JP4486486B2 - Probe for probe card - Google Patents

Description

The present invention relates to a probe for a probe card where a current test in contact with the electrode pads of the semiconductor devices formed on a semiconductor wafer.

  In a semiconductor integrated circuit manufacturing process, there is a probe test process in which after a plurality of integrated circuits are completed on a wafer, each integrated circuit is confirmed to operate normally in the wafer state. A probe card is an inspection component that electrically connects the integrated circuit inspection apparatus that performs the probe test and the electrode pads of the semiconductor integrated circuit to be inspected.

  The probe card is provided with a plurality of probes, and each of the probes is in contact with a plurality of electrode pads of the semiconductor integrated circuit, and the inspection is performed. Therefore, a narrow member is required as the wire diameter of each probe.

  Taking a semiconductor integrated circuit used for a liquid crystal driver as an example, a pitch between electrodes of 40 μm to 30 μm is currently required, and an electrode pad is further increased as the number of scanning lines increases in order to form a higher definition image. The pitch between them tends to narrow. For this reason, there is an increasing demand for thinning the probe for the probe card.

  The thinning of the probe reduces the rigidity of the probe itself, which makes it impossible to secure a sufficient contact pressure between the probe and the electrode pad under test, resulting in unstable electrical continuity between the probe and the electrode pad. Will occur. Currently, ReW (rhenium tungsten) needles and NP7D (trade name) needles that are used as probes for probe cards have a problem that tensile strength and hardness are insufficient when thinned.

That is, as a probe for a probe card for inspecting a semiconductor device, when the wire diameter is 10 μm to 100 μm, it is desired to obtain a state where the electrical resistance value is 0.5 Ω / cm ² or less in contact with the gold electrode of the semiconductor device However, copper and beryllium have a small electrical resistance value but a low tensile strength, so there is a problem that it becomes impossible to obtain a contact pressure as a probe by thinning. Conversely, if tungsten with a high tensile strength is used, tungsten is When used repeatedly due to its crystalline nature, there has been a problem that the residue of the insulating material of the object to be inspected enters the crystal grain boundary, resulting in an increase in contact resistance.

Further, metal glass is known as a material having high tensile strength, and Patent Document 1 proposes to use this metal glass as a probe for a probe card. Certainly, the metallic glass exhibits a decrease in viscosity at a high temperature and has the property of plastic deformation. Therefore, even in the thinning due to the narrow pitch, it can be finely processed at about 600 ° C. It is a material that can be expected to make use of the characteristic that a sufficient tensile strength can be obtained as a probe. However, it is known that metal glass has a high electric resistance value. In Patent Document 1, a probe for a probe card is configured using metal glass, and an electric signal obtained from the probe is more than the metal glass. A special structure has been proposed, such as flowing through a signal transmission line made of a material with low electrical resistance.
JP 2001-326259 A

  As described above, there is a problem that the tensile strength decreases when the probe for the probe card is thinned in response to the narrow pitch accompanying the increase in the density of the semiconductor integrated circuit. Has a problem that the electrical resistance value becomes high, and there has been no probe of an optimal material having a high tensile strength and a low electrical resistance value as a probe card probe.

This invention may be thinned so as to correspond to the pitch of the test object, tensile strength is high, yet it is an object to provide a probe for a probe card electrical resistance has a low qualities.

  The present inventor has advanced research for the purpose of completing a probe for a probe card while taking advantage of the excellent characteristics of metallic glass, and has completed the present invention.

  Metallic glass is a stable amorphous material such as oxide glass that has a supercooled liquid region, although it is a metal, and has a supercooled liquid region. It has the characteristic that it can maintain high precision without the need for consideration. On the other hand, as an amorphous alloy, mechanical characteristics and electrical characteristics vary depending on the shape and dimensions of thin plates or thin wires. Especially in the case of extremely thin wire shapes such as probes for probe cards, new materials are used as metallic glass. In practice, mixing with the probe has not been even considered because there is a possibility that the characteristics of the main material itself may be impaired and the characteristics may become uneven between the probes.

  In order to achieve the above object, the present invention provides a probe card probe with a main material of 0-dimensional (particle), 1-dimensional (fiber), 2-dimensional (sheet), and 3-dimensional nanostructure carbons. A metallic glass mixed with at least one kind is used. The carbon nanostructures of each dimension described above are known as carbon nanotubes, carbon nanofibers, carbon nanohorns, and fullerenes.

In particular, carbon nanotubes, carbon nanohorn, fullerene, the mixing amount of the nanostructure carbon composed of at least one kind of carbon nano fiber, and to metallic glass component 0. The main material of the probe for a probe card is 5 to 10 wt%.

  In addition, as a probe card probe manufacturing method, at least one of carbon nanotubes, carbon nanofibers, carbon nanohorns, and fullerenes is mixed and melted in a vacuum or an argon gas atmosphere in a solid metal mixture ratio that can be used for metallic glass. A member is manufactured and thinned by drawing or the like.

  In addition, as a probe card probe manufacturing method, a dispersion material is dispersed in a plurality of fine metal and metal ion solutions for forming metal glass, and carbon nanotubes, carbon nanofibers, carbon nanohorns, and fullerenes are further dispersed in this solution. At least one of them is put in and a probe for a probe card is manufactured by an electroforming method.

In order to obtain a probe for a probe card having optimum electrical and mechanical characteristics, tungsten is used as a core member, and the core member is covered with metal glass. , Carbon nanofibers, carbon nanohorns, fullerenes containing at least one kind of nanostructure carbon, and the amount of nanostructure carbon mixed is 0.5 to 10 wt% with respect to the metallic glass component. .

  Furthermore, the metal glass that covers the core member is made into a multilayer, and at least one of carbon nanotubes, carbon nanofibers, carbon nanohorns, and fullerenes is contained in the layer close to the surface, so that the optimum electrical and mechanical properties are obtained. Provided is a probe for a probe card having

  In general, even if a small amount of a conductive member is added to a high-resistance base material, it is not possible to expect a reduction in resistance so much. The high tensile property of the resistance member is impaired. However, by searching for the relationship between the selection of the conductive member to be added and the addition amount, it is possible to obtain a wire rod with characteristics that deviate from expectations.

  That is, for an amorphous material (that is, metallic glass) having a supercooled liquid region, carbon as 0-dimensional (particle), 1-dimensional (fiber), 2-dimensional (sheet), and 3-dimensional nanostructure carbon The material mixed with at least one selected from nanotubes, carbon nanofibers, carbon nanohorns, and fullerenes can reduce resistance while maintaining the high tensile strength of the metallic glass, making it ideal for probes for probe cards It is possible to obtain excellent characteristics. In particular, since each nanostructure carbon is extremely small, an ideal high tensile strength and ideal electrical characteristics can be obtained by uniformly diffusing and distributing in a predetermined region of the metallic glass.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS.

  FIG. 1 is a flowchart showing a procedure of a method for manufacturing a probe for a probe card according to the present invention. As shown in the figure, in the first step 11, first, a metallic glass material and a carbon nanotube (hereinafter abbreviated as CNT) are mixed. An example of the metal glass used here is Fe-Co-Cr-Si, and nanoscale fine powder CNT is added to this and stirred so as to obtain a substantially uniform mixed state.

  Next, in the second step 12, as shown in FIG. 2, the mixed material is put into a boat 20, the boat 20 is placed in a reaction furnace 200 equipped with a heating device 21, and heated in an argon gas atmosphere. Then, by melting, a metallic glass containing CNTs is produced. In the third step 13, the CNT-containing metal glass is elongated by plastic working. As a result, a wire 31 for producing a probe for a probe card as shown in FIG. 3A can be created, and the subsequent method of manufacturing the probe 32 as shown in FIG. It can be performed by almost the same procedure as that for producing a metal wire and creating a probe for a probe card from the wire.

The composition of the probe for the probe card manufactured by the manufacturing method shown in FIGS. 1 to 3 is about 27 wt% Fe, about 57 wt% Co, about 11 wt% Cr, about 5 wt% Si, As a result of adding about 3 wt% of CNT and making it a thin wire as a CNT-containing metal glass, in the case of a metal glass having a composition before containing CNT, the hardness Hv is 970 DPN, and the tensile strength σB is 3400 N / mm ^2. However, in the case of the CNT-containing metallic glass, the hardness Hv was 1200 DPN and the tensile strength σB was 4500 N / mm ² .

  About the material generally called a metallic glass, various conditions were similarly changed about CNT, carbon nanofiber, carbon nanohorn, and fullerene, and the characteristic was confirmed. The result is shown in FIG. Here, the carbon nanohorn is one of the structures of a single-walled CNT, and the CNT is a cylindrical (tube-shaped) sheet of carbon molecules having a graphite structure, and has a diameter of 1 to 2 nm. In contrast, a nanohorn is shaped like a horn (horn of a cow or the like) with its tip closed in a conical shape.

  FIG. 4 shows an arbitrary selection of metallic glass serving as a base, and combinations of CNT, carbon nanohorn, and fullerene added thereto are (1) CNT, (2) carbon nanofiber, (3) carbon nanohorn, (4 ) Fullerene, (5) mixing (1) and (2) above, (6) mixing (1) and (3) above, (7) mixing (1) and (4) above, (8) above ( 2) and (3), (9) Mixing of the above (2) and (4), (10) Ten types of compositions of the above (3) and (4), the addition amount was changed, respectively, for the probe card The overall judgment of hardness, tensile strength, and electrical resistance value as the characteristics as a probe is performed, and the evaluation results of “optimum” ◎, “suitable” ◯, and “examination” △ are shown.

  From the evaluation results shown in FIG. 4, the material to be added is almost the same regardless of whether it is CNT, carbon nanofiber, carbon nanohorn, or fullerene, but the use of CNT and carbon nanofiber is particularly excellent. Yes. By adding these additive materials in an amount range of 0.5 to 15.0 wt%, it is possible to have characteristics suitable as a probe for a probe card, and further, 3.0 to 5.0 wt%. If it is an added amount, it is judged that optimum properties can be given in terms of tensile strength and electrical resistance.

  The above evaluation was performed by testing several hundreds of wire rod diameters in the range of several μm to 200 μm as probes for probe cards. The difference based on the change in the wire rod diameter is particularly significant. However, the effect of the additive member increases as the wire diameter decreases, and the effect of the additive member increases at a wire diameter of 10 μm to 100 μm, particularly 10 μm to 50 μm. In some cases, the effect of a small amount of the additive member tended to be large.

  There are various methods for producing probes for probe cards. As described above, CNT and metallic glass are heated and melted to produce CNT-containing metallic glass, which is then stretched by plastic working to produce a wire rod. One method is to create and process this wire, and there is a method described below other than this manufacturing method.

  FIG. 5 is a diagram for explaining a method of manufacturing the probe for a probe card according to the present invention by electroforming, in which 51 is a first step in the preparation stage, 52 is a second step in the middle of manufacturing, and 53 is This is the third step leading to the finished product.

  First, in the first step 51, as shown in the drawing, a conductive film 512 is formed on a Si substrate 511, a photoresist 513 is formed on the conductive film 512, and this photoresist 513 is exposed to expose a probe for a probe for a probe card. A pattern 514 necessary for the shape is formed on the conductive film 512.

  Next, in the second step 52, the Si substrate 511 prepared in the first step 51 is immersed in a plating bath 520 and electroforming is performed. In this plating bath 520, a plurality of fine metals for forming a metallic glass and their metal ions are dispersed in a solution, and a small amount of CNT, carbon nanofiber, carbon nanohorn, and fullerene is mixed in the solution. Is. Examples of the material for forming the metallic glass include Ni, Co, Au, W, Mn, Pd, Pt, Zn, Sn, Cu, Co, Cr, and the like, and these ion solutions are used in combination.

  As a result, a probe card probe having a predetermined shape is obtained as the third step 53. Inside the probe card probe having a predetermined shape obtained here, CNT and carbon nano-particles mixed in the solution are obtained. Since fibers, carbon nanohorns, and fullerenes are retained, they have characteristics suitable as probes for probe cards.

  Furthermore, the use of tungsten with a high tensile strength was studied and favorable results were obtained. Tungsten is used as a core member, and the surface of the core member is covered with a metallic glass layer. Since tungsten, which is crystalline, does not contact the object to be inspected, there is no change in the contact resistance of tungsten, and metal By diffusing and distributing the nanostructure carbon in the glass layer, a probe for a probe card with ideal electrical and mechanical characteristics can be completed.

  Furthermore, as a method of manufacturing a probe for a probe card having electrical characteristics and mechanical characteristics optimal for high-frequency signals, a process of using tungsten as a core member and forming a multilayer metal glass layer on the surface of the core member This will be described with reference to FIG.

  The first step 61 in FIG. 6 shows the preparation of tungsten as the core member 601. General precautions for the production of the probe for the probe card (the initial set size determined from the size of the final product and The core member 601 is prepared in a shape satisfying surface processing and the like.

  In the second step 62 of FIG. 6, a solution 602 is prepared by dispersing a dispersion material in a plurality of fine metal and metal ion solutions for forming a metallic glass, and a core member 601 is set in the solution 602. The process of once forming the metallic glass layer on the surface of the core member 601 by the electroforming method is shown.

  Thereafter, as shown in the third step 63 of FIG. 6, the electroforming operation is temporarily stopped, and the carbon nanotubes, carbon nanofibers, carbon nanohorns, and fullerenes are contained in the electroforming solution 602 as carbon nanostructures. At least one of them is inserted from the insertion port 603. In addition, after charging, the solution 602 is stirred by the stirring device 604 so that the nanostructured carbon is more uniformly diffused and distributed, and then the electroforming operation is restarted, and the carbon nanotubes, A metal glass layer containing at least one of carbon nanofibers, carbon nanohorns, and fullerenes is formed.

  By passing through these first to third steps, the appearance shown in (a) can be obtained as the finished product step 64. In the probe card probe, as shown in (b), the surface of the core member 601 is covered with a metallic glass layer 605 not containing nanostructured carbon and a metallic glass layer 606 containing nanostructured carbon. It will be. (C) shows the electrical characteristics of this probe corresponding to the cross section, and shows that the conductivity of the central part and the peripheral part is high.

  In the above description, an example in which a solution that does not contain nanostructure carbon and a solution that contains nanostructure carbon is used stepwise is given. A metallic glass layer can also be formed in a continuous concentration change of body carbon, and in this case, it is substantially the same as a multilayer structure with a continuous concentration change.

  Thus, being able to increase the electrical conductivity of the surface of the probe for the probe card is suitable for a probe intended for a high-frequency signal.

  As described above, in the probe for a probe card of the present invention, high tensile strength and low electrical power are obtained by using, as a main material, metallic glass mixed with at least one of carbon nanotubes, carbon nanofibers, carbon nanohorns, and fullerenes. It is possible to realize a probe for a probe card having a characteristic of resistance value.

It is a flowchart which shows the procedure of the manufacturing method of the probe by this invention. It is the schematic which shows the manufacturing apparatus of the probe by this invention. It is a figure which shows the member of the probe manufactured by this invention. It is drawing which shows the evaluation result of the probe by this invention. It is a figure which shows the other manufacturing method of the probe by this invention. It is a figure which shows the further another manufacturing method of the probe by this invention.

Explanation of symbols

31 Wire rod 32 Probe 51 First step 52 Second step 53 Third step 511 Si substrate 512 Conductive film 513 Photoresist 514 Pattern 520 Plating bath
61 First Step 62 Second Step 63 Third Step 64 Finished Product Step 601 Core Member 605 Metallic Glass Layer 606 Not Containing Nanostructured Carbon 606 Metallic Glass Layer Containing Nanostructured Carbon

Claims (2)

In a probe for a probe card whose main material is metallic glass mixed with nanostructure carbon,
The nanostructure carbon mixed in the metal glass is composed of at least one of carbon nanotubes, carbon nanohorns, fullerenes, and carbon nanofibers, and the amount of the nanostructure carbon mixed is set to 0. 0 to the metal glass component . A probe for a probe card, characterized by being 5 to 10 wt%. In a probe for a probe card comprising a core member made of tungsten and a metal glass layer containing nanostructure carbon provided on the surface of the core member,
The nanostructure carbon contained in the metal glass layer is composed of at least one of carbon nanotubes, carbon nanohorns, fullerenes, and carbon nanofibers, and the amount of the nanostructure carbon mixed is set to 0. 0 to the metal glass component . A probe for a probe card, characterized by being 5 to 10 wt% .

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