frequency agile microwave oven bonding system (famobs)€¦ · a gain of productivity traditional...

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Frequency Agile Microwave OvenFrequency Agile Microwave Oven

Bonding SystemBonding System

(FAMOBS)(FAMOBS)

Dr. Marc Desmulliez Dr. Marc Desmulliez

Prof. Alan J. SangsterProf. Alan J. Sangster

Mr Keith I SinclairMr Keith I Sinclair

IeMRC Annual Review Conference – University of Loughborough – 27th March 2006

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A six month feasibility studyA six month feasibility study

• To manufacture a proof-of-concept device for a partially open,

variable frequency microwave (VFM) oven.

• The device configuration is suitable to be installed on the arm of a

die or flip-chip bonding machine for micron accuracy alignment

capability.

• The main design features are simultaneous alignment, curing &

bonding, multiple selective ‘hot-spot’ heating points, superior

control of position of the ‘hot-spots’ of energy & sequential curing

leading to fast packaging.


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A gain of productivityA gain of productivity

Traditional Assembly Process

FAMOBS Manufacturing Process

(Source: Prof. Chris Bailey, University of Greenwich)


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Concept and first prototypeConcept and first prototype


Microwave Heater on Die

Placement Arm

Die, Adhesives, Encapsulants,

Underfills, etcOpen Cavity Oven

(Source : Prof. Bailey)

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The sole competition : Lambda Technologies The sole competition : Lambda Technologies TMTM

(http://(http://www.microcure.comwww.microcure.com/)/)

MicrocureMicrocure 2100 2100

• Variable Frequency Microwave (VFM) Heating

• System offers several operating features including

User-defined profiling event cycles,

IR monitoring system for closed loop feedback.

• Cavity Dimensions = 55mm x 59mm x 75mm


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LambdaLambda FAMOBSFAMOBS

• Established product within

market

• Feasibility stage

• Multi-step assembly process • Combined assembly steps lead

to increased productivity

• Variable Frequency Microwave

curing permits the curing of high

conductivity materials

• Pulsed Single Frequency

Mode source prevents charge

build up


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LambdaLambda FAMOBSFAMOBS

• No selective heating possible • Single Frequency Mode

permits placement of ‘hot-

spots” of high electric field

• Possible high thermal stress• Low thermal stress due to

selective heating

• Uniform electric field pattern

using continuous frequency

sweep

• ‘User defined’ electric field

pattern using ‘targeted

frequency hopping / jittering’


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Layout of large scale open cavity ovenLayout of large scale open cavity oven

(Second prototype)(Second prototype)

• To be attached to precision placement machine

• Open cavity with conducting rods or dielectric recess


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Symmetry

Planes

Interface

Air Region

Using evanescent fringing fields for heatingUsing evanescent fringing fields for heating

• No propagation in air region

• Electric / Magnetic field decays rapidly


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Using evanescent fringing fields for heating

High ‘k’ dielectric material:

• Reduction in resonant freq. of mode

• Reduction in fringing field depth

• Increase in Q thus avoiding quasi-

degeneracy

• Greater change of normal electric

field through the interface


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Measurement LayoutMeasurement Layout

TWT (20W)

Sig. Gen.

Cavity

Circulator

Coupler

Power

Meter

Load


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Single Feed, Multiple Heating Spots @ Single Feed, Multiple Heating Spots @ 10.19GHz10.19GHz


(Black 25oC, red 26oC, green 28oC, blue 30oC)

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Closed cavity curing simulationClosed cavity curing simulation

TM334 mode; d = 6 Electric field through gap


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Specific Absorption Rate SimulationSpecific Absorption Rate Simulation

((EpotekEpotek 930 epoxy adhesive) 930 epoxy adhesive)

Epoxy radius = 0.5 mm Epoxy radius = 2 mm


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Summary of the project in a nutshell (1/2)Summary of the project in a nutshell (1/2)

A means of

• containing electromagnetic fields within an open cavity oven

for the purpose of heating.

• attaching the oven to a flip-chip bonding or die bonding

machine for combined alignment and heating.

• adjusting the length of the cavity to aid in the control of the

heating process.

• controlling the field penetration through the interface by

utilising a high k material.


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Summary of the project in a nutshell (2/2)Summary of the project in a nutshell (2/2)

A means of

• maximising the field strength by the novel use of a

Frequency Selective Surface.

• achieving VFM operation by the use of ‘targeted mode

jittering’.

• reducing the likelihood of arcing in Single Frequency Mode

by using a pulsed source.


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OutputsOutputs

Successful device demonstrating proof-of-conceptSuccessful device demonstrating proof-of-concept

heatingheating

1 patent filed1 patent filed

PublicationsPublications::

1 paper accepted at ESTC (June 2006)1 paper accepted at ESTC (June 2006)

1 paper for IEEE MTT scheduled1 paper for IEEE MTT scheduled

1 paper in IEEE in Advanced Packaging scheduled1 paper in IEEE in Advanced Packaging scheduled


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Future ResearchFuture Research

Micro-patterning of the open cavity to increaseMicro-patterning of the open cavity to increaseefficiency of the cavityefficiency of the cavity

CharacterisationCharacterisation of the curing of the different of the curing of the differentadhesives and pastes (adhesives and pastes (modellingmodelling and andexperimental)experimental)

Installation of the new generation of deviceInstallation of the new generation of deviceonto precision bonding machineonto precision bonding machine

CharacterisationCharacterisation of fully packaged devices of fully packaged devicesusing this methodusing this method


frequency agile microwave oven bonding system (famobs)€¦ · a gain of productivity traditional...

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