SEMI International Standards
Standards New Activity Report Form (SNARF)
Date Prepared: 05/23/2016Revised (if Applicable):

Document Number: 6071
SNARF for: New Standard: Test Method for Polymer Foil dependent Discoloration of Silver Fingers on PV modules

Originating Global Technical Committee: Photovoltaic
Originating TC Chapter: Taiwan
Task Force (TF) in which work is to be carried out: PV Reliability Test Method Task Force
Note: If a new task force is needed, also submit a task force organization form (TFOF)

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1. Rationale:
a. Describe the need or problem addressed by this activity.
(Indicate the customer, what benefits they will receive, and if possible, quantify the impact on the return on investment [ROI] if the Document is implemented.)
After several months of operation, many PV modules develop a discoloration defect called “snail trails” which appear as irregular dark traces across the cells. It was shown at microscopic scale that the snail trail discolorations appear at sites where silver nanoparticles were formed from partly dissolved grid finger material. Recent studies show, that those discolorations do not impair the module performance. However, they still concern PV operators and hence, PV module manufacturer aim to avoid this defect. Thus, this activity addresses a method which can be used to optimize the material composition in order to avoid “snail trail” formation.
The test method is based on the finding that – besides the presence of moisture and cell cracks –the additive composition of the polymer foils used for manufacturing PV modules determines the susceptibility or resistivity to snail-trail formation. The influence of foil combination on discoloration of silver fingers is tested directly. Samples will be subjected to an environment with high temperature and high humidity generated inside a chamber. The designed method is going to evaluate combinations of encapsulation and back-sheet foils with respect to their susceptibility for discoloration (snail trails) on silver fingers, and to realize potential risks from applied PV modules with certain materials.
This activity shall develop a new evaluation method to identify those back sheet and/or encapsulation foil which protect the PV modules from silver nanoparticle based discoloration.



b. Estimate effect on industry.
2: Major effect on an industry sector - identify the relevant sector
Sector or Company Information:

c. Estimate technical difficulty of the activity.
II: Some Difficulty - Disagreements on known requirements exist but developing consensus is possible

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2. Scope:
a: Describe the technical areas to be covered or addressed by this Document development activity. For Subordinate Standards, list common concepts or criteria that the Subordinate Standard inherits from the Primary Standard, as well as differences from the Primary Standard:
This activity shall develop a new test method for grid finger discoloration with mini PV modules or standard size PV modules as test specimens. The objective is to focus on the color change of silver fingers after certain indoor test, and provides some actions as below:
(1) Define the specific structure of test specimen. (Mini modules or full modules, etc.)
(2) Define the specific testing conditions. (Temperature, humidity, time, etc.)
(3) Define the specific method to inspect the tested samples and evaluate the discoloration of silver fingers (light microscopy, laser scanning microscopy, etc.)


b: Expected result of activity
New Standard or Safety Guideline (including replacement of an existing Standard or Safety Guideline)

For a new Subordinate Standard, identify the Primary Standard here:




For Standards, identify the Standard Subtype below:
Test Method

Miscellaneous (describe below):

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3. Projected Timetable for Completion:

a: General Milestones
a. Activity Start: 06/01/2016b. 1st Draft by: 02/01/2017
c. (Optional) Informational Ballot by: 04/01/2017d. Letter Ballot by: 05/01/2017
e. TC Chapter Approval By:07/01/2017

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4. Liaisons with other Global Technical Committees/TC Chapters/Subcommittees/TFs:
a.
List SEMI global technical committees, TC Chapters, subcommittees, or task forces in your or other Regions/Locales that should be kept informed regarding the progress of this activity. (Refer to SEMI Standards organization charts and global technical committee charters and scopes as needed.)
Japan PV Materials Committee / EU PV Committee / NA PV Committee/ China PV Committee

b. List any planned Type I Liaisons with external nonprofit organizations (e.g., SDO) that should receive Draft Documents from Standards staff for feedback during this activity and be notified when the Letter Ballot is issued (refer to Procedure Manual § 7):


c. Intercommittee Ballots:
will be issued – identify the recipient global technical committee(s):

Identify the recipient global technical committee(s):
Photovoltaic (PV) - Materials
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5. Safety Considerations:
The resulting document is expected:
NOT to be a Safety Guideline

NOTE FOR "to be a Safety Guideline": When all safety-related information is removed from the Document, the Document is NOT technically sound and complete - Refer to Section 15.1 of the Regulations for special procedures to be followed.

NOTE FOR "NOT to be a Safety Guideline": When all safety-related information is removed from the Document, the Document is still technically sound and complete.

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6. Intellectual Property Considerations:
a. For a new Standard or Safety Guideline and for any part to be modified or added in a Revision of published Standards and Safety Guidelines:
the use of patented technology is NOT required.

If "patented technology is intended to be included in the proposed Standard(s) or Safety Guideline(s) " is selected above, then also check one:


b. For Revision, Reapproval, Reinstatement, or Withdrawal of existing Standard(s) and Safety Guideline(s):
there is no known material patented technology necessary to use or implement the Standard(s) and Safety Guideline(s)

c. The body of the Document and any Appendices, Complementary Files, Related Information sections, or Various Materials that may or may not be a part of the Document by reference:



NOTE FORthe use of patented technology or the incorporation of Copyrighted Item(s) is NOT required’: If in the course of developing the Document, it is determined that the use of patented technology or Copyrighted Item(s) is necessary for the Document, the provisions of Regulations § 16 must be followed.

NOTE FORwill incorporate Copyrighted Item’: A copyright release letter must be obtained from the copyright owner prior to publication.

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7. Comments, Special Circumstances:
None.

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8. TC Member Review:
took place between (put dates below ) before approval at the TC Chapter Meeting, or

Member Review Start Date; 07/01/2016.
Member Review End Date: 07/14/2016.

NOTE FOR ‘TC Member Review’ is required by the Regulations for a period of at least two weeks
before approval of a new, or a major revision of an existing, Standard or Safety Guideline. (Refer to Regulations ¶ 8.2.1)
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9. SNARF Approval Dates:
TC Chapter or GCS07/22/2016
Recorded in TC Minutes07/22/2016

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10. SNARF Extension Dates:
TC Chapter Extension Granted on
Extension Expires on