5 Basic Glass PCB Materials: DIY Guide FXPCB China 2022
Glass PCB Material Properties
Printed circuit boards are generally made up of flat laminated non-conductive materials with layers of copper on all surfaces. In the manufacturing of glass PCB( printed circuit board), these are the following material that is used.
1- Piece of Glass
2- UV photoresist
3-Baking soda
4- Copper foil
5- Chloride of iron
6- OHP printout
5- Glue
These above mention materials are used in making glass PCB. Here we will discuss in detail.
Piece of Glass
Glass serves as the foundation of glass PCB manufacturing. The substrate of PCB glass is ultra-clear float glass. Glass should be waterproof, moisture-free, best resistance of corrosion, high thermal dissipation, high reflectivity, low expansion coefficient, feasibility to laminate with other materials. Glass PCBs are used in those fields which have demands of high thermal dissipation and light transmittance.
UV Photoresist
UV light is used for transferring the image from a plotted film onto a bare copper clad laminate. There are two types of UV resist film i.e., positive and negative. Negative is when the developer added to the resist, exposed parts remain undissolved and others dissolved. Positive is the reverse of negative. UV box has a case with organic glass, panel, UV lamps ballasts and starters, and Controllers.
Baking Soda
Baking soda has qualities of alkalinity and abrasive that are good for PCB glass. Baking soda is used as the cleaner for PCBs corrosion. To eliminate the corrosion, it is used. Baking soda cleans and eliminates all the corrosion without damaging the PCB. Use the solution of baking soda, about 150ml, and water. If baking soda is not available then use rinse powder.
Copper Foil
Choose a copper foil whose thickness is almost 0.05mm, that is perfect for PCB. The high thickness of the copper foil is very expensive that is sometimes not affordable. There are two types of copper foil used in glass PCB: ED( electrodeposited) and RA( rolled-annealed) copper. The manufacturing of both coppers is different, and different treatments are given to them.
Chloride of Iron or Iron Chloride
Chloride of iron or Ferric chloride powder is also involved in making glass PCB. FeCl3, one iron part, and three chloride parts are available in both forms i.e., powder and liquid. Powder costs less, but it’s dangerous if not used carefully. For PCB liquid is used. About 150ml of ferric chloride powder is added to water to make the solution. Ferric chloride powder is used in all unwanted copper.
OHP Printout
The design of PCB (printed circuit board) is usually printed on OHP print. After making the layout of the PCB design then print the design through OHP transparent sheet. OHP sheet is the thinnest sheet, it is easy to use the thinnest sheet. The thinnest sheet facilitates ironing on PCB without crumpling. OHP print is important to blocks the UV light exposure of the resist in unwanted regions.
Glue
PCB glue or adhesive would be a two-part epoxy. They are inexpensive and average volume is required. It protects and saves the PCB from moisture and a harsh environment. Curing would take one day at normal temperature.
- Published in Informative
