One-dimensional nanostructures, such as nanowhisker, nanorod, nanowire, nanopillar, nanocone, nanotip, nanoneedle, have attracted significant attentions in the past decades owing to their numerous applications in electronics, photonics, energy conversion and storage, and interfacing with biomolecules and living cells. The manufacturing of nanostructured devices relies on either bottom-up approaches such as synthesis or growth process or top-down approaches such as lithography or etching process. Here we report a unique, synchronized, and simultaneous top-down and bottom-up nanofabrication approach called simultaneous plasma enhanced reactive ion synthesis and etching (SPERISE). For the first time the atomic addition and subtraction of nanomaterials are concurrently observed and precisely controlled in a single-step process permitting ultrahigh-throughput, lithography-less, wafer-scale, and room-temperature nanomanufacturing. Rapid low-cost manufacturing of high-density, high-uniformity, light-trapping nanocone arrays was demonstrated on single crystalline and polycrystalline silicon wafers, as well as amorphous silicon thin films. The proposed nanofabrication mechanisms also provide a general guideline to designing new SPERISE methods for other solid-state materials besides silicon.

This paper addresses implementation of a heating and cooling temperature ramp rate requirement and its impact on packaging processes. A complex multi-chip module packaging design includes a printed wiring board, solder attachment of a AlSiC-9 back plate, solder attachment of a multi-room seal frame, soldered surface mount components, power die soldered directly to a heat sink, epoxy attached chip-and-wire die, a welded lid and ribbon cable. Because of complex material interactions that exist in the design, concerns arose about cracking and other thermally induced damage that might occur during temperature excursions. The assembly challenge that resulted was a product requirement to limit the heating and cooling temperature ramp rates during packaging processes. Working together, the design agency and production agency ultimately came to an agreement on what the temperature ramp rate requirement should be and how to qualify the processes and the periodic determination of compliance. The requirement was implemented on all packaging processes that saw a heating and cooling cycle. Epoxy cure after die attach and wire bonding were modified most significantly and are specifically addressed in this paper. Solutions were implemented to minimize impact to assembly flowtime and to minimize the chance of processing errors. Temperature profiles had the ramp rates calculated then documented and qualified based on the process parameters (set point temperatures and dwell times) and the assembly machines, ovens, hot plates and tooling used. Compliance is proved through thermal profiling and calculation of ramp rate. Deviation from the set process will require approval from the design agency.

Low Temperature Cofired Ceramic (LTCC) technology can be applied in numerous functions due to a wide variety of benefits, particularly related to flexibility of applications. Controlling the LTCC shrinkage tolerances in the x, y, and z dimensions is critical during manufacturing and avoids an assortment of down-stream issues that will affect yields. All manufacturers of LTCC tape provide a Certificate of Analysis (COA), which contains the results of the manufacturer's shrinkage testing so production variation can be established from lot to lot. Data from this COA is generally used as a starting point in the shrinkage predictions for manufacturing purposes; however, verification of this data must be performed prior to initiating an LTCC build. This paper investigates validation of one manufacturer's COA data and explains how shrinkage differences can occur between the COA data and the data collected during the verification process. The tracking of this data is also presented as a means to ensure proper controls are in place, and the type and style of lamination and cofiring are shown to be significant contributors to these differences. Data will then be presented in association with characterization prior to and after relocation of LTCC fabrication equipment. Additionally, the COA data can be incorporated into shrinkage estimates that will be utilized to set up process parameters, tolerances, and a control plan.