PCB ink several important technical performance
PCB ink quality is excellent, in principle can not be separated from the combination of the above major components. Ink quality is excellent, the formulation of scientific, advanced and environmental protection of the comprehensive embodiment. It is embodied in:
(1) viscosity: is the abbreviation of dynamic viscosity. Generally expressed in viscosity, the shear stress divided by the flow direction of fluid flow velocity gradient, the international unit for palmer/SEC or mm/SEC. In PCB production refers to the ink driven by external fluid.
(2) plasticity: refers to the properties of the ink before deformation after deformation due to external forces. The plasticity of ink can improve printing accuracy.
(3) thixotropy: a property of ink that is gelatinous when it is static, but changes in viscosity when it is touched.
(4) fluidity: the degree to which the ink expands around under the action of external forces. Fluidity is the inverse of viscosity, fluidity and ink plasticity and thixotropy. If the plasticity and thixotropy are large, the fluidity is large. The blots that are highly mobile tend to expand. Small fluidity, easy to appear network, inking phenomenon, also known as net;
(5) viscoelasticity: refers to the performance of the ink that is sheared and fractured after the scratch of the scratch board. It is required that the ink deforms quickly and the ink bounces back quickly to facilitate printing.
(6) dryness: the slower the ink dry on the screen, the better, and the faster the ink transfer to the substrate, the better;
(7) fineness: the size of pigment and solid particles. PCB ink is generally less than 10 micromm. The fineness should be less than one-third of the opening of the mesh.
(8) wiredrawing: the extent to which the filamentous ink does not break when lifting ink with an ink spatula is called wiredrawing. The length of the inks, in the ink and printing surface appear many fine wires, so that substrate and plate stained, or even unable to print;
(9) ink transparency and cover: for PCB ink, according to the use and requirements of different ink transparency and cover also put forward various requirements. Generally speaking, line ink, conductive ink and character ink, all require high cover. Resistance flux is more flexible.
(10) chemical resistance of ink: PCB ink requires strict standards for acid, alkali, salt and solvent according to different purposes. (Impedance PCB manufacturer china)
(11) physical resistance of ink: PCB ink must meet the requirements of external scratch resistance, thermal shock resistance, mechanical stripping resistance and various strict electrical performance requirements;
(12) safety and environmental protection of ink: PCB ink requires low toxicity, odorless, safety and environmental protection.