Glossary of Industry Terms

The terms contained in this glossary are those commonly used in our industry to describe coated films and the processes used in their manufacture. The definitions presented are those commonly used by the industry, but in some cases we have made adjustments for purposes of clarity and to reduce any potential confusion of meaning.

The glossary terms are presented in alphabetical order.

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

A

Abrasion Resistant Coating - a coating which resists scratching; it may be hard or alternatively slippery.

Absorptance - the ratio of the amount of radiative energy absorbed in a coating or film to the incident energy.

Active-Matrix LCD - refers to the type of technology that an LCD monitor is based on. Also known as thin film transistor (TFT) technology, active matrix is one of the two main technologies used for desktop PC and laptop displays. On a TFT display, one or more transistors control each pixel on the screen. Compared to the other widely used display type, passive matrix (STN, or DSTN), the active matrix type generally has a higher resolution, sharper picture, wider viewing angle, and is capable of displaying more colors.

Aluminize - to coat a surface by vacuum evaporation of aluminum. Also called metallization.

Angstrom (Å) - one ten billionth of a meter (10-10m); a unit commonly used when discussing coating thickness.

Anti-glare Coating - a coating, which reduces the reflectance of a surface by increasing the diffuse reflectance from that surface.

Anti-reflective Coating - a coating, which reduces the reflectance of a surface by better optical coupling to the surface and therefore increasing the overall transmittance of the film.

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B

Blocking - the sticking together of layers of film on a roll often caused by a coating which has been deposited on the film.

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C

Capacitive Touchscreen - a type of touchscreen interface technology that is based upon a thin, clear, metallic layer over a glass or film panel. When a finger or conductive stylus makes contact with the screen, a small amount of voltage is drawn at the point of contact. The amount of voltage drawn from each corner of the screen is used to determine the point of touch contact. A touchscreen controller is used to process these voltages and send data to the PC to be read as a touch event.

Cathode - the negatively charged electrode in a glow discharge system. In sputtering, the cathode is often called the target. It is attacked by positively charged ions and is composed of the material to be deposited.

Chill Drum - the central drum in a vacuum roll coating machine, which maintains the film at a constant temperature while it is being coated.

Coating - the thin layer of material, which is deposited onto the polymer film substrate.

Color Temperature - the temperature of a black body, which emits light with the same spectral characteristics as the surface under consideration.

Controller (Touchscreen) - the hardware interface between a touchscreen system and its corresponding computer. It processes signals from a touch input sensor and passes touch event data to the corresponding PC, normally by PC serial or bus interface.

Core - a cardboard, resin impregnated cardboard or plastic tube around which a roll of film is wound.

Core Plug - a plastic plug which is fitted into the ends of a core to retain an end plate and packaging material.

CRT (Cathode Ray Tube) Monitor - a type of computer monitor that uses a large picture tube, similar to a television. This is currently the most common type of PC monitor. The display works by moving an electron beam back and forth across the back of the screen to light up phosphor dots on the inside of the glass tube. By drawing many lines from the top to the bottom of the screen, an entire screen full of images is created.

Cylindrical CRT - refers to the shape and curvature of the actual picture tube in a CRT monitor. The screen from a cylindrical CRT will be curved on the horizontal axis yet flat on the vertical axis. A touchscreen overlay must also be cylindrical shape or be able to bend to cylindrical shape if it is to be installed inside a monitor with a cylindrical CRT.

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D

Decibel (dB) - a unit of power loss or attenuation used in EMI/RFI shielding:

1 decibel = 10 log (Power in/Power out).

A 3dB loss is a fifty percent power reduction.

Diffuse - light which is either incident on or reflected from a film in all directions.

Dimple - an indentation in film caused by improper film manufacturing or a dirt particle.

Dot Pitch - a measurement in millimeters of the vertical distance between the pixels of a computer display. A smaller number means a crisper display because the pixels are closer together. A common dot pitch for a computer monitor is between .20 to .30.

Drift - a gradual loss of accuracy in the alignment of a touchscreen system. Over time, touches to the screen will gradually drift, or move away, from their proper on-screen targets. If the alignment of a touchscreen becomes poor, the touchscreen will need to be calibrated to restore proper alignment.

Dyed Film - film, typically PET polyester, which has been colored by impregnation of a dyestuff into the film.

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E

Electron Beam (e-beam) Evaporation - a vacuum evaporation process which uses a high power electron beam to melt the evaporant. This process is presently only used in large scale for aluminum and magnetic alloys.

Electrostatic Charge - an electrical charge, which builds up on a film due to its high dielectric strength, which is caused by rubbing of film against itself or against another non-metallic surface. This charge will cause large amounts of dust to be attracted to the film if it is not neutralized and can be either negative or positive.

EMI/RFI (Electromagnetic Interference/Radio Frequency Interference) - is interference to a signal caused by an external source, which is reduced by appropriate shielding.

Emittance - the ratio of the amount of energy emitted by a surface to that is emitted by a black body at a particular temperature and wavelength. At a given wavelength, under identical conditions,

Emittance = Absorptance

End Plate - an oversize, square cardboard or wooden plate which suspends a roll of film and keeps it from touching the ground. It is held in place by a core plug.

Etch - a process of controlled selective chemical or laser removal of a coating to produce a pattern. Usually a mask, such as photoresist, is deposited on the coating. The exposed areas are then etched away, and then the mask is removed to expose the pattern.

External Touchscreen - a touchscreen input device that is designed to mount on the outside of a PC monitor. The external touchscreen does not require any difficult installation or opening of the monitor. It is commonly a touch sensitive glass panel that uses an external touchscreen controller and a software driver to interface with a PC system.

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F

Feedback - An audible or visual response to user input in a multimedia presentation. For touchscreen applications, feedback lets the user know that their input has been received. A good example of feedback is a button that changes color and makes a 'click' sound when pressed.

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G

Gauge - a measure of the thickness of films: 100 gauge = 1.0 mil = 25.4 micrometers (micron).

Gauge Band - a variation in the thickness of a roll of film in the transverse direction, observed as a dark band in the roll.

Gloss Level - a measure of the amount of non-specularly or diffusely reflected light from a surface. A highly diffuse surface has a low gloss level.

Glow Discharge - a process of electrical conduction through a gas caused by the ionization of the gas molecules and accompanied by the emission of light. Film is commonly treated to improve adhesion by subjecting it to a glow discharge. Sputtering is a form of glow discharge.

Ground Plane - a conductive coating on film, which is at earth (ground) potential.

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H

Hardcoat - a coating deposited on a surface, which is hard and resists abrasion. It may also be an anti-glare coating.

Haze - the amount of light, which is non-specularly transmitted through or reflected from a film.

Heat Stabilized - the effect of heating film to a temperature above its temperature of use so that its thermal shrinkage properties are minimized.

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I

Internal Touchscreen Panel - a touchscreen input device that is designed to be installed on the inside of a PC monitor. It is commonly a touch sensitive glass panel that uses a touchscreen controller and a software driver to interface with a PC system. The internal touchscreen requires a sometimes technical installation, as the monitor needs to be opened and in some cases the touchscreen controller needs to be wired to a power source inside the monitor. This installation also will commonly void the manufacturers' warranty of the monitor.

Indium-Tin Oxide (ITO) - a semi-conducting coating which is transparent to visible light and yet can be made to be electrically conductive. It can be readily patterned by means of etching.

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J

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K

Kiosk - a booth, stand, or display that provides useful services or information to a user. A touchscreen kiosk uses a touchscreen as the main user interface to a PC based software application or multimedia presentation. Besides providing information, such as directories and guides, kiosks can also be used to offer services such as self-service bill payment, electronic ordering, and more.

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L

Lamination - a process to bond together two films or a film and a solid surface with or without a separate adhesive layer.

LCD (Liquid Crystal Display) Monitor - an advanced type of computer monitor that uses a flat screen to provide full color images. This type of monitor is currently growing in popularity. The screen is based upon Liquid Crystal Display technology, which uses a liquid crystal solution between thin polarizing layers. An electric current passes through the liquid to align the crystals, either blocking light or to allowing it to pass, creating an image on the screen. Because they use flat screens, LCD monitors have great space-saving advantages over traditional CRT monitors. They also use less power and do not emit harmful radiation.

Light Transmission - refers to the amount of light that passes through a touchscreen panel. Most touchscreen systems incorporate a glass or acrylic panel, sometimes with additional layers or coatings that are applied. These layers can limit light passing through the touch panel. A higher light transmission means that the display will appear brighter and clearer. Common light transmission ratings for touchscreens are in the range of 70% to 95%.

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M

Magnetron Sputtering - a glow-discharge film deposition process related to sputtering where a shaped magnetic field is used to confine electrons in the discharge and greatly increase its efficiency and the deposition rate.

Metallize - to coat a surface by vacuum evaporation, usually with aluminum.

Micron - a micrometer, i.e., one millionth of a meter.

Mil - one thousandth of an inch.

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N

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O

Ohms/square (Ω/_) - the measure of electrical resistance of a coating.

Optical Density - a logarithmic measure of the transmission of a coating;

Optical Density, OD = - log 10(T), where T is the transmittance.

OSD (On Screen Display) - refers to the display controls on a PC monitor. Instead of knobs or dials, many monitors now use several electronic buttons that control their display settings. The buttons allow the user to navigate through an on-screen menu that controls all of the options for the display. Typical OSD menu options include screen height and width, vertical and horizontal position, color settings, and more.

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P

Passive Matrix LCD - refers to the type of technology that an LCD monitor is based on. Passive matrix (STN, DSTN) is one of the two main technologies used for desktop PC and laptop displays. Compared to the other widely used display type, active matrix (TFT), the passive matrix type is more affordable yet the displays are generally not as crisp or colorful as the active type. Recent advances in LCD technology, however, are showing brighter, more colorful passive type screens that are almost rivaling the active types.

PET Polyester - polyethylene terephthalate polyester film, which has excellent optical clarity, smoothness and processability.

Photometer - an instrument for measuring the transmittance, optical density, or reflectance of a coating.

Planar Magnetron - a type of magnetron sputtering source in which deposition occurs from a planar surface, usually a metal plate.

Plasma - a highly ionized gas caused by electrical breakdown of the gas between the electrodes of a glow discharge or sputtering system.

Plasma Deposition - a glow discharge thin film deposition process in which gases introduced into the glow discharge react chemically to produce a coating.

Polycarbonate - a film with high light transmission, clarity and toughness, but low chemical resistance. Abrasion-resistant protective coatings are available to improve its chemical resistance.

Polyimide - a film with high heat tolerance and a distinctive amber color. Used primarily in the flex-circuit industry.

Pounds/Ream of Coating - a measure of the amount of dry coating or adhesive applied to a surface. One ream equals 3,000 square feet.

Pressure Sensitive (P/S) Adhesive - an inherently tacky adhesive, which develops maximum bond strength when applied with only light pressure.

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Q

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R

Reflectance - the ratio of the amount of energy reflected by a coating to the amount of incident energy. Note that for a semi-transparent film,

Transmittance + Absorptance + Reflectance = 1.

Release Sheet - a sheet of film used to protect a surface, such as a coating or adhesive, which has a light tack to that surface and is removed prior to use.

Resistive Touchscreen - a type of touchscreen interface technology that is based upon thin metallic electrically conductive and resistive layers. When pressure is applied to the screen, the layers are pressed together, causing a change in electrical current. A touchscreen controller is used to process this electrical change and send data to the PC to be read as a touch event.

Resolution (Display) - display resolution refers to the number of pixels (dots) that make up the video image on a computer monitor. A 640 x 480 screen resolution means that the screen image is 640 pixels wide and 480 lines high. A higher resolution, or number of pixels, means that the display will be sharper and clearer.

Resolution (Touchscreen) - touch point resolution refers to the number of touch sensitive points on the touchscreen. Many touchscreen systems today have a very high touch point resolution, over 100 points per inch. Some touchscreen systems have such high resolution that they are capable of capturing human signatures.

Response Time - refers to the length of time that it takes for a touchscreen system to respond when it is touched. Most touchscreen systems today have response times in the 5 - 20 millisecond range.

Rotatable Magnetron - a type of magnetron sputtering source in which deposition occurs from a cylindrical source, usually a metal tube. Typically more efficient than planar magnetrons; however source materials are not as readily available.

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S

Scratch Resistant (S/R) Coating - see Abrasion Resistant Coating.

Sealability - refers to the ability of a touchscreen system to be sealed so that its internal components are protected and not exposed. A touchscreen system can be sealed so that it is protected from water splashes, etc., and also can be sealed for use in sterile environments like cleanrooms.

Sensor - refers to the touch sensitive portion of a touchscreen system. This is commonly a glass or acrylic panel that has a touch sensitive layer applied to it. Three different types of sensor technology are resistive, capacitive and surface wave.

Serial Controller - a serial port (RS-232) is a common method of interfacing with a PC system. Most touchscreen systems are available with a controller that is designed to connect to a PC serial port.

Sheet Resistance - for a rectangularly shaped section of coating, the resistance measured in a direction parallel to the coating surface is

R = rL/S

where the surface through which the current flows is (S) = the coating thickness (t) x the breadth of the coating section (b), and L is the length of the coating section. The resistivity of the coating is r, with units of ohm-cm, etc. If L = b, then

R = r/t

i.e., the resistance of a square of coating is independent of the size of the square and is called the sheet resistance.

Silicone Coating - a type of coating often used on a release sheet.

Slitting - the process of cutting a large roll of film to several shorter or narrower rolls.

Spectrophotometer - an instrument for measuring the transmittance and reflectance of a coating as a function of wavelength.

Specular - radiation which is incident or reflected from one direction only, i.e., in a mirror-like fashion.

Spherical CRT - refers to the shape and curvature of the actual picture tube in a CRT monitor. The screen from a spherical CRT will be curved on the horizontal axis and also curved on the vertical axis. A touchscreen overlay must also have a spherical shape if it is to be installed inside a monitor with a spherical CRT.

Spreader Roller - a roller in film transport equipment which prevents thin film from wrinkling.

Sputtering - glow discharge thin film deposition process where energetic inert gas ions bombard a cathode (target) and cause atoms of the target to be ejected and to land on a substrate. In reactive sputtering, a reactive gas is added to the discharge and this gas reacts with the coating as it forms on the substrate.

STN (super twist nematic) LCD - display technology, also known as passive matrix, which is used in LCD monitors. This technology attempts to improve screen image quality by twisting light rays. There is also DSTN, or double super twist nematic, which improves contrast through the use of more twists.

Stylus - a pen-like pointing device that can be used with a touchscreen system. A stylus usually has a much finer point than a finger and therefore is useful for more precise touchscreen operation.

Surface Wave (SAW) Touchscreen - a type of touchscreen interface technology that is based upon ultrasonic waves passing over a glass panel. A series of transducers and reflectors are used to direct waves across the glass. When a finger makes contact with the screen, a portion of the wave is absorbed. This change is used to calculate the position of the touch event. A touchscreen controller is used to digitize the touch event information and send data to the PC.

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T

Target - the face of the cathode in a sputtering apparatus. It is the material which is converted to the coating.

Telescoping - a distortion of a roll of film where the individual layers slide over each other laterally and cause scratches in the film.

TFT (thin film transistor) LCD - also known as Active Matrix technology.

Touchscreen - an input device for a PC system. It uses a touch sensitive screen that is placed over the PC's video display, allowing the user to simply 'touch the screen' to interact with the PC. The touchscreen system normally consists of a sensor, a controller and a software driver.

Touch Coordinates - X and Y axis coordinates that determine the location of a touch on a touchscreen sensor. Touch coordinates are translated to display coordinates to determine the corresponding point on a video display.

Touch Target - an on-screen object such as a graphic, button, or icon, that the user can press to trigger some type of action in a multimedia presentation or other software.

Transmittance - the ratio of the amount of transmitted energy to the amount of incident energy.

Transparent Conductor - a coating which is at least semi-transparent and which has a finite electrical conductivity. These coatings are generally of two types; (1) metal oxides which are highly transparent but which have a low conductivity and; (2) thin metal coatings which have lower transmittance but a high conductivity.

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U

UV Cured Coating - a coating, which is reacted or polymerized through the action of ultraviolet light rather than heat.

Uniformity - the lack of variation in the properties of a coating along and across a piece of film.

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V

Visible Light Transmittance (VLT) - the average transmittance of a coating weighted for the visual response of the human eye.

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W

Web - a general term for a roll of film or other material.

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X

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Y

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Z

Z-Axis - a third measurement that can be read from some touchscreen systems. Z-axis allows touch pressure to be sensed in addition to x and y touch coordinates. Pressure levels can be set through software that allows different actions to take place depending on the pressure of the touch.

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