LMP s Contributions in

Manufacturing Process Research

September 28, 2007

Outline

• Introduction

• Selective Examples

• Summary

Introduction

• Founded as an interdepartmentallaboratory within the School ofEngineering in 1977.

• Mission: Establishing manufacturingscience base & innovation

• More than 700 alumni, 1000publications and 100 patents

Selective Manufacturing ProcessResearch Activities at LMP

• Design (Axiomatic Design).

• Polymer processing (MIT-Industry Polymer ProcessingProgram, MIT-Industry Microcellular Plastics Consortium,Polymer MicroFabrication Program).

• Metal processing (Mixalloy process, Discrete Die SheetMetal Forming, Droplet-Based Manufacturing Program,CastScan Consortium).

• Ceramics processing (3D Printing Program).

• Semiconductor processing (CMP, Photoresist Coating).

• Control (Precision Engineering, Robotics, Welding).

Microcelluar Plastics

(Courtesy of Trexel, Inc.)

Microcellular Plastics (MCP) is definedas the plastic that has a large number ofsmall bubbles, typically less than 30microns.

What is a Microcellular Plastic?

MuCell Technology: Simultaneousnucleation of an extremely largenumber of cells.

(1) Rapid dissolution of gas into molten,flowing polymer to form a solution,

(2) Nucleation of a large number of cells,(3) Control of the cell size, and(4) Control of the geometry of the final

product.

Design of a ContinuousProcess/Equipment forMicrocellular Plastics

Design of a Continuous Process

Schematic of the Microcellular extrusion system used for theshaping and cell growth control experiments (FromBaldwin, Park and Suh, 1997)

Motor & Gear Drive

Metered Gas Supply

Pb

Pn

Tn

Hopper with

Pellets

Gas/Polymer Solution Formation

System

Polymer Processing

System

Heaters

Barrel

Two-Stage Screw

Foaming/Shaping

Die

Vent Port

Breaker Plate/ Flow Stabilizer

Static Mixer

Single-Phase Polymer/Gas

Solution

Nucleation Nozzle

Injection Molded Printer Chassis

(Courtesy of Trexel, Inc.)

Unanticipated Advantage ofMuCell Technology

• Decrease in viscosity.

• Lowering of melting point and glasstransition temperature.

• Elimination of shrinkage.

Discrete Die Sheet Metal Forming

Conventional Tooling

Tool

Pallet

Parking Lot

60 Ton Matched Discrete DiePress (Robinson et al, 1987)

Tool SetupActuators

Programmable Tool

Passive Tool

Press Motion

-

SHAPEMEASUREMENT

SHAPECONTROLLER

WORKPIECE

desiredshape +

shapeerror

finishedpartDISCRETE DIE

SURFACE

DISCRETE DIE

FORMING PRESS

CONTROLLER

TRACING CMM

Part Error

Die Shape

Change

New

Part

Shape

The Shape Control Concept

Cylindrical Part Error Reduction

0

10

20

30

40

50

60

P1 P2 P3 P4

PART CYCLE

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

RM

S E

rro

r [x

0.0

01

in

.]

MAX

RMS

SSYYSSTTEEMM EERRRROORR TTHHRREESSHHOOLLDD

MA

XIM

AL

SH

AP

E E

RR

OR

[x0.0

01 in

.]

Large Scale Tool

6 feet

Stretch Forming with Reconfigurable

Tool @ Northrop Grumman

Droplet-Based Manufacturing

Uniform-Droplet Spray (UDS) Process

Piezoelectric

Actuator

Inert GasSupply

Uniform Droplets

ChargingRing

Orifice

Crucible

Thermocouple

Liquid Metal

Shaft & Disk

Vibration

transmitter

Heater

-

+

Ball-Grid Array (BGA) Packaging and

Chip-Scale Package (CSP)

SOLDER BUMPS

CHIP DIE

PROTECTIVE CAP

BGA Packaging Chip-Scale Package

SOLDER BUMPSTHERMAL/GROUND VIAEPOXY PCBSOLDER MASK

PLATED COPPER

CONDUCTORDIE PADCHIP DIEWIRE BONDSIGNAL/

GROUND

VIA

On-Line Size Measurement

1 mm

Actual CCD

Camera

Image

Orifice

3/1

2

2

3 ���

=ODdd

Control Scheme

Voltage Amplifier

Vibration Frequency

TTL Frequency Signal

F / 10

Frequency

Divider

Stroboscope CCD Camera

Computer Motherboard

Computer

Frame GrabberFunction

Generator

UDS Generator

UDS Apparatuses

Spray Forming Chamber Automated UDS Generator

Three Dimensional Printing(3D Printing, 3DP)

Emanuel SachsFred Fort Flowers and Daniel Fort Flowers

Professor of Mechanical Engineering sachs@mit.edu

3D Printing

Office Modeler Z Corp., Burlington, MA

• Market Leader in “Office Modeling” (fastest growing sector).• 500 machines in field (over 40 at universities).• Office environment (water binder, starch powder or plaster based)• High reliability.• FAST

Other Commercial Applications

• Medical: drug delivery, scaffolds for tissue eng., tools forendoscopic surgery

• Ceramic molds for metal casting

• Direct printing of metal tooling

• Cutting tools

• Electronic ceramic parts

• Ceramic filters

Current Research Programs

• Center for Polymer Microfabrication(SMA)

• Chemical Mechanical Polishing

• Portable Fuel Cells

• MEMS Fabrication Processes

• Ink Jet Printing

LMP’s Educational and Research Programs

Systems

- Factory

- Supply chain

- Information

Sustainability- Environmentally-

benign mfg

- photvoltaics

Processes and equipment- Micro- & nano-scale

processes

- Precision equipment

Systems-level

design

Educational Initiative

- Mfg-related subjects