Properties and Characterization of Low Alkali Borosilicat Glass/Al2O3/Cordierite Composites for Low Temperature Co-fired Ceramic Applications

Abstract

The rising demands of microwave wireless communication require lightweight, com-pact, cost-effective, high-performance ceramics. Low Temperature Co-fired Ceramics (LTCC) provide key advantages for high-frequency applications in communication, automotive, and medical devices. In this study, glass/ceramic composite materials capable of densifying at low sintering temperatures were developed. The material systems were formulated using low-alkali borosilicate glass, alumina (Al₂O₃), and cor-dierite powders. Three different composite formulations were prepared and shaped via the tape casting method. The samples were sintered at 800, 850, and 900 °C for 1 hour, and their microstructures were analyzed using scanning electron microscopy (SEM) and X-ray diffraction (XRD). Dielectric and thermal properties were also evaluated. The results indicated that all composites reached their maximum densities at 850 °C, which was identified as the optimal sintering temperature for LTCC applications. The G6A4 composite, with high alumina content, exhibited the highest bulk density (2.39 g/cm³) and thermal conductivity (4.4 W/mK), making it a suitable candidate for microelect-ronic applications requiring effective thermal management. In contrast, the G6A1K3 composite with higher cordierite content showed lower density and thermal conductivity but demonstrated superior electrical performance with a dielectric constant of 5 and a very low dielectric loss of 0.0011 at 1 MHz, indicating its potential for high-frequency electronic applications.

Keywords

• glass/ceramic composites
• LTCC
• dielectric properties.

Düşük Sıcaklıkta Birlikte Sinterlenen Cam/Al₂O₃/Kordiyerit Esaslı LTCC Kompozitlerinin Termal ve Dielektrik Özelliklerinin İncelenmesi

Abstract

Mikrodalga kablosuz iletişim sistemlerinde artan ihtiyaçlar doğrultusunda, hafif, kompakt, düşük maliyetli ve yüksek performanslı seramik tabanlı malzemelerin ge-liştirilmesi kritik hale gelmiştir. Bu bağlamda, düşük sıcaklıkta birlikte sinterlenen se-ramikler (LTCC), başta kablosuz iletişim, otomotiv elektroniği ve tıbbi cihazlar olmak üzere birçok yüksek frekanslı uygulamada önemli avantajlar sunmaktadır. Bu ça-lışmada, düşük sinterleme sıcaklıklarında yoğunlaşma sağlayabilecek cam/seramik kompozitler geliştirmek amacıyla, düşük alkali içerikli borosilikat cam, alümina (Al₂O₃) ve kordiyerit tozları kullanılmıştır. Hazırlanan üç farklı kompozit formülasyonu, şerit döküm yöntemiyle şekillendirilmiş ve 800, 850 ve 900 °C’de 1 saat sinterlenmiştir. Mikroyapısal karakterizasyonlar taramalı elektron mikroskobu (SEM) ve X-ışını kı-rınımı (XRD) ile gerçekleştirilmiş, dielektrik ve termal özellikler ölçülmüştür. Elde edilen bulgulara göre, tüm kompozitler 850 °C’de maksimum yoğunluklarına ulaşmış ve bu sıcaklık LTCC uygulamaları için optimum sinterleme sıcaklığı olarak belirlenmiştir. Alümina içeriği yüksek olan G6A4 kompoziti, en yüksek yoğunluğu (2.39 g/cm³) ve en iyi termal iletkenlik değerini (4.4 W/mK) sergileyerek, ısı yönetimi gerektiren mikroe-lektronik uygulamalar için uygun bir aday olduğunu göstermiştir. Buna karşılık, kor-diyerit içeriği yüksek olan G6A1K3 kompoziti, daha düşük yoğunluk ve termal ilet-kenlik göstermesine rağmen, 1 MHz frekansında 5 değerinde dielektrik sabiti ve 0.0011 gibi çok düşük bir dielektrik kayıp sunarak yüksek frekanslı elektronik uygulamalarda elektriksel performans açısından öne çıkmıştır.

Keywords

• cam/seramik kompozitler
• LTCC
• dielektrik özellikler

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