical operation type probe card according to the embodiment of the present invention.
[Explanation of symbols]
REFERENCE SIGNS LIST 100 probe 110 micro probe 111A recess 120 needle probe 200 substrate 300 probe support member

Claims (3)

A probe that vertically contacts the electrode of the measurement object, a substrate on which a wiring pattern to which the probe is connected is formed, and a probe support member provided on the lower surface side of the substrate and supporting the probe is provided. The probe has a microprobe perpendicular to the electrode of the object to be measured and a needle probe whose tip fits into a concave portion formed in the microprobe, and the microprobe has an upper end. The diameter of the portion is set to 40 to 50 μm , the distance from the upper end surface to the contact portion at the lower end is set to 1 mm , the depth of the concave portion is set to 150 to 200 μm , and the probe support member is a first support for supporting the needle probe. And a second support portion for supporting the micro probe via an elastic resin applied to the upper surface side, and the second support portion is detachable from the first support portion. Vertically-acting type probe card according to claim Rukoto. The probe card according to claim 1, wherein the microprobe is formed by using a LIGA process. The vertical operation type probe card according to claim 1, wherein the micro probe is made of a Ni—W alloy or an Fe—W alloy.

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