IEC 61249-4-19:2013

IEC 61249-4-19 ®
Edition 1.0 2013-11
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Materials for printed boards and other interconnecting structures –
Part 4-19: Sectional specification set for prepreg materials, unclad (for the
manufacture of multilayer boards) – High performance non-halogenated epoxide
woven E-glass prepreg of defined flammability (vertical burning test) for lead-
free assembly
Matériaux pour circuits imprimés et autres structures d'interconnexion –
Partie 4-19: Série de spécifications intermédiaires pour matériaux préimprégnés,
non plaqués (pour la fabrication des cartes multicouches) – Tissu de verre
époxyde préimprégné non halogéné de type E à haute performance,
d'inflammabilité définie (essai de combustion verticale), pour les assemblages
sans plomb
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IEC 61249-4-19 ®
Edition 1.0 2013-11
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Materials for printed boards and other interconnecting structures –

Part 4-19: Sectional specification set for prepreg materials, unclad (for the

manufacture of multilayer boards) – High performance non-halogenated epoxide

woven E-glass prepreg of defined flammability (vertical burning test) for lead-

free assembly
Matériaux pour circuits imprimés et autres structures d'interconnexion –

Partie 4-19: Série de spécifications intermédiaires pour matériaux préimprégnés,

non plaqués (pour la fabrication des cartes multicouches) – Tissu de verre

époxyde préimprégné non halogéné de type E à haute performance,

d'inflammabilité définie (essai de combustion verticale), pour les assemblages

sans plomb
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX N
ICS 31.180 ISBN 978-2-8322-1167-0

– 2 – 61249-4-19 © IEC:2013
CONTENTS
FOREWORD . 4
1 Scope . 6
2 Normative references . 6
3 Materials and construction . 6
3.1 General . 6
3.2 Reinforcement . 7
3.3 Resin system . 7
4 Properties . 7
4.1 Properties related to the appearance of the prepreg. 7
4.1.1 General . 7
4.1.2 Dewetted areas (fish eyes) . 7
4.1.3 Broken filaments . 7
4.1.4 Distortion . 7
4.1.5 Creases . 7
4.1.6 Edge conditions . 8
4.2 Properties related to B-stage prepreg . 8
4.2.1 General . 8
4.2.2 Resin content . 8
4.2.3 Treated weight . 8
4.2.4 Resin flow . 9
4.2.5 Scaled flow thickness . 9
4.2.6 Melting viscosity . 9
4.2.7 Gel time . 9
4.2.8 Volatile content . 9
4.3 Properties related to prepreg after curing . 9
4.3.1 Electric strength. 9
4.3.2 Flammability . 9
4.3.3 Relative permittivity and dissipation factor . 10
4.3.4 Cured thickness . 10
4.3.5 Glass transition temperature (T ) . 10
g
4.3.6 Decomposition temperature (T ) . 10
d
4.3.7 Time to delamination . 10
4.3.8 Z-axis expansion . 11
5 Delivery form . 11
5.1 General . 11
5.2 Rolls . 11
5.3 Sheets . 11
5.4 Cut panels . 11
6 Quality assurance . 11
6.1 Quality system . 11
6.2 Responsibility for inspection. 12
6.3 Qualification inspection . 12
6.4 Quality conformance inspection . 12
6.5 Certificate of conformance . 12
6.6 Safety data sheet . 12

61249-4-19 © IEC:2013 – 3 –
7 Packaging and marking . 12
8 Shelf life . 13
9 Ordering information . 13
Bibliography . 14

Table 1 – Flammability, vertical burning test . 10
Table 2 – Decomposition temperature requirements . 10
Table 3 – Time to delamination requirements . 11
Table 4 – Z-axis expansion requirements . 11

– 4 – 61249-4-19 © IEC:2013
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
MATERIALS FOR PRINTED BOARDS
AND OTHER INTERCONNECTING STRUCTURES –

Part 4-19: Sectional specification set for prepreg materials,
unclad (for the manufacture of multilayer boards) –
High performance non-halogenated epoxide woven E-glass prepreg
of defined flammability (vertical burning test) for lead-free assembly

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
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Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
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with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
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between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 61249-4-19 has been prepared by IEC technical committee 91:
Electronics assembly technology.
The text of this standard is based on the following documents:
FDIS Report on voting
91/1126/FDIS 91/1148/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.

61249-4-19 © IEC:2013 – 5 –
A list of all parts of the IEC 61249 series, under the general title Materials for printed boards
and other interconnecting structures, can be found on the IEC website.
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
– 6 – 61249-4-19 © IEC:2013
MATERIALS FOR PRINTED BOARDS
AND OTHER INTERCONNECTING STRUCTURES –

Part 4-19: Sectional specification set for prepreg materials,
unclad (for the manufacture of multilayer boards) –
High performance non-halogenated epoxide woven E-glass prepreg
of defined flammability (vertical burning test) for lead-free assembly

1 Scope
This part of IEC 61249 gives requirements for properties of prepreg that is mainly intended to
be used as bonding sheets in connection with laminates according to IEC 61249-2-40 when
manufacturing multilayer boards according to IEC 62326-4. Multilayer boards comprised of
these materials are suitable for lead-free assembly processes. This material may be also used
to bond other types of laminates.
Prepreg according to this standard is of defined flammability (vertical burning test). The
flammability rating on fully cured prepreg is achieved through the use of non-halogenated fire
retardants contained as an integral part of the polymeric structure. After curing of the prepreg
according to the supplier’s instructions, the glass transition temperature is defined to be
170 °C minimum.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and
are indispensable for its application. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any
amendments) applies.
IEC 61189-2:2006, Test methods for electrical materials, interconnection structures and
assemblies – Part 2: Test methods for materials for interconnection structures
IEC 61249-2-40, Materials for printed boards and other interconnecting structures – Part 2-40:
Reinforced base materials clad and unclad – High performance, non-halogenated epoxide
woven E-glass laminate sheets of defined flammability (vertical burning test), copper-clad for
lead-free assembly
IEC/PAS 61249-6-3:2011, Materials for printed boards and other interconnecting structures –
Part 6-3: Reinforcements – Woven fibreglass fabrics
ISO 9000:2005, Quality management systems – Fundamentals and vocabulary
ISO 11014:2009, Safety data sheet for chemical products – Content and order of sections
ISO 14001:2004, Environmental management systems – Requirements with guidance for use
3 Materials and construction
3.1 General
The prepreg consists of a reinforcing E-glass fabric which is impregnated with high
performance, non-halogenated epoxide resin, partially cured to the B-stage. The flammability

61249-4-19 © IEC:2013 – 7 –
rating is achieved through the use of non-halogenated flame retardants reacted into the
polymer. Inorganic fillers may be used. Contrast agents may be added to enhance processing
such as automated optical inspection (AOI).
Its flame resistance is defined in terms of the flammability requirements of 4.3.2.
3.2 Reinforcement
Woven E-glass as specified in IEC/PAS 61249-6-3: woven E-glass fabric (for the manufacture
of prepreg and copper-clad laminate).
3.3 Resin system
High performance, non-halogenated epoxide with a glass transition temperature after curing
according to the manufacturer’s instructions of 170 °C minimum. The flammability rating is
achieved through the use of non-halogenated flame retardants reacted into the polymer.
Inorganic fillers may be used. Contrast agents may be added to enhance processing such as
automated optical inspection (AOI). The maximum total halogens contained in the resin plus
reinforcement matrix is 1 500 ppm with a maximum chlorine of 900 ppm and maximum
bromine being 900 ppm.
4 Properties
4.1 Properties related to the appearance of the prepreg
4.1.1 General
The prepreg shall be substantially free from defects that may have an impact on the material’s
fitness for use for the intended purpose.
For the following specific defects the requirements given shall apply when inspection is made
in accordance with IEC 61189-2 test method 3V01.
4.1.2 Dewetted areas (fish eyes)
Dewetted areas with a diameter > 10 mm are not permissible.
Dewetted areas with a diameter ≤ 10 mm are permitted to an extent of a maximum 10 fish
eyes in any 300 mm × 300 mm area of the prepreg.
4.1.3 Broken filaments
When judging the presence of broken filaments their sizes and frequency of occurrence are
important for assessing acceptability but also the flow characteristic of the prepreg shall be
taken into consideration. The acceptance conditions for broken filaments shall be as agreed
upon between the user and supplier.
4.1.4 Distortion
When the prepreg is tested in accordance with test method 2M29 (under consideration) of
IEC 61189-2, the distortion or non-perpendicular orientation of the fill or weft yarns in the
glass fabric shall not exceed 10 % measured over any 300 mm test distance.
4.1.5 Creases
Creases caused by handling of the prepreg where only a negligible loss of resin has occurred
are permitted.
– 8 – 61249-4-19 © IEC:2013
Creases where the glass yarns are exposed due to loss of resin are not permitted.
4.1.6 Edge conditions
Cut-to-size panels shall have even edges and shall not show loss of resin at the edge due to
the cutting process more than 2 mm. Excessive occurrence of resin dust released during the
cutting shall be removed before packaging for shipment.
4.2 Properties related to B-stage prepreg
4.2.1 General
A number of characteristics can describe thickness, reactivity and rheology of B-stage
prepreg. The choice of characteristics to be used as qualification and quality conformance
testing as well as the nominal performance levels are as agreed upon between the user and
supplier.
Several of the characteristics shown below are interrelated and should not be specified
individually. Ordering requirements should preferably be restricted to the glass style, one
characteristics marked (a) in combination with one characteristic marked (b). A maximum of
one optional characteristic (c) of B-stage prepreg may be included.
Glass style
Thickness parameter
• Resin content (a)
• Treated weight (a)
Reactivity/rheology parameter
• Resin flow (b)
• Scaled flow thickness (b)
• Melt viscosity (b)
• Cured thickness (b)
Optional parameter
• Volatile content (c)
• Gel time (c)
4.2.2 Resin content
When tested in accordance with test method 2C03 or 2C10 of IEC 61189-2, the nominal resin
content shall be as agreed upon between the user and supplier.
The tolerance around the ordered nominal value shall be ± 3 %, e.g., (45 ± 3) %.
4.2.3 Treated weight
When tested in accordance with test method 2C03 of IEC 61189-2, the nominal treated weight
shall be as agreed upon between the user and supplier.
The tolerance around the ordered nominal value shall be ± 3 %, e.g. (350 ± 10,5) g.

61249-4-19 © IEC:2013 – 9 –
4.2.4 Resin flow
When tested in accordance with test method 2M09 of IEC 61189-2, the nominal resin flow
shall be as agreed upon between the user and supplier.
The tolerance around the ordered nominal value shall be ± 5 %, e.g., (25 ± 5) %.
4.2.5 Scaled flow thickness
When tested in accordance with test method 2M26 of IEC 61189-2, the nominal scaled flow
and the tolerance shall be as agreed upon between the user and supplier.
4.2.6 Melting viscosity
When tested in accordance with test method 2C09 of IEC 61189-2, the nominal melt viscosity
shall be as agreed upon between the user and supplier.
The tolerance around the ordered nominal value shall be ± 20 mPa·s, e.g., (240 ± 20) mPa·s.
4.2.7 Gel time
When tested in accordance with test method 2C02 of IEC 61189-2, the nominal gel time shall
be as agreed upon between the user and supplier.
The tolerance around the ordered nominal value shall be ± 20 s, e.g., (160 ± 20) s.
4.2.8 Volatile content
When tested in accordance with test method 2C04 of IEC 61189-2, the volatile content shall
be 0,5 % maximum.
4.3 Properties related to prepreg after curing
4.3.1 Electric strength
A total of 2 plies of prepreg of minimum size 300 mm × 300 mm shall be bonded together and
cured in accordance with the manufacturer’s recommendations whereupon the thickness shall
be determined using a micrometer.
When tested in accordance with test method 2E11 of IEC 61189-2, the minimum electric
strength shall be 25 V/µm.
4.3.2 Flammability
A number of plies of minimum size 300 mm × 300 mm of the prepreg under test shall be
bonded together and cured in accordance with the manufacturer’s recommendations. The
number of plies shall be chosen so that a specimen thickness of approximately 0,4 mm to
0,5 mm is obtained as measured with a micrometer.
When tested in accordance with test method 2C06 of IEC 61189-2, the flammability shall be
as shown in Table 1.
– 10 – 61249-4-19 © IEC:2013
Table 1 – Flammability, vertical burning test
Property Test method Requirement
(61189-2)
Designation
FV-0
Flammability 2C06
Flaming combustion time after each application of the flame for each
≤ 10 s
test specimen
Total flaming combustion time for the 10 flame applications for each ≤ 50 s
set of five specimens
Glowing combustion time after the second removal of the test flame
≤ 30 s
Flaming or glowing combustion up to the holding clamp None

Dripping flaming particles that ignite the tissue paper None

4.3.3 Relative permittivity and dissipation factor
A total of 2 plies of prepreg of minimum size 300 mm × 300 mm shall be bonded together and
fully cured in accordance with the manufacturer’s recommendations whereupon the thickness
shall be determined using a micrometer.
When tested in accordance with test method 2E10 of IEC 61189-2, the relative permittivity
and dissipation factor at 1 MHz shall be 5,4 and 0,035 maximum respectively.
4.3.4 Cured thickness
The nominal thickness and the tolerance of the cured prepreg using the user’s lamination
cycle shall be as agreed upon between the user and supplier. The test method shall be as
agreed upon between the user and supplier.
4.3.5 Glass transition temperature (T )
g
The glass transition temperature of the cured prepreg using the user’s lamination cycle shall
be 170 °C minimum as determined by test method 2M03 or 2M10 of IEC 61189-2.
4.3.6 Decomposition temperature (T )
d
The requirement for decomposition temperature is found in Table 2.
Table 2 – Decomposition temperature requirements
Property Test method Requirement
(IEC 61189-2)
a
Decomposition temperature 2MXX
≥ 340 °C
a
Under consideration.
4.3.7 Time to delamination
The requirements for time to delamination are found in Table 3. The temperature of each test
may be found in the column labelled “property”.

61249-4-19 © IEC:2013 – 11 –
Table 3 – Time to delamination requirements
Property Test method Requirement
(IEC 61189-2)
T260 2M25
≥ 30 min
T288 ≥ 15 min
T300
≥ 2 min
4.3.8 Z-axis expansion
The requirements for Z-Axis expansion are found in Table 4.
Table 4 – Z-axis expansion requirements
Property Test method Requirement
(IEC 61189-2)
a
Z-axis Alpha 1 (below T ) 2MXX
≤ 60 ppm/°C
g
Z-axis Alpha 2 (above T )
≤ 300 ppm/°C
g
3,0% maximum
Z-axis % 50 to 250 °C
a
Under consideration.
5 Delivery form
5.1 General
Prepreg may be ordered and delivered as rolls, sheets or cut panels.
5.2 Rolls
Roll sizes shall be as agreed upon between the user and supplier. For rolls ≥ 50 m in length,
cut outs from quality conformance inspection are allowed. The size of the roll delivered by the
+20
supplier shall not deviate more than mm in the width and ± 5 m in the length from the
ordered size. Extra linear meters shall be added to compensate for any cut-outs for quality
conformance testing.
5.3 Sheets
Sheet sizes shall be as agreed upon between the user and supplier. The size of the sheet
+20
delivered shall not deviate more than mm from the ordered size.
5.4 Cut panels
Cut panel sizes shall be as agreed upon between the user and supplier. The size of the cut
panels delivered shall not deviate more than ± 3 mm from the ordered size.
6 Quality assurance
6.1 Quality system
The supplier shall operate a quality system, ISO 9000 or similar, to support quality
conformance inspection.
– 12 – 61249-4-19 © IEC:2013
The supplier shall operate a quality system, ISO 14001 or similar, to support environmental
considerations.
6.2 Responsibility for inspection
The supplier is responsible for all inspection of the manufactured material. Inspection is
auditable by the purchaser or an appointed third party.
6.3 Qualification inspection
Prepregs furnished under this standard shall be qualified. Qualification testing shall be
performed to demonstrate the manufacturer’s ability to meet the requirements of this
standard. Qualification testing shall be conducted at a laboratory compliant with IEC
laboratory requirements. The manufacturer shall retain on file the data which supports that the
materials meet this standard and shall be readily available for review upon request.
6.4 Quality conformance inspection
The supplier shall operate a quality plan to assure product conformance to this standard.
Such a quality plan, when appropriate, should utilize statistical methods rather than lot by lot
inspection. It is the responsibility of the supplier based on the quality plan to determine the
frequency of test to assure conforming products.
A combination of the following techniques may be used to show compliance with the
requirements which can be used to reduce the frequency of testing. The data supporting the
reduction of testing frequency shall be available for review upon request.
– In process parameter control
– In process inspection
– Periodic final inspection
– Final lot inspection
6.5 Certificate of conformance
The supplier shall on request from the purchaser issue a certificate of conformance to this
standard in electronic or paper format.
6.6 Safety data sheet
A safety data sheet in accordance with ISO 11014 shall be available for products
manufactured and delivered in accordance with this standard.
7 Packaging and marking
Prepregs in rolls, sheets and cut panels shall be packaged in a manner, which will provide
adequate protection against deterioration and physical damage during shipment and storage.
If not otherwise specified in the purchase order, prepreg shall be marked on the smallest
package with the manufacturer’s designation, lot number and date of manufacture.
The shipping container shall have a label that shall remain securely affixed and legible during
normal handling. Location of the label and the type of marking shall be as specified in the
drawing or ordering data, or if not specified shall be the supplier’s standard labelling and
marking. The following information is to be included:
a) type of material;
b) manufacturer’s designation;

61249-4-19 © IEC:2013 – 13 –
c) lot number;
d) date of manufacture;
e) quantity;
f) dimensions;
g) gross weight;
h) manufacturer’s name and address;
i) date of packaging.
8 Shelf life
Prepreg shall be capable of being stored at either of
...