PCBs Fabrication of Exposure---WonderfulPCB(hk)Limited

The photo resist board needs to be exposed to ultra-violet light through the artwork, using a UV exposure box.

UV exposure units can easily be made using standard fluorescent lamp ballasts and UV tubes. For small PCBs, two or four 8 watt 12" tubes will be adequate, for larger (A3) units, four 15" 15 watt tubes are ideal. To determine the tube to glass spacing, place a sheet of tracing paper on the glass and adjust the distance to get the most even light level over the surface of the paper. Even illumination is a lot easier to obtain with 4-tube units. The UV tubes you need are those sold either as replacements for UV exposure units, insect killers or 'black light' tubes for disco lighting etc. They look white or occasionally black/blue when off, and light up with a light purple, which makes fluorescent paper etc. glow brightly. DO NOT use short-wave UV lamps like EPROM eraser tubes or germicidal lamps, which have clear glass - these emit short-wave UV which can cause eye and skin damage.
A timer which switches off the UV lamps automatically is essential, and should allow exposure times from 2 to 10 minutes in 15-30 second increments. It is useful if the timer has an audible indication when the timing period has completed. A timer from a scrap microwave oven would be ideal.

Short-term eye exposure to the correct type of UV lamp is not harmful, but can cause discomfort, especially with bigger units. Use glass sheet rather than plastic for the top of the UV unit, as it will flex less and be less prone to scratches.
If you do a lot of Multilayer pcb, it may be worth making a double-sided exposure unit, where the PCB can be sandwiched between two light sources to expose both sides simultaneously.

You will need to experiment to find the required exposure time for a particular UV unit and laminate type, expose a test piece in 30 second increments from 2 to 8 minutes, develop and use the time which gave the best image. Generally speaking, overexposure is better than underexposure.

For a single-sided PCB, place the artwork with toner side up on the UV box glass, peel off the protective film from the laminate and place it sensitive side down on top of the artwork. The laminate must be pressed firmly down to ensure good contact all over the artwork, and this can be done either by placing weights on the back of the laminate, or by fitting the UV box with a hinged lid lined with foam rubber, which can be used to clamp the PCB and artwork.

Ms. Jodie Zhou
Wonderful PCB
T +86-755-86229518-807 | F  +86 755 2607 3529|  e  wonderful09@wonderfulpcb.com |
www.wonderfulpcb.com | Skype: jodiezhou0710  | MSN: wonderfulpcb06@hotmail.com
Welcome to our trading shows:
1. Booth:  L32, Expo Electronics 2013, Apr.10-12th in CROCUS EXPO, Moscow, Russia
2. Booth: 11J36, HK Global sources Apr.12-15th, 2013 Asia World-Expo, and Hong Kong 
3. Booth: 9J35, HK Global sources Oct.12-15th, 2013 Asia World-Expo, Hong Kong

PCB design and PCB manufacture

In the increasing developed electronic industry, no matter manufacturing for a large multinational tech company or a small electronics company, PCB assembly can be riddled with numerous challenges. Effective assembly requires smooth collaboration between designers, fabricators and manufacturers in order to deliver a high quality circuit board to the market. Mistakes made in design can hold grave consequences to the whole organization, especially where the design failures result in substandard products reaching the market.

Design Services
The design of PCB board (PCBs) is one of the most important steps in manufacturing a quality electronic device. The functionality and efficiency of your electronics depend on the design and layout out of the board (or "brain") of the gadget, meaning that nothing can be left to chance. Through careful attention to detail, the board can be designed to meet all product specifications without wasting any space or utilizing excessive components. A truly qualified electronic design and manufacture contractor can provide you with numerous solutions throughout the design process, such as:

Prototyping - If you have an idea for a device, it can be created - as long as you have the right resources at your fingertips. The design services provided by PCB Company can help to bring your prototype to life, quickly and efficiently. The fast-turnaround will enable you to familiarize yourself with your device, so that you can explain and present it to your prospect clients for future orders. And careful, detailed planning ensures that your product will operate without a hitch.

Review - These individuals have years of industry experience, enabling them to quickly spot any flaws in your design schematics, or areas that could be improved. Ultimately, this could result in more compact, affordable boards, and a faster, more efficient device.

Reworking - In some cases, your team may be stuck on a problem with one of your boards. However, engineers could have experience to help to check and rework these problems.

Manufacturing Assembly Services

It's very important to turn your designs into a reality with skill, speed, and precision.

Skillful assembly production - A reliable electronic design and manufacture company will have a comprehensive understanding of the demands of systems assembly. Assembly Company should have the ability to provide you with a customized solution that may include services like configure/build to order, assembly at the chassis, cage, or rack level, custom cabling, documentation, etc. All of this should be handled in direct compliance with industry standards.


Troubleshoot and repair - Beyond manufacturing, your third party contractor should stand behind its electronic design and manufacture services to the point where it offers troubleshooting and repair for the devices that it produces. By taking the time to systematically seek out the underlying issue at its source, your partner company can help you to repair your boards without being forced to replace the unit entirely. This helps your business to save significantly on time and money.

PCB, CCL application CQC authentication problem solving-（2）---Wonderful PCB (hk) Limited

7, application considerations of CQC standard sample production?
A: cQc application process, a lot of samples, such as single, double-sided and multilayer Rigid-flex pcb must be in accordance with the relevant standard production standard test pattern. , therefore, should read carefully the sample when making standard graphics shows that for the appearance of the sample size, drilling and welding plate diameter, width of wire spacing, especially the laminated lining graphical distribution of parameters such as pay special attention to, in order to reduce due to the improper understanding during sample preparation and the amount of time the sample error.

Printed Circuit Board Words

1、印制电路：printed circuit
2、印制线路：printed wiring
3、印制板：printed board
4、印制板电路：printed circuit board (PCB)
5、印制线路板：printed wiring board(PWB)
6、印制元件：printed component
7、印制接点：printed contact
8、印制板装配：printed board assembly
9、板：board
10、单面印制板：single-sided printed board(SSB)
11、双面印制板：double-sided printed board(DSB)
12、多层印制板：mulitlayer printed board(MLB)
13、多层印制电路板：mulitlayer printed circuit board
14、多层印制线路板：mulitlayer prited wiring board
15、刚性印制板：rigid printed board
16、刚性单面印制板：rigid single-sided printed borad
17、刚性双面印制板：rigid double-sided printed borad
18、刚性多层印制板：rigid multilayer printed board
19、挠性多层印制板：flexible multilayer printed board
20、挠性印制板：flexible printed board
21、挠性单面印制板：flexible single-sided printed board
22、挠性双面印制板：flexible double-sided printed board
23、挠性印制电路：flexible printed circuit (FPC)
24、挠性印制线路：flexible printed wiring
25、刚性印制板：flex-rigid printed board, rigid-flex printed board
26、刚性双面印制板：flex-rigid double-sided printed board, rigid-flex double-sided printed
27、刚性多层印制板：flex-rigid multilayer printed board, rigid-flex multilayer printed board
28、齐平印制板：flush printed board
29、金属芯印制板：metal core printed board
30、金属基印制板：metal base printed board
31、多重布线印制板：mulit-wiring printed board
32、陶瓷印制板：ceramic substrate printed board
33、导电胶印制板：electroconductive paste printed board
34、模塑电路板：molded circuit board
35、模压印制板：stamped printed wiring board
36、顺序层压多层印制板：sequentially-laminated mulitlayer
37、散线印制板：discrete wiring board
38、微线印制板：micro wire board
39、积层印制板：buile-up printed board
40、积层多层印制板：build-up mulitlayer printed board (BUM)
41、积层挠印制板：build-up flexible printed board
42、表面层合电路板：surface laminar circuit (SLC)
43、埋入凸块连印制板：B2it printed board
44、多层膜基板：multi-layered film substrate(MFS)
45、层间全内导通多层印制板：ALIVH multilayer printed board
46、载芯片板：chip on board (COB)
47、埋电阻板：buried resistance board
48、母板：mother board
49、子板：daughter board
50、背板：backplane
51、裸板：bare board

Sophie Deng
_______________________________________
Wonderful PCB Limited
NO.32A,Building NO.1, XianDaiC hengHuaTing,ChuangYeRoad|NanShan District,ShenZhen City 518054|  China  T +86-755-86229518-806 | F  +86 755 2607 3529|  e  wonderful08@wonderfulpcb.com |
w  www.wonderfulpcb.com  | Skype:wonderful-07   |                                                   
Welcome to our trading shows:
1.Booth: L32,Expo Electronic 2013,Apr.10-12th in CROCUS EXPO,Moscow,Russia
2.Booth: 11J36, HK Global sources  Apr.12-15th, 2013 Asia World-Expo, Hong Kong
3.Booth: 9J35, HK Global sources Oct.12-15th,2013 Asia World-Expo, Hong Kong
4.Booth: 70206, CES  2014  Jan,8th-11th in Las Vegas, USA

Some other PCB concepts to explore

Soldermask – If I had to guess what you think of when I say “PCB” I would bet that it is probably something green. Did you know that PCB’s are not this color as a result of what material is used? This is in fact another layer that is applied to the board after manufacturing. The purpose is to keep solder paste from spreading where it shouldn’t be, but it also has the effect of giving the board a definite style.
Fiducials – These are special markings on your board that allow a pick-and-place automated assembly machine to calibrate itself. Fiducials are usually just a circle where the soldermask has not been applied with copper circle in the middle. This makes the point appear fairly reflective.
Silkscreen – This is also another layer of the Flexible pcb added after fabrication. Silkscreen is used to provide visual cues to the user, document board information, identify proper component placement, or for branding. There are conflicting suggestions on proper usage of silkscreen and I will address this in part 2.
Copper fill - Deciding whether to use a ground/power plane in your design will be an important decision to make during the design stage. The most common reasons for using a copper fill are to suppress noise on the ground circuitry, dissipate heat from a particularly active device, or because someone told you that was the way to do it.
That’s enough of learning what goes into PCBs though, let’s discuss how to get started on your design.

Following will be continued in next chapter.

Shirley Xia
Oversea sales
Wonderful PCB

A Floor 6, Nanyuan Fengye Mansion, Nanshan Avenue, Nanshan District, Shenzhen City 518054, China.
T +86-755-86229518-821 / Cell phone and whatsApp:008613480796172
F  +86 755 2607 3529|
e  wonderful25@wonderfulpcb.com |
w  www.wonderfulpcb.com  | Skype:wonderful-pcb02
Welcome to our trading shows:
Booth: 9G27, HK Globalsources Oct.11-14th,2014 AsiaWorld-Expo, Hongkong
Booth：A3.274-1，2014.11.11-2014.11.14，the Electronica in Munich, Germany

Impedance Control on PCB

1.Introduction
The development of wireless communications requires more compact electronic devices. Further, the more precise for electric products, the more special technology is needed for their main board. A PCB (printed circuit board) planar inductor is one that is printed directly on the PCB board with a copper track employed as the turn of the windings, thereby the conventional inductor flat. Efforts have been made on its design and calculation as well as its applications. The frequency dependence of a PCB inductor must be considered at higher frequencies. The effective trace resistance of a multi-turn spiral inductor operating at high frequencies is known to increase dramatically above its DC value, due to proximity effect or current crowding.

2.Why need to control impedance?
We need controlled impedances because the function of a wire or trace is to transfer signal power. Maximum signal power is achieved with matching impedances. The same considerations apply to signal transfer through traces on a PCB. When board traces carry high frequency signals, care must be taken to design traces matching the impedance of the driver and receiver devices. The longer the trace or the higher the frequencies, the higher is the need to control the trace impedance.
PCB manufacturers control impedance by varying the dimensions and spacing of the trace or laminate. We at Wonderful PCB Technology Co., Ltd experience an increase in demands for multi layers with controlled impedance. An estimated 75% of the multi layer PCB’s with eight layers or more are designed with controlled impedance.

3.Controlled impedances on PCBA manufacturer traces.
Any impedance mismatch can be extremely difficult to analyze once a PCB is loaded with components. Components have a range of tolerances, so that one bath of components may tolerate an impedance mismatch, while another batch might not. Moreover, a component’s characteristics may come and go. Thus, if changing a component appears to cure a problem, the components may become the suspects instead of the trace. Component selection becomes the solution, and build costs are driven up, while all the time the real fault- race impedance mismatch-goes undetected!
For these reasons, a PCB designer will specify trace impedance and tolerance, and should work with the PCB manufacturer to ensure that the PCB meets the specifications.

4.The future of PCB impedance control.
In near future virtually all PCB’s will likely include at least some impedance requirements. As the operating speed of electronic circuits has increased, so has the need for PCBs to have controlled impedances and the majority of PCB manufacturers are producing them.