A thermally compatible electronic packaging ceramic material for GaAs semiconductors and its preparation method

Abstract

This invention belongs to the field of ceramic packaging materials technology, specifically an electronic packaging ceramic material thermally matched with GaAs semiconductors and its preparation method, with the molecular formula ZnAl. 2‑x B x O4 (0.02≤x≤0.08). This invention, based on the excellent dielectric properties of ZnAl2O4 ceramics, utilizes B... 3+ Substitution of Al with the same valence state and similar radius 3+ Through B 3+ For Al 3+ The pure-phase substitution enhances the microwave dielectric properties and CTE of this ceramic, thus making it suitable as an electronic packaging ceramic material for thermal matching of GaAs semiconductors in high-frequency, high-power, and ultra-large-scale integrated circuits. Preferably, ZnAl is obtained by pre-firing at 1300℃ and sintering at 1450℃ with x = 0.04. 1.96 B 0.04 O4 ceramics, microwave dielectric properties and CTE: ε r =8.3, Q×f=68586GHz, τ f =‑46.5ppm / ℃、CTE=7.21×10 ‑6 K ‑1 .

Description

Technical Field

[0001] This invention belongs to the field of ceramic packaging materials technology, specifically relating to an electronic packaging ceramic material thermally matched with GaAs semiconductors and its preparation method, with the molecular formula ZnAl. 2-x B x O4 has excellent microwave dielectric properties and a thermal expansion coefficient that matches GaAs semiconductors, making it suitable as a ceramic material for electronic packaging in integrated circuits. Background Technology

[0002] As a key factor in the long-term reliability of integrated circuit products, electronic packaging primarily assembles various microelectronic components into chips that are protected from harsh environments. Common electronic packaging materials include metals, plastics, and ceramics. In comparison, ceramic packaging materials possess excellent electrical and mechanical properties, such as a low dielectric constant (ε). r Factors such as the quality factor (Q×f value) and the appropriate coefficient of thermal expansion (CTE) are crucial. Among these, the appropriate CTE between the ceramic and semiconductor is the most critical. Otherwise, internal stress can easily accumulate between the ceramic and semiconductor in a thermal cycling system, leading to an increased probability of chip failure.

[0003] Common semiconductor materials used in integrated circuits include Si, GaAs, and GaN. Among them, GaAs (CTE = 6.97 × 10⁻⁶ K⁻¹) is the most common. -1 Due to its high electron mobility, high saturation drift velocity, and wide bandgap, GaAs is widely used in communication applications requiring high frequency, high speed, high power, and high temperature, making it the fastest-growing, most widely used, and highest-volume semiconductor material after silicon. However, ceramic packaging materials to complement GaAs semiconductors are not yet fully developed. Summary of the Invention

[0004] To address the aforementioned problems and shortcomings, and to fill the technological gap in electronic packaging ceramic materials for GaAs semiconductors, this invention provides an electronic packaging ceramic material thermally matched to GaAs semiconductors and its preparation method. Ba was achieved in the ZnAl2O4 ceramic system. 3+ For Al 3+ The pure-phase substitution improved the microwave dielectric properties while reducing the CTE, thus achieving ε r =8.3, Q×f=68586GHz, τ f =-46.5ppm / ℃、CTE=7.21×10 -6 K -1 The ceramic material can be used as an electronic packaging material for GaAs semiconductors in integrated circuits.

[0005] An electronic packaging ceramic material with the molecular formula ZnAl that is thermally matched to GaAs semiconductors. 2-x B xO4, 0.02≤x≤0.08; prepared by pre-firing the raw materials of each element component at 1200℃~1300℃ using a solid-state reaction method, pressing them into shape, and then sintering them at 1425℃~1475℃.

[0006] Furthermore, the x = 0.04, pre-fired at 1300℃, and sintered at 1450℃; the corresponding ZnAl 1.96 B 0.04 The microwave dielectric properties and CTE of O4 ceramic are: ε r =8.3, Q×f=68586GHz, τ f =-46.5ppm / ℃、CTE=7.21×10 -6 K -1 .

[0007] The preparation method of the above-mentioned electronic packaging ceramic material thermally matched with GaAs semiconductors includes the following steps:

[0008] Step 1: According to the molecular formula ZnAl 2-x B x O4 (0.02≤x≤0.08) uses stoichiometric weighing of ZnO, Al2O3 and B2O3 raw materials, all with a purity ≥98%.

[0009] Step 2: Grind the raw materials weighed in Step 1 into a paste using a ball mill, and then dry them.

[0010] Step 3: Calcine the dried material obtained in Step 2 at a temperature of 1200℃~1300℃ for 2h~4h to obtain pre-calcined material, wherein the heating and cooling rates are both set to 1℃ / min~3℃ / min.

[0011] Step 4: Ball mill the pre-calcined material obtained in Step 3 again until it is homogeneous, and then dry it.

[0012] Step 5: Add 10wt% to 12wt% of binder (such as polyvinyl alcohol) to the dried material obtained in step 4 for granulation, and press it into a green body under a pressure of 20MPa to 24MPa for a holding time of 90s to 120s.

[0013] Step 6: Sinter the green body obtained in Step 5 at 1425℃~1475℃ to obtain ZnAl. 2-x B x O4 ceramic material, heat preservation time is 3h to 5h.

[0014] Furthermore, the drying temperatures in steps 2 and 4 are both higher than 100°C.

[0015] Common microwave dielectric ceramics often struggle to balance microwave dielectric properties with compatible CTE (coulombic conductivity). ZnAl₂O₄, due to its excellent mechanical properties, thermal stability, hydrophobicity, low surface acidity, and UV blocking properties, is frequently used in high-temperature ceramics, thermally conductive ceramics, luminescent substrates, optical coatings, catalysts, and activator carriers. This invention utilizes the superior microwave dielectric properties (ε) of ZnAl₂O₄. r =8.5, Q×f=56300GHz, τ f =-79ppm / ℃) and high CTE (10.7×10 -6 K -1 By modifying the ceramic with pure-phase substitution properties, the microwave dielectric properties and CTE of the ceramic can be improved, making it suitable for use as an electronic packaging ceramic material for thermal matching of GaAs semiconductors.

[0016] In summary, this invention, based on the excellent dielectric properties of ZnAl2O4 ceramics, utilizes B... 3+ Substitution of Al with the same valence state and similar radius 3+ Through B 3+ For Al 3+ The pure-phase substitution enhances the microwave dielectric properties and CTE of this ceramic, making it suitable as an electronic packaging ceramic material for thermal matching of GaAs semiconductors in high-frequency, high-power, and ultra-large-scale integrated circuits. The optimal microwave dielectric properties and CTE are obtained when x = 0.04, pre-fired at 1300℃, and sintered at 1450℃: ε r =8.3, Q×f=68586GHz, τ f =-46.5ppm / ℃、CTE=7.21×10 -6 K -1 . Attached Figure Description

[0017] Figure 1 This is a process flow diagram of the present invention;

[0018] Figure 2 ZnAl in Examples 1-4 2-x B x XRD pattern of O4 ceramic material;

[0019] Figure 3 ZnAl in Examples 1-4 2-x B x SEM image of O4 ceramic material;

[0020] Figure 4 ZnAl in Examples 1-4 2-x B x The coefficient of thermal expansion of O4 ceramic materials;

[0021] Figure 5ZnAl in Examples 1-4 2-x B x Microwave dielectric properties of O4 ceramic materials; Detailed Implementation

[0022] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0023] Example 1:

[0024] (1) The aforementioned solid-state reaction method is used to prepare ZnAl material according to the following raw material composition. 1.98 B 0.02 O4, x = 0.02.

[0025] Table 1: Formulation Table for Example 1 (Unit: mol)

[0026]

[0027]

[0028] (2) Weigh the raw materials according to the formula ratio in Table 1, and process the raw materials sequentially through ball milling, drying, pre-sintering, granulation, pressing and sintering to obtain ceramic materials. The concentration of polyvinyl alcohol binder is 12wt%, the drying temperature is 100℃, the pre-firing temperature is 1300℃, the pre-firing time is 3h, the molding pressure is 20MPa, the holding time is 120s, the sintering temperatures are 1425℃, 1450℃ and 1475℃, the heating rate and cooling rate are both 2℃ / min, the holding time is 4h, and the temperature is naturally cooled after dropping to 400℃.

[0029] Example 2:

[0030] (1) The aforementioned solid-state reaction method is used to prepare ZnAl material according to the following raw material composition. 1.96 B 0.04 O4, x = 0.04.

[0031] Table 2: Formulation table for Example 1 (unit: mol)

[0032] 1 0.98 0.02

[0033] (2) Weigh the raw materials according to the formula ratio in Table 2, and process the raw materials sequentially through ball milling, drying, pre-sintering, granulation, pressing and sintering to obtain ceramic materials. The concentration of polyvinyl alcohol binder is 12wt%, the drying temperature is 100℃, the pre-firing temperature is 1300℃, the pre-firing time is 3h, the molding pressure is 20MPa, the holding time is 120s, the sintering temperatures are 1425℃, 1450℃ and 1475℃, the heating rate and cooling rate are both 2℃ / min, the holding time is 4h, and the temperature is naturally cooled after dropping to 400℃.

[0034] Example 3:

[0035] (1) The aforementioned solid-state reaction method is used to prepare ZnAl material according to the following raw material composition. 1.94 B 0.06 O4, x = 0.06.

[0036] Table 3: Formulation Table for Example 1 (Unit: mol)

[0037] 1 0.97 0.03

[0038] (2) Weigh the raw materials according to the formula ratio in Table 3, and process the raw materials sequentially through ball milling, drying, pre-sintering, granulation, pressing and sintering to obtain ceramic materials. The concentration of polyvinyl alcohol binder is 12wt%, the drying temperature is 100℃, the pre-firing temperature is 1300℃, the pre-firing time is 3h, the molding pressure is 20MPa, the holding time is 120s, the sintering temperatures are 1425℃, 1450℃ and 1475℃, the heating rate and cooling rate are both 2℃ / min, the holding time is 4h, and the temperature is naturally cooled after dropping to 400℃.

[0039] Example 4:

[0040] (1) The aforementioned solid-state reaction method is used to prepare ZnAl material according to the following raw material composition. 1.92 B 0.08 O4, x = 0.08.

[0041] Table 4: Formulation Table for Example 1 (Unit: mol)

[0042] 1 0.96 0.04

[0043] (2) Weigh the raw materials according to the formula ratio in Table 4, and sequentially process the raw materials through ball milling, drying, pre-sintering, granulation, pressing, and sintering to obtain ceramic materials. The concentration of polyvinyl alcohol binder is 12wt%, the drying temperature is 100℃, the pre-firing temperature is 1300℃, the pre-firing time is 3h, the molding pressure is 20MPa, the holding time is 120s, the sintering temperatures are 1425℃, 1450℃, and 1475℃, the heating and cooling rates are both 2℃ / min, the holding time is 4h, and the material is allowed to cool naturally after the temperature drops to 400℃. Comparative Example:

[0044] Using the same process conditions as in Example 1, the difference is that x = 0, the sintered ceramic ZnAl2O4 is used as a comparative example.

[0045] The ceramic materials prepared in the above four embodiments and comparative examples were tested, and the results are as follows: Figures 2-5 As shown. The XRD and SEM test results for Examples 1-4 and the comparative examples are as follows. Figure 2 and Figure 3 As shown, it can be seen that B 3+ Al replaced in ZnAl2O4 3+ No second phase appeared, and B 3+ It helps with grain bonding.

[0046] The coefficients of thermal expansion of the ceramic materials prepared in Examples 1-4 and the comparative examples were tested, and the test results are as follows: Figure 4 As shown. The coefficient of thermal expansion of the best-matched GaAs semiconductor is 7.21 × 10⁻⁶. -6 K -1 The microwave dielectric properties of the ceramic materials prepared in Examples 1-4 were tested, and the test results are as follows: Figure 5 As shown. The optimal microwave dielectric property is ε. r =8.3, Q×f=68586GHz and τ f = -46.5ppm / ℃.

[0047] As can be seen from the above embodiments, the present invention adopts a method based on ZnAl2O4 ceramics, through B... 3+ For Al 3+ The pure phase substitution not only improves the microwave dielectric properties of the ceramic but also reduces the coefficient of thermal expansion, thus obtaining an electronic packaging ceramic material suitable for GaAs semiconductors, which effectively solves the problem of electronic packaging ceramic materials for GaAs semiconductors.

Claims

1. An electronic packaging ceramic material thermally matched with GaAs semiconductors, characterized in that: The molecular formula is ZnAl 2-x B x O4, 0.02≤x≤0.08; prepared by pre-firing the raw materials of each element component at 1200℃~1300℃ using a solid-state reaction method, pressing them into shape, and then sintering them at 1425℃~1475℃.

2. The electronic packaging ceramic material thermally matched with GaAs semiconductor as described in claim 1, characterized in that: The x = 0.04, pre-fired at 1300℃, and sintered at 1450℃; the corresponding ZnAl 1.96 B 0.04 The microwave dielectric properties and CTE of O4 ceramic are: ε r =8.3, Q×f=68586GHz, τ f =-46.5ppm / ℃、CTE=7.21×10 -6 K -1 .

3. The method for preparing electronic packaging ceramic material thermally matched with GaAs semiconductor as described in claim 1, characterized in that, Includes the following steps: Step 1: According to the molecular formula ZnAl 2-x B x O4 uses stoichiometric weighing of ZnO, Al2O3 and B2O3 raw materials, all with a purity ≥98% and 0.02≤x≤0.08; Step 2: Grind the raw materials weighed in Step 1 into a paste using a ball mill, and then dry them. Step 3: Calcine the dried material obtained in Step 2 at a temperature of 1200℃~1300℃ for 2h~4h to obtain pre-calcined material, wherein the heating and cooling rates are both set to 1℃ / min~3℃ / min; Step 4: Ball mill the pre-calcined material obtained in Step 3 again until it is homogeneous, and then dry it. Step 5: Add 10wt% to 12wt% of binder to the dried material obtained in step 4 for granulation, and press it into a green body under a pressure of 20MPa to 24MPa for a holding time of 90s to 120s. Step 6: Sinter the green body obtained in Step 5 at 1425℃~1475℃ to obtain ZnAl. 2-x B x O4 ceramic material, heat preservation time is 3h to 5h.

4. The method for preparing the electronic packaging ceramic material thermally matched with GaAs semiconductor as described in claim 3, characterized in that: The drying temperatures in steps 2 and 4 are both above 100°C.

5. The method for preparing the electronic packaging ceramic material thermally matched with GaAs semiconductor as described in claim 3, characterized in that: The adhesive used in step 5 is polyvinyl alcohol.

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