institute for material analysis...pcb pad copper conventional preparation of microsection ß mixed...

Institute for material analysis

Comprehensive analytical services for quality assurance and failure analysis

To ensure perfect functionality and quality the

analysis of electronic components becomes more

and more important for component manufacturers

and those who apply them.

It is essential to find together with the customer the

appropriate analysis plan out of the wide range of

the offered analytical services. Thus, a specific and

reliable examination of electronic components and

assemblies can be performed at a highly detailed

test level as well as a comprehensive analysis of the

occurred errors.

A modern, constantly expanding machinery park

-adapted to the increasing test and analysis

requirements- and a team of more than 220 engineers,

doctors, technicians and skilled workers provide

insight into all details and aspects of electronic

components into the lowest structure levels.

This evaluation is of significant importance especially

for electronic components of uncertain origin to

HTV offers a variety of analyses, for example:

• In-processqualitycontrolandfailureanalyses

• Analysesofproductsofuncertainorigin,processerrors,printedcircuitboarddefectsandcomponentfailures

• Materialidentification

• Determinationwithregardstocomponentmanipulationaswellasevaluationofthe

authenticity/counterfeit screening

• Determinationofthecurrentagingsituationandprocessability

• Prospectsintermsofstorability

• EvaluationofbareprintedcircuitboardsandassembliesaccordingtoIPC-A-600andIPC-A-610

• Assemblyandcomponentqualifications

• Measurementofioniccontaminationaccordingtocurrentstandards

maintain the quality of the particular products. A sin-

gle component of poor quality or a bad solder joint

can compromise the function and the quality of the

entire electronic assembly.

Therefore, it is important to secure the component

quality and availability in advance: various strategies

and analysis procedures as well as HTV’s experience

over many years enable the identification of poten-

tial weak points and errors, on time. Hence, as part

of an anticipatory company policy the risk of huge

production issues, contractual penalties when deli-

vering not just in time and potential recourse claims

are minimized.

Already existing errors can quickly and entirely be

identified, located and analysed in detail.

Additionally, the comprehensive test laboratory pro-

vides the inspection of the electrical function as well

as of the data sheet values.

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HTV Conservation GmbHRobert-Bosch-Str.28•D-64625BensheimPhone:+49(0)6251/84800-0•Fax:+49(0)6251/84800-30E-Mail:[email protected]•Internet:www.HTV-Conservation.com© HTV® All rights reserved

Visual evaluation for the determination of component manipulation

Possible applications:

• Documentationofgoodsuponreceipt(DryPack,indicator,packing,possibleimpurity)

• Visualinspectionofthecontactpinsforexampleinviewofdeformationsandsolderresidues

• Lightmicroscopicexaminations

• Verificationofthepackagedimensionsaccordingtodatasheet

• X-rayinspection

• Inspectionofpackageinscriptionandsurfacebywipetest

• Chemicalcomponentdecapsulationforchipidentification

The number of manipulated electronic components is

steadilyincreasingonthefreemarket.

Next to already desoldered components, failure parts

thatdonotmeettherequiredparametersorevencom-

ponents with an incorrect respectively no die inside,

aboveallrelabeledcomponentsareproclaimedandsold

asoriginalproducts.

The ultramodern HTV analysis laboratory offers nu-

merousextensiveopportunitiestoperformevaluations

inviewoforiginalityandqualityofsuppliedpartssothat

possiblecomponentmanipulationscanbedetected.

Theoriginalityofthepurchasedpartsisensuredbyva-

riousdetailedexaminationsoftheexternalappearance

(e.g.incominginspection,lightmicroscopy)aswellasof

theinternalstructureafterchemicalcomponentdecap-

sulation(e.g.chipidentification).

Thisevaluation isofessential importanceespecially for

electroniccomponentsofuncertainorigin,thusthequa-

lityofownproductscanbemaintained.

Forexample,bymeansofawipetest,inwhichthesur-

faceofthecomponentistreatedwithspecialchemicals,

itispossibletodeterminewhetherthecomponentwas

relabeledormanipulated.

Additionally, further analyses like solderability test or

data sheet tests canbeperformed to complement the

visualevaluationofgoods.

Specially composed analysis packages allow the indi-

vidual evaluation of goods for each application, de-

pending on the required extent:

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Visual evaluation of goods

Light microscopy

Wipe test

Inspection of the component pins

Incoming inspection

LIGHT1

Light microscopy

Wipe test


Incoming inspection

Chemical component decapsulation

BASIC2

Light microscopy

Wipe test


Incoming inspection


X-Ray inspection

ADVANCED3

HTV Conservation GmbHRobert-Bosch-Str.28•D-64625BensheimPhone:+49(0)6251/84800-0•Fax:+49(0)6251/84800-30E-Mail:[email protected]•Internet:www.HTV-Conservation.com©HTV®Allrightsreserved

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Light microscopy

HTV Conservation GmbHRobert-Bosch-Str. 28 • D-64625 Bensheim Phone: +49 (0) 62 51 / 8 48 00-0 • Fax: +49 (0) 62 51 / 8 48 00-30E-Mail: [email protected] • Internet: www.HTV-Conservation.com© HTV® All rights reserved

Light microscopy as analysis and documentation method


• Analysis of printed circuit boards and assemblies

• Surface examination of contact pins of electronic components

• Investigation regarding occurrence of oxidation and diffusion effects

• Measurement of layer thicknesses and layer structures

• Documentation of deformation, damages and cracks at electronic components

• Examination of solder joints

For the documentation of damaged components and

for the examination of solder joints or already prepared

samples, e.g. microsections, the light microscopy is an

essential and important analysis method.

Depending on the problem and the size of the samples a

variety of modern high-resolution microscopes with se-

veral configuration options are available to achieve opti-

mum analysis results, e.g. reflected and transmitted light

as well as dark field inspection methods.

Images are digitized by use of high-resolution cameras

and are standardly provided in a complete examination

report.

Due to special image processing tools identified prob-

lem areas can be clearly highlighted and marked.

The light microscopy is an essential method, for example,

to inspect printed circuit boards according to IPC-A-610.

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MicrosectioningIon beam etching

Applied standards:- DIN EN ISO 1463- IPC-TM-650 Method 2.1.1

BGA-ball SMD-pin


Microsectioning and ion beam etching for visualizing finest details on sample surface


• Visualization of surface structures down to the nanometer scale

• Investigation of microstructures

• Determination of layer thicknesses on component pins

• Analysis and evaluation of solder joints, plated through holes and bonding areas

• Determination of failure mechanisms of electronic components

• Determination of inclusions, cracks and other damages, e.g. resulting from the soldering process

or mechanical stress

• Detection of delamination effects at printed circuit boards

• Analysis of aging processes

For a more detailed analysis of electronic components and printed circuit boards as well as assemblies, the microsectioning provides a useful extension of the light microscopic examination.

The specimen is divided by a high-precision cut along a defined line at the required position. After embedding the sample in special resin, it is prepared for further analy-ses via grinding and polishing steps according to sample-specific recipes.

In addition, the material of a polished sample can be stripped off at atomic level by performing the ion beam etching process. Thus, possible blurrings are removed and smallest details can be revealed.

Subsequently, the prepared samples can be further ana-lysed, for example, by scanning electron microscopy (SEM) even at nanometer scale.

Detail: Bond-connection

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MetaFinePrep®


MetaFinePrep® for qualitative and quantitative analysis of the microstructure of metallic materials


• Conclusion as to hardness, toughness, brittleness, solderability and chemical structure of the microstructure

• Identification of irregularities in the area of the intermetallic compound transition

(weakening of solder joint adhesion)

Metallographic-microstructure-preparation

The increasing availability of various composite materials and of new or enhanced materials requires more and more ad-

vanced and in-depth analysis methods in order to carry out appropriate inspections with the required quality standards.

Via the metallographic-microstructure-preparation MetaFinePrep® developed by HTV additional detailed conclusions

about the inner structure of the materials used are gained, which conventional testing methods do not provide.

Highly selective preparation of microsection with

HTV-MetaFinePrep®

Samples prepared with the highly-selective MetaFinePrep® method

show in contrast to conventionally processed samples the inner metallic

microstructure.

In combination with analyses in the scanning electron microscope

(SEM) metallic materials can be comprehensively assessed to compe-

tently evaluate microstructures and compound transitions in terms of

their quality and reliability.

SMD-pin copper

Tin/lead solder

PCB pad copper

Conventional preparation of microsection

ß mixed crystal tin grains with max. 1 % dissolved lead

Eutectic tin/lead (63/37) within the interstices of tin grains

SMD pin with dendritic copper structureafter high-selective MetaFinePrep® preparation.

Porous intermetallic phase transition

Hypereutectic tin/leadCrystal mixture structure (95/5)

PCB pad with grainy copper structure

Conventional preparation of microsection without

HTV-MetaFinePrep®

Using the example of SMD pins the solder connection of a conventional

preparation of microsection appears inconspicuous and with a perfect

adhesion.

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X-ray inspection


X-ray inspection for non-destructive examination of components and assemblies

Possible applications:2D X-ray:• Inspection of hidden solder joints (e.g. BGA inspection of solder ball shape and voids)• Inspection of bonding areas (e.g. broken bonds) and lead frames• Inspection of contacts and solder joints (anomaly, crack formation)• Analysis of bonding wires and of chip orientation in the component• Inspection of the die-attach with the lead-frame (e.g. on voids)• Inspection of the PCB via regarding CAF (Conductive Anodic Filament)• Inspection in view of ESD and EOS damage

3D X-ray / computed tomography (CT):• Color-highlighting of different materials to localize and analyze material defect and processing error within components and assemblies• Inspection of bond areas and lead-frames (3D model)• Determination of contact area of spring loaded press-fit pins• Investigation of crimp contacts• Analysis of moulded components such as of wire connections within transformers• Determination of section planes within the scope of the sample preparation for detailed analyses, e.g. micrograph

Applied standards:- DIN EN 61191-6- MIL-STD-883 Method 2012

The necessity of a non-destructive examination of com-ponents or assemblies oftentimes requires an inspection via X-ray technology. In the analysis for instance lead frames, bond wires and chip orientations of the compo-nent can be inspected. In case of printed circuit boards an examination of the inner conductive path layers is possible.

In the event of components whose origin is doubtful an X-ray inspection can show if a chip is generally integra-ted in the component, if there is no deviation in the bond sequence or if improper bond wire junctions can be recognized.

With the three-dimensional presentation of X-ray images via computed tomography (CT), for the plastic represen-tation of hidden details, different materials can be high-lighted with colors, localized and analyzed. This offers an additional option for an examination of components as well as for assemblies in view of possibly existing material defects or processing errors.

SEM for investigating structures and gradients in the nanometer range


• Surfaceinspectionofelectroniccomponents• Determinationofthelayercomposition,e.g.ofcomponentpinsandprintedcircuitboards• Analysisofpoorlyconductingsamplesandsurfacesinlow-vacuumoperation• Detectionofmicro-cracks• Whiskerdetection

Applied standards:

-DINENISO9220

Duetomoreandmorecomplexandfinestcomponentstructuresthe

scanningelectronmicroscopyisofincreasingimportanceforquality

controlofcomponents.Theareastobeexaminedaresystematically

scannedbyanelectronbeam.Thus,theresultinginteractionsofthe

electronswiththesampleareusedtogenerateimageswithamagni-

ficationfactorofupto100000.

Bymeansofthesehighqualityimageswithahighresolution,even

criticalsamplescanbeclearlyanalyzedanddocumentedintermsof

agingprocessesandweakpointsrespectivelycomponentfailuresor

production-relateddeficiencies.

EDX for determining the elemental composition of samples


• Materialidentification(e.g.fornon-permittedsubstancessuchaslead)anddeterminationofconcentration

• Analysisofthediffusionprogressatthetransitionareasofdifferentmaterials,i.e.measurementofthe

intermetalliccompounds

• Determinationoftheagingofthecomponentsandtheirprocessabilityaswellasstorability

• Investigationofthematerialshomogeneity

• 2Dvisualizationoftheelementalcompositionviamappings

IncombinationwiththeSEMtheemittedspecificradiationallowsa

detailedstatementaboutthepresentelementsinthesample,their

localizationaswellastheageofthecomponentsortheirprocessabi-

lityandstorability.

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Scanning Electron Microscopy (SEM)Energy Dispersive X-ray Spectroscopy (EDX)

HTV Conservation GmbHRobert-Bosch-Str.28•D-64625BensheimPhone:+49(0)6251/84800-0•Fax:+49(0)6251/84800-30E-Mail:[email protected]•Internet:www.HTV-Conservation.com©HTV®Allrightsreserved

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X-ray fluorescence analysis (XRF)

Applied standards:- DIN EN ISO 3497- ASTM B 568- DIN EN/IEC 62321


X-ray fluorescence analysis (XRF) for non-destructive measurement of layer thicknesses and trace analysis


• Analysis of composition (i.a. „lead-free„ substances) and coating thicknesses of solder contacts

of electronic components

• Identification respectively determination of the elemental composition of unknown substances

• RoHS screening in view of mercury, chromium, cadmium, lead and bromine

• Non-destructive measurement of surface finishes of bare printed circuit boards

• Hotspot mapping for identification of solder joints containing lead on assembled printed circuit boards

The non-destructive measurement XRF is the most

frequently used method for qualitative and quantita-

tive determination of layer thicknesses of a sample in

the nanometer and micrometer scale.

For the qualification or quality control of coatings in series

production, e.g. the hard gold plating on plug connectors

or layer thicknesses of printed circuit board finishes can be

examined quickly and non-destructively. Also the identi-

fication or determination of the elemental composition

of unknown substances, such as inorganic impurities on

printed circuit boards, is possible by using XRF.

Due to low limits of detection the XRF is in many cases

suited for performing a screening of RoHS restricted sub-

stances.

Differences between XRF and energy dispersive X-ray

spectroscopy (EDX/EDS) in the scanning electron

microscope (SEM)

• The XRF does not use an electron beam for excitation

but an X-ray tube. This enables, in addition to signifi-

cantly deeper insights into the area to be inspected,

especially also the examination of moist or liquid

samples since vacuum is not necessary.

• Considerably simplified sample preparation since the

sample to be analyzed does not need electrical conduc-

tivity, so that even insulators such as FR4 PCBs or cera-

mics can be examined without any additional effort.

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Fourier Transform Infrared Spectroscopy (FTIR)


Fourier transform infrared spectroscopy (FTIR) for analysis and evaluation of organic materials and substances


• Identification of plastics

• Measurement of solid or liquid organic materials

• Determination of the composition of plastic materials, e.g. of assembly housings and mold material

• Determination of volatile components and substances

• Determination, evaluation and monitoring of the aging condition of organic materials

During FTIR spectroscopy, a special variant of IR spect-

roscopy, the sample to be examined is illuminated with

infrared radiation and the resulting excitation of the mo-

lecule-specific vibration states is examined.

Depending on the structure of the molecules different

energies of the exciting radiation are absorbed.

Thus, material characteristic peaks and spectra are recor-

ded. The infrared spectroscopy is applicable for both the

quantitative determination of known organic substances

as well as the identification of unknown organic substan-

ces by spectra libraries.

During the long-term conservation of electronic compo-

nents the FTIR spectra database of HTV was expanded

by the know-how gained from intensive cooperation

with universities. This enables the evaluation of organic

materials of electronic components and assemblies with

regard to material changes and aging resistance within a

short timescale.

When comparing the spectra in a specified period, of

one year for instance, an indicator for the progression of

aging processes in the material is obtained.

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Fully automated solderability test


Fully automated solderability test for evaluation of the processability of electronic components


• Solderability tests on components, printed circuit boards, SMD pads and plated through holes

• Measurement of wetting forces

• Determination of the processability of components during the soldering process

• Documentation of wetting problems

• Determination of deviations in solderability behavior of diverse batches of components / components of different age

• Monitoring of processability by cyclic performance of solderability tests

In the particular case of aged components the issue arises to deter-mine the solderability objectively and quantitatively.

Highly precise and fully automated solderability test systems enable the determination and documentation of the exact wetting force – i.e. that force that keeps the sample in the solder – for each com-ponent pin by immersing and extracting the sample into molten solder material.

From the progression of the wetting forces and the reached maxi-mum force values, the expected processability of the component in the real soldering process can be estimated.

Alternatively, a dip & look test is performed depending on the pa-ckage of the component.

Abb. 1: T = 0: Kontaktierung des Prüflings mit dem Lot Tb: Benetzungskraft > 0 T2/3: 2/3 der max. Benetzungskraft (Fmax) erreicht T1: Definierte Zeit (Messung F1) TFmax: Zeitpunkt max. Benetzungskraft (Fmax) erreicht T2: Testende (Messung F2)

Schematische Benetzungskurve

Zeit

Kra

ft

TFmax 0

0

Fmax

Tb T2/3 T1 T2

F2/3 F1 F2

+

- Time

Wettability graph diagramForce

Further advantages of the fully automated solderability test:• Colored, graphical presentation of test results • Quantitative statement regarding the wetting forces• Video documentation• High reproducibility

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Applied standards:- MIL-STD-883 Method 2010- MIL-STD-883 Method 2013


Chemical component decapsulation for direct examination of the chip surface


• Detection of overloads (ESD, EOS)

• Determination of manufacturers (authenticity)

• Investigation of bonding areas, micro cracks, structural defects

• Bonding, pull and shear tests

In cases where a direct examination of the chip surface is

necessary, e.g. to determine the exact version of the used

chip or its manufacturer, the chemical decapsulation of

electronic components is of great importance.

The semi-automatic chemical opening process, develo-

ped at HTV, requires special expertise and component

specific formulations to prevent unintentional, internal

damages.

By subsequent investigations via light or scanning elect-

ron microscopy the chip surface can be inspected. Thus,

any functional impairment, possibly resulting from an

overstress of the component via ESD and EOS events,

mechanical stress or similar effects, can be determined.

Precise pull and shear testers enable the high-speed veri-

fication of the quality of wire bonding.

Nanoindentation (instrumented indentation test)

HTV Conservation GmbHRobert-Bosch-Str. 28 • D-64625 Bensheim Phone: +49 (0) 62 51 / 8 48 00-0 • Fax: +49 (0) 62 51 / 8 48 00-30E-Mail: [email protected] • Internet: www.HTV-Conservation.com© HTV® All rights reserved W

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Applied standards:- DIN EN ISO 4516- DIN EN ISO 14577-1- ASTM E 2546

Nanoindentation as hardness tests with additional gained mechanical and elastic parameters

During nanoindentation, a pyramidal test tip, only a few

micrometers large, is pressed into the sample surface to

be examined. Both, the penetration force applied as well

as the penetration distance of the probe tip into the sam-

ple surface are measured simultaneously.

Distance0,1 µm

Indenter tip

Sample

Force

Distance0,1 µm


• Determination of the material homogeneity of polymers, metals or ceramics (elastic and plastic parameters)

• Analysis of thin layers (less than 1 µm thickness) without being affected by the substrate material

• Examination of changes with regards to elasticity and plasticity to analyze the aging behavior of polymers

(evaluation of brittleness)

• Hardness determination of separated layers such as gold pads and nickel coatings

• Examination of welds or soldering areas in view of their material homogeneity based on microsections

By means of the data obtained from nanoindentation

numerous classical hardness parameters, such as Mar-

tens hardness, can be determined.

In addition, the very precise, nearly non-destructive

nanoindentation enables, contrary to conventional de-

structive hardness tests, also the determination of a vari-

ety of further material properties and parameters within

smallest sample volumes (nano- and micrometer range).

Further benefits of nanoindentation at a glance:

• Objective and error-free parameter determination

even within smallest sample volumes

• Fast and simple sample preparation

• Variable sample geometry

• Temperature-dependent measurements up to 200 °C

Sample

Sample

institute for material analysis...pcb pad copper conventional preparation of microsection ß mixed...

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