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Phototool
A phototool is a printed film used in the process of manufacturing a printed circuit board (PCB). The phototool is used as a mask to expose a photoresist material. The main alternative to using phototools is maskless lithography, more commonly referred to as direct imaging. Traditionally, phototools were made with silver halide film or diazo film, but in recent years, many suppliers have come out with films that do not fit into either of these categories. All dry-film phototools are printed using a similar process to film photograph. The steps for using a phototool are as follows: * A PCB (typically consisting of a laminate material with copper adhered to the surface) is prepared and cleaned. * The PCB is coated with a photoresist material that can be cured with UV light * The phototool is positioned over the PCB * UV light (or other actinic radiation) shines through the phototool, selectively curing the material. * The uncured material is washed away, usually using a mild w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Printed Circuit Board
A printed circuit board (PCB; also printed wiring board or PWB) is a medium used in Electrical engineering, electrical and electronic engineering to connect electronic components to one another in a controlled manner. It takes the form of a Lamination, laminated sandwich structure of conductive and insulating layers: each of the conductive layers is designed with an artwork pattern of traces, planes and other features (similar to wires on a flat surface) Chemical milling, etched from one or more sheet layers of copper Lamination, laminated onto and/or between sheet layers of a Insulator (electricity), non-conductive substrate. Electrical components may be fixed to conductive pads on the outer layers in the shape designed to accept the component's terminals, generally by means of soldering, to both electrically connect and mechanically fasten them to it. Another manufacturing process adds Via (electronics), vias: plated-through holes that allow interconnections between layers. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photoresist
A photoresist (also known simply as a resist) is a light-sensitive material used in several processes, such as photolithography and photoengraving, to form a patterned coating on a surface. This process is crucial in the electronic industry. The process begins by coating a substrate with a light-sensitive organic material. A patterned mask is then applied to the surface to block light, so that only unmasked regions of the material will be exposed to light. A solvent, called a developer, is then applied to the surface. In the case of a positive photoresist, the photo-sensitive material is degraded by light and the developer will dissolve away the regions that were exposed to light, leaving behind a coating where the mask was placed. In the case of a negative photoresist, the photosensitive material is strengthened (either polymerized or cross-linked) by light, and the developer will dissolve away only the regions that were not exposed to light, leaving behind a coating in areas w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maskless Lithography
Maskless lithography (MPL) is a photomask-less photolithography-like technology used to project or focal-spot write the image pattern onto a chemical resist-coated substrate (e.g. wafer) by means of UV radiation or electron beam. In microlithography, typically UV radiation casts an image of a time constant mask onto a photosensitive emulsion (or photoresist). Traditionally, mask aligners, steppers, scanners, and other kinds of non-optical techniques are used for high speed microfabrication of microstructures, but in case of MPL, some of these become redundant. Maskless lithography has two approaches to project a pattern: rasterized and vectorized. In the first one it utilizes generation of a time-variant intermittent image on an electronically modifiable (virtual) mask that is projected with known means (also known as Laser Direct Imaging and other synonyms). In the vectored approach, direct writing is achieved by radiation that is focused to a narrow beam that is scanned in vect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silver Halide Film
Silver is a chemical element with the Symbol (chemistry), symbol Ag (from the Latin ', derived from the Proto-Indo-European wikt:Reconstruction:Proto-Indo-European/h₂erǵ-, ''h₂erǵ'': "shiny" or "white") and atomic number 47. A soft, white, lustrous transition metal, it exhibits the highest electrical conductivity, thermal conductivity, and reflectivity of any metal. The metal is found in the Earth's crust in the pure, free elemental form ("native silver"), as an alloy with gold and other metals, and in minerals such as argentite and chlorargyrite. Most silver is produced as a byproduct of copper, gold, lead, and zinc Refining (metallurgy), refining. Silver has long been valued as a precious metal. Silver metal is used in many bullion coins, sometimes bimetallism, alongside gold: while it is more abundant than gold, it is much less abundant as a native metal. Its purity is typically measured on a per-mille basis; a 94%-pure alloy is described as "0.940 fine". As one of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diazo Film
Whiteprint describes a document reproduction produced by using the diazo chemical process. It is also known as the blue-line process since the result is blue lines on a white background. It is a contact printing process which accurately reproduces the original in size, but cannot reproduce continuous tones or colors. The light-sensitivity of the chemicals used was known in the 1890s and several related printing processes were patented at that time. Whiteprinting replaced the blueprint process for reproducing architectural and engineering drawings because the process was simpler and involved fewer toxic chemicals. A blue-line print is not permanent and will fade if exposed to light for weeks or months, but a drawing print that lasts only a few months is sufficient for many purposes. The diazo printing process Two components underpin diazo printing:{{Ullmann , doi=10.1002/14356007.o13_o08.pub2, title=Imaging Technology, 2. Copying and Nonimpact Printing Processes, last1=Pai, first ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Actinic Radiation
Actinism () is the property of solar radiation that leads to the production of photochemical and photobiological effects. ''Actinism'' is derived from the Ancient Greek ἀκτίς, ἀκτῖνος ("ray, beam"). The word ''actinism'' is found, for example, in the terminology of imaging technology (esp. photography), medicine (concerning sunburn), and chemistry (concerning containers that protect from photo-degradation), and the concept of actinism is applied, for example, in chemical photography and X-ray imaging. Actinic () chemicals include silver salts used in photography and other light sensitive chemicals. In chemistry In chemical terms, actinism is the property of radiation that lets it be absorbed by a molecule and cause a photochemical reaction as a result. Albert Einstein was the first to correctly theorize that each photon would be able to cause only one molecular reaction. This distinction separates photochemical reactions from exothermic reduction reactions trigge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photolithography
In integrated circuit manufacturing, photolithography or optical lithography is a general term used for techniques that use light to produce minutely patterned thin films of suitable materials over a substrate, such as a silicon wafer, to protect selected areas of it during subsequent etching, deposition, or implantation operations. Typically, ultraviolet light is used to transfer a geometric design from an optical mask to a light-sensitive chemical (photoresist) coated on the substrate. The photoresist either breaks down or hardens where it is exposed to light. The patterned film is then created by removing the softer parts of the coating with appropriate solvents. Conventional photoresists typically consists of three components: resin, sensitizer, and solvent. Photolithography processes can be classified according to the type of light used, such as ultraviolet, deep ultraviolet, extreme ultraviolet, or X-ray. The wavelength of light used determines the minimum feature si ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photoengraving
Photoengraving is a process that uses a light-sensitive photoresist applied to the surface to be engraved to create a mask that protects some areas during a subsequent operation which etches, dissolves, or otherwise removes some or all of the material from the unshielded areas of a substrate. Normally applied to metal, it can also be used on glass, plastic and other materials. A photoresist is selected which is resistant to the particular acid or other etching compound to be used. It may be a liquid applied by brushing, spraying, pouring or other means and then allowed to set, or it may come in sheet form and be applied by laminating. It is then exposed to light—usually strong ultraviolet (UV) light—through a photographic, mechanically printed, or manually created image or pattern on transparent film. Alternatively, a lens may be used to project an image directly onto it. Typically, the photoresist is hardened where it receives sufficient exposure to light, but some photoresis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
