No abstract

Low-temperature co-fired ceramic (LTCC) offers many advantages as a material of multi-functional substrates for high-density, high-frequency microelectronic applications, as well as for enabling microsystems. One of the key challenges in manufacturing multilayered ceramic substrates is fabricating micro patterns on unfired green ceramic sheets, and micro embossing is an alternative and promising method for this purpose. This paper presents our achievements in fabricating micro patterns over a large area on multilayered green ceramic substrates using micro roller embossing. A commercialized roller laminating machine was modified and used as the roller embossing apparatus. The feasibility of micro roller embossing on green ceramic substrates with an effective panel size of 150 mm × 150 mm has been successfully demonstrated. Micro patterns, including channels and electrical passives with 50 µm line-width, were formed over the whole panel area. The influence of main process parameters on the pattern quality of roller embossing has been investigated and confirmed.

In this paper, we report a novel approach to fabricate a low cost, large area and flexible mould and its applications in large area roller embossing. A liquid crystal polymer (LCP) film, which had a high glass transition temperature of 280°C, was clad with copper foils on both sides, was used as a starting material for mould fabrication. The LCP film and the copper foils were 50 and 36 lm thick, respectively. The LCP-Cu flexible mould was obtained through photolithographic patterning and wet etching of the copper foil on top surface of the LCP film. Using this proposed method, a polymer-metal hybrid flexible mould with an area of 150 mm 9 150 mm was fabricated. The fabricated mould has a minimum feature size of 25 lm, and has been successfully used to demonstrate large area micro roller embossing. Micro channels, micro dots and micro mixers were embossed on polymeric as well as ceramic green substrates.

This paper presents a micro roller embossing process for patterning large-area substrates of laminated green ceramic tapes. The aim of this research is to develop a large-area microstructure formation technique for green ceramic substrates using a thermal roller laminator, which is compatible with screen printing apparatus. A thin film nickel mold was developed via photolithographic patterning and nickel electroplating on a 75-lm-thick nickel film. The mold had an effective panel size of 150 mm 9 150 mm with the height of plated protrusive patterns being about 38 lm. Formation of micro patterns was successfully demonstrated over the whole panel area on laminated green ceramic tapes using roller embossing. Micro patterns for inductors, heaters as well as interconnection with 50 lm line-width were embossed on green ceramic substrates. By means of tuning process parameters including roller temperature, applied pressure and feeding speed, we have demonstrated that micro roller embossing is a promising method for patterning large-area green ceramic substrates.

-This paper presents our latest achievements in developing large area patterning of multilayered ceramic green composites using micro roller embossing. The aim of this research is to develop large area pattern technique for ceramic green substrates using a modified roller laminator, which is compatible with screen printing apparatus, for integration of micro embossing and printing in the future stage. A thin film nickel mold was developed via photolithography, nickel electroplating and photoresist strip-off. The mold had an effective panel size of 150 mm× × × × 150 mm with the height of protrusive micro patterns being about 40 µm. Formation of micro patterns was successfully demonstrated over the whole panel area using roller embossing on laminated ceramic green tapes (HL2000 from Heraeus). Micro patterns for inductors, capacitors as well as interconnection with 50 µm line width were embossed on ceramic green substrates. With the optimized process parameters (including feeding speed, roller temperature and applied pressure), we have demonstrated that micro roller embossing is a promising method for large area patterning of ceramic green substrates.