JP5737925B2 - Ceramic circuit board for probe card and probe card using the same - Google Patents

Description

  The present invention relates to a ceramic wiring board for a probe card provided with fine wiring for measuring electrical characteristics of a semiconductor wafer, and a probe card using the same.

  For semiconductor elements with large-scale integrated circuits that are simultaneously formed on a semiconductor wafer such as a Si wafer, a product with poor electrical connection and electrical characteristics at a substantially constant rate due to electrical failure due to adhesion of foreign matter, etc. It is included.

  As a device for detecting a defective product of the semiconductor element, a probe card capable of simultaneously inspecting electrical characteristics of a large number of semiconductor elements at the same time in a semiconductor wafer state is known (see, for example, Patent Document 1). ).

  This probe card has a wiring board in which fine wiring is formed on the main surface and inside of an insulating base made of an alumina sintered body, and a plurality of measuring terminals called probe pins arranged with high precision on the surface of the wiring board. By applying this probe pin to the terminals of many semiconductor elements, measuring the output when voltage is applied and comparing it with the expected value, the quality of the many semiconductor elements can be collectively evaluated. Judgment.

  In recent years, with the miniaturization of integrated circuit wiring formed in semiconductor elements, it has been required to increase the number of probe pins per unit area of the probe card, and wiring formed on the probe card ceramic wiring board is also required. There is a demand for further miniaturization.

However, in the probe card ceramic wiring board in which the insulating base is formed of the alumina sintered body described in Patent Document 1, the thermal expansion coefficient of the insulating base is the thermal expansion coefficient of alumina (about 7 × 10 ⁻⁶ / ° C.). Because it is close, there is a large difference from the thermal expansion coefficient of the Si wafer to be inspected. Therefore, it is provided on the probe card ceramic wiring board during the thermal load test (burn-in test) performed before measuring the electrical characteristics of the semiconductor element. The measurement terminals (probe pins) thus formed are displaced from the position of the measurement pad formed on the surface of the Si wafer, and there is a problem that the electrical characteristics cannot be inspected.

  On the other hand, an attempt has been made to apply a mullite sintered body having a thermal expansion coefficient smaller than that of an alumina sintered body as an insulating base of a probe card wiring board (see, for example, Patent Document 2).

Japanese Patent Laid-Open No. 11-160356 JP 2010-93197 A

The mullite sintered body described in Patent Document 2 is dense and has a thermal expansion coefficient closer to that of the semiconductor element (Si) than that of the alumina sintered body. Although the misalignment between the measurement terminal provided on the probe card ceramic wiring board and the measurement pad formed on the surface of the Si wafer can be reduced in the thermal load test (burn-in test), The grain boundary of mullite particles, which are the main crystal particles, contains a lot of glass phase mainly composed of silicon dioxide. During firing, the glass phase oozes out on the surface of the insulating substrate and reacts with the setter material for firing to setter material. As a result, a part of the adhesive adheres to the surface of the probe card ceramic wiring board as a foreign substance, resulting in a problem of poor appearance and chemical resistance.

  Accordingly, the present invention has been made in view of such circumstances, and at the time of a thermal load test, a measurement terminal provided on the probe card ceramic wiring board and a measurement pad formed on the surface of the Si wafer. An object of the present invention is to provide a probe card ceramic wiring board having a small misalignment, no appearance defect due to adhesion of foreign matters due to a seepage of a glass phase during firing, and a probe card using the same.

The ceramic wiring board for a probe card of the present invention comprises a ceramic sintered body having mullite main crystal particles and a grain boundary portion present around the main crystal particles and containing Mn, Ti, Mo and W. And a conductor layer made of a composite conductor of Cu and W provided in the insulating base, and 100 parts by mass of the total amount of Al converted to Al ₂ O ₃ and Si converted to SiO ₂ The Mn is 2.0 to 4.0 parts by mass in terms of Mn ₂ O ₃ , the Ti is 4.0 to 8.0 parts by mass in terms of TiO ₂ , and the Mo is 0.02 in terms of MoO ₃ . 4 to 1.2 parts by mass and the alloy of Mo and W at the grain boundary, and the ceramic sintered body has a diffraction intensity of the mullite main peak in X-ray diffraction. Alloy of Mo and W against The ratio of the diffraction intensity of the main peak is characterized by a 0.17 to 0.90.

  In the above probe card ceramic wiring board, the conductor layer is a composite conductor having a composition of Cu of 40 to 60% by volume and W of 40 to 60% by volume. The ratio of the diffraction intensity of the main peak of the alloy of Mo and W to the diffraction intensity of the main peak of mullite is preferably 0.20 to 0.78.

  In the probe card of the present invention, a surface wiring layer is provided on the surface of the above-described probe card ceramic wiring board, and a measurement terminal for measuring electrical characteristics of a semiconductor element is connected to the surface wiring layer. It is characterized by.

  According to the present invention, since it has a thermal expansion coefficient close to that of Si, the positional deviation from the measurement pad formed on the surface of the Si wafer is small, the chemical resistance is good, and the glass phase exudes during firing. Thus, there can be obtained a ceramic wiring board for a probe card which has no appearance defect due to adhesion of foreign matter and has excellent chemical resistance, and a probe card using the same.

It is a schematic sectional drawing of one Embodiment of the ceramic wiring board for probe cards of this invention. It is explanatory drawing of the evaluation apparatus of the semiconductor element using one Embodiment of the probe card of this invention.

An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic cross-sectional view of one embodiment of a ceramic wiring board for a probe card of the present invention. A probe card ceramic wiring substrate 1 shown in FIG. 1 includes an insulating base 11 made of a ceramic sintered body, an internal wiring layer 12 formed inside the insulating base 11, and a surface wiring formed on the surface of the insulating base 11. And a via-hole conductor 14 that electrically connects the internal wiring layers 12 or the internal wiring layer 12 and the surface wiring layer 13 inside the insulating base 11. The internal wiring layer 12 and the surface wiring layer 13 are collectively referred to as a conductor layer.

  The insulating substrate 11 is composed of a plurality of ceramic insulating layers 11a, 11b, 11c, and 11d, and each ceramic insulating layer 11a, 11b, 11c, and 11d is formed of a ceramic sintered body containing mullite as a main component. Hereinafter, a ceramic sintered body containing mullite as a main component is referred to as a mullite sintered body.

  Here, in the probe card ceramic wiring substrate 1 of the present embodiment, mullite, which is the main component of the mullite-based sintered body constituting the insulating base 11, exists as particulate or columnar crystals. Since mullite has improved thermal conductivity as the crystal grain size increases and strength increases as the crystal grain size decreases, it is suitable for the average grain size range of mullite in terms of both high thermal conductivity and high strength. In this case, it is desirable that the average particle size of mullite is 1.0 to 5.0 μm, particularly 1.7 to 2.5 μm, because it has high thermal conductivity and high strength. .

  The average grain size of the main crystal grains of mullite is determined by polishing the mullite sintered body portion cut out from the wiring board and taking a photograph of the internal structure of the etched sample using a scanning electron microscope. Draw about 50 circles in the circle, select the crystal grains that fall within and around the circle, then image-process the outline of each crystal grain to determine the area of each crystal grain, and create a circle with the same area. The diameter at the time of replacement is calculated and obtained from the average value.

When the insulating base 11 is a mullite sintered body, the thermal expansion coefficient (room temperature to 300 ° C.) of the insulating base 11 can be in the range of 3 to 5 × 10 ⁻⁶ / ° C. As a result, the probe card ceramic wiring board 1 of the present embodiment is misaligned between the measurement terminals provided on the probe card ceramic wiring board 1 and the measurement pads formed on the surface of the Si wafer during a thermal load test. Therefore, it can be suitably used for inspection of electrical characteristics.

  Further, in the probe card ceramic wiring board 1 of the present embodiment, the mullite sintered body as the insulating base 11 has mullite as a main crystal phase, and is present around the main crystal particles constituting the main crystal phase. Mn (manganese), Ti (titanium), Mo (molybdenum), and W (tungsten) are present in the grain boundary part.

In addition, when the total amount of Al contained in the sintered body is converted to Al ₂ O ₃ and Si is converted to SiO ₂ is 100 parts by mass, the mullite sintered body has Mn as Mn ₂ O _3. 2.0 to 4.0 parts by mass in terms of conversion, 4.0 to 8.0 parts by mass in terms of TiO _{2 and} Ti to 0.4 to 2.1 parts by mass in terms of MoO ₃ . Thereby, since the seepage of the glass phase in the insulating substrate 11 can be suppressed, appearance defects due to adhesion of foreign substances are hardly caused and chemical resistance can be improved.

  Usually, a sintering temperature of at least 1450 ° C. is required to sinter a molded body material containing mullite as a main component. Sometimes a glass phase mainly composed of silicon dioxide oozes out on the surface of the mullite sintered body and reacts with a setter material for firing sandwiching the formed body during firing. As a result, a part of the setter material adheres to the surface of the mullite sintered body as a foreign substance, so that the obtained insulating substrate 11 made of the mullite sintered body may have a poor appearance, and silicon dioxide is mainly used. The chemical resistance deteriorates due to the presence of the glass phase as a component.

On the other hand, as described above, the probe card ceramic wiring board 1 of the present embodiment is as follows.
When the mullite sintered body which is the insulating substrate 11 is 100 parts by mass, the total amount of Al contained in the mullite sintered body converted to Al ₂ O ₃ and Si converted to SiO ₂ is 100 parts by mass. _While containing 2.0 to 4.0 parts by mass in terms of ₂ O ₃ , 4.0 to 8.0 parts by mass in terms of Ti and TiO ₂ and 0.4 to 1.2 parts by mass in terms of MoO ₃ , Since it contains W, it becomes possible to obtain a dense mullite sintered body at a firing temperature of 1380 ° C. to 1420 ° C., which will be described later, and W, which is a high melting point material, is contained in the mullite sintered body. Since it exists, it can suppress exudation due to a decrease in the viscosity of the glass phase and improve chemical resistance.

  Further, the probe card ceramic wiring board 1 of the present embodiment includes a conductor layer made of a composite conductor of Cu and W in an insulating base 11, and the mullite sintered body to be the insulating base 11 is And an alloy of Mo and W (hereinafter referred to as Mo-W alloy) at the grain boundary, and in X-ray diffraction, the main peak of the Mo-W alloy with respect to the diffraction intensity of the mullite main peak ((210) plane) The diffraction intensity ratio of ((110) plane) is 0.17 to 0.90. Thereby, it can suppress that the wiring resistance of the conductor layer of the ceramic wiring board for probe cards becomes high.

  In the probe card ceramic wiring substrate 1 of the present embodiment, when the W-Mo alloy is present in the grain boundary portion of the mullite sintered body constituting the insulating base 11, diffusion of W contained in the conductor layer is suppressed. For this reason, since the shape of the conductor layer is maintained, for example, defects such as thinning are less likely to occur in the conductor layer.

  On the other hand, when the ratio of each component of Mn, Ti and Mo contained in the mullite sintered body is out of the composition in the present embodiment, the chemical resistance is lowered or the appearance of the insulating substrate is poor. Or the sheet resistance of the conductor layer may increase.

  Here, the presence of Mn, Ti, Mo and W contained in the insulating substrate 11 can be confirmed from an element analyzer provided in a transmission electron microscope or a scanning electron microscope. The composition of Mn, Ti, Mo and W contained in the insulating substrate 11 can be confirmed by atomic absorption analysis and ICP (Inductivity Coupled Plasma) analysis.

  In the probe card wiring board 1 of the present embodiment, the conductor layer is preferably a composite conductor having a composition of 40 to 60% by volume of Cu and 40 to 60% by volume of W.

  A material for forming the internal wiring layer 12 that can be fired simultaneously with the mullite sintered body is W, which is a refractory metal, and the internal wiring layer 12 made of W has a high electric resistance value. On the other hand, a low resistance metal such as Cu has a melting point considerably lower than the firing temperature of a ceramic sintered body containing mullite as a main component, so only Cu, which is a low resistance metal, is simultaneously used with a ceramic sintered body containing mullite as a main component. It cannot be fired. Therefore, by making the internal wiring layer 12 a composite conductor of Cu and W, the electrical resistance value is somewhat higher than that of Cu alone, but at a firing temperature of 1380 ° C. to 1420 ° C. described later, Can be fired simultaneously.

  However, even if simultaneous firing is possible, since firing is performed at a temperature exceeding the melting point of Cu, it is necessary to suppress the melting of Cu and maintain the shape of the internal wiring layer 12. Therefore, in order to achieve both the low resistance and the shape retention of the internal wiring layer 12, it is preferable to set the ratio of Cu to 40 to 60% by volume and W to 40 to 60% by volume.

Here, the composition of Cu and W of the internal wiring layer 12 was determined by cutting out a portion where the internal wiring layer 12 was formed from the probe card wiring substrate 1, and using a solution obtained by dissolving this in an acid using an ICP analysis. The contents of Cu and W are determined by mass. Next, the volume of Cu and W calculated | required as mass is divided | segmented by each density, each volume is calculated | required, and the ratio of Cu and W when the total volume of Cu and W is made into 100% next is calculated | required.

  The surface wiring layer 13 may have the same composition as that of the internal wiring layer 13 or may be different, and may be formed of only refractory metal W or Mo.

  Further, it is desirable that the via-hole conductor 14 has the same composition as that of the surface wiring layer 13 in order to prevent the conductor component from dropping off from the via-hole conductor 14 during firing.

  Further, in the probe card wiring board 1 of the present embodiment, the ratio of the Mo—W alloy mainly present in the grain boundary portion is based on the diffraction intensity of the mullite main peak ((210) plane) in X-ray diffraction. The ratio of the diffraction intensity of the main peak ((110) plane) of the Mo—W alloy is preferably 0.20 to 0.78. As a result, the average value of the wiring resistance of the conductor layer (internal wiring layer) can be 2.5 mΩ / □ or less and the maximum value can be 5 mΩ / □ or less in terms of sheet resistance, thereby suppressing an increase in wiring resistance. it can. And by suppressing the increase in wiring resistance, the disturbance of the electrical signal can be reduced as the probe card wiring board 1, thereby preventing an inspection error.

Here, the presence of the Mo—W alloy contained in the insulating substrate 11 is confirmed by pulverizing the insulating substrate 11 and performing powder X-ray diffraction.

Further, the probe card ceramic wiring board 1 of the present embodiment has a MnTiO ₃ crystal phase at the grain boundary portion of the mullite main crystal particles, and the amount of glass components present at the grain boundary portion of the mullite main crystal particles. Therefore, even when the insulating substrate 11 is immersed in a 40 mass% potassium hydroxide aqueous solution for 5 hours, the glass component contained in the mullite sintered body is hardly eluted.

Here, the presence of the MnTiO ₃ crystal phase contained in the insulating substrate 11 is determined as follows. First, an area of 300 μm square on the surface of the sample polished for analysis is observed using a scanning electron microscope provided with an X-ray microanalyzer (EPMA) to confirm the presence of the MnTiO ₃ crystal phase. Here, the total amount of Al contained in the mullite sintered body in terms of Al ₂ O ₃ and Si in terms of SiO ₂ is 100 parts by mass. The content of aluminum (Al), silicon (Si), manganese (Mn), titanium (Ti), and molybdenum (Mo) contained in the insulating substrate 11 is determined by ICP analysis after being dissolved in an acid. The elements are calculated by converting to Al ₂ O ₃ , SiO ₂ , Mn ₂ O ₃ , TiO ₂ , and MoO ₃ , respectively.

  In addition, in the mullite sintered body in the present embodiment, in addition to Mn, at least one selected from Ca, Sr, B, Cr, and the like as an auxiliary component that enhances sinterability is chemical resistance and foreign matter adhesion. It may be contained to the extent that it does not impair characteristics such as the appearance defect occurrence rate.

  The above-described ceramic wiring board for probe card 1 of the present embodiment includes a measurement terminal (probe pin) provided on the ceramic wiring board for probe card 1 and a measurement pad formed on the surface of the Si wafer during a thermal load test. Can be suitably used for inspection of electrical characteristics. Further, when the mullite sintered body has a specific composition, it becomes dense.

Further, on the main surface of the insulating base 11 constituting the probe card ceramic wiring substrate 1 shown in FIG. 1, a land pattern (FIG. 1) originally connected to the via-hole conductor 14 instead of the surface wiring layer 13 immediately after firing. (Not shown) is formed. This land pattern is formed after the internal wiring layer 12 and via-hole conductor 14 of the ceramic wiring board 1 for probe card after firing.
It is provided to perform a short or open inspection of the electrical connection. Then, after performing a short or open inspection of the electrical connection between the internal wiring layer 12 of the probe card ceramic wiring board 1 and the via-hole conductor 14, the land pattern is removed by polishing, and the via-hole conductor 14 is exposed. The surface wiring layer 13 is formed by a thin film method such as sputtering or vapor deposition, and further, measurement terminals (probe pins) are formed on the surface of the surface wiring layer 13 to produce the probe card 2 shown in FIG. The

  FIG. 2 is an explanatory diagram of a semiconductor element evaluation apparatus using one embodiment of the probe card of the present invention. The probe card ceramic wiring board 1 described above can be used as a probe card 2 as shown in FIG. 2, for example.

  In the probe card 2 shown in FIG. 2, a surface wiring layer (not shown) connected to the internal wiring layer 12 is formed on one main surface of the probe card ceramic wiring substrate 1, and a semiconductor element is formed on the surface wiring layer. A probe (measurement terminal 21) for measuring the electrical characteristics of the external circuit board 4 is connected, and the external circuit board 4 is joined to the surface opposite to the surface on which the measurement terminal 21 is formed via the connection terminal 3. It has been configured.

  Here, the external circuit board 4 is connected to the tester 5, and the measurement terminal 21 of the probe card 2 is brought into contact with the upper surface of the semiconductor wafer 7 placed on the stage 6 to measure the electrical characteristics of the semiconductor element. can do.

  Note that the probe card 2 can be driven up and down by the elevating device 8, and the measurement terminal 21 of the probe card 2 is brought into contact with or separated from the upper surface of the semiconductor wafer 7.

  When the probe card ceramic wiring board 1 of the present embodiment is applied as the wiring board of the probe card 2, first, at the time of the thermal load test, the measurement terminal 21 provided on the probe card ceramic wiring board 1 and the Si wafer 7 are used. There is no positional deviation with respect to the measurement pad formed on the surface, and it can be suitably used for inspection of electrical characteristics.

  Next, a method for manufacturing the above-described probe card ceramic wiring board 1 will be described.

First, in order to form the insulating substrate 11, a mullite (3Al ₂ O ₃ · 2SiO ₂ ) powder having a purity of 99% or more and an average particle size of 0.5 to 2.5 μm is used. By making the average particle size of mullite powder 0.5 μm or more, sheet formability is improved, and by making it 2.5 μm or less, it is possible to promote densification by firing at a temperature of 1420 ° C. or less. It becomes.

Next, with respect to 100 parts by mass of mullite powder, 2.0 to 4.0 parts by mass of Mn ₂ O ₃ powder, 4.0 to 8.0 parts by mass of TiO ₂ powder, and 0.4 to 0.4 of MoO ₃ powder. 2.1 Add parts by weight and a trace amount of W powder. In this case, the average particle size of the Mn ₂ O ₃ powder used as an additive is 0.5 to 3 μm, the TiO ₂ powder is 0.5 to ₂ μm, the MoO ₃ powder is 0.5 to ₂ μm, and the W powder is 0.3 to ₃ μm. It is good to use what is 1 micrometer. The purity of the Mn ₂ O ₃ powder, TiO ₂ powder, MoO ₃ powder and W powder is preferably 99% by mass or more. Thereby, sheet moldability can be made favorable, diffusion of Mn, Ti and Mo can be improved, and sinterability at a temperature of 1380 ° C. to 1420 ° C. can be improved.

As described above, the probe card wiring board 1 of the present embodiment adds W powder together with Mn ₂ O ₃ powder, TiO ₂ powder and MoO ₃ powder to a green sheet for forming a mullite sintered body. When the W powder is added to the green sheet, the metal Mo and W powder formed by reduction of the MoO ₃ powder contained in the green sheet are combined and alloyed during firing. Usually, when the green sheet contains a Mo component and the wiring pattern serving as the internal wiring layer contains W, the W in the wiring pattern easily combines with the Mo contained in the green sheet. However, in the probe card wiring board 1 of the present embodiment, since the green sheet to be the insulating base 11 contains W in advance as described above, Combine with Mo, which is also contained in the green sheet, and alloy. For this reason, the diffusion of W from the internal wiring layer can be suppressed. In addition, since this Mo-W alloy is a metal, it is difficult to combine with the mullite sintered body that is a metal oxide, so that the Mo-W alloy is present at the grain boundary around the main crystal phase of mullite. In the probe card wiring board 1 of the present embodiment, since the diffusion of W constituting the internal wiring layer can be suppressed as described above, the shape retention of the internal wiring layer can be maintained, whereby the wiring of the internal wiring layer can be maintained. An increase in resistance can be suppressed.

Moreover, when manufacturing the ceramic wiring board 1 for probe cards of this embodiment, when MoO ₃ powder and W powder are added together with Mn ₂ O ₃ powder and TiO ₂ powder to mullite powder, the glass phase oozes out. Therefore, appearance defects due to adhesion of foreign substances are less likely to occur. In particular, when the MoO ₃ powder and the TiO ₂ powder are in a predetermined ratio (MoO ₃ powder: TiO ₂ powder = 0.9 to 1.1: 1.8 to 2.2, the same ratio even after firing), it is obtained. Whitening in the vicinity of the wiring of the insulating base 11 can be suppressed, thereby increasing the color contrast between the insulating base 11 and the wiring, and as a result, it is possible to reduce numerical variations when the wiring is inspected. Become.

  Mn, Ti, and Mo may be added as carbonates, nitrates, acetates, and the like that can form oxides by firing in addition to the above oxide powders.

Furthermore, for the reason that the densification of the mullite sintered body and the simultaneous sinterability of the composite metal forming the internal wiring layer 12 are enhanced, the group of Ca, Sr, B and Cr with respect to 100 parts by mass of the mullite powder. One or more oxide powders selected from (CaO powder, SrO powder, B ₂ O ₃ powder, Cr ₂ O ₃ powder) or a powder composed of carbonate, nitrate, acetate capable of forming an oxide by firing, You may add in the ratio which does not change the thermal expansion coefficient of the ceramic wiring board 1 for probe cards of this embodiment, and does not deteriorate chemical resistance.

  Next, an organic binder and a solvent are added to the mixed powder to prepare a slurry, and then a green sheet is produced by a molding method such as a press method, a doctor blade method, a rolling method, and an injection method. Alternatively, an organic binder is added to the mixed powder, and a green sheet having a predetermined thickness is produced by a method such as press molding or rolling. In addition, although the thickness of a green sheet can be 50-300 micrometers, for example, it is not specifically limited.

  Then, a through hole having a diameter of 50 to 250 μm is appropriately formed on the green sheet by a micro drill, a laser, or the like.

  The conductor sheet is prepared by mixing Cu powder and W powder with the above-described ratio (Cu is 40 to 60% by volume, W is 40 to 60% by volume) to the green sheet thus prepared. The conductive paste is prepared and filled in the through holes of each green sheet, and printed and applied by a method such as screen printing or gravure printing to form a wiring pattern.

  In this conductive paste, alumina powder or a mixed powder of the same composition as that of the insulating base 11 may be added in addition to the above metal powder in order to improve adhesion to the insulating base 11, and further Ni Active metals such as those or oxides thereof may be added at a ratio of 0.05 to 2% by volume with respect to the entire conductor paste.

  Thereafter, the green sheet on which the conductor paste is printed is aligned and laminated and pressure-bonded, and then the laminate is fired in a non-oxidizing atmosphere (nitrogen atmosphere or a mixed atmosphere of nitrogen and hydrogen).

  Here, the maximum temperature during firing is preferably 1380 ° C. to 1420 ° C. When the maximum temperature during firing is 1380 ° C. to 1420 ° C., the mullite sintered body can be densified by adjusting the holding time at a temperature in this range.

  Further, in the mullite sintered body that is the insulating base 11 constituting the probe card ceramic wiring substrate 1 of the present embodiment, when a predetermined amount of at least Mn, Ti, and Mo is contained and fired, neck growth of mullite particles is suppressed. Therefore, abnormal grain growth of mullite can be suppressed, and a mullite sintered body having a high Young's modulus can be obtained.

Further, when producing the probe card ceramic wiring board 1 of the present embodiment, the rate of temperature increase from 1000 ° C. to the highest firing temperature for densifying the mullite sintered body is 50 ° C./hr.
To 150 ° C./hr, particularly 75 ° C./hr to 100 ° C./hr, and the rate of temperature decrease from the highest firing temperature to 1000 ° C. is 50 ° C./hr to 300 ° C./hr, in particular 50 ° C./hr. h
It is desirable to set it to r-100 degreeC / hr.

  Furthermore, the firing atmosphere is a non-oxidizing atmosphere containing hydrogen and nitrogen and having a dew point of not higher than + 30 ° C., particularly not higher than + 25 ° C., for the purpose of suppressing diffusion of Cu in the internal wiring layer 12. Is desirable. If the dew point during firing is higher than + 30 ° C., oxide ceramics react with moisture in the atmosphere during firing to form an oxide film, and this oxide film and copper react to reduce the resistance of the conductor. This is not only a hindrance, but also promotes the diffusion of Cu. Note that an inert gas such as argon gas may be mixed in this atmosphere as desired.

  The probe card ceramic wiring board 1 manufactured by the method described above includes Cu and W as main components, has an internal wiring layer 12 with low wiring resistance, and has a thermal expansion coefficient of the heat of the Si wafer to be inspected. It is close to the expansion coefficient.

Mn ₂ O ₃ powder with a purity of 99% and an average particle size of 1.5 μm, with a purity of 99% and an average particle size of 2.1 μm. 1.0 μm TiO ₂ powder, MoO ₃ powder with a purity of 99% and average particle diameter of 1.0 μm, and W powder with a purity of 99% and average particle diameter of 0.5 μm are mixed in the proportions shown in Table 1. After that, an acrylic binder as an organic resin for forming (organic binder) and toluene as an organic solvent were mixed to prepare a ceramic slurry, which was then molded into a sheet having a thickness of 200 μm by a doctor blade method. A green sheet was produced.

  15 layers of the obtained green sheets were laminated, degreased in a nitrogen-hydrogen mixed atmosphere with a dew point of + 25 ° C. at a temperature from room temperature to 600 ° C., and then fired. Firing was performed in a nitrogen-hydrogen mixed atmosphere with a dew point of + 25 ° C. at 1380 ° C. for 1 hour and then cooled to obtain a mullite sintered body.

Here, the appearance defect occurrence rate of the insulating base shown in Table 1 is obtained by calculating the probability of seeping out and adhering foreign matter after 39 samples were inspected. Here, the state in which the sample is exuded is such that a slightly glossy glass phase can be confirmed on the surface of the insulating substrate by visual observation or observation with a stereomicroscope of about 50 times, and foreign matter adheres. The state of being carried out is a case where a particulate state adheres to the surface of the insulating substrate by the same confirmation method.

  Further, as an indicator of chemical resistance, the initial mass of the mullite sintered body and the mass of the mullite sintered body after being immersed in a 40% by weight aqueous solution of potassium hydroxide at 100 ° C. for 5 hours were measured, and the weight decreased. Ratio (“initial mass of mullite sintered body” − “mass of mullite sintered body after being immersed in an aqueous solution of 40 mass% potassium hydroxide at 100 ° C. for 5 hours” / “initial mass of mullite sintered body” ”× 100 [%]). Here, the chemical resistance was determined to be acceptable when the weight change rate was 0.12% by mass or less. The number of samples was 3, and the average value was obtained.

  In addition, a conductor paste prepared by making Cu powder and W powder 45% by volume of Cu and W by 55% by volume is printed on the surface of each green sheet, and the internal wiring pattern is formed on the produced green sheet. A green sheet in which via conductors were formed by filling Mo through paste in the through holes was prepared.

  At this time, 12 evaluation patterns having a line width of 100 μm and a length of 20 mm are formed in a part of the internal wiring pattern for wiring width measurement, and this internal wiring pattern is connected to the via conductor, A land pattern was formed at the end of the internal wiring pattern for connection to the via conductor.

  The ceramic green sheets thus produced were aligned and laminated and pressed to produce a laminate. In the laminate produced here, a ceramic green sheet provided with pads for contacting measurement terminals for resistance measurement is arranged on the uppermost layer, and an internal wiring pattern and land for resistance measurement are arranged on the second layer. A ceramic green sheet on which a pattern is printed is placed, and the through hole (filled with Mo conductor paste) provided in the uppermost layer is electrically connected to the land on which the second layer is printed. As described above, the alignment is performed, and a total of 30 ceramic green sheets are laminated.

  Next, this laminate was fired under the same degreasing and firing conditions as described above to produce a probe card ceramic wiring board. The substrate size was 340 mm × 340 mm and the thickness was 5 mm.

  Next, after polishing the surface of the produced probe card ceramic wiring board and removing the land pattern, the surface of the probe card ceramic wiring board is made of titanium and copper having a thickness of about 2 μm by sputtering. Conductive thin films were formed in order.

  Next, a conductive thin film of titanium and copper is patterned by photolithography, and nickel and gold electrolytic plating films are formed in this order on the copper surface, and on the via-hole conductor on the surface of the probe card ceramic wiring board. A surface wiring layer was formed.

  Next, a Si measurement terminal (probe pin) was joined to the surface of the surface wiring layer formed on the surface of the probe card ceramic wiring substrate to produce a probe card.

  Next, the probe pin that is the measurement terminal of the probe card is brought into contact with the upper surface of the Si wafer placed on the stage and held at a temperature of 90 ° C., using a stereomicroscope from the side of the probe card, The positional deviation between the probe pin and the measurement pad formed on the surface of the Si wafer was observed. In this case, when the measurement terminal (probe pin) and the measurement pad formed on the outermost periphery of the probe card and the Si wafer are observed, the tip of the measurement terminal (probe pin) is displaced laterally from the measurement pad. Was assumed to be misaligned. None of the fabricated samples showed any misalignment.

  The wiring resistance is expressed by the relational expression: R × W / L, where R is the resistance of the conductor obtained by measurement at 12 locations, L is the total length of the internal wiring layer to be measured, and W is the width of the internal wiring layer. Resistance value (referred to as sheet resistance, the unit is mΩ / □). The electrical resistance was measured by a four-terminal method using a digital multimeter, and the maximum value and average value of 12 data were confirmed.

  Further, the ratio of the Mo—W alloy contained in the insulating substrate was measured by powder X-ray analysis (XRD analysis) after pulverizing the insulating substrate. In this case, it was obtained from the ratio (a / b) of the intensity a of the peak (110 plane) of 2θ = 40.4 ° indicating the Mo—W alloy and the intensity b of the maximum peak (210 plane) of mullite.

The content of Al, Si, Mn, Ti, Mo and W contained in the insulating substrate is determined by first dissolving the insulating substrate cut out from the probe card wiring board in an acid, A qualitative analysis of the elements contained in the body porcelain was performed, and then, a standard solution diluted with a standard solution for each identified element was used as a standard sample for quantification by ICP emission spectroscopic analysis. In this case, the contents of aluminum (Al), silicon (Si), manganese (Mn), titanium (Ti), molybdenum (Mo) and tungsten (W) contained in the insulating substrate are obtained by ICP analysis, and these analyzes are performed. Among the values, the amount of mullite (3Al ₂ O ₃ · 2SiO ₂ ) was determined from aluminum (Al) and silicon (Si), and the amounts of Mn, Ti, and Mo relative to the amount of mullite were determined in terms of oxides. As a result, the compositions of Mn, Ti and Mo contained in the sintered body were in agreement with the compositions shown in Table 1, respectively.

  Further, the composition of Cu and W of the internal wiring layer is a conductor material obtained by cutting out a portion where the internal wiring layer is formed from the probe card wiring board and dissolving the solution in an acid using ICP analysis. The contents of Cu and W were determined by mass. Next, the amounts of Cu and W obtained as masses were divided by the respective densities to determine the respective volumes, and then the ratio of Cu and W when the total volume of Cu and W was taken as 100% was determined. . In addition, it was confirmed that the internal wiring layer formed on the produced probe card wiring board was 45% by volume of Cu and 55% by volume of W. These results are shown in Table 1.

  As is clear from the results in Table 1, in the samples of the present invention (sample Nos. 5 to 8 and 13 to 16), the weight change rate in the chemical resistance test is 0.09% by mass or less, and the chemical resistance is low. Satisfied, there was no foreign matter adhering to the surface of the insulating substrate, and the appearance defect rate was zero%. Moreover, the average value of wiring resistance (sheet resistance) was 2.5 mΩ / □, and the maximum values were all low at 7 mΩ / □ or less.

  In particular, in the X-ray diffraction of the ceramic sintered body, a sample in which the ratio of the diffraction intensity of the main peak of the Mo—W alloy to the diffraction intensity of the main peak of mullite is 0.2 to 0.78 (sample Nos. 6 to 8). And 13 to 15), the average value of the wiring resistance (sheet resistance) was 2.5 mΩ / □, and the maximum values were all as low as 5 mΩ / □, indicating a stable resistance value.

  On the other hand, the samples outside the scope of the present invention (Sample Nos. 1-4, 9-12, and 17-21) have a chemical change resistance with a weight change rate of greater than 0.12% by mass. It was bad, or foreign matter adhered to the surface of the insulating substrate, or the wiring resistance was as high as 10 mΩ / □.

1: Ceramic wiring board for probe card 11: Insulating substrate 12: Internal wiring layer 13: Surface wiring layer 14: Via hole conductor 2: Probe card 21: Measurement terminal

Claims (3)

An insulating substrate made of a ceramic sintered body having mullite main crystal particles and a grain boundary portion existing around the main crystal particles and containing Mn, Ti, Mo and W, and provided in the insulating substrate When the total amount of Al converted to Al ₂ O ₃ and Si converted to SiO ₂ is 100 parts by mass, the Mn is converted to Mn ₂ O. _While containing 2.0 to 4.0 parts by mass in terms of 3; 4.0 to 8.0 parts by mass in terms of TiO _{2 and} Ti to 0.4 to 1.2 parts by mass in terms of MoO ₃ ; In the grain boundary portion, the alloy of Mo and W is included, and the ceramic sintered body is the main of the alloy of Mo and W with respect to the diffraction intensity of the main peak of mullite in X-ray diffraction. Peak diffraction intensity ratio is 0.17 to 0.9 Ceramic wiring board for probe card, characterized in that it.   The conductor layer is a composite conductor having a composition of Cu of 40 to 60% by volume and W of 40 to 60% by volume, and the ceramic sintered body has a diffraction intensity of the mullite main peak in X-ray diffraction. 2. The probe card ceramic wiring board according to claim 1, wherein the ratio of the diffraction intensity of the main peak of the alloy of Mo and W with respect to is 0.20 to 0.78.   A surface wiring layer is provided on the surface of the probe card ceramic wiring board according to claim 1, and a measurement terminal for measuring electrical characteristics of the semiconductor element is connected to the surface wiring layer. Featured probe card.

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