Basic material of PCBA

The substrate is generally classified by the insulating part of the substrate. Common raw materials are bakelite, fiberglass board, and various types of plastic boards. And PCB manufacturers generally use an insulating part composed of glass fiber, non-woven material, and resin, and then use epoxy resin and copper foil to press the “adhesive sheet” (prepreg).


The common base materials and main ingredients:


FR-1 ──Phenolic cotton paper, this base material is generally called bakelite (more economical than FR-2)
FR-2 ──Phenolic cotton paper
FR-3 ──CottON paper, epoxy resin
FR-4 ──Woven glass, epoxy resin
FR-5 ──Glass cloth, epoxy resin
FR-6 ──Masked glass, polyester
G-10 ──Glass cloth, epoxy resin
CEM-1 ──Cotton paper, epoxy resin (flame retardant)
CEM-2 ──Cotton paper, epoxy resin (non-flame retardant)
CEM-3 ──Glass cloth, epoxy resin
CEM-4 ──Glass cloth, epoxy resin
CEM-5 ──Glass cloth, polyester
AIN ── Aluminum Nitride
SIC ──Silicon Carbide

Metal coating

The metal coating is not only the wiring on the substrate, but also the place where the circuit of the substrate is soldered to the electronic components. In addition, different metals also have different prices, and different will directly affect the cost of production; different metals also have different solderability, contact properties, and different resistance values, which will directly affect the performance of the device.

Commonly used metal coatings are:


copper
tin
The thickness is usually 5 to 15μm[4]
Lead-tin alloy (or tin-copper alloy)
Namely solder, the thickness is usually 5 to 25μm, and the tin content is about 63%
gold
Generally only plated on the interface
silver
Generally it will only be plated on the interface, or an alloy that is also silver as a whole

Circuit design

The design of the printed circuit board is based on the electronic circuit diagram to realize the functions required by the circuit user. The design of the printed circuit board mainly refers to the layout design, which requires various factors such as the layout of internal electronic components, metal connections, through holes and external connections, electromagnetic protection, heat dissipation, and crosstalk. Excellent circuit design can save production costs and achieve good circuit performance and heat dissipation performance. Simple layout design can be realized by hand, but complex circuit design generally needs to be realized with computer-aided design (CAD), and well-known design software includes Protel, OrCAD, PowerPCB, FreePCB, etc.

Production methods


SMT and DIP are both ways to integrate parts on the PCB. The main difference is that SMT does not need to drill holes on the PCB. In DIP, the PIN of the part needs to be inserted into the drilled hole.

SMT (Surface Mounted Technology)
Surface mount technology mainly uses mounters to mount some tiny parts on PCB boards. The production process is: PCB board positioning, solder paste printing, mounter mounting, reflow oven and final inspection. With the development of technology, SMT can also mount some large-size parts, for example, some larger-size mechanical parts can be mounted on the motherboard.

SMT is very sensitive to positioning and the size of parts during integration. In addition, the quality of solder paste and printing quality also play a key role.

DIP
DIP stands for “plug-in”, that is, inserting parts on the PCB board. Because the parts are large in size and not suitable for placement or the manufacturer’s production process cannot use SMT technology, the parts are integrated in the form of plug-ins. At present, there are two implementation methods of manual plug-in and robot plug-in in the industry. The main production process is: sticking adhesive (to prevent tin plating to the place where it should not be), plug-in, inspection, wave soldering, and brushing (removal in the furnace Stains left in the process) and made inspection.

Application:


Computers and related products, communication products and consumer electronics and other 3C products are the main application areas of PCB. According to data published by the Consumer Electronics Association (CEA), global consumer electronics sales will reach US$964 billion in 2011, an increase of 10% year-on-year. The data in 2011 is quite close to US$1 trillion. CEA said that the biggest demand comes from Smart phones and notebook computers, and other products that are very prominently sold include digital cameras, LCD TVs and other products.

smart phone
According to the latest market research report released by Markets and Markets, the global mobile phone market will increase to 341.4 billion U.S. dollars in 2015, of which smartphone sales revenue will reach 258.9 billion U.S. dollars, accounting for 76% of the total mobile phone market revenue; and Apple will Leading the global mobile phone market with a market share of 26%.
iPhone 4 PCB uses Any Layer HDI board, any layer of high-density connection board. In order to fit all the chips on the front and back sides of the iPhone 4 in a very small PCB area, the Any Layer HDI board is used to avoid the waste of space caused by booting or drilling, and to achieve the purpose of enabling any layer to be conductive.

Touch panel
With the popularity of iPhone and iPad all over the world and the popularity of multi-touch applications, it is predicted that the touch wave will become the next wave of growth driving engines for soft boards. DisplaySearch predicts that tablet PCs will require 260 million touch screen shipments in 2016, an increase of 333% over 2011.

Computer
Gartner analysts pointed out that notebook computers have been the growth engine of the personal computer market in the past five years, with an average annual growth rate of nearly 40%. Based on expectations of weaker demand for notebook computers, Gartner predicts that global PC shipments will reach 387.8 million units in 2011 and 440.6 million units in 2012, an increase of 13.6% over 2011. CEA stated that in 2011, sales of mobile computers, including tablets, will reach $220 billion, and sales of desktop computers will reach $96 billion, bringing total sales of personal computers to $316 billion.

The iPad 2 was officially released on March 3, 2011, and the fourth-order Any Layer HDI will be used in the PCB manufacturing process. The Any Layer HDI adopted by Apple iPhone 4 and iPad 2 will trigger an upsurge in the industry. It is expected that Any Layer HDI will be used in more and more high-end mobile phones and tablets in the future.

Ebook
According to the forecast of DIGITIMES Research, global e-book shipments are expected to reach 28 million units in 2013, and the compound annual growth rate from 2008 to 2013 will be 386%. The analysis pointed out that by 2013, the global e-book market will reach 3 billion US dollars. The design trend of PCB boards for e-books: First, the number of layers should be increased; second, the blind buried via process is required; third, the PCB substrate suitable for high-frequency signals is required.

Digital camera
iSuppli said that as the market becomes saturated, digital camera production will begin to stagnate in 2014. It is estimated that shipments in 2014 will drop by 0.6% to 135.4 million units, and low-end digital cameras will encounter strong competition from camera phones. However, certain areas of the industry can still achieve growth, such as hybrid high-definition (HD) cameras, future 3D cameras, and digital single-lens reflex (DSLR) such more high-end cameras. Other growth areas for digital cameras include the integration of GPS and Wi-Fi functions to increase their appeal and potential for daily use. Promote the further improvement of the FPC market, in fact, any light, thin and short electronic products have strong demand for FPC.

LCD TV
Market research company DisplaySearch predicts that global LCD TV shipments will reach 215 million units in 2011, a year-on-year increase of 13%. In 2011, as manufacturers gradually replace the backlight of LCD TVs, LED backlight modules will gradually become the mainstream. The technological trends brought to the LED heat dissipation substrate: a high heat dissipation, precision size heat dissipation substrate; two strict line alignment Accuracy, high-quality metal circuit adhesion; Third, use yellow light lithography to make thin-film ceramic heat dissipation substrates to improve LED high power.

LED lighting
Analysts of DIGITIMES Research pointed out that in response to the ban on the production and sales of incandescent lamps in 2012, LED bulb shipments will grow significantly in 2011, and the output value is estimated to be as high as about 8 billion U.S. dollars. In addition, North America, Japan, South Korea, etc. Green products such as LED lighting implement subsidy policies, and the high willingness of stores, shops and workshops to replace them into LED lighting and other factors, in terms of output value, the global LED lighting market penetration rate has a great chance to exceed 10%. LED lighting, which took off in 2011, will surely drive a large demand for aluminum substrates.

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