SEMI International Standards
SEMI New Activity Report Form (SNARF)

Activity Number: 4804
SNARF for: New Standard: Specification for a Horizontal Communication Between Equipment for Photovoltaic Fabrication System

Originating Global Technical Committee: Photovoltaic (PV) - Automation
Originating Technical Committee Region: Europe
Task Force in which work is to be carried out: Photovoltaic – Equipment Interface Specification (PV-EIS)

1. Rationale: IT Equipment integration as a basis for other shop floor IT systems

Looking into today’s photovoltaic production lines, there is an increasing need to improve the mass production and to achieve the best possible quality for each final product.

Tasks, such as equipment efficiency monitoring, substrate-related quality check during the whole production process, a blanket transparency of all process steps as well as equipment and at least the comprehensive comparability of equipment. Currently the production process is a black box related to a single substrate. At present there exists no standardized procedure in the photovoltaic industry how to get substrate-related-data from the tool and how to ensure that all equipment report the same ID for a single substrate.
There are two basic approaches for single substrate tracking:
Single Substrate tracking based on ID Tags, which is common in the Thin Film industry, or single substrate tracking based on virtual IDs.
To use ID Tags leads to more and more embarrassments. There are some significant drawbacks, like nonreadable tags, a high breakage rate or an inefficient reading speed during the throughput.
Admittedly the alternative solution of using virtual ID’s requires a communication between the equipment to ensure that all equipment identify the substrate exactly. Prerequisite to provide single substrate tracking is that the equipment sends substrate-related data assign to the substrate ID. Finally it doesn’t matter who is creating the substrate ID, this can be done by the equipment cluster loader or by the MES.

Another important thing to demonstrate is the non availability of a consistent concept in which case material data has to be sent and even more no consistent concept when material data has to be delivered from equipment to equipment as well as equipment to MES.
This kind of communication is a time and money consuming matter. Currently there exist proprietary solutions for connection and communication between equipment only.
Adjustment costs and time consumption for the adaptation depend on individual situation.

Task force objectives – revisited

For the reasons named above the overall objective of the PV-EIS task force is first to develop a standard providing a communication specification between adjacent equipment (horizontal communication) to be used for PV fabrication system or similar one. Equipment includes here process, handling / transport metrology equipment etc.

To lower costs for equipment integration, including invest, installation, integration and test.
To reduce required ramp-up time.
To improve data quality.
To compare wafer suppliers and also identical equipment
Transparency of production process, debugging and optimization the equipment.

Rate the Estimated Effect on the Industry
2: Major effect on an industry sector - identify the relevant sector

Rate the Estimated Technical Difficulty of the Activity
II: Some Difficulty - Disagreements on known requirements exist but developing consensus is possible

2. Scope:
a: Define the areas to be covered or addressed by this activity or document:
The focus of this document is the development of a standard to specify and to define a generic horizontal communication (equipment to equipment) interface layer for photovoltaic (PV) production equipment – independent of the used base technology (crystalline silicon / thin film photovoltaic’s). In order to meet this overall objective, the scope for this document is defined as follows:

1. To specify a generic protocol for horizontal communication (equipment to equipment) in PV industry.
Result describing the following:
a. Material transfer operations for single work piece such as “Single substrate”, “Multiple substrates (as a set) without carrier” and “Multiple substrates in carrier” by single cycle with associated “Material data”.

b. Single HC line defined in this document to cover track types of “Uni-Direction”, “Alternate-Direction” and “Bi-Direction”, and multiple set and/or combination of them.

c. Functional coverage – Single HC line in this document covers concurrent operation of one full duplex “General Data” transfer channel” and n “Material and Material Data” transfer channel(s).
d. Communication tiers in scope:
i. Handshake and State Models
ii. Informational structure for Horizontal Communication
iii. Data Model
e. Data Definition layer as well as Media specific implementation is not in scope of this document and has to be solved in a subordinate document(s).

b: Expected result of activity
New Standard

3. Projected Timetable for Completion:
a: General Milestones
a. Activity Start: 03/04/2009b. 1st Draft by: 08/01/2009
c. Preballot by: d. Technical Ballot by: 03/01/2012
e. Committee Approval By:07/01/2012

Safety Considerations:
The resulting document is expected NOT to be a Safety Guideline

Intellectual Property Considerations:
a. In complying with the standard or safety guideline to be developed, the use of patented technology or a copyrighted item(s) is NOT required
b. The body of the standard and any appendices or related information sections will NOT include copyrighted material

Comments, Special Circumstances: None.

Approval: Activity approved by Committee/GCS on March 23, 2011

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4804 Rationale and Scope Detail.doc