rob linke, mimforms llc - slide 1 metal injection molded photonic device packaging rob linke...

Rob Linke, MIMforms LLC - Slide 1

Metal Injection Molded Photonic Device Packaging

Rob LinkeMIMforms LLC


Outline

1. Metal injection molding defined

2. Manufacturing process

3. Materials for photonics packaging

4. Benefits of metal injection molding

5. Future directions

6. Conclusions and resources


What is MIM?


Metal Injection Molding

Utilizes wealth of technology developed for plastic injection molding

Injection molding of metal powder compounded with binder (plastic/wax)

Debinding of component (solvent or thermal) Sintering of part to final density


Manufacturing Process

Design of Component Tooling of Mold Injection Molding Debinding Sintering Optional CNC Machining Finishing/Plating


Compounding

Components Metal powder Wax Polymers

Goals Sufficient binder

to fill all voids Uniform mixture Metal powder at 100x

D50 : 2-10 µm


Injection Molding

Virtually identical to plastic injection molding

“Feedstock” is molded at low temperatures (150oC) with consistency of toothpaste

Consists of metal powder in binder matrix (~ 40% binder by volume)

Yields “green” part


Debinding

Binder removal from matrix (disposable component)

Solvent – water or other solvent Thermal decomposition Results in structurally weak

component with small amount of binder remaining


Sintering

Sintering densification increases the atomic bonds between particles

Temperature is near melting point

Density of up to 98.5% Real world example –

ice cubes sticking together in freezer

Sintering Furnace


Shrinkage in Sintering

Green part typically shrinks 15% during sintering

Density increases Strength increases Final mechanical

properties attained


Post-Sintering Structure

3000x Magnification


CNC Machining and Plating

MIM tolerances +/- 0.5% For features <4.0 mm it

is +/- 0.02 mm

CNC tolerances +/- 15 µm

Plating Gold Nickel Other


MIM Materials: Kovar®

Photonic and optoelectronics packages which match CTE of borosilicate glass29% W, 17% Co, 53% Fe

Properties CTE (30-400oC) 4.4-5.2 ppm/ oC Density – 7.95 g/cm3

% Density – 97%


MIM Materials: Iron-Nickel

Photonic and optoelectronics packages50% Fe, 50% Ni

Properties CTE – 8.8 ppm/ oC Density – 7.75 g/cm3

% Density - 95%


MIM Materials: Tungsten-Copper

Heatsinks for photonic housings which mirror CTE of borosilicate glass

80%W, 20% Cu as Example

Properties CTE – 7.4 ppm/ oC at 50oC Themal Conductivity – 189 W/m K Density – 14.89 g/cm3

% Density - 95%


Infiltrated Tungsten skeleton with liquid Copper

Vacuum Sintered Tungsten-Copper

powder

Tungsten Copper Structures


Why use MIM?

Reduce or eliminate individual CNC machining

Reduce material waste Enable mass production of

intricate, highly detailed structures

Reduce total costKovar Lens Holder


Machine Once or Many?

CNC machining Each part is machined

to final shape individually

MIM The mold is machined

once and parts are molded to final shape

production volume ►

package cost ►CNCMIM


Shape Complexity

CNC machining Each detail adds to

cost (and time)

MIM Details are machined

into the mold – once Reproduced in each

package during molding shape complexity ►

package cost ►CNCMIM


Material Waste Reduction

CNC removes large amounts of metal to yield housing

MIM uses only metal necessary

75% waste reduction typical

Runners, gates can be recycled on-site

Material waste with CNC Machining


Future Directions

Complex designs specifically for MIM manufacturing

Custom MIM alloys/mixtures Higher dimensional tolerance

MIM components Increasing adoption of MIM

package use in North America


Conclusions

MIM can be an enabling technology for photonic and optoelectronic packaging

Mass production Low/no cost structures Reduced material waste Designs not possible or economical with

CNC machining Greater alloy flexibility through batch

compounding


Additional Information on MIM

Organization:CISP-Center for Innovative Sintered Products-Penn State

Book:Injection Molding of Metals and Ceramics German & Bose

rob linke, mimforms llc - slide 1 metal injection molded photonic device packaging rob linke...

Documents

mimforms llc slide

magnification slide

final density slide

sintering density

thermal sintering

sintering green

binder matrix

debinding binder removal