In order to improve the electromagnetic shielding performance of a high transparency metallic mesh and to enhance its environment resistance
some experiments of electroless Ni plating on a thin copper mesh with a 9 m line width
0.3 m thickness and 400 m400m period were carried out. Firstly
a sample of thin copper mesh on a K9 substrate was fabricated by the processes of coating photoresist
laser direct writing
developing
vacuum coating and removing photoresist. Then
the sample was cleaned by the supersonic wave
and was immersed about 10 s to 15 s by a 10% hydrochloric acid solution to activate the copper. After that
the sample was immersed again by an electroless nickel plating solution prepared according to a standard
and was maintained about 40 min to 60 min on a constant temperature condition of 85 ℃. Finally
the sample was taken out from the solution
and was baked by a cabinet drier. Experimental results indicate that the coating is homogeneous and strong joined
and the average electromagnetic shield effectiveness of the mesh is approximately 32 dBm when it is tested by a coaxial test method
which has increased by 11 dBm as compared with that test value before nickel-plating.Furthermore
the optical transmission of the mesh reduces less than 1%from 400 nm to 800 nm after nickel-plating. It is concluded that the nickel can be plated for a thin copper mesh
and can increase fairly the electromagnetic shielding effectiveness of the mesh without effect on the optical transmission.