Low Loss Gap Waveguide Transmission line and Transitions at 220–320 GHz Using Dry Film Micromachining

Abstract This paper describes the demonstration of a low loss substrate (laminated glass) for high-frequency transmission using a dry film build-up material with low loss tangent (Df). This paper also evaluates filter characteristics and dielectric characteristics of the substrate in the mm-Wave band. The advanced low loss dry film build-up material was newly developed, and applicable to high frequency transmission. This material has a Df of 0.0025 at 10 GHz and also exhibits excellent adhesion and electrical reliability required for advanced dielectric materials. In addition, glass was used as a core material in this paper because of its excellent signal transmission characteristics compared to silicon wafers or organic substrates. To demonstrate the benefit of low loss materials for high frequency transmission, passive components for high frequency filter substrates were fabricated using - 6-inch square thin (0.2mm) glass panel with various build-up materials (Material A with a Df of 0.0025, and Material B with a Df 0.0042 at 10 GHz) laminated. Copper wiring patterns on the dielectric layers were fabricated by a semi-additive process (SAP). Circuit patterns with low pass filters and band pass filters were also fabricated. First, transmission characteristics and characteristic impedances were measured to check the electrical performance. The measured lowest transmission loss of < 1.43 dB at 39 GHz were achieved when Material A was applied as the build-up material. Second, biased-highly accelerated stress test (bHAST) was conducted to evaluate the reliability performance of the substrates with two build-up materials, Material A and a conventional material. The test condition was based on the JEDEC level 2 standard. The substrate with Material A retained good insulation properties over 300 hours of bHAST treatment, demonstrating its excellent insulating performance. In summary, Material A has been shown in this paper to exhibit reduced transmission loss in high-frequency filter substrates at millimeter wave frequencies.

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A Low Loss Fully Embedded Stripline Parallel Coupled BPF for Applications using the 60 GHz Band

Additional Conferences (Device Packaging HiTEC HiTEN & CICMT) ◽

10.4071/cicmt-2011-ta22 ◽

2011 ◽

Vol 2011 (CICMT) ◽

pp. 000050-000053

Author(s):

Alexander Schulz ◽

Sven Rentsch ◽

Lei Xia ◽

Robert Mueller ◽

Jens Mueller

Keyword(s):

Return Loss ◽

Bandpass Filter ◽

Coplanar Waveguide ◽

Center Frequency ◽

60 Ghz ◽

Low Loss ◽

Wireless Applications ◽

High Data ◽

V Band ◽

Waveguide Transmission

This paper presents a low loss fully embedded bandpass filter (BPF) using low temperature co-fired ceramic (LTCC) for multilayer System-in-Package (SiP) and Multi-Chip-Module (MCM) applications, e.g. wireless applications for the unlicensed 60 GHz band. The measured insertion loss was 1.5 dB at the center frequency 58 GHz, and a return loss of less than −10 dB was achieved, including two grounded coplanar waveguide transmission line (CPWg) to stripline transitions. The four layers BPF has a 3 dB bandwidth of about 11 GHz which supplies e.g. broadband and high data rate applications. The whole BPF requires a substrate area of 5.6 × 2.1 × 0.42 mm3 with transitions and a shielding via fence. This BPF suits well for V-band applications in a LTCC package because of the compact dimensions and the good performance.

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