Recent lma_pmg items

Designing Imprint Rolls for Fluid Pathway Fabrication

Mon, 29 Oct 2012 00:00:00 +0000

This paper discusses a novel method for designing imprint rolls for the fabrication of fluid pathways. Roller imprint processes have applications in diverse areas including fuel cell manufacturing and microfluidic device fabrication. Robust design methods are required for developing imprint rolls with optimal features. In the method discussed in this paper, the rolls are designed procedurally with the fluid pathway design given as input. The pathways are decomposed into repeating features (or tiles), and the rolls are designed by first modeling a small set of unique tiles and then combining them to model the entire roll. The tiling strategy decreases the complexity of the model, and reduces the time taken for designing the rolls. The modular nature of the tiles also improves the efficiency of post-processing operations like feature identification and optimization, and the generation of toolpaths for machining the roll.

Precision Manufacturing of Imprint Rolls for the Roller Imprinting Process

Mon, 29 Oct 2012 00:00:00 +0000

The roller imprinting process is being developed for the efficient and accurate fabrication of microfluidic devices. As the precision of the imprinted features is dependent on the features of the imprint rolls used in the process, it is critical that the rolls are manufactured very accurately, conforming closely to their design. It is also important that imprint rolls are manufactured rapidly and cost-effectively to control the cost and lead-time of roller imprinting. This paper looks at the application of micromachining technology in the manufacturing of imprint rolls. Sources of error during the manufacturing process are identified, and their effect on the precision of the final imprinted feature is discussed. Toolpath planning strategies are presented for generating very smooth surfaces. The paper presents a framework of precision manufacturing requirements for the roller imprinting process.

A model of material removal and post process surface topography for copper CMP

Thu, 22 Mar 2012 00:00:00 +0000

Increasing systemic error during copper CMP (Chemical Mechanical Planarization) is due to the uneven surfacetopography generated during the process. A mechanistic model based on a fundamental understanding of the processconstituents was proposed to predict material removal rates and the post CMP topography. Two synergisticmechanisms were proposed: 1) chemically dominant behavior is explained by the repetitive removal and formation ofa protective layer on copper surface and chemical dissolution during the process, 2) mechanically dominant removalmechanism is due to the material behavior of copper at the nano-scale and subsequent oxidation and removal of theplastically deformed copper. As a step forward to optimize the process and the manufacturing system, this model wasextended to explain pattern dependent variability during copper CMP.

DESIGN AND FABRICATION OF A ROLLER IMPRINTING DEVICE FOR MICROFLUIDIC DEVICE MANUFACTURING

Thu, 20 Jan 2011 00:00:00 +0000

Microfluidic devices are gaining popularity in a variety of applications, ranging from molecular biology to bio-defense. However, the widespread adoption of this technology is constrained by the lack of efficient and cost-effective manufacturing processes. This paper focuses on the roller imprinting process, which is being developed to rapidly and inexpensively fabricate micro-fluidic devices. In this process, a cylindrical roll with raised features on its surface creates imprints by rolling over a fixed workpiece substrate and mechanically deforming it. Roller imprinting aims to replace processes that were developed for laboratory scale prototyping which tend to not be scalable and have high equipment requirements and overheads. We discuss the limitations of PDMS soft lithography in large-scale manufacture of microfluidic devices. We also discuss the design, fabrication, and testing of a simple roller imprinting device. This imprinter has been developed based on the principles...

ADDRESSING PROCESS PLANNING AND VERIFICATION ISSUES WITH MTCONNECT

Thu, 20 Jan 2011 00:00:00 +0000

Robust interoperability methods are needed in manufacturing systems to implement computeraided process planning algorithms and to verify their effectiveness. In this paper we discuss applying MTConnect, an open-source standard for data exchange in manufacturing systems, in addressing two specific issues in process planning and verification. We use data from an MTConnect-compliant machine tool to estimate the cycle time required for machining complex parts in that machine. MTConnect data is also used in verifying the conformance of toolpaths to the required part features by comparing the features created by the actual tool positions to the required part features using CAD tools. We demonstrate the capabilities of MTConnect in easily enabling process planning and verification in an industrial environment.

CMP Modeling as a part of Design for Manufacturing

Thu, 20 Jan 2011 00:00:00 +0000

dielectric materials, including predicting stresses and damage, and designing very low stress polishing processes; and c) designing new planarization processes for new materials and new requirements.

To address these, a multi-scale (feature/die/wafer) CMP modeling framework is being developed for enabling Design for Manufacturing (DfM) and Manufacturing for Design (MfD). Topographic evolution has been studied for Shallow Trench Isolation CMP and is now being extended to copper CMP. A detailed, quantitative understanding of the mechanism(s) of CMP is being elucidated, using fundamental experiments and a mechanistic model based on physical data....

Surface finishes from turning and facing with round nosed tools