Background Statement for SEMI Draft Document 5696
Reapproval of SEMI D9-0303 (Reapproved 0709), TERMINOLOGY FOR
FPD SUBSTRATES
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
SEMI D9 is due for 5-year review. At the meeting of the Japan FPD Materials & Components Committee on February 14, 2014,
the committee agreed to ballot SEMI D9 for reapproval without changes.
This letter ballot contains only the Purpose, Scope, Referenced Standards and Documents and Terminology sections of the
Standard being proposed for approval. Full copy of this Standard is available upon request. Voter requests for access to the full
Standards must be made at least three business days before the voting deadline.
Ballot responses submitted for doc. #5696 will be adjudicated at the Japan FPD Materials & Components
Committee meeting to be held on October 30, 2014.
This meeting’s details are subject to change, and additional review sessions may be scheduled if necessary. Please contact
Standards staff (Naoko Tejima at ntejima@semi.org) for confirmation.
Semiconductor Equipment and Materials International
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Phone: 408.943.6900, Fax: 408.943.7943
DRAFT
SEMI Draft Document 5696
Reapproval of SEMI D9-0303 (Reapproved 0709), TERMINOLOGY FOR
FPD SUBSTRATES
1 Purpose
1.1 This document provides terms and definitions of materials and defects within and on the surface of flat panel
display (FPD) substrates and of dimensional, thermal, chemical, optical and mechanical properties of FPD substrates.
2 Scope
2.1 These terms and definitions are applicable to both front and back substrates used in FPD fabrication.
NOTICE: This standard does not purport to address safety issues, if any, associated with its use. It is the
responsibility of the users of this standard to establish appropriate safety and health practices and determine the
applicability of regulatory or other limitations prior to use.
3 Referenced Standards and Documents
3.1 SEMI Standards
SEMI D3 — Quality Area Specification for Flat Panel Display Substrates
SEMI D5 — Standard Size for Flat Panel Display Substrates
SEMI D7 — FPD Glass Substrate Surface Roughness Measurement Method
SEMI D11 — Specification for Flat Panel Display Glass Substrate Cassettes
SEMI D12 — Specification for Edge Conditions of Flat Panel Display (FPD) Substrates
SEMI D15 — FPD Glass Substrate Surface Waviness Measurement Method
SEMI D24 — Specification for Glass Substrates Used to Manufacture Flat Panel Displays
3.2 ASTM Standards1
ASTM C336 — Standard Test Method for Annealing Point and Strain Point of Glass by Fiber Elongation Test
Method (Elongation of Glass Fibers)
ASTM C338 — Standard Test Method for Softening Point of Glass
ASTM C598 — Standards Test method for Annealing Point and Strain Point by Beam Bending
NOTICE: Unless otherwise indicated, all documents cited shall be the latest published versions.
4 Terminology
NOTE 1: SEAJ Liquid Crystal Display Manufacturing Equipment Dictionay is referred as to every term in § 4.
4.1 Internal Defects
4.1.1 bubble — a gaseous inclusion.
4.1.2 open bubble — a gaseous inclusion which is so close to the surface that it is obviously open and/or one so
close to the surface that it may be broken open with the point of a soft lead pencil.
4.1.3 inclusion — opaque or partially melted particle of refractory or batch material embedded in glass. Its size is
usually determined by the size of the distorted area.
4.1.4 devitrification — a crystalline area within the glass.
4.1.5 knot — an embedded glassy, transparent, lump having an irregular or tangled appearance. Its size is usually
determined by the size of the distorted area.
1
American Society for Testing and Materials, 100 Barr Harbor Drive, West Conshohocken, Pennsylvania 19428-2959, USA. Telephone:
610.832.9585; Fax: 610.832.9555; http://www.astm.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.
Page 1
Doc. 5696  SEMI
LETTER (YELLOW) BALLOT
Document Number: 5696
Date: 2/8/2016
Semiconductor Equipment and Materials International
3081 Zanker Road
San Jose, CA 95134-2127
Phone: 408.943.6900, Fax: 408.943.7943
DRAFT
4.2 Material on the Surface
4.2.1 Cullet — small transparent glass particles that are adhered or fused to the glass substrate surface.
4.2.2 particle — a micron-size piece of foreign material on the glass surface.
4.2.3 stain — organic or inorganic material on the surface.
4.2.4 blur — any erosion of the surface; generally cloudy in appearance, it sometimes exhibits an apparent color.
4.3 Surface Defects
4.3.1 scratch — a surface fissure generally caused during handling.
4.3.2 sleek — a very shallow type of scratch on the polished surface that is sometimes invisible when the viewing
angle is changed.
4.3.3 latent scratch — a scratch which is usually invisible but when subjected to an etching action by dipping into a
detergent or a corrosive solution, such as an acid, the previously invisible scratch becomes visible due to the minor
removal of surface glass.
4.3.4 chip — a region of material missing from the edge of the glass substrate, which is sometimes caused by
processing or handling.
4.3.5 pit/dig — small indentation on the glass substrate surface.
4.3.6 bump — a small protuberance on the glass substrate.
4.3.7 crack — a fissure located at the sheet edge area or central area.
4.3.8 streak — a defect with a very small undulation on the glass substrate surface.
4.4 Dimensional Properties
4.4.1 outsize dimension — vertical and horizontal dimensions of the glass substrate.
4.4.2 thickness — the distance between the front surface and the back surface of a glass substrate at same single
point.
4.4.3 thickness variation — any differences between maximum and minimum values within the thickness of a glass
substrate.
4.4.4 warp — defined as the maximum distance from a reference plane to the guaranteed surface; this includes
twists, partial rises or declines in the glass compared with the reference plane. Warp expression a condition of the
whole glass (substrate).
4.4.5 waviness — the residual unevenness after the long wavelength component (warp) and the short wavelength
component (surface roughness) have been eliminated. This is also called “FPD Waviness” when referring
specifically to FPD substrates, as in SEMI D15.
4.4.6 surface roughness — the criterion for the smoothness of the sheet surface. Usually the randomly selected
areas on the sheet surface are measured by a surface analyzer. Details are defined in SEMI D7.
4.4.7 beveling — grinding out or shaping substrate edges by lapping or grinding.
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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Doc. 5696  SEMI
LETTER (YELLOW) BALLOT
Document Number: 5696
Date: 2/8/2016
Semiconductor Equipment and Materials International
3081 Zanker Road
San Jose, CA 95134-2127
Phone: 408.943.6900, Fax: 408.943.7943
DRAFT
X
chamfered edge
Y
W
radiused edge
R
Figure 1
Beveling
4.4.7.1 chamfered edge — a beveled angle of approximately 45° in respect to the surface and cut edge surface. One
characteristic is that part of the cut edge surface remains. For this reason, R-beveled edges have come to be used in
conjunction with chamfered edges in liquid crystal applications. Chamfered edges with particularly small widths are
also referred to as “string bevels.” (See Figure 1.)
4.4.7.2 R beveled edge — a beveled shape of an arc in respect to the surface and cut edge surface. One
characteristic is that the complete cut edge surface is ground with a wheel and processed into a frosted glass state.
Generally, in TFT liquid crystals, R-beveled edges are used more often. (See Figure 1.)
4.4.8 orientation corner — the corner of a substrate which identifies the pattern surface and the rotational
orientation. It is defined by the X and Y dimensions in the following figure. It is also commonly known as
“orientation flat” or “orifra.”
4.4.9 corner cut — removal of the corners of the substrate by either lapping or grinding. As with the orientation
corner, this is defined by the X and Y dimensions, but generally, most corner cuts have a X and Y of the same length.
X
orientation
corner
Y
corner cut
(3 places)
Figure 2
Orientation Corner and Corner Cut
4.4.10 squareness — deviation of the outline of the substrate from a true square or rectangle. Using the drawing
below, it is defined as PS or PL, but must be recorded with a or b dimensions. Dimensions a and b can be decided
voluntarily, but generally, most applications use a = S and b = L. (See Figure 3.)
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.
Page 3
Doc. 5696  SEMI
LETTER (YELLOW) BALLOT
Document Number: 5696
Date: 2/8/2016
Semiconductor Equipment and Materials International
3081 Zanker Road
San Jose, CA 95134-2127
Phone: 408.943.6900, Fax: 408.943.7943
DRAFT
PL
PS
S
a
L
b
LS
Figure 3
Squareness
4.5 Thermal Properties
4.5.1 coefficient of thermal expansion — expansion is the change in length per initial length caused by a thermal
change. Concretely, it is shown as ΔL/L0, where ΔL = L2 – L1 and L0, L1, and L2 are the lengths of the material at
the temperature T0, T1, T2 respectively. Usually, the coefficient of expansion (A), means the average coefficient of
expansion over the temperature range T1 to T2. This is shown in the following equation.
  (L/T)/L0 = [(L 2 – L 1)/(T2 – T1)]/L 0
(1)
4.5.2 thermal shrinkage — when the substrate is heat treated along a specific thermal profile, the relaxation of
thermal stress and the structure change occur in material, and create the shrinkage of the substrate. Usually it is
described with ΔL/L0, where, ΔL is the amount of change and shown as ΔL = L0 – L. L0 is the length of material
before heat treatment, and L is after heat treatment.
4.5.3 strain point — temperature of the glass when its viscosity is approximately 1014..5 dPa·s. Strain point is
defined by two methods in ASTM: Test Method C336 (Elongation of Glass Fibers) and Test Method C598 (Bending
in Glass Beams). In practice, the strain point of glass is the maximum temperature at which glass can be processed
without triggering unnecessary strain. Internal strain can be relieved by keeping (the glass) at this temperature for 4
hours.
4.5.4 annealing point — temperature of the glass when its viscosity is approximately 1013 dPa·s. The annealing
point is the temperature at which internal strain can be relieved in 15 minutes.
4.5.5 softening point — temperature of the glass when its viscosity is approximately 107.6 dPa·s. Softening point is
defined in ASTM C338.
4.6 Chemical Properties
4.6.1 chemical durability — a measure of corrosion or attack of a glass surface when subjected to a specific reagent,
such as acid, base, or water at a specific concentration for a specific time and temperature.
4.7 Optical Properties
4.7.1 transmittance — percentage of incident light which permeates the glass. It is defined as I/Io, where Io is the
strength of the incident light, and I is strength of the permeated light. Transmittance is effected by material
composition, temperature, thickness and light wavelength.
4.7.2 refractive index — ratio of the speed of light in the material and in a vacuum at a specific wavelength. The
refractive index of substrate glass is between approximately 1.50 and 1.53.
4.8 Mechanical Properties
4.8.1 density — mass per unit volume. Decided by the mass of the material’s atomic composition and the volume
(comparative capacity, mol capacity) which it occupies.
4.8.2 Young’s modulus — a type of elasticity ratio, which shows the stretch (or compression) elasticity. When
stretch (or compression) deformation stress σ and the strain ε resulting from the stress are proportionate, the
proportionate constant E = σ/ ε is called Young’s modulus, a material characteristic.
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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Doc. 5696  SEMI
LETTER (YELLOW) BALLOT
Document Number: 5696
Date: 2/8/2016
Semiconductor Equipment and Materials International
3081 Zanker Road
San Jose, CA 95134-2127
Phone: 408.943.6900, Fax: 408.943.7943
DRAFT
4.8.3 shear modulus — a type of elasticity ratio which shows divergence elasticity. When divergent deformation
stress τ and the strain Φ resulting from the stress are proportionate, the proportionate constant G = τ/Φ is called
Shear Modulus, a material characteristic.
4.8.4 Poisson’s ratio — the ratio between Young’s modulus and shear modulus.
4.8.5 Vickers hardness — a type of pressure test. A diamond pyramid indentator with a face angle of 136° is
pressed into the glass surface to find the degree of hardness by measuring trace indentation on the overall squareness.
4.9 Electrical Properties
4.9.1 dielectric constant — the proportionate dielectric constant which is the ratio between a vacuum dielectric
constant and the material dielectric constant.
4.9.2 dielectric loss — the phenomenon, or volume, of (electricity) loss through heat when a dielectric is introduced
to an alternating current.
4.9.3 resistivity — the reciprocal of electric conductivity.
4.10 pattern surface — the main area where device patterns can be formed, determined by the orientation corner,
etc.
4.11 quality area — the center area to the substrate where specified substrate quality criteria (primarily internal
defects, surface contamination, surface defects, waviness, and surface roughness) are applicable.
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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Doc. 5696  SEMI
LETTER (YELLOW) BALLOT
Document Number: 5696
Date: 2/8/2016