Background Statement for SEMI Draft Document 5428A
NEW STANDARD: SPECIFICATION FOR IMPURITIES IN
POLYETHYLENE PACKAGING MATERIALS FOR POLYSILICON
FEEDSTOCK
Notice: This background statement is not part of the balloted item. It is provided solely to assist
the recipient in reaching an informed decision based on the rationale of the activity that preceded
the creation of this Document.
Notice: Recipients of this Document are invited to submit, with their comments, notification of
any relevant patented technology or copyrighted items of which they are aware and to provide
supporting documentation. In this context, “patented technology” is defined as technology for
which a patent has issued or has been applied for. In the latter case, only publicly available
information on the contents of the patent application is to be provided.
Background Statement
Polyethylene(PE)packaging material is used to pack high purity polysilicon. The quality of
Polyethylene(PE) bags is critical as poor quality PE bags may contaminate polysilicon and cause
contamination during transportation.
Despite the importance of PE packaging material, however, there currently is no industry-consensus
standard in the Photovoltaic industry for PE material.Forming an industry-consensus standard will
minimize contamination and associated costs and improve communication between supplier and user.
Review and Adjudication Information
Task Force Review
Group:
Committee Adjudication
Poly-Silicon Packaging Materials Task Force China PV Committee
Date:
TBD
Time &Timezone:
TBD
Location:
TBD
City,
State/Country:
China
Leader(s):
Jinbiao Lv (GCL)
Xiaoxia Liu( GCL)
Binglin Lu(CPRTC)
Guangchun Zhang(CanadianSolar)
Jun Liu(CESI)
Standards Staff:
Kris Shen(SEMI China)
kshen@semi.org
Kris Shen(SEMI China)
kshen@semi.org
Oct.23th, 2013
9AM—5PM & China
Worldhotel Grand Juna Wuxi
China
Meeting date and time are subject to change, and additional TF review sessions may be scheduled if
necessary. Contact the task force leaders or Standards staff for
confirmation.Checkwww.semi.org/standards for the latest schedule.
If you have any questions, please contact the Poly-Silicon Packaging Materials TF Leader.
Xiaoxia Liu/ GCL
Tel: +86 516 85868888-88500
E-mail: liuxiaoxia@gclsolarenergy.com
Or contact SEMI Staff, Kris Shenatkshen@semi.org
Semiconductor Equipment and Materials International
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DRAFT
SEMI Draft Document 5428A
NEW STANDARD: SPECIFICATION FOR IMPURITIES IN
POLYETHYLENE PACKAGING MATERIALS FOR POLYSILICON
FEEDSTOCK
1 Purpose
1.1 This specification is intended for the quality and the testing method of Polyethylene (PE) bags. The quality of
PE bags is critical as poor quality PE bags may contaminate polysilicon and cause contamination during
transportation. Forming an industry-consensus standard will minimize contamination, control the associated costs
and improve communication between supplier and user.
2 Scope
2.1 This standard will cover the quality criteria and the associated test method for impurities contained in PE bags
used for polysilicon feedstock packaging. The size and the metal impurities (Al, Zn, Na, Ca, K, Ni, etc.) on both
surface and in the body of the bag are defined in this document.
NOTICE: SEMI Standards and Safety Guidelines do not purport to address all safety issues associated with their
use. It is the responsibility of the users of the Documents to establish appropriate safety and health practices, and
determine the applicability of regulatory or other limitations prior to use.
3 Limitations
3.1 None.
4 Referenced Standards and Documents
4.1 ISO Standards1
ISO 291:1997— Plastics — Standard Atmospheres for Conditioning and Testing
ISO 527—Plastics — Determination of Tensile Properties
ISO 8296—Plastics — Film and Sheeting-Determination of Wetting Tension
ISO 14782—Plastics — Determination of Haze for Transparent Materials
ISO 15105—Plastics — Film and Sheeting-Determination of Gas-transmission rate
ISO 15106—Plastics — Film and Sheeting-Determination of Water Vapor Transmission Rate
4.2 ASTM Standards2
ASTM E122—Standard Practice for Calculating Sample Size to Estimate, With Specified Precision, the Average for
a Characteristic of a Lot or Process
4.3 ANSI/ASQCStandards3
ANSI/ASQC Z1.4-1993—Sampling Procedures and Tables for Inspection by Attributes.
NOTICE: Unless otherwise indicated, all documents cited shall be the latest published versions.
1
International Organization for Standardization, ISO Central Secretariat, 1 rue de Varembé, Case postale 56, CH-1211 Geneva 20, Switzerland.
Telephone: 41.22.749.01.11; Fax: 41.22.733.34.30; http://www.iso.ch
2
American Society for Testing and Materials, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, USA; Telephone: 610.832.9585,
Fax: 610.832.9555, http://www.astm.org
3
American National Standards Institute/American Society of Quality Control.Customer Service Department25 W 43rd Street, 4th FloorNew
York, NY, 10036Telephone: 212.642.4980,Fax: 212.302.1286;http://www.ansi.org
This is a Draft Document of the SEMI International Standards program. No material on this page is to be construed as an official or adopted Standard or Safety Guideline.
Permission is granted to reproduce and/or distribute this document, in whole or in part, only within the scope of SEMI International Standards committee (document
development) activity. All other reproduction and/or distribution without the prior written consent of SEMI is prohibited.
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Document Number: 5428A
Date: 2/6/2016
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5 Terminology
5.1 Abbreviations and Acronyms
5.1.1 ICP-MS— Inductively coupled plasma mass spectrometry
5.1.2 PE — Polyethylene
6 Test Methods
6.1 Appearance — By eye-measurement
6.2 Dimensions —By tape measure or flexible rule, etc.
6.3 Physical properties—It shall be in accordance with ISO 527, ISO 15105, ISO 15106, ISO 14782, and ISO 8296;
6.4 Surface impurities contamination —In accordance with Appendix 1.
6.5 Bulk impurities contamination —In accordance with Appendix 2.
7 Requirements
7.1 Appearance —films shall be visibly free of flaws, wrinkles, stains, foreign matter or any marks that impair its
serviceability.
7.2 The splicing of two films in a roll shall be prominently marked in order to provide a visible indication from the
side of the roll. The interested parties shall agree upon the method of marking the splice.
7.3 Dimensions
7.3.1 General
7.3.1.1 For any individual film selected at random from any delivery, the dimension listed in § 7.3.2 to § 7.3.5,
including their nominal values, shall be agreed upon among interested parties.
7.3.2 Width
7.3.2.1 The tolerance of width of the films shall be within4mm.
7.3.2.2 An example of film width with corresponding tolerance is given in Table 1.
Table 1 Example of AFilm Width and Tolerance
Width
Tolerance
mm
mm
500+40n#1
+4
0
#1 n:integer,0,1,2,…In width steps of 40 mm.
7.3.3 Length of Film in Roll
7.3.3.1 The tolerance of film length in a roll shall be within +10%of the nominal value.
7.3.3.2 Examples of film length and corresponding tolerance in a roll are shown in Table 2.
Table 2 Examples of Film Length in Roll and Their Tolerance
Length of film
Tolerance of length of film
Nominal length
Length in roll
m
km
4000
4
+40
0
6000
6
+60
m
This is a Draft Document of the SEMI International Standards program. No material on this page is to be construed as an official or adopted Standard or Safety Guideline.
Permission is granted to reproduce and/or distribute this document, in whole or in part, only within the scope of SEMI International Standards committee (document
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0
8000
8
+80
0
>8000
>8
1% of nominal length
7.3.4 Inside Diameter of Core of Roll
7.3.4.1 The inside diameter tolerance of a core of a roll shall be within +20mm of the nominal value.
7.3.4.2 Examples of inside diameter of core in a roll, and corresponding tolerance are given in Table 3
Table 3 Examples of Inside Diameter of A Core in A Roll and Their Tolerances
Inside diameter of core
Tolerance on inside diameter of core
mm
mm
76
+2
0
152
+2
0
7.3.5 Thickness
7.3.5.1 The thickness tolerance shall be within ±10% of the nominal value.
7.3.5.2 Examples of thickness and corresponding tolerance are given in Table 4
Table 4 Examples of Thickness and Their Tolerance
Thickness
Tolerance
Nominal
Thickness
No.
μm
12
12
±1.2
16
16
±1.6
25
25
±2.5
μm
7.4 Physical Properties
7.4.1.1 Films shall meet the requirements for physical properties listed in Table 5.
Table 5 Properties of Film
Requirements
Properties
Unit
Test method
Longitudinal#1
Transverse#2
≤3
≤3
Dimensional change heating
%
ISO 15988
Coefficient of oxygen
transmission
foml.100μm/
(m2·s·pa)
ISO 15105-1 or
ISO 15105-2
≤140
Coefficient of water vapor
transmission #4
g/100μm/
(m2·24h)
ISO 15106-1,
ISO 15106-2 or
ISO 15106-3
≤10
Wetting tension#5
mN/m
ISO 8296
≥40
#1 Longitudinal :direction parallel to extrusion or “machine direction”
#2 Transverse: direction perpendicular to extrusion.
This is a Draft Document of the SEMI International Standards program. No material on this page is to be construed as an official or adopted Standard or Safety Guideline.
Permission is granted to reproduce and/or distribute this document, in whole or in part, only within the scope of SEMI International Standards committee (document
development) activity. All other reproduction and/or distribution without the prior written consent of SEMI is prohibited.
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Document Number: 5428A
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DRAFT
#3 23℃,0% relative humidity.
#4 40℃,90% relative humidity.
#5 The wetting tension shall only apply to films with corona discharge
7.5 Surface Impurities Contamination
7.5.1 The total content of 15 elements impurities (B、Na、Mg、Al、P、K、Ca、Cr、Mn、Fe、Ni、Cu、Zn、
As、Pb) on the surface of PE material ≤20ppbw
7.6 Bulk Impurities Contamination
7.6.1 The total content of 15 elements impurities (B、Na、Mg、Al、P、K、Ca、Cr、Mn、Fe、Ni、Cu、Zn、
As、Pb) in the body of PE material≤1000ppbw
8 Sampling
8.1 The atmosphere when Polyethylene packaging material is tested should be in accordance with ISO 291:1997
8.2 Unless otherwise specified, sampling should be in accordance with ASTM E122. When specified, appropriate
sample sizes shall be selected from each lot in accordance with ANSI/ASQC Z1.4-1993. Inspection levels shall be
agreed upon between the supplier and the purchaser.
9 Certification
9.1 Upon request of the purchaser in the contract or order, a manufacturer’s or supplier’s certification where the
material was manufactured and tested in accordance with the specification should be furnished at the time of
shipment (Certificate of Compliance). Upon request, a report of the test results may also be required (Certificate of
Analysis).
10 Package and Package Labeling
10.1 Packaging and size of unit packaging shall be agreed upon between the supplier and the customer.
10.2 The following shall be clearly marked on the package:
10.2.1 Name of products of symbol;
10.2.2 Classification of film, whether treated corona discharge or not;
10.2.3 Nominal thickness ,width and length of a roll;
10.2.4 Year and month of manufacture;
10.2.5 Name of manufacture or symbol.
11 Related Document
ISO 15988:2003— Plastics— Film and sheeting —Biaxially Oriented Poly (ethylene terephthalate) (PET) Films
This is a Draft Document of the SEMI International Standards program. No material on this page is to be construed as an official or adopted Standard or Safety Guideline.
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Document Number: 5428A
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APPENDIX 1
TEST METHOD FOR THE SURFACE METAL CONCENTRATION OF
POLYETHYLENE PACKAGING MATERIALS FOR POLYSILICON
FEEDSTOCK
NOTICE: The material in this Appendix is an official part of SEMI Doc. 5428 and was approved by full letter ballot
procedures on [A&R approval date].
A1-1 Procedure
A1-1.1 Choose one 20-piecespackage of PE material from a lot to be sampled.
A1-1.2 Deliver the bag to the clean room for sampling.
A1-1.3 Choose one piece randomly from the package as the lot sample.
A1-1.4 Then cut out 6 small pieces which must be taken from the different location of the piece. Each small piece
shall be with an approximate size of 5 by 5 cm.If the sample must be taken in a location other than the analytical
laboratory, seal the sample in double bags and send to the laboratory. To minimize contamination from the room
environment and the analyst, all sample collection and analysis steps are carried out in a clean room and laminar
flow hood, with analysts in full clean room attire. A minimum of a Class 6 clean room, as established in ISO 14644–
1, is required to minimize interferences from environmental sources. In the laboratory, open the double bag
according to standard clean room practice and transfer the pieces to a clean, numbered PFA beaker and weigh to
four decimal places.
A1-1.5 Add about 10 ml5% nitric acid etching mixture to each beaker to cover the pieces and seal with PFA lids.
A1-1.6 Place the sealed beakers onto the hot plate in the fume hood and heat for about 60 min at about 70°C.
Remove from heat and cool, then remove each piece with PTFE tongs, rinsing the surface with DI water into the
beaker, weigh the beakers with the solution in.
A1-1.7 Along with the samples, prepare at least 2 digest blanks.
A1-1.8 Prepare appropriate calibration standards, control standards.
A1-1.9 Load samples and standards into the ICP-MS instrument sample carrousel tray.Each run shall include the
following:
 Acid blank,
 Calibration standards,
 Control standards,
 DI water,
 First digested blank,
 Lot samples.
A1-1.10 Choose and record the instrument parameters, according to the instrument manufacturer's instructions, for
the sample measurement.
A1-2 Calculation
A1-2.1 Calculate the results as follows:
M= (I− B)×(m-m0)
where:
M= concentration of analyte, ,
I= instrument reading of analyte, ppbw,
B= instrument reading of average of two blanks, ppbw,
m = weight of the beakers with solution after etching, gram,
(A1-1)
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Document Number: 5428A
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LETTER (YELLOW) BALLOT
m0 = weight of the beakers without solution, gram.
This is a Draft Document of the SEMI International Standards program. No material on this page is to be construed as an official or adopted Standard or Safety Guideline.
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APPENDIX 2
TEST METHOD FOR THE BULK METAL CONCENTRATION OF
POLYTHYLENE PACKAGING MATERIALS FOR POLYSILICON
FEEDSTOCK
NOTICE: The material in this Appendix is an official part of SEMI Doc. 5428 and was approved by full letter ballot
procedures on [A&R approval date].
A2-1 Procedure
A2-1.1 Choose one 20-piecespackage of PE material from a lot to be sampled.
A2-1.2 Deliver the bag to the clean room for sampling.
A2-1.3 Choose one piece randomly from the package as the lot sample.
A2-1.4 Then cut out 3 small pieces which must be taken from the different location of the piece. Each small piece
shall be with an approximate weight of 1g.
A2-1.5 Clean them with DI water. Using ceramic scissors, cut them small piece with a approximate size of
2mm*10mm.
A2-1.6 Put the small pieces of PE with an approximate weight of 1g into a digestion tank,
A2-1.7 Add about 10 ml nitric acid etching mixture to each tank.
NOTE: Steps above are suggested to be done in the cleanroom to avoid contamination.
A2-1.8 Seal the tanks, then put them into the micro digestion system.
A2-1.9 After digestion, cool and transfer them back into the cleanroom.
A2-1.10 Open the tank, transfer the solution into a 25ml volumetric flask, rinse the tank with DI water more than 2
times into the volumetric flask, dilute with DI water to volume, and mix.
A2-1.11 Along with the samples, prepare at least 2 digest blanks.
A2-1.12 Prepare appropriate calibration standards, control standards.
A2-1.13 Load samples and standards into the ICP-MS/ICP-OES instrument sample carrousel tray.Each run shall
include the following:
 Acid blank,
 Calibration standards,
 Control standards,
 DI water,
 First digested blank,
 Lot samples.
A2-1.14 Choose and record the instrument parameters, according to the instrument manufacturer’s instructions, for
the sample measurement.
A2-2 Calculation
A2-2.1 Calculate the results as follows:
M= (I− B)×V/m0
(A2-1)
where:
M= concentration of analyte, ng/g,
I= instrument reading of analyte, ng/ml,
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B= instrument reading of average of two blanks, ng/ml,
V= volume of the solution after dilution, ml,
m0 = weight of the sample to be digested in the tank, gram.
NOTICE: Semiconductor Equipment and Materials International (SEMI) makes no warranties or representations as
to the suitability of the Standards and Safety Guidelines set forth herein for any particular application. The
determination of the suitability of the Standard or Safety Guideline is solely the responsibility of the user. Users are
cautioned to refer to manufacturer’s instructions, product labels, product data sheets, and other relevant literature,
respecting any materials or equipment mentioned herein. Standards and Safety Guidelines are subject to change
without notice.
By publication of this Standard or Safety Guideline, SEMI takes no position respecting the validity of any patent
rights or copyrights asserted in connection with any items mentioned in this Standard or Safety Guideline. Users of
this Standard or Safety Guideline are expressly advised that determination of any such patent rights or copyrights,
and the risk of infringement of such rights are entirely their own responsibility.
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