embedded inductors for power converter applications...mobile devices, automotive, industrial,...

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Embedded Inductors forPower Converter Applications

GaNonCMOS Summer School 2019

Gerald Weis

10.07.2019

GaNonCMOS Summer School 2019 / Gerald Weis / Leoben / 10.07.2019 1

Embedded Inductors for Power Converter Applications

AT&S Introduction

Embedding of components

Magnetics

Simulation

Demonstrators

Conclusion


AT&S – a world leading high-tech PCB & IC substrates company

High-end interconnect solutionsfor

Mobile Devices, Automotive, Industrial,

Medical Applications and Semiconductor

Industry

Outperforming

market growth

over the last

decade

€ 1bnrevenue in

FY 2018/19

Among top 10 PCB producers

worldwide*

# 3 in high-end technology

worldwide*

10,000Employees**

Efficient global production

footprint with

6 plants in Europe and Asia

* For CY 2017 Source: N.T. Information Ltd (July 2018); Prismark** For AT&S FY 2018/19

https://ats.net/wp-content/uploads/2019/01/ATS_IR-Presentation_EN_January_2019-1.pdf


3

Market Segments & Product Applications served by AT&S

Computer, Communication,

Consumer

Smartphones, Tablets, Wearables, Ultrabooks,

Solid State Drives, Microserver

Industrial

Machine-2-Machine Communication,

Robots, Industrial Computer,

X2X Communication

Automotive

Advanced Driver Assistance Systems,

Emergency-Call, X2X Communication

Medical

Patient Monitoring, Hearing Aids,

Pacemaker, Neurostimulation, Drug

Delivery, Prosthesis

IC substrates

High Performance Computer, Microserver

Segment Mobile Devices & Substrates Segment Automotive, Industrial, Medical


Global footprint ensures proximity to supply chain & cost efficiency

974* 404* 1,241* 2,369* 4,461* 289*

Shanghai China

AnsanKorea

ChongqingChina

Leoben, HeadquartersAustria

FehringAustria

NanjangudIndia

AT&S plant & sales office

AT&S sales office

AT&S Headquarters

*Staff, Average, FTE, FY 2018/19; 73 employees in other locations


R&D as the key for technological leadership

6.6% R&D Quota

(in % in relation to revenue) 258 Patents

International R&D Partners

As of FY 2017/18 (ended 31/03/2018)* Revenue generated with products with new, innovative technologies introduced to the market within the last three years

40.4%Innovation Revenue Rate *

R&DHeadquarters

AustriaIndustrialization at the respective

production site



AT&S Introduction


Magnetics

Simulation

Demonstrators

Conclusion


What is ECP®AT&S ECP® - Embedded Component Packaging

ECP® (Embedded Component Packaging) uses the free space in an organic, laminate substrate (Printed Circuit Board) for active and/or passive components

Components are integrated in the core of the PCB and connected by copper plated micro vias

ECP® contains three main manufacturing steps:

Component assembly

Lamination

Interconnect & imaging

CT image of embedded capacitors in a 4 layer PCB


Keyfacts

Laser drilled micro vias

Electrolytic plated copper

HDI PCB processes

PCB material and processes

Various combination of stack-ups possible

Active and/or passive components as well as mechanical components

Copper surface on IO‘s

Component (body) thickness 60µm - 300µm (min/max values)

Miniaturization

Reliable interconnection

Performance

Protection of components

Possibilities and requirements for an embedding project


Embedding Technology Development and Industrialization

1970First concepts for passive

component embedding introduced.

2000First step of AT&S into embedded

components. Research and

development on printed resistors and

capacitors inside the PCB.

2006First silicon bare die

followed by an IC

integrated. 2004Embedding of discrete

capacitors and

resistors in an organic

laminate substrate.

AT&S is part of various

development projects.

2012AT&S starts serial production of

ECP® products at the plant in

Leoben.

2010Industrialization of the AT&S

embedding technology ECP®

within the project “HERMES”.

Several product demonstrators

manufactured.

2018Second generation embedding

technology „Center Core ECP®“

qualified for mass production.

2016Project “empower” successfully

finished with prototypes for

electromobility.


Possible ArchitecturesECP® Core combined with standard PCB technology

Finish as 2 layer module

Sequential 4,6,8,10 layer build up

Multiple core build up

ECP® Core


Why ECP®

Unique Selling Propositions … in detail

Miniaturization• Footprint reduction • Higher component integration (additional assembly layer)

Electrical performance• Improved signal performance (higher data rates)• Reduction of parasitic effects

Mechanical performance

• Higher durability and reliability through copper-to-copper connections (copper filled micro vias)

• Package enables protective enclosure• High drop, shock and vibration tolerance

Thermal management• Improved heat dissipation through direct copper connection• Improved heat dissipation FR4 versus air (compared to SMD)

Additional functions Reduction of overall cost EMI shielding

• EMV shielding (partial or full shielding of a package)• Package is the housing no additional molding required

ECP is supporting the trend towards modularization

• Customization of footprint and module versions can be done due to digital imaging - no separate tooling necessary (e.g. QFN)

Anti-Tamper and Security • Hidden electronics preventing reverse engineering and counterfeiting


Embedding ProcessOverview

Core manufacturing

01

Lamination

02

Structuring

03

• Core preparation• Cavity cutting• Carrier lamination• Component assembly

• Soft lamination• Carrier removal• Final lamination

Laser drilling (component interconnection) Mechanical drilling (PTH) Plating and structuring Testing


ECP® Application Examples

Application GaN transistor package

Package size / Type Various

Substrate Construction/ Thickness 2 layer (double side connection)~540 um

# of embedded components 1

Voltage 100 – 650V

Link

https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=2ahUKEwjGj9LA14ncAhUGMuwKHTRMAHEQjRx6BAgBEAU&url=https://gansystems.com/&psig=AOvVaw1VtMGfJKuGyfl-jdHdd-gc&ust=1530939308537395

https://www.youtube.com/watch?v=k5aUmbV0MI8


ECP® Advantages: Thermal & Electrical Performance

Comparison between standard SMT and embedded transistor power modules show outstanding performance differences.

Power electronics: Half bridge module

Feature Standard Embedded

Output power [W] 1385 1385

Temperature [degC] 47.5 42

Module losses [W] 8.8 5.4

Device cooling area [mm²] 20.11 295.7

Thermal resistance @ 4W losses [K/W] 16.6 13.6

Thermal resistance, forced air @ 4W losses [K/W] 7.3 4.9

Commutation loop area [mm²] 12.4 7.74

Module thickness [mm] 1.29 0.75

ConclusionDistinct electrical and thermal performance improvements for embedded versionOptimized conduction loop leads to lower voltage ringingIncreased system efficiency Paper: PCIM 2018



AT&S Introduction


Magnetics

Simulation

Demonstrators

Conclusion


ECP® Embedded InductorsIntroduction

Buried ferrite sheets(embedding)

Inductive paste(printing)

Combination of paste and sheets

At the moment the following PCB inductors are feasible at AT&S:


ECP® Embedded InductorsPaste Materials

The graph shows a comparison of different past materials. The permeability is unfortunately not very high (< 30 H/m).

AT&S formulate a paste material with a permeability of 19 H/m for testing purposes.

The maximal printing thickness of the material is 60um(done by screen printing process)

Coating prototypes show results up to 500um material thickness thick material (non-automated experimental process)

Sintered ferrite sheets reaches permeability values up to 400 H/m.


Process Flow Ferrite Paste Embedding

Imaging

Mass lam

CORE

Start Core

Screen PrintingCORE

CORE

CORE Metallization

Automatic Inspection

Drying/CuringCORE

Wet film to dry filmthickness ratio is approximately 2:1.

Standard PCB

production


ECP® Embedded InductorsAdvanced shapes

Magnetic core

Copper

FR4 Core

Paste

Prepreg

Advanced core shapes+ Multi-core PCB necessary+ Flexible in forming air gaps+ Combination with embedded components possible+ Low leakage flux+ Can be combined with board in board technologies


ECP® Embedded InductorsPossible core shapes

Toroid+ very low leakage flux- Less space for vias in opening- Complex construction

Solenoid/Rectangular+ Easy design+ Easy manufacturing+ Enough via spacing- highest leakage flux

EE/EI-Core+ Perfect for coupled inductors+ Enough via spacing+ low leakage flux- Complex PCB construction

UI-Core+ Enough via spacing+ „normal“ leakage flux- Complex PCB construction

Magnetic core

CopperDue to high flexibility other core shapes are possible as well. This slide only shows the standard solutions tested up to now.


ECP® Embedded InductorsCalculation of Inductors in General

𝐿 =𝑁2

𝑙𝑒 − 𝑙𝑔𝜇0 × 𝜇𝑅 × 𝐴𝑒

+𝑙𝑔

𝜇0 × 𝐹 × 𝐴𝑒

𝐹 = 1 +𝑙𝑔

𝐴𝑒𝑙𝑛

2𝑙𝑊𝑙𝑔

Source:E. C. Snelling, "Soft Ferrites Properties and Applications", Iliffe Book Ltd, first edition, London, Chapter 4, pp. 171-193, 1969.Colonel Wm. T. McLyman, "Transformer and Inductor Design Handbook", Marcel Dekker, Inc., third edition, New York, Chapter 8, 2004.

L Inductance

N Number of turns

le Effective length of magnetic path

lg Length of air gap

μ0 Permeability in vacuum

μr Relative permeability of magnetic material

Ae Effective area of magnetic material

F Fringing factor

lw Length of windings

Development complex Formula's are strongly shape dependent Fringing calculation not accurate enough Many degrees of freedom


ECP® Embedded InductorsTransformers

Uses electrical energy to turn it into magneticfield and then again into electrical energy

AC input voltage creates magnetic field inside thecore

Magnetic flux induces current in the secondarywinding

Provides safety isolation in case of failures on primary circuit

Used for high side power supplies of half bridgecircuits

Source:https://de.wikipedia.org/wiki/Transformatorhttp://www.ht-transformer.net/high-frequency-transformer/


Soruce:Zo Ouyang, “High Frequency Planar Magnetics for Power Conversion,” ECPE Tutorial, Technical University of Denmark, Copenhagen, Sep. 2018.

ECP® EMBEDDED INDUCTORSState of the Art



AT&S Introduction


Magnetics

Simulation

Demonstrators

Conclusion


SimulationGeneral

Used to verify the calculated results

Better prediction of the inductors behavior

EMI check by H-field distribution

Inductance vs. Frequency characteristics

Inductance vs. Current curve

“Stored” energy observation

DC Resistance

AC Losses

Thermal behavior simulated (TRM)

Thermal Risk Management, Version: 2018

Simulation tool is the CST Studio suite, Version: 2018


N = 16R1 = 1.5 mmR2 = 5.25 mmh = 300 µm

Magnetic field lines distribution at 2.5 A

SIMULATIONFirst Inductor Demonstrator


ECP® Embedded InductorsSimulation Inductors

The following values where simulated:• B-Field• H-Field• Variation over frequency• Current characteristics• DC-Resistance• Temperature


ECP® Embedded InductorsWireless charging coil simulation

The following values where simulated:• H-Field• Optimized for charging mobile phones• Q-factor prediction• AC losses• DC resistance• Temperature (TRM)


ECP® Embedded InductorsTransformer Simulation

The following values where simulated:• B-Field• H-Field• Leakage inductance• Mutual inductance• Translation ratio• Thermal simulation (TRM)

Source:https://ront.info/systemwirkung-ront/grundlagen-ront/ersatzschaltbild/


SimulationThermal Simulations (TRM)

First demonstrator optimized for production

Large inlays cause warpage

Semi-automated assembly

Second version thermally and electrically optimized as well

V1

V2



AT&S Introduction


Magnetics

Simulation

Demonstrators

Conclusion


ECP® Embedded Inductors

Assembled parts need to have a midpoint

X, Y size of component is critical

3 air gap demonstrator contains 4 assembled parts

Prototype manufacturing is semi-automated

Fully automated assembly for components with electrical connection(s)

High volume production requires fully automated assembly

Assembly of inlays


DEMONSTRATOR ASSEMBLY

The assembly of the inlay was done on a semi-automatic assembly equipment. The ring cores werepicked up with a porous nozzle and dropped at the right position in the core cavity.

Semi-automated assembly equipment

Alignment fiducial


ECP® Embedded InductorsDemonstrator overview

# Type Version Information

1 Inductor V1 12 mm in diameter, 16 windings, 300um inlay, 0 to 3 air gap versions

2 Inductor V2 Miniaturized #1, 7.5 mm in diameter, but with thicker magnetic material inlay

3 Wireless Charger V1 45 mm x 45 mm QI compatible charger, 6 layer

4 Wireless Charger V2 Improved version of #1. Inlay size increased to 50 mm x 50 mm, 6 layer

5 DC/DC Converter V1 DC/DC converter, 6 layer, embedded inductor with SMT components

6 Transformer V1 Work in progress


ECP® Embedded InductorsDemonstrator #1 (Inductor) - Construction

Geometry Value Unit

Inner diameter 3 mm

Outer diameter 10.5 mm

Total thickness 0.5 mm

Windings 16 turns

Outer diameter (blue circle) 12.3 mm

Facts 4 layer construction No copper on CCE layers Different thicknesses possible (in this case 300um ferrite sheet) Copper height 40um (increasable)


ECP® Embedded InductorsDemonstrator #1 (Inductor) – Characterization I

Used measurement devices AC characteristics: Keysight E4991B 1 MHz to 3 GHz DC measurement: Fluke 289

Properties Test Condition Value Unit

Inductance 1MHz/9mA L 2.2 uH

Rated Current dT = 40K Ir 1.8 A

Saturation Current -30% of initial L Isat 1.5 A

DC Resistance 0.1A Rdc 81 mΩ

Self-resonance frequency Fres 35 MHz

Thermal Resistance x and y direction λ 18 W/mK

Thermal Resistance z direction λ 2 W/mK

Operating Temperature Top -40 -> 150 deg C


ECP® Embedded InductorsDemonstrator #1 (Inductor) – Characterization II

(2) Würth Electronics (74438323012)

Source: Paper PCIM 2019: Calculation, simulation and production of PCB integrated inductors with focus on fringing effect


Thermal evaluation based on in-house infrared camera measurements. At 2.5 A the temperature raised from an ambient 25°C to a steady state temperature of approximately 100°C.

The copper height is 40 um.

Increased copper layer height will lead to lower resistances resulting in lower temperatures.

ECP® Embedded InductorsDemonstrator #1 (Inductor) – Temperatures at 2.5 A


Facts:

2.5 A inductor with smaller footprint

Thicker copper lowers the DC resistance

Improved thermal behaviour (40°C temperature rise @ 2.5A)

Saturation current of 5A is larger due to increased air gap

Increased magnetic inlay height (500 um) leads to smaller outline

Due to assembly tests, the 3 gap version was produced only

ECP® EMBEDDED INDUCTORSDemonstrator #2 (Inductor) - Construction


Qi compatible charging dock with embedded magnetic inlay

45 mm x 45 mm x 300 um stacked nanocrystalline material

Aim was to find the maximum embeddable inlay size

Overall 6 layer PCB thickness is 600 µm

Maximum component thickness is 1,6 mm

Power rating: 2.5 W, wireless charging current: 500 mA

ECP® EMBEDDED INDUCTORSDemonstrator #3 (Wireless transmitter pad) - Construction

Copper defined charging coil

Magnetic material inlay

USB power socket

All results shown in Paper presented at the Wireless Power Week 2019


Currently in production Improved version handles up to 5W wireless charging power Dramatically reduced temperatures Stack of 500 um nanocrystalline material inlay improves

coupling Planned initial start-up is end of July

ECP® EMBEDDED INDUCTORSDemonstrator #4 (Wireless transmitter pad) – Improved version


12V to 3.3V with buried inductor

2 µH inductance at a current of 3 A

Module size: 13.3 x 14 mm

8 layer concept (6 metal layers)

PCB thickness 1.4 mm

DC/DC based on single IC solution

No components embedded

Demonstrator to initiate industrialisation

ECP® EMBEDDED INDUCTORSDemonstrator #5 – DC/DC converter module


ECP® EMBEDDED INDUCTORSDemonstrator #5 – DC/DC converter module


ECP® EMBEDDED INDUCTORSDemonstrator #5 – DC/DC converter module measurement

SMT Assembly managed by Recom

Electrical/Efficiency measurement done on a Recom eval board (picture)

Testing parameters:

1 air gap version

3 air gaps version

Input voltage variation

Output voltage either 5 V or 3.3V

Switching frequency 2.1 MHz


1 air gap 3 air gaps



Converter efficiency 5V/3A 2.1MHz


Effi

cien

cy


Converter efficiency 3.3V/3A 2.1MHz


Effi

cien

cy


ECP® EMBEDDED INDUCTORSDemonstrator #6 – Transformer

Application: Supply high side mosfet drivers

Isolation barrier for up to 3kV

Simulation shows good results

Work in progress – no finished prototype available now



AT&S Introduction


Magnetics

Simulation

Demonstrators

Conclusion


PCB based Inductors for Power ApplicationsConclusion

PCB-based production offers customizable solutions

FEM simulation is needed to predict inductor properties

Thinner solution in comparison to standard components

Decreased proximity effects (depends on the shape)

PCB-based inductors help to minimize power electronic systems

Technology can be used for inductors and transformers

Materials must fit to PCB production

System reliability is topic of further work

Assembly of components can be critical


Contact

Gerald Weis

Contact details

Hardware Development Center

Fabriksgasse 13

A-8700 Leoben

Austria

Tel.: +43 676 8955 6060

Email: [email protected]

mailto:[email protected]


www.ats.net

AT & S Austria Technologie &Systemtechnik Aktiengesellschaft

(Headquarters)Fabriksgasse 13,

8700 Leoben, AustriaTel.: + 43 3842 200-0

AT&S – First choice for advanced applications


This presentation is provided by AT & S Austria Technologie & Systemtechnik Aktiengesellschaft, having its headquarter at Fabriksgasse 13, 8700 Leoben, Austria, or one of its affiliatedcompanies (“AT&S”), and the contents are proprietary to AT&S and for information only.

AT&S does not provide any representations or warranties with regard to this presentation or for the correctness and completeness of the statements contained therein, and no reliancemay be placed for any purpose whatsoever on the information contained in this presentation, which has not been independently verified. You are expressly cautioned not to place unduereliance on this information.

This presentation may contain forward-looking statements which were made on the basis of the information available at the time of preparation and on management‘s expectations andassumptions. However, such statements are by their very nature subject to known and unknown risks and uncertainties. As a result, actual developments, results, performance or eventsmay vary significantly from the statements contained explicitly or implicitly herein.

Neither AT&S, nor any affiliated company, or any of their directors, officers, employees, advisors or agents accept any responsibility or liability (for negligence or otherwise) for any losswhatsoever out of the use of or otherwise in connection with this presentation. AT&S undertakes no obligation to update or revise any forward-looking statements, whether as a resultof changed assumptions or expectations, new information or future events.

This presentation does not constitute a recommendation, an offer or invitation, or solicitation of an offer, to subscribe for or purchase any securities, and neither this presentation noranything contained herein shall form the basis of any contract or commitment whatsoever. This presentation does not constitute any financial analysis or financial research and may notbe construed to be or form part of a prospectus. This presentation is not directed at, or intended for distribution to or use by, any person or entity that is a citizen or resident or locatedin any locality, state, country or other jurisdiction where such distribution, publication, availability or use would be contrary to law or regulation or which would require any registrationor licensing within such jurisdiction.

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embedded inductors for power converter applications...mobile devices, automotive, industrial,...

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