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Polyester resin adhesive Polyester resin film thermoplastic adhesive is a high yield and low cost material that can be rolled and processed. It can be made into heat resistant material with copper sheet, and conforms to the specification of ul-94vtm-0. It can't pass drift tin test, the biggest using temperature is 110 ℃. Polyester resin adhesives are typically used in polyester resin based materials, although they are occasionally used in other materials, depending on the type of application. Acrylic adhesive Acrylic adhesive is the preferred choice for making  multi layer flexible PCB  for a long time. Acrylic adhesives provide reasonable heat resistance, are simple to manufacture and are inherently good with many different materials.  Epoxy resin and modified adhesive Epoxy resin is the most commonly used adhesive material in the world, which is inevitably applied in multi layer flexible PCB. The high temperature resistance of epoxy resin is very good, and it ca...

High Tg means high heat resistance. General Tg board for more than 130 degrees,   high Tg PCB   generally greater than 170 degrees, medium Tg is greater than 150 degrees, usually Tg of 170 ° C or PCB, PCB, called high Tg circuit board. With the rapid development of electronic industry, especially electronic products represented by computer, the development towards high function and high multilayer requires higher heat resistance of PCB substrate material as an important guarantee. The appearance and development of high density installation technology represented by SMT and CMT make PCB more and more inseparable from the support of high heat resistance of substrate in small aperture, fine wiring and thin type. The Tg of substrate is improved. The characteristics of PCB such as heat resistance, moisture resistance, chemical resistance and stability are improved. The higher the TG value, the better the temperature resistance. Therefore, high Tg is more widely used. The higher the...

High frequency PCB   wiring design principle 1. Minimize logical fan out, preferably with only one load.  2. Avoid using a through hole between the output of the high-speed signal line and the receiving end as far as possible to avoid the cross of the pin figure. Clock signal lines, in particular, require special attention.  3. Adjacent signal lines should be perpendicular to each other to avoid turning at right angles.  4. Load resistors connected in parallel shall be as close to the receiving end as possible. 5. In order to ensure minimum reflection, all open routes (or lines without end match) must meet the relevant mathematical formula  6. When the opening length of the high frequency printed circuit board exceeds the above value, the series damping resistor shall be used and the series terminal resistance shall be connected to the pin of the output terminal as far as possible.  7. To ensure that analog and digital circuits are separated, the hig...

Digital devices are developing towards the direction of high speed, low consumption, small size and high anti-interference, which development trend puts forward many new requirements for the design of   high frequency PCB . Based on years of experience in hardware design, the author summarizes some rules of arrangement of high frequency PCB components.  Rules of arrangement of high frequency PCB components. 1). Under normal conditions, all components should be arranged on the same surface of the printed circuit. Only when the top layer is too dense, some devices with limited height and small heat output, such as patch resistance, patch capacitance and patch IC, can be placed on the bottom layer.  2) on the premise of ensuring the electrical performance, the components shall be placed on the grid, parallel or perpendicular to each other, so as to be neat and beautiful. In general, the components are not allowed to overlap; The elements should be arranged compa...

Digital devices are developing towards the direction of high speed, low consumption, small size and high anti-interference, which development trend puts forward many new requirements for the design of  high frequency PCB . Based on years of experience in hardware design, the author summarizes some techniques of high frequency PCB wiring for your reference.  (1) High frequency PCB tend to have high integration and high wiring density. The use of multilayer boards is both necessary for wiring and an effective means to reduce interference.  (2) The less the lead bending between the pins of high-speed circuit devices, the better.  (3) The shorter the lead between the pins of high-frequency circuit devices, the better.  (4) The less alternating lead layers between the pins of high-frequency circuit devices, the better.  (5) In hf circuit wiring, attention should be paid to the "cross interference" introduced by the signal line running parallel at close...

Aluminum printed circuit board   composition. 1. Circuit layer The circuit layer (generally using electrolytic copper foil) is etched to form printed circuit for the assembly and connection of devices. Using the same thickness and wire width, the printed circuit board can carry higher current than the traditional fr-4.  2. Insulation layer Insulation layer is the core of aluminum printed circuit board technology, mainly plays the role of adhesion, insulation and thermal conductivity. Aluminum substrate insulation layer is the largest thermal barrier in power module structure. The better the heat conduction performance of the insulation layer is, the more beneficial it will be for the heat generated during the device operation to diffuse, and the more beneficial it will be for reducing the operating temperature of the device, so as to improve the power load of the module, reduce the volume, extend the service life and increase the power output.  3. The metal ...

Aluminum printed circuit board  (PCB) is a unique metal base copper clad board, PCB aluminum substrate has good thermal conductivity, electrical insulation and mechanical processing properties.  Features: Aluminum printed circuit board surface use mount technology (SMT); PCB aluminum substrate has good heat dissipation performance in the circuit design scheme; Aluminum printed circuit board can reduce the temperature, improve the product power density and reliability, extend the service life of the product;  Aluminum printed circuit board can reduce the size, hardware and assembly costs; Aluminum printed circuit boards can replace ceramic substrates for better mechanical endurance.  1. Audio equipment: input and output amplifiers, balanced amplifiers, audio amplifiers, preamplifiers, power amplifiers, etc.  2. Power equipment: switching regulator ‘DC/AC converter’ SW regulator, etc.  3. Communication electronic equipment: high frequency increase ‘filteri...

Aluminum printed circuit board  (PCB) is a kind of PCB: Aluminum printed circuit board (PCB) is a kind of metal base copper clad board with good heat dissipation function. Generally, a single panel is composed of three layers, which are circuit layer (copper foil), insulation layer and metal base. For high-end use there is also a design for double panels, the structure of the circuit layer, insulation layer, aluminum base, insulation layer, circuit layer. Very few applications for multilayer board, can be made of ordinary multilayer board and insulation layer, aluminum base laminated.  Single aluminum substrate: is only one layer of conductive graphics layer and insulation materials plus aluminum (substrate).  Double-sided line aluminum substrate: there are two layers of conductive graphics layer and insulation material plus aluminum (substrate) superimposed together.  Multilayer printed aluminum-based circuit board: a printed circuit board made by bonding three or...

Except for some materials, materials used in  double sided flexible PCB  are basically rolled. As not all processes must be processed by the tape winding process, some processes must be cut into sheets before processing. For example, the drilling of metallization holes of double sided flexible PCB can only be carried out in the form of sheets at present, so the first process of double sided flexible PCB is to open materials.  Flexible copper foil laminate to bear the external force is very poor, it is easy to be injured. If the material is damaged in the opening will have a serious impact on the passing rate of the subsequent processes. Therefore, in order to ensure the quality of materials, even if it seems to be very simple, enough attention must be paid. If the amount is less, you can use manual shears or hob cutters, large quantities, you can use automatic shears. Whether it is single-sided or double-sided copper foil laminate or covering film, the precision of openin...

1.  Double sided flexible PCB  upper line screen printing First we need to select materials, baking pretreatment, in order to prevent the contraction of the material deformation to the process after the trouble.  2. The diameter of blanking carbon hole for double sided flexible PCB The blanking carbon hole is generally 0. 8 to 1. 0 m m. Pay attention to the carbon hole must be selected properly, the hole is too large, in the screen printing lower line, through the carbon hole infiltration of carbon ink too much, excess ink will flow through the carbon hole remains in the screen printing table, easy to cause the short circuit of the line. 3. Double sided flexible PCB bottom line screen printing Take the locating hole as the datum, prints the lower layer line in the non-screen printing surface. In the process of screen printing, if the use of machine printing, the table using vacuum suction device is conducive to the flow of conductive ink, but often easy ...

There are a variety forms of flexible printed circuit boards, even if it is a single sided structure, its covering film, reinforced plate material and shape, the process will change greatly. A seemingly simple single sided flexible printed circuit board may have more than 20 basic processes.  Double sided flexible PCB  has two conductive layers, which can obtain higher package density. Double sided flexible PCB is widely used in disk drives.  Double flexible PCB and flexible manufacturing method of the single panel there is a big difference, as shown in the following is ordinary have reinforced plate hole metallization double the gm of flexible printed circuit board manufacturing process: Cutting a drill guide hole, hole metallization cleaning a resist coating on the surface of the copper foil a formation of conductive graphics etching, resist stripping a covering film of a terminal plating surface shape and hole machining a reinforced plate processing, check the packagin...

Aluminum substrate is made of aluminum substrate, due to its strong heat dissipation ability, so most are used in LED lighting products. The single panel of aluminum substrate is composed of three layers: circuit layer, insulation layer and metal base layer. The structure of the double panel is composed of circuit layer, insulating layer, aluminum base, insulating layer and circuit layer.  Copper prototype board  is the most expensive kind of metal substrate, is made of copper plate. The thermal conductivity of Copper prototype board is better than that of aluminum substrate and iron substrate.  Copper prototype board and aluminum substrate compared to a lot of performance advantages: 1, copper substrate thermal conductivity is twice as high as aluminum substrate, thermal conductivity, heat transfer efficiency is higher, heat dissipation performance is better. 2, copper substrate can be processed into a metal hole, and aluminum substrate can not. 3, the copper and aluminu...

Copper prototype board  is a kind of thermal conductivity than aluminum substrate and iron substrate are many times better metal substrate, suitable for high frequency circuits and high and low temperature change of large areas and precision communication equipment heat dissipation and construction decoration industry, generally sunken gold copper substrate, silver copper substrate, tin copper substrate, copper oxide substrate.  Copper prototype board circuit layer requires a large current-carrying capacity, so should use thick copper foil, the thickness of the general 35 m~280 m; Thermal insulation layer is the core technology of copper substrate. The core thermal conductivity component is composed of aluminum oxide and silicon powder and epoxy resin filled polymer, with small thermal resistance (0.15), excellent viscoelastic properties, thermal aging resistance and mechanical and thermal stress tolerance.  Copper prototype board metal base is the support member of coppe...

Copper prototype board  quality reliability to kingboard laminate for good, Copper prototype board is one of the most expensive metal substrates, heat dissipation effect than aluminum substrates and iron substrates are many times better, suitable for high frequency circuits and high and low temperature change of large areas and precision communication equipment heat dissipation and building decoration industry. Generally, there are gold plated copper substrates, silver plated copper substrates, tin prayed copper substrates, antioxidant copper substrates. Copper printed circuit board circuit layer requires a large current-carrying capacity, so should use thick copper foil, the thickness of the general 35 m~280 m; Thermal insulation layer is the core technology of copper substrate. The core thermal conductivity component is composed of aluminum oxide and silicon powder and epoxy resin filled polymer, with small thermal resistance (0.15), excellent viscoelastic properties, thermal agi...

Electroplating can be divided into hard gold and soft gold. Hard gold electroplating is an alloy, so its hardness is relatively hard. It is suitable for use in places requiring force and friction. It is generally used as the edge contact point of PCB (commonly known as golden finger). Soft gold, On the other hand, is commonly used to connect aluminum wires On the COB (Chip On Board) or On the touch surface of mobile phone keys, and more recently, it is widely used On both sides of BGA boards. The distinction of hard gold and soft gold, it is the component of this layer of gold that goes up finally plating, when gold-plating can choose electroplate pure gold or alloy, because the hardness of pure gold is softer, so also call "soft gold". Hard gold plating PCB  has excellent electrical conductivity, wear resistance, oxidation resistance and reduced contact resistance. But gold is extremely expensive, so it is only used for topical gold plating or chemical gold on goldfinger.  H...

Electroplating can be divided into hard gold and soft gold. Hard gold electroplating is an alloy, so its hardness is relatively hard. It is suitable for use in places requiring force and friction. It is generally used as the edge contact point of PCB (commonly known as golden finger). Soft gold, On the other hand, is commonly used to connect aluminum wires On the COB (Chip On Board) or On the touch surface of mobile phone keys, and more recently, it is widely used On both sides of BGA boards. The distinction of hard gold and soft gold, it is the component of this layer of gold that goes up finally plating, when gold-plating can choose electroplate pure gold or alloy, because the hardness of pure gold is softer, so also call "soft gold". Function of auxiliary components in   hard gold plating PCB   plating solution: Boric acid ACTS: as a buffer, which can maintain a relatively balanced PH value of hard gold-plated PCB plating solution with a concentration of 35~55g/l; Nicke...

The purpose of   hard gold plating PCB   adhesive tape: is to expose only the part of the board to be plated with hard gold, and to cover the rest with adhesive tape to prevent plating. Tape sticking is a delicate work. It is not allowed to stick the golden finger with tape and it is too far away from the golden finger. It is necessary to prevent cutting the board when removing the excess tape and avoid wiping the flower artificially.  Pay attention to the use of tape not degumming phenomenon, in order to avoid the copper surface residual glue stains. This step is the most labor-intensive, automatic tape machine on the market, will bring about another industrial revolution.  The purpose of hard gold plating PCB roll adhesive tape is to stick the adhesive tape to the board surface through the roller machine, so as to avoid cross contamination between the cylinder of medicine caused by the Tibetan medicine water in the belt during the nickel-gold plating because th...