MgF2-doped modified czp ceramic material and preparation method and application thereof

Abstract

The application belongs to the technical field of electronic ceramic materials, and particularly relates to a MgF2 doped modified CZP ceramic material and a preparation method and application thereof. The application is based on the CZP ceramic material with a negative thermal expansion coefficient and a low dielectric constant, and the sintering performance of the CZP ceramic is improved by doping MgF2. By means of different doping amounts, the sintering densification is carried out at a low temperature of 1000 DEG C to 1100 DEG C, so that the thermal expansion coefficient CTE of the modified CZP ceramic material is 2.9*10 ‑6 / ℃ to 5.87*10 ‑6 / ℃, the dielectric constant is 5.63 to 9.19, and the Young's modulus is 40 GPa to 147 GPa. The application provides a CZP composite ceramic material with a low dielectric constant, a low thermal expansion coefficient close to silicon, high mechanical strength and good density, and the CZP composite ceramic material can be applied to the production of wafer probe card ceramic conversion substrates based on the multilayer ceramic co-firing technology.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of electronic ceramic materials, and particularly relates to a MgF2 doped modified CZP ceramic material and a preparation method and application thereof. BACKGROUND

[0002] With the rapid development of the semiconductor industry, a large number of chips need to be detected before packaging, and a probe card needs to be used in this process, and corresponding contact points are made according to the actual position of the soldering point to complete the connection of the detection circuit. When the distance between the measured pad (electrical contact point) and the pad is less than 200 um, the industry (mainly Japanese Kyocera, Samsung and other companies) often uses a multi-layer ceramic structure adapter plate to complete the conversion from a small-pitch pad to a large-pitch pad by using a high-precision printing process.

[0003] In order to ensure the accuracy and stability of the adapter plate, it is crucial to develop a ceramic material with a low thermal expansion coefficient (CTE, close to the wafer Si material) and high mechanical strength. Among many ceramic materials, CaZr4(PO4)6 (referred to as CZP) phosphate ceramic material has attracted much attention due to its low thermal expansion coefficient (-1.6 x 10 -6 / ℃), adjustable thermal expansion performance, good thermal shock resistance and non-toxicity. However, the sintering of CZP ceramic is difficult, the density is low, and the mechanical properties are poor, which seriously limits its application. Researchers have tried to improve the sintering performance of CZP ceramic by adding MgO sintering aid, whisker toughening and rapid hot-pressing sintering process, etc., to improve the mechanical strength of CZP ceramic, but the effect is not enough.

[0004] Therefore, if a suitable sintering aid can be found to improve the sintering performance of CZP, increase the density, and adjust the thermal expansion coefficient close to silicon and maintain high mechanical strength, it will be the simplest and most effective technical solution to solve the problem of using such ceramic materials in wafer probe card ceramic adapter substrates. SUMMARY

[0005] In view of the above problems or deficiencies, in order to improve the density and sintering performance of CZP ceramic material, and adjust the thermal expansion coefficient close to silicon and maintain high mechanical strength, the application provides a MgF2 doped modified CZP ceramic material and a preparation method and application thereof. The material can be densified at a lower temperature, has a low thermal expansion coefficient and good mechanical strength, and can be used in wafer probe card ceramic adapter substrates based on multi-layer ceramic co-firing technology.

[0006] The application discloses a MgF2 doped modified CZP ceramic material, and relates to the technical field of ceramic materials. -6 / ℃~5.87×10 -6 / ℃), low dielectric constant (5.63-9.19), and high Young's modulus (40GPa-147Gpa).

[0007] The preparation method of the MgF2 doped modified CZP ceramic material comprises the following steps.

[0008] Step 1, uniformly mixing CaZr4(PO4)6 powder as a main base material with MgF2 powder accounting for 5wt%-15wt% of the CaZr4(PO4)6 powder.

[0009] Step 2, granulating the uniformly mixed powder in step 1 by adding PVA aqueous solution (concentration: 8wt%-12wt%) as a binder, and performing compression molding at 18MPa-20MPa, and the pressure maintaining time is 2min-3min.

[0010] Step 3, sintering the compression molded sample in step 2 at 1000℃-1100℃, the heating rate is 1℃ / min-2℃ / min, and the holding time is 4h-6h; and then naturally cooling the sample to obtain the MgF2 doped modified CZP ceramic material with low thermal expansion coefficient, low dielectric constant and high Young's modulus.

[0011] Further, the uniform mixing method in step 1 is as follows: the mass ratio of the material CaZr4(PO4)6+MgF2: deionized water: ball is 1:1:1.2-1.5, the rotation speed of the ball mill is 250r / min-300r / min, and the ball milling time is 12h-18h; and then drying at 80℃-120℃.

[0012] Further, the preparation method of the CaZr4(PO4)6 powder is as follows.

[0013] Step 1, preparing raw materials CaCO3: ZrO2: NH4H2PO4 according to the molar ratio.

[0014] Step 2, uniformly mixing the prepared raw materials in step 1 according to the mass ratio of the material: deionized water: ball of 1:1:1.2-1.5, the rotation speed of the ball mill is 250r / min-300r / min, and the ball milling time is 8h-12h; and then drying at 80℃-120℃ and sieving through a 40-mesh screen.

[0015] Step 3, the ball mill powder obtained in step 2 is pre-fired at 1250-1300 DEG C, the holding time is 6-10 hours, and the heating rate is 1-10 DEG C / min.

[0016] Further, the MgF2 doped modified CZP ceramic material is applied to wafer probe card ceramic adapter substrate material based on multilayer ceramic co-firing technology.

[0017] In summary, the application is based on the CZP ceramic material with negative thermal expansion coefficient and low dielectric constant, the sintering performance of the CZP ceramic is improved by adding MgF2, and a ceramic material with low dielectric constant, low thermal expansion coefficient, high mechanical strength and good density is provided. By different doping amounts, sintering at 1000-1100 DEG C, the thermal expansion coefficient (CTE) of the CZP ceramic material is between 2.9*10 -6 / ℃-5.87*10 -6 / ℃, the dielectric constant is 5.63-9.19, the Young's modulus is 40-147 GPa, and it can be applied to wafer probe card ceramic adapter substrate material based on multilayer ceramic co-firing technology. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is the process flow chart of the solid phase reaction method for preparing the material of the application;

[0019] Figure 2 It is the XRD graph of the CZP ceramic material in examples 1-5, wherein x represents the mass ratio of MgF2;

[0020] Figure 3 It is the thermal expansion coefficient value of the CZP ceramic material in examples 1-5;

[0021] Figure 4 It is the dielectric constant value of the CZP ceramic material in examples 1-5;

[0022] Figure 5 It is the density value of the CZP ceramic material in examples 1-5;

[0023] Figure 6 It is the Young's modulus value of the CZP ceramic material in examples 1-5;

[0024] Figure 7 It is the XY axis shrinkage rate value of the CZP ceramic material in examples 1-5;

[0025] Figure 8 It is the Z axis shrinkage rate value of the CZP ceramic material in examples 1-5;

[0026] Figure 9A wafer probe card multilayer ceramic adapter substrate made of the doped CZP ceramic material of Example 3 is shown in the figure;

[0027] Figure 10 A partial enlarged view of the wafer probe card multilayer ceramic adapter substrate of Example 3 is shown in the figure. DETAILED DESCRIPTION

[0028] The following examples are prepared by the aforementioned solid phase method of the present application to verify the technical effects of the present application and to further illustrate the present application in detail.

[0029] Example:

[0030] A method for preparing a MgF2-doped modified CZP ceramic material (as shown in Figure 1 The method comprises the following steps:

[0031] Step 1, preparation of CaZr4(PO4)6 powder: raw materials are prepared according to the molar ratio CaCO3:ZrO2:NH4H2PO4 of 1:4:6, and the raw materials are sequentially subjected to ball milling, drying, crushing, sieving, 1250℃ pre-sintering, and heat preservation for 8h to obtain CaZr4(PO4)6 material with negative thermal expansion coefficient. The pre-sintering temperature is 1250℃, and the heat preservation time is 8h.

[0032] Step 2, ball milling and uniformly mixing CaZr4(PO4)6 powder with MgF2 powder accounting for x proportion of the weight of CaZr4(PO4)6, and drying at 100℃; that is, 100wt% CaZr4(PO4)6+xMgF2, x=0.05-0.15.

[0033] Step 3, adding PVA aqueous solution (concentration 10wt%) as a binder to granulate the uniformly mixed and dried powder of Step 2, and pressing into shape at 20MPa, and holding for 2min.

[0034] Step 4, sintering the sample pressed into shape in Step 3 at 1000℃-1100℃, with a heating rate of 2℃ / min, and heat preservation time of 5h, and naturally cooling after the temperature drops to 500℃, to obtain CZP ceramic composite material with low thermal expansion coefficient, low dielectric constant, and high Young's modulus.

[0035] There are a total of 5 groups of examples, and other process conditions are the same, x=0.05, x=0.075, x=0.1, x=0.125, and x=0.15, respectively, corresponding to Examples 1-5.

[0036] The material samples prepared in the above 5 groups of examples are tested, and the results are as follows Figures 2-8 .

[0037] Figure 2XRD patterns of the CZP ceramic materials in Examples 1-5 groups, wherein x represents the mass ratio of MgF2 to CaZr4(PO4)6 powder. The thermal expansion coefficient test results of Examples 1-5 groups are shown in Figure 3 As shown, it is shown that the thermal expansion coefficient of the CZP ceramic can be adjusted with the increase of the MgF2 addition amount, and the near-silicon thermal expansion coefficient (3.4×10 -6 / ℃) can be obtained when the doping amount is 7.5wt%-10wt%.

[0038] The dielectric constant test results of Examples 1-5 groups are shown in Figure 4 As shown, the dielectric constant of the CZP ceramic presents a decreasing trend with the increase of the MgF2 addition amount, and the decrease is more obvious when the doping amount is greater than 12.5wt%.

[0039] The density and Young's modulus test results of Examples 1-5 groups are shown in Figure 5 , Figure 6 As shown, the density of the CZP ceramic first increases and then decreases with the increase of the MgF2 addition amount, and the Young's modulus is basically stable at more than 100Gpa when the doping amount is less than 15wt%, and the Young's modulus can reach 147Gpa when the doping amount is 12.5wt% and the sintering temperature is 1100℃.

[0040] The shrinkage test results of Examples 1-5 groups are shown in Figure 7 , Figure 8 As shown, the XY axis shrinkage of the CZP ceramic is basically stable at the same sintering temperature with the increase of the MgF2 addition amount, and the Z axis shrinkage basically increases with the increase of the MgF2 addition amount when the doping amount is less than 12.5wt%, and decreases when the doping amount is greater than 12.5wt% due to the appearance of micro-cracks.

[0041] The green ceramic substrate obtained after casting, punching and layering of the CZP ceramic material of Example 3 and the substrate after sintering are shown in Figures 9-10 , which can be applied to the wafer probe card ceramic conversion substrate material based on the multi-layer ceramic co-sintering technology. Figure 9 , Figure 10 The left picture in Figure 10 is before sintering, and the right picture is after sintering; Figure 9 is a partial enlarged view.

[0042] As can be seen from the above examples, the CZP ceramic material with a negative thermal expansion coefficient and a low dielectric constant is used as the basis, the sintering performance of the CZP ceramic is improved by doping MgF2, and the thermal expansion coefficient CTE of the modified CZP ceramic material is 2.9×10 -6 / ℃~5.87*10 -6 / ℃, dielectric constant is 5.63~9.19, Young's modulus is 40GPa~147Gpa. The application provides a CZP composite ceramic material with low dielectric constant, near-silicon low thermal expansion coefficient, higher mechanical strength and good density, which can be applied to the production of wafer probe card ceramic transfer substrate material based on multilayer ceramic co-firing technology.

Claims

1. A MgF2 doped CZP ceramic material, characterized in that: CaZr4(PO4)6 powder and MgF2 powder accounting for 5wt%-15wt% of the CaZr4(PO4)6 powder are prepared by solid phase method at 1000-1100℃ without pressure sintering, the thermal expansion coefficient is 2.9*10 -6 / ℃-5.87*10 -6 / ℃, the dielectric constant is 5.63-9.19, and the Young's modulus is 40GPa-147GPa.

2. The method for preparing MgF2-doped modified CZP ceramic material as described in claim 1, characterized in that, comprising the following steps: Step 1, uniformly mixing CaZr4 (PO4) 6 powder with 5wt%-15wt% of MgF2 powder; Step 2, adding PVA aqueous solution as a binder to granulate the uniformly mixed powder of Step 1, and pressing into a shape under 18MPa-20MPa, with a pressure holding time of 2min-3min; Step 3, sintering the sample pressed into a shape in Step 2 at 1000℃-1100℃, with a heating rate of 1℃ / min-2℃ / min, and a holding time of 4h-6h; and naturally cooling the sample to obtain the MgF2 doped CZP ceramic material.

3. The method for preparing MgF2-doped modified CZP ceramic material as described in claim 2, characterized in that, The mixing method in Step 1 is: According to the mass ratio of material CaZr4 (PO4) 6+MgF2:deionized water:ball of 1:1:1.2-1.5, the ball mill speed is 250r / min-300r / min, and the ball milling time is 12h-18h; and then drying at 80℃-120℃.

4. The method for preparing MgF2-doped modified CZP ceramic material as described in claim 2, characterized in that, The preparation method of the CaZr4 (PO4) 6 powder is: Step 1, preparing raw materials CaCO3:ZrO2:NH4H2PO4 according to the molar ratio; Step 2, uniformly mixing the prepared raw materials in Step 1 according to the mass ratio of material:deionized water:ball of 1:1:1.2-1.5, the ball mill speed is 250r / min-300r / min, and the ball milling time is 8h-12h; and then drying at 80℃-120℃ and passing through a 40 mesh screen; Step 3, pre-sintering the ball milled powder obtained in Step 2 at 1250℃-1300℃, with a holding time of 6h-10h, and a heating rate of 1℃ / min-10℃ / min. 5.The application of a CZP ceramic material prepared by the preparation method of the MgF2 doped CZP ceramic material according to claim 2 as a wafer probe card ceramic transfer substrate material based on multi-layer ceramic co-firing technology.

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