Getting ready CCB with professional touch

PCB design drawing to be transferred to CCB

Getting ready CCB with professional touch

Having discussed the manual method of transformation of PCB design on the copper clad board (CCB), one can easily get ready the CCB to proceed to fabrication work directly. Now, in this post we shall get to know the popular print transfer method in detail.

Print Method 

In this method the drawing design of the circuit diagram is transferred to a glossy photo paper. The actual size of the PCB design is get laser printed on the photo paper. The laser print-out gives very sharp and clumsy free drawing on the paper. Inkjet print may not give that much sharpness of the design on the photo paper. Smudged appearance of the drawing will be resulted. As such to get near professional grade PCB, laser print is preferred. Hence the exact size of the drawing is laser printed on the photographic paper and this may be trimmed later to the required size and sharp edges.

Getting ready CCB 

A piece of CCB suitable to the size of the print out may be cut and kept ready. The CCB will be thoroughly cleaned so that the surface of copper lamination is free from any oily or greasy matter. The board will be dried and the drawing design is placed over that piece of the board such that the drawing side faces the copper layer side. If necessary the photo paper may be wrapped with sticky tape so that the paper does not shake during the transformation process.

Thermal transfer method

Now a hot electric iron (iron box) is prepared and pressed over the photograph facing the copper side. Gently the hot iron is moved over the paper in all direction in rotary motion. This process is continued for about 10 minutes. Please allow the board to cool down.

Now the board along with the paper attached is immersed in cold water placed in a small tray and soaked for some time. The photo paper is slowly peeled off and fully removed leaving only the circuit track left over the board. Thus the design is obtained on CCB as black pattern.

Error correction

The board is then cleaned gently with water taking care not to scratch the connection tracks and then dried. Now the board is ready for the next process. One important task is to observe the track continuity and for any errors. Errors if any found are to be corrected at this stage. There may be short in the track with the adjacent ones. This has to be carefully observed and rectified. Incomplete track connections have to be corrected with the OHP pen.

CCB Finishing 

Ruler can be used to rectify the lines for sharp and precise adjustments. Shorts with adjacent lines may be removed using sharp knife or blade. This correction work gives us nearly professional type PCB. Once the mistake continues it will be carried over in the finished product also. Hence one should give more attention at this stage. Now the CCB with the printed circuit pattern is ready to proceed with the next process to get the real PCB.

In the coming post we shall discus the next step of fabrication work to get the real product for our purpose.