Wire bonding, 382 defined

A newer BBIT process has been defined to manufacture wire-bonding and flip-chip substrates. In this BBIT process (shown in Fig. 23.32), the prepreg is laser-drilled so that smaller cream Ag solder can be used to bond to the copper. 

The as-grown samples were investigated by optical microscopy and room temperature PL measurements. 300 x 300 gm square diode were defined by chlorine-based RIE. Electron beam deposited Pd/Au (20/200 nm) and Al/Au (30/300 nm) were used as p-GaN and n-GaN contacts, respectively. For packaging, the wafer was diced into discrete dies for attachment to submounts. Conventional die-bonding and wire-bonding techniques were then apphed, and the individual LEDs were packaged into conventional epoxy-encapsulated lamps. The electrical and luminescence characteristics of the diode were... 

Adhesive Bonding Technique. Standard procedures for preparing adhesive bond specimens were used. The composite was initially sanded with 240 grit emery paper and then thoroughly rinsed with methylene chloride. Steel substrates were rinsed thoroughly with methylene chloride. Bonds were prepared as one inch overlap shear specimens bond thickness was 0.75 mm. Bond thickness was defined using 1.5 mm long wires of the appropriate thickness. 

Figure 12.12 (a) Idealised single-molecule transport experiment, (b) Single-molecule transport experiment with optimal structural control based on a (1) epitaxial molecular monolayer with well-characterised adsorbate-substrate bond and (2) a specific, chemically well-defined tip-molecule contact, (c) Mechanically gated single-molecule wire based on experiment in b and STM tip retraction. 

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