First SEMI HB-LED Standards Task Force Meetings held in the New Year
The SEMI North America (NA) HB-LED Standards Committee held its inaugural meeting last November in conjunction with the NA Standards Fall 2010 meetings at SEMI Headquarters in San Jose, CA. At the November 11 meeting, the committee identified wafers, carriers, automation, and assembly as the first areas that it would focus on.
Since the inaugural meeting, the HB-LED Wafer Task Force and HB-LED Equipment Automation Interfaces Task Force held its first meetings in early January 2011 to continue its discussions toward the development of HB-LED standards.
HB-LED Wafer Task Force
The HB-LED Wafer Task Force was chartered to define physical geometry of wafers used in HB-LED manufacturing starting with 150 mm diameter sapphire wafers. The task force held its first meeting on January 10 and was attended by representatives from the following companies: OSRAM, GT Crystal Systems, SUMCO, Veeco, AIS Automation, Novellus, Kulicke & Soffa, Oxford Instruments, and BayTech Group.
The task force identified and discussed the following priorities:
- Wafer Fiducial (notch vs. flat) – Some 150 mm production uses a single flat. Replacing this with a notch would increase the available device area. Flats are currently being used and will need a lot of work to change. However, notch is preferable in the long term.
Wafer ID Mark – Analogous to the machine-readable data matrix and human-readable alphanumeric (A/N) marks currently deployed for 300 mm Si wafers. The data matrix mark can fit within a 3 mm edge exclusion area. The A/N mark is larger but could be placed close to the 3 mm edge exclusion area. These can be placed adjacent to the Wafer Fiducial. It was suggested the marks be placed on the wafer’s back surface. This isolates them from front side devices and improves readability; it has proven well for 300 mm Si wafers for those reasons.
Two figures for 150 mm wafers will be developed – one for notched and one for a flatted wafer – and will be distributed to the TF for review. OSRAM and Veeco have agreed to provide inputs.
- Center Point Thickness / TTV, Warp, Bow, and other “flatness” parameters – An industry survey will be developed and deployed by the end of February to gather feedback from various stakeholders on these identified priorities. The results of the survey will be discussed during the NA Standards Spring 2010 Meetingsat SEMI Headquarters in San Jose, CA (March 28-31).
- Bulk characteristics issues – To be discussed at the next TF meeting
The next HB-LED Wafer Task Force meeting is scheduled for January 28.
Equipment Automation Interfaces Task Force
The Equipment Automation Interfaces Task Force was chartered to define physical interfaces of substrate carriers as well as process and metrology tools of wafer/substrate carriers used in HB-LED manufacturing.
As HB-LED factory requirements are still developing and since the carrier is one component of the factory automation system with interface to other multiple components (load port, storage, lot ID, etc.), leaders from the former HB-LED Carrier and HB-LED Automation groups have agreed to combine into one task force. A combined task force will benefit from having all suppliers participate in the discussion of these interfaces and their inter-dependencies. As the basic requirements unfold, sub-groups will be formed for focused discussion on each component of the factory automation.
The task force held its first meeting on January 11 and was attended by representatives from the following companies (partial list): Brooks Automation, Entegris, OSRAM, Aixtron, Veeco, AIS Automation, Novellus, Applied Materials, MKS Instruments, Oxford Instruments, and Kulicke & Soffa.
In its inaugural meeting, the task force reviewed the scope of its activities and discussed whether software communications as well as process carriers and transport carriers should also be addressed. It was also suggested that the task force should identify which existing standards can be reused and only focus on the areas which are unique to LED. The task force agreed to discuss these topics further at their next meeting.
The task force also discussed developing a common vision for the future HB-LED factory depicting how each of the factory elements would interface together. This effort would educate the members and help bound the group’s discussion.
TF members OSRAM and Aixtron requested that communication and data transfer in tools should be addressed by the group. Furthermore, it was suggested that the carrier specification must consider the different substrate materials and processes and their impact on wafer handling. For example, if the handling will be edge grip than the standards must consider this type of handling in the scope.
The term “carrier” has multiple definitions within the task force membership. An early decision is required on the terminology for each of the carrier types which exist within an HB-LED factory (i.e., tool-to-tool transport carrier, intra-tool process carrier etc.) Proposals were solicited on how to delineate between carrier types.
The next HB-LED Equipment Automation Interfaces Task Force meeting is scheduled for the end of January. Meeting date and time will be finalized shortly.
Assembly Task Force
Currently, wire bonding and other assembly steps are highly varied depending on the unique optical, thermal, and electrical requirements of today’s advanced lighting applications— resulting in higher costs and lower throughput. The objective of the proposed Assembly Task Force is to examine industry standards — relating to issues like machine vision, device orientation, handling interface, and other areas — that will enable lower-cost, higher-throughput assembly while recognizing diversity of component types in a typical HB-LED manufacturing environment.
Some committee members expressed interest in defining strip carriers as currently no standards are available. Back-end assembly is considered a major component in LED manufacturing. Physical attributes of die-level conductor elements need to be optimized for pick-and-place and other assembly systems, employing automatic pattern recognition used in HB-LED manufacturing.
The committee is finalizing the scope of the Assembly Task Force with plans to officially charter this group and schedule its first meeting by the end of January.
Next NA HB-LED Standards Committee and Task Force Meetings
The next SEMI HB-LED Standards meeting will be held in conjunction with the Strategies in Light Conference (February 22-24, 2011) at the Santa Clara Convention Center in Santa Clara, California. The committee will also meet in conjunction with the NA Standards Spring 2010 Meetings at SEMI Headquarters in San Jose, CA. Meeting dates and times for these events will be finalized soon.
If your company is involved in manufacturing HB-LEDs, this is your opportunity to get involved and participate in developing the standards that will affect your company. For additional information on the HB-LED Standards Committee and its task forces; or how to join the Committee, please contact Paul Trio at firstname.lastname@example.org.
Upcoming LED Events
If you are interested in showcasing your technology, upcoming SEMI LED events include: LED Korea (January 26-28), LED Manufacturing Pavilion and Forum at SEMICON China 2011 (March 15-17), and Extreme Electronics LED Manufacturing at SEMICON West 2011 (July12-14).
SEMI International Standards
The SEMI International Standards Program, established in 1973, covers all aspects of micro- and nano-manufacturing, from wafer manufacturing to test, assembly and packaging, in the semiconductor, display, PV, MEMS/MST and related industries (now including HB-LED). Currently, there are over 800 SEMI Standards and Safety Guidelines available. More than 3,000 industry experts worldwide participate in the program, which is made up of 23 global technical committees. Visit www.semi.org/standards for further details about SEMI Standards. Participation in SEMI International Standards is free to all industry stakeholders.