Screen printing, carbon ink, silver glue, strippable and copper paste process - Switzerland TETKO screen tension meter

1. Angle of Attack The angle of attack refers to the angle between the screed surface and the plane formed by the screen plane during the screen printing.

2, Bias diagonal mesh, diagonal weaving refers to a special method of screen printing screen printing method, that is to give up the net cloth latitude and longitude parallel to the outer frame of the Orthodox Zhang method, deliberately to make the mesh warp and the two sides of the frame A combination of 22° is formed longitudinally. As for the paste of the graphic plate, it is still in the direction of the frame. Pushing the ink forward with the squeegee will cause the ink to produce a side-driving force. For example, when green lacquer is printed, it can have more ink distribution behind the board line. However, this "diagonal network" method is a waste of mesh. In general, it is still possible to use a positive sheet mesh instead of a diagonal sheet printing method, or to print each sheet once and again, which also solves the missing printing problem. Bias also refers to the weave of warp and weft yarns that are not vertical.

3, Bleach rinse refers to the screen printing preparation project, in order to make the mesh between the regenerated screen, and the film (Stencil) or photosensitive adhesive has a better adhesion, the used mesh cloth must be bleached Water or fine gold sand is a builder, which is brushed, washed, and roughened for regeneration. Bleach is called.

4, Bleeding overflow in the circuit board process often refers to the completion of the copper wall through the hole, there may be holes, so that often residual liquid outflow. Sometimes referred to as the printed liquid resist pattern, there may be a slight amount of components spilled from the edge of the liquid resist pattern during the subsequent drying process.

5. After Blockout Closure is indirect, the stencil must be coated with a hydrosol after the stencil is in place to prevent ink leakage at the edges.

6, Blotting dry printing
After several times of "stencil printing" after the squeegee printing, there is often excess residual ink on the downward facing printing surface. A white paper must be used instead of the circuit board, and a dry squeegee (the mainland industry is called a squeegee) should be used to print once. The residual ink that sucks away the edges of the graphics is called Blotting. The traditional baking type green paint must be continuously printed in order to maintain the quality of the green paint edge printed on the circuit board.

7, Blotting Paper absorbent paper used to absorb excess liquid paper.

8, Calendered Fabric rolled flat mesh is for the traditional PET mesh (trade name Te Duo Long), Nai net mesh and stainless steel mesh, etc., its scraping surface is particularly rolled on one side, so that easy to scrape ink and Make "ink" thinner, and UV ink exposure easier and more thorough. It is said that the sizes of some types of mesh are more stable and the thickness of the ink is more uniform, but there are also some reports from utility operators that are not entirely consistent. And this "rolling leveling project" is not easy to carry out, often rolled uneven thickness, or even the situation of premature death, the current UV ink has been quite advanced, so this type of rolling mesh cloth has disappeared.

9. The Carlson Pin Cartridge locating tip is a thin, flat (1.5" x 0.75") base, and the short stainless steel tip of the stake allows the base to be glued with a thin tape when the plate is to be printed. Affixed to the fixed position of the printing table surface, and then put the tool hole of the plate to be printed into the short tip to facilitate the alignment of the screen pattern. The short tip is a corner welded to a rectangular base surface by spot welding. Usually, the diameter of the tip is 0.125" and the height is 0.060".

10. When the Chase frame is screen printing method as a tool for image transfer, the square frame that supports the mesh and the film is called a frame. The current mesh frame is mostly welded with hollow or solid aluminum bars, also known as Frame.

11, Copper paste Copper paste is a paste made of copper powder and organic carrier, can be printed on the board surface of a simple line conductor.

12, Cure hardening, curing polymer in the monomer state with the help of the catalyst, will absorb heat energy or light energy and chemical reactions, and gradually change its original nature, this cross-linked polymer phenomenon called Cure. Curing Agents refers to hardeners.

13, Direct Emulsion direct emulsion is a single-panel printed mesh used in the emulsion resist, the mesh can be directly sealed, than the indirect version of the film on the cloth (Stencil) is more durable. However, the “finality” definition of the edge of the pattern is not good, so it can only be used for the transfer of single-panel images with thick lines.

14. Direct/Indirect Stencil is an indirect version of the film that is attached to the mesh fabric because the film is very thick, and after the water spray, there will be capillary action and the film will swell into the fabric. There are also benefits of direct latex, such as Ulano's CD-5.

15, Durometer rubber hardness tester is the use of spring force of the metal probe (Indentor), pressed on the softer rubber or plastic, to measure its hardness. As the common Durometer "A", that is, after taking 1 kg of gravitational pressure for 1 second, the number of degrees seen on the surface is the representation of this hardness. The PU scraper required for screen printing has a hardness of about 60-80 degrees, which is also measured by this hardness meter.
16. Fabric mesh refers to the carrier “mesh” stretched on the screen frame by the printed screen. Usually, the material is polyester (PET), stainless steel, and Nylon. The word is also known as Cloth.

17, Flood stroke Print Ink stroke printing refers to the actual printing pattern, the first with a flood knife (Flood Bar) the ink is evenly coated on the net cloth, and then scraper to scrape. This method is useful for Thixotropic inks.

18, Ghost Image shadow in the screen printing may be due to the mesh or the edge of the imprint, resulting in the edge of the printed image is not deep or fuzzy, known as Ghost Image. Hardner (or Curing Agent) - refers to epoxy-based thermosetting coatings (such as green paint, text white paint, liquid photosensitive green paint, etc.), with two components of the two liquid packaging, one of which is hardener. Once the two liquids are blended and applied, they will be hardened or hardened by the cross-linking function of such hardeners at high temperatures, that is, polymerization (Polynorization) or cross-inking (Crossinkage) occurs. The reaction becomes a polymer that cannot be turned back. There are other names for this hardener, such as bridging agents, cross-linking agents, etc.

19, Legend text mark, symbol refers to the printed circuit board finished product symbols or numbers, is used to indicate the location of various parts of the assembly or repair. Usually, the arrangement of various parts (such as R of a resistor, C of a capacitor, and U of an integrated circuit) is from the upper left corner of the front side of the board, and then goes first to the right and then downward, and the rows are arranged in order. The parts have been given the word and number respectively. This kind of character printing is mostly made of permanent epoxy white paint, and a few are also printed yellow paint. When printing, care must be taken not to contaminate the solder pads so as not to affect their solderability.

20, Mask resist means that the whole board enters a certain process environment and wants to perform a certain process, and if its partial board surface does not want to accept processing, it must adopt some kind of protection to cover and mask it, and isolate from the environment. Its effect. This kind of masking film is called "Mask resister", such as "Solder Mask solder mask".

21. Marking Marks are letters (P/N), Revision Letters, Logos, etc. printed on the surface of the board with white epoxy paint, and Legend may sometimes be used. Interoperable, but not the same.
22. Mechanical Stretcher A mechanical stretcher is a machine that stretches a mesh to a desired tension. When the mesh is pulled flat, it can be fixed on the frame to form a screen carrier for printing. In the early days, the net cloth was stretched on all four sides. It was a mechanical rod type output tool. Now it has been changed to a pneumatic tensioner (Pneumatic Tensioner) to make the tension more uniform and the stretching action is also more moderate, so as to reduce the crack of the net cloth. .

23. Mesh Count Mesh Count This refers to the number of warp and weft threads and the weaving density, ie, the number of threads per unit length or the number of openings, which is an important parameter for screen printing. The higher the Mesh number is, the smaller the opening degree is, and the better the edge resolution of the printed figure is. Since this type of stainless steel or polyester mesh cloth is produced in a number of countries that use metric systems such as Japan and Switzerland, its number is based on the number of wires per cm. For example, a 55T mesh cloth printed with green paint can be converted into 140T per inch, and a 120T printed wire can be replaced with 305T. The metric system is more accurate. The letters followed by various network numbers are used to express the fine details of the mesh, including three types of S(Small), T(Thick) and HD (Heavy Duty). Currently, there are few S-purposes, so Only the last two are left in the product.

24. Metallized Fabric The metalized mesh is on the surface of the mesh of Polyester (Polyester, also known as Triton). The other is coated with a chemical nickel layer to make the mesh stronger and more stable, and to make the mesh opening. The ink leakage is also smoother, making the performance similar to stainless steel mesh, but the price is much cheaper. However, the elasticity of this "metallized mesh" is not very good, and the opening will be smaller. When it is used, the nickel layer will be broken. In Taiwan's high-humidity marine climate, it is easier to rust, so it has not been used in the country.

25. Monofilament Monofilament refers to the appearance of the threads in the mesh used for screen printing. At present, almost all types of mesh fabrics have been completely monofilament, and multifilament yarns have been used in the early days. Due to the mesh opening degree, resolution, and mastery of characteristics, they are far inferior to monofilament mesh fabrics. Gradually eliminated. The existing stainless steel or synthetic yarns are also much improved in their properties in various aspects than in the early days.

26, Negative Stencil Negative photosensitive film refers to the photosensitive film that can produce polymerization reaction after photosensitivity. The word Stencil is a photosensitive film that can be attached to a stretched mesh to allow screen printing for image transfer to complete indirect printing screens. Almost all the graphic printing used by the various circles are using this cheaper photosensitive chemical as an image tool.

27. Newton (N) Newton When a mass of 1 kg mass receives an acceleration of 1 m/s2 per second per second by an external force, its external force is 1 "Newton", abbreviated as 1 N. . In the preparation of screen printing, the unit tension of the Zhangwang.com (a Chinese term for a stretch net, which seems to be more appropriate) can be achieved using several N/cm2 (1 N/cm2=129 g/cm2) as the expression.

28, Nomencleature Marked text symbols refer to the white characters and symbols printed on the green paint surface for the convenience of downstream assembly or maintenance. The purpose is to indicate the parts that need to be installed to avoid errors. There are other expressions for such “marked characters”, such as Legend, letter, and Marking. And there are other colors such as yellow, black, etc. in the early days, and now it is almost unified with white epoxy resin ink.

29. Nylon Nalon was previously translated as "nylon" and is one of the Polyamides Polyamides. It is a Thermoplastic resin and has a tensile strength over a wide temperature range (0 to 150°C). (Tensile) Strength) and flexural strength (Flexural Strengths) have very good results, and resistance to electricity, acid and alkali resistance and solvent resistance is also very good. In the electronics industry, peripheral insulation layers and fillers used for enameled wires are used in the circuit board industry for screen printing of mesh materials.

30. In Off-Contact overhead screen printing combination, when the ink surface of the mesh is not under construction operation, there is still an overhead height distance from the copper surface of the board (Off-Contact-Distance, OCD, usually 0.125 inch). Only when the scraper blade is pressed by the straight edge line does the net cloth show a V-shaped local contact on the copper surface. This kind of actual situation is not completely flat and is called Off-Contact. Another automatic dry film image transfer, its clean room parallel light exposure station, between the glass film and the circuit board surface, also presented this non-contact "overhead" to facilitate the free transport of the board forward. This aerial exposure method is the highest level of photographic transfer.

31, On-Contact Printing sticky printing means that the printing plate is completely flat on the surface of the part to be printed, and then the printing method for pushing the ink with a squeegee, such as the Stencil printing method. This method can be printed after the full version of the shelf at the same time rise off the print surface, leaving solder paste on the circuit board. Unlike the Off-Contact Printing method, the tension of the stretching net is used. When the squeegee is pushed forward and pressed down, the net after the squeegee is also lifted up at the same time. Printed patterns can be kept clear, and common screen printing methods are the same. The schematic diagram of solder paste printing is to illustrate the difference between the two.

32. Plain Weave Weaving refers to a weaving method used in the screen printing, that is, when the warp and weft yarns are knitted in a One Over One Under manner, it is called a "flat weave method." For the screen printing method, the flat weave method has the best ink leakage. Nowadays, popular mesh fabrics are all made from monofilaments. When the number of meshes increases continuously to a certain limit, the wire diameter is so thin that the strength is insufficient and we cannot weave the mesh required for printing. . In general, when synthetic fibers (predominantly polyester-based "Tedoron") reach 300 mesh/inch (120 mesh/cm) or more, they cannot be used because of insufficient tension. Stainless steel can be re-dense to 415 heads/inch (or 165 mesh/cm) but still maintain sufficient tension. At present, the plain weave mesh used in the "screen printing" uses only monofilaments for easy cleaning and regeneration and convenient weaving. However, the multi-filament weaving method is still used for the weaving of fiberglass cloth in the sheet film (Pupreg) in order to improve the dimensional stability and facilitate the impregnation and penetration of the resin, as well as increase the contact area and adhesion.

33, Plug pins, plugs in the circuit board often refers to the connector or male plug part of the socket, can be inserted into the hole for the use of the interconnection can also be extracted at any time. The word Plugging is sometimes referred to as a "plug hole" and is a special resist that protects the wall of the hole so that the outer plate is positively etched, for the same purpose as the lid hole method. However, the plughole method can achieve the outer layerlessness to increase the density of wiring.

34, Pneumatic Stretcher pneumatic stretcher is a stretching tool for screen making, can be mesh from the four sides with its jaws to clamp it, and "pneumatic" mode carefully and slowly stretching uniform, Tension is set and changed. After it reaches the required data, it is fixed on the frame with glue, and it becomes the carrier of the circuit pattern and the squeegee. Because the tension can be controlled from the air pressure, it is more accurate than the "mechanical" tension, which helps the implementation of precision printing. The left picture shows the quick jaw and pneumatic cylinder of the "pneumatic tensioner". The picture on the right shows a lifting and tensioning net platform with multiple tensioners.

35. Poise is a unit of "viscosity" equal to 1 dyne. Sec/cm2, commonly used in centimeters Centipoise (referred to as Cp). The commonly used solder paste has a viscosity of 600,000 Cp to 1 million Cp.

36, pot life, pot life (processable time)
Refers to a two-liquid type of glue or coating (such as green paint). When the main agent and its special solvent or catalyst (or hardener) are mixed in a container, it becomes a workable material. However, once it is mixed, its chemical reaction is also started until it is nearing sclerosis and its useable time in the container is called Pot Life or Working Life.

37. Reclaiming regeneration refers to the process of screen printing between screen printing. When the original film (Stencil) on the fabric needs to be removed, and the new film is to be applied, the original film should be chemically used. It is softened and rinsed with warm water, or the mesh is further coarsened so that the new film can be fastened. These processes are called Reclaiming.
38. Again, this word also refers to the recycling of certain wastes. Relaxation is relaxation, relaxation is an abnormal phenomenon in the process of Zhang network. When the “net clamp” tightens the net cloth and suddenly tightens, the net cloth will feel loose and weak temporarily. After a period of reaction, the net cloth will gradually become tense. This is because of the phenomenon of "cold deformation" of the material itself and the process of redistribution of bit energy on the entire mesh. On-site operations should use the correct "net" step. Before the next tightening, it is necessary to relax a little, and then pull it to a greater tension to reduce the above "slack".

39, Resistor Paste resistance paste to the uniform particle size of carbon powder deployment paste, can be used as 20 ~ 50Ω/sq printed resistor (Resistor) purposes. This printing type "resistor" must meet the requirement of uniform thickness and neat edges, but the simple type resistor will gradually deteriorate after being used for some time in a warm and humid environment unless the use environment is particularly good.

40. The layout map of the Roadmap circuit and parts refers to the use of non-conductive paint, which is printed as a plan layout of circuit boards and parts to facilitate service and repair work.

41. Screen Printing screen printing is the use of a negative pattern of the net cloth, using a scraper to scrape the right amount of ink (ie, the resist), forming a positive pattern through the local net cloth, printed on the flat copper of the substrate. On the other hand, it constitutes a kind of masking agent and is prepared for subsequent selective etching or plating. This type of transfer is commonly referred to as "screen printing," and the mainland industry is called "screen printing." The screen materials used are: polyester, stainless steel, nylon, and silk that have been eliminated. Screen printing can also be used in other fields.

42, Screenability screen printing capacity refers to the screen printing construction, the ink in the scraping pressure action, through the exposed part of the net cloth, and the smooth leakage to the board or copper surface, and have a good ability to attach Words. When the obtained ink pattern also has a good resolution, the plate surface, the ink, or the machinery used can be said to have a good “printing ability”.

43, Silk Screen screen printing, silk screen printing with polyester mesh or stainless steel mesh cloth as a carrier, the positive and negative film pattern can be direct latex or indirect version of the film, transferred to the net frame on the cloth to form a screen As a tool for the printing of flat surfaces, it is called "screen printing". The continental term is abbreviated as "silkscreen."
44, Silver Migration silver migration refers to the silver paste jumper or silver paste through hole (STH) and other conductors, in a long time of high-humidity aging process, there is a DC bias between adjacent (Bias, refers to the two conductors When the potentials are not equal), there will be several mils of silver ion crystals extending each other, resulting in degradation of the isolation quality (Isolation) and even leakage, which is called "silver migration."

45. Silver Paste silver paste refers to a polymer paste prepared from 70% by weight of fine silver chips and 30% resin, and a small amount of high-boiling solvent as a thinning agent to facilitate the construction of screen printing. In addition to the jumper or through-hole conduction added on the board surface, silver paste can be used instead of the orthodox PTH. The latter is sometimes referred to as STH (Silver Through Hole). This method has the advantages of simple equipment, rapid construction, troublesome wastewater, and good conduction quality. Its resistance value is only 40mΩ/sq. The general STH costs less than two-thirds of the PTH, and is the darling of low-power, simple-function boards. It is often used in electronic equipment such as various remote controls or desk phones. Most of the global production of STH panels is concentrated in Southeast Asia and South Korea. Silver paste is mainly used by Japanese goods such as Fujikura and Hokuriku brands. In recent years, many board jumpers have been changed to carbon paste, and silver paste is used exclusively in the area of ​​through-hole double-panels. The "silver through hole" technology to achieve customer acceptance is not simple, often appear fracture, loose, and "migration" (Migration) and other issues. There are not many documents available for reference. The scene is only self-seeking and blessing. Experience is the main task to overcome difficulties.

46, Skip Printing, Skip Plating missed, leak plating in the dead side of the board printing process in some areas, due to poor ink distribution and the formation of missed printing, known as Skipping. This phenomenon is most likely to occur in Conformal Costing or green lacquer printing processes. Due to the corners on the back of the three-dimensional circuit, the green is often not sufficiently green due to uneven application of force or insufficient ink. Paint replenishment will result in "leakage". In the case of drain plating, electroplating may occur in a region where the bath fluid is strongly disturbed or in a low-current region, such as in the vicinity of the orifice and in the center of the pore wall of the pore, or due to the obstruction of bubbles, resulting in a poor distribution of the plating, and gradually causing Plating is difficult to grow. See also Step Plating.

47. The snapback height of Snap-off refers to the height of the net cloth from the board surface when performing screen printing; that is, the depth that the blade presses down to reach the board surface. Another way of saying this is the "air-height" Off-Contact Distance.

48, Squeege scraper refers to the screen printing tool to promote the ink walking on the screen. The main material of the squeegee is PU (Polyurethane Polyamines), which can be used to press the ink through the opening of the mesh and reach the surface of the printed plate to complete its graphics. Transfer.
49. Indirect screens, one of the important tools for screen printing on Stencil, have a pattern on the “ink surface” of the mesh. This kind of Stencil also uses a special photosensitive film, which can be transferred from the film first, exposed to light, and attached to the mesh after the image is developed. After the film is torn off by baking, it becomes a screen.

50. Tensiomenter Tensiometer When the mesh on the frame has been properly secured, use the "tension meter" to measure the tension of the mesh. The unit is generally Newtown/cm. The principle of this kind of measurement is to have two fixed support rods on both sides of the base, and a short, free-settling movable support rod in the center. This "activating short rod" is under the gravity of the counterweight. There will be a "falling" action pressing on the mesh to be measured, so that the "tension" supported by the partial mesh can be measured. The method of calibration is to first place the "tension meter" upright on a flat glass plate, and then adjust the zero reading of the surface reading from the lower hexagonal screw to measure the tension of the mesh cloth. (We are grateful to Mr. Yang Zhixiong, the director of the company. We hereby thank you.)

51, Thinner thinning agent that is used to dilute the "solvent", generally speaking, the thinning agent must not be chemically reacted with the diluted solute.

52、Thixotropy anti-sagging, shaking, thixotropic, static coagulation of certain colloidal substances, such as stirring, shaking, or shaking will appear liquefaction and flow phenomenon occurs, but when it is completely still, then it has become stale In the case of solidification, this characteristic is called Thixotropy. Common people such as ketchup or clay mud and so on. Printing inks used in the circuit board industry, especially green paints or solder pastes, must have this kind of "anti-sagging property" so that the printed three-dimensional "ink" or "cream blocks" will not collapse or flow. And other undesirable phenomena.

53. Ultra Violet Curing (UV Curing) Ultraviolet Hardening Ultraviolet light refers to light with a wavelength of 200 to 400 nm (nm means 10-9m; it can also be written as mμ, mili-micron), which is beyond human vision. outer. Light waves in this area have strong energy, and the photosensitive materials used for general plate making have the most sensitive wavelengths between 260 and 410 nm. The use of its specific energy to rapidly harden photosensitive glossy coatings without the need for baking and without the need for a diluent is very advantageous for automation. The circuit board industry can use UV-curing inks for circuit printing and has a wide range of applications for direct etching of single- or inner-layer boards.
54, Twill Weave diagonal weaving method, diamond weaving method is a kind of twill weave, a common plain weave method (Plain Weave), the warp and weft yarn in the cloth material is a combination of ups and downs. The oblique weaving method is one-two-up, two-two-two-jump and other weaving methods, and it looks like a twill cloth in a large area. The effect of such a net cloth on the surface printing has not been seen in various documents.

55, Viscosity Viscosity, viscosity The word in the circuit board process, simply refers to the ink in the flow (Flow) by the external thrust, the emergence of a resistance (Resistance), known as Viscosity. Generally thinner inks have lower viscosity, while thicker inks have higher viscosity. The true definition of viscosity is related to the properties of various fluids, and its calculation is quite complicated (see the special paper of the 47th Issue of the Circuit Information Magazine). CCL Copper Clad Laminates ; Copper Foil Substrate (Continent Called "CCL")

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