Well this sound amazing and scary. Everyone knows that printer toner usually is transferred with special glossy paper and iron, but printing directly… anyway fact is that it is possible and gives amazing results. Author claims and proves that he was able to print 2mill traces what means four traces between two DIP pins.
There isn’t any information about how it’s done as other people claim that printers modified as flat doesn’t give even close results. Take a look for more photos in gallery.
Posted in UV PCB Making
Tagged Better PCB, Direct PCB toner transfer, laser printer PCB, PCB technologies
You have to prepare many multi-platform eagle designs for manufacture, but you have no ideas what to do about it?
Well, there are many ways to turn an eagle design into an actual PCB. One of the best ways is to save the eagle designs as industry-standard gerber files, where you can use the gerbers files to order a single prototype or in a full panel.
For your information, the toner transfer is the favorite choice of beginners to make a PCB, as the total investment in materials is minimal comparing with other methods. Most of the PCBs are made with the photo-resist process, since the photo process makes nice boards, but it requires a bit of equipments.
While some of the board manufactures, such as the olimex, can be used to make PCBs directly from eagle .brd files. Olimex requires a minimum order of one eurocard-sized PCB (100mmx160mm).
Here’s the simple process of Eagle Designs:
The best and cheapest option you can get is to submit gerber files like the professionals, and the best part about it is any of the PCB manufacturers will accept gerber formatted design files without any further modification!
Posted in UV PCB Making
Tagged Eagle Designs, gerber files, Olimex, PCB, toner transfer
Probably you have read about our PCB etcher on our site. We planed to make it fully automatic with heater, bubble machine and thermostat. But fact is that it wasn’t finished. But we are actively using it with aquarium heater only and manual mixing 
.
If you are looking for something similar that has a bubble machine installed you should see YourITronics brand new PCB etcher with aquarium pump and heater. They use a bubble machine that speeds up etching process and you don’t have to mix solution.
The tank is made of plexiglas and holds 1.5L of liquid. All together with pump, heater and other materials etcher costed about $41 – this is much cheaper than buying from store. This tool is a must have along with UV exposure unit.
This PCB drill is made of wood and looks really cool. Wouldn’t mind to have one on my table. Design is very unique – it uses various custom made parts, motors from old printers and VCR’s. Author even simulated all design code on a Labcenter’s Proteus VSM.
Still struggling with various PCB making technologies and cannot do it right, you should try Photo Etching method which is becoming more and more common among radio amateurs. All materials needed are easily accessed. Probably the hardest part is to obtain UV light source. But you can find tons of sources on the internet how to build one.
Posted in UV PCB Making
Tagged PCB making guide, PCB technologies, Photo etching method, UV led source
The term circuit technology usually refers to the various techniques that used in the manufacture of electrical circuits. A large number of devices that are used today make use of printed circuit boards (PCBs). These devices provide a mechanical support for the various components present within the given device and also, the electrical connections between the components.
The electrical connections present on the PCB are made out of copper sheets that are laminated on a non-conducting material. Initially a large copper sheet is laminated on the board and then the sections that are not required are removed. Various techniques are used for removal of unwanted copper. Some of them are:
Posted in Electronics Tutorial, UV PCB Making
Tagged PCB, PCB etching, PCB Milling, PCB technologies, Photoengraving, Silk Screen Printing
I came across this interesting project. The guy decided to make UV PCB exposure box made of UV light LED’s. The main reason why he used LED was the power dissipation and compactness. Assuming that one UV tube would take about 6W while one UV LED would take about (20mAx3.2V=64mW). Most of that energy UV tubes dissipate as heat energy.
So he took:
54 x UV LEDs of 400nm (6000 – 7000 mcd) – 100 units in Ebay costed 12€;
18 x 68ohms resistors 1/4W – 0,36 €;
1 connector – 0.50€;
1 electrolytic condenser of 2200uF – 30v;
1 Eurocard Plate 100×160 about 5 € ;
The the plate of LEDs is powered by 12V power supply. LEDs radiation angle is 20º , so they took about 8cm heigh box that light could cover the whole PCB area when distances between LEDs are 18mm.
Download circuit and PCB from original site.
Lets go through few examples how to place electronic parts correctly on PCB board.
SMD electronic parts especially if lead pitch is above 1 mm, then placement of leads has to be symmetrical on copper planes:
If IC has smaller lead pitch like 0.5 – 0.8mm positioning by hand become harder. Sometimes it is recommended to use special glue to fix SMD part before soldering.
DIP electronic parts has to be soldered as close to PCB board as possible to make them stand stabile and to avoid heat resistance.
Electronic parts with axial leads are placed vertically for better air ventilation. Because of this diodes and Zener diodes has to mounted with cathodes up with gap of 1-2 mm between electronic part and PCB board. If there is enough place – they can be mounted horizontally. This way between electronic part and PCB has to be a gap of about 1 – 2 mm.
Single side pin electronic components like ceramic, electrolytic capacitors, crystals, semiconductor fuses have to be placed with minimal gap (about 1 mm) between PCB.
H49U crystals have to be placed with minimal gap between PCB. It under resonator there is no via holes or tracks, then it is better to solder them without gaps. Crystals with high packages H49 it is better to bend them towards PCB with Ground plane. It is recommended to glue side of crystal to PCB.
LED’s with diameter of 5mm it is recommended to mount close to PCB without gaps. Miniature LED’s (diameter of 3mm) are mounted at the fixed length left on leads.
Bigger electrolytic capacitors can be mounted close to PCB or bended:
Mechanical parts like buttons, jumpers, LCD usually have fixers or screw holes to be fixed to PCB. In other cases parts have to be fixed tightly closer to PCB.
Posted in Electronics, UV PCB Making
How repeatedly make good PCB? Many hobbyists faces this issue every time they are prototyping their ideas. Designing the PCB layout (doesn’t matter is it a through hole or surface mount) may be tricky task especially when dealing with dimensions like 0.2mm tracks or 0.5mm surface mount pitches. Laser printer, plotting or other similar transfer technologies can’t deal with such dimensions.
After I have tried photographic method of PCB artwork transfer, I don’t even want to touch Iron and laser printer. Using photosensitive laminate and single transparent media I can repeatedly make any number of PCB’s. Benefits of using photographic methods are as follows:
Pay the biggest attention to artwork fabrication. Without good artwork you won’t be able to make good PCB. From My experience I can say, that I always do small mistakes with PCB artworks and I spot them usually after PCB is etched. Devote more time for PCB artwork tracing and you will save much more time while soldering.
The artwork should be:
For Artwork transfer it is not necessary to use transparent media. Paper (UV translucent) can be good too. It may require longer exposure. Why I saying this? Because laser printers likes paper more than acetate film. The toner stays flatter on paper and black is smoother than on film. Especially using printers with refilled cartridges I would recommend use paper instead of film. I used to use film but results is rather disappointing than promising.
The printer itself should have following:
The next important thing in PCB development is Photoresist PCB laminate. It has to be good quality especially when dealing with small tracks. If you use pre-coated PCB, then inspect if there is no scratches in covering, check the PCB age. When handling just avoid direct sunlight and unnecessary light exposure. And develop just after exposure. If you decide to spray photoresist by yourself, remember that area should be clean from dust. It works for low resolution boards, but for higher resolution, I would recommend buying pre-coated boards.
Exposing of photoresistive boards are done under Ultraviolet lamps. This is not very critical issue, but still:
For developing boards I don’t recommend to use sodium hydroxide. This is dreadful stuff. It is sensitive to temperature and concentration and it is aggressive chemical. It may easily strip all photoresist. Solution doesn’t last long. Better use silicate based products. This isn’t sensitive to temperature or concentration. It is hard to overdevelop. Solution lasts much longer and you can make stronger solution for faster developing. As this would be your PCB killing by using sodium hydroxide.
Fro etching I would not recommend to use ferric chloride. This is really messy stuff. But if so, then avoid any contact with metal as it attack almost any metal. Use plastic or glass tank. As better alternative use Ammonium persuphate. As this is transparent solution, doesn’t mess, it is not aggressive as ferric chloride. But it gives even better result in etching. It usually doesn’t etch under the track what is important when board is high resolution.
This is only generic guidelines of making PCB. Further I would recommend reading following sources:
AVR controlled signal generator-1 layer PCB prototype
Posted in UV PCB Making
After UV-80 vas built there was a thought about automatic PCB Etcher with autonomous Heater and bubble machine. This project is hanging in prefinished phase but it does a job. It was used to etch several PCB’s. As this etcher supposed to be used for making PCB’s using photoresitive technology, the controller supposed to control both = the heater of etching tank and heater of developer. As Sensors there are used AD7416 digital temperature sensors. I decided to publish this small project as this is not clear when it will be finished. When it will be, I will update this article.
There is a little dirty drawing with dimensions:
The dimensions are as follows 215x275x30 exterior. Inner volume is smaller as glass is 4mm thick. So overall volume is less than 1,2 liter. It is ideal volume to use one bag of ammonium persulphate or 250 grams of FeCl3. The glass plates are glued with aqua silicone. Sides are strengthened with aluminum profiles (not necessary if you have skills of gluing aquariums).
As you can see it is only manual control Thermometer, heater and tank with etchant.
Thermometer has scale with more than 50°C as solution shouldn’t exceed this value. Heater is used from fish tank 90W:
This heater heats solution up to 50 degrees in about half an hour. This is enough time to expose and develop your PCB. If you need to heat water faster – you should use more powerful heater.
This is nothing to add more to this part. This is working well, but you have to stare and not to overheat the solution.
In order to make heater work automatically we decided to create controller with temperature sensor. Due to problems in assembly, this part is not finished. And there is no bubble machine purchased. Bubble machine is good to speed up etching and process is going smoother. As bubble machine we probably will use aquarium bubble pomp.
So what do we have now?
We have simple circuit on atmega8 with ability to read two temperature sensors and ability to control two relays to control two heaters.
There also is two temperature sensors soldered to be ready to glue to tank glass. I thin it should read temperature quite well – maybe little calibration will be needed.
The sensor view:
All control board will be placed in PC power block – we just have one spare to use. As it has already 5V to power controller and 12V for relays and developer heater. FYI, developer heater will be heating wire from some medical equipment. It is powered from 12V and takes about 2 – 3 A (36W). It is enough, as developer shouldn’t exceed 30 degrees.
And here is the total view of controller. It still looks messy and not assembled. I hope one day it will be finished
To be continued…
Source code: Source Code
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