CCL each performance is mainly required to meet the PCB processing, application requirements from three aspects. These three aspects are: from printed circuit boards CCL aspects of the proposed performance requirements; the whole product from the operational aspects of the performance requirements set forth CCL; CCL from the installation components of the proposed performance requirements.
Printed circuit board processing aspects of the CCL feature requests
In the printed circuit boards, the main focus of CCL surface smoothness, dimensional stability, heat resistance, plate, Copper foil substrate, and the substrate in the interlayer adhesion, sheet flatness (warping, twisting), process ability hole (drill resin Dirty sex), plating resistance, chemical resistance, moisture absorption properties. In recent years, it also appeared on the CCL UV shielding, CO2 laser drilling and other performance requirements. CCL said all aspects of performance requirements and quality PCB manufacturing are closely linked. If you are not able to meet with CCL PCB processing requirements, will result in PCB processing defects of the substrate, and even waste.
In terms of components installed on the PCB, the performance requirements of the CCL
To ensure the smooth installation of components on the PCB, and for installation of high quality, it is necessary to use CCL PCB required number of performance. These requirements mainly in: dimensional stability (low thermal expansion coefficient), solder heat resistance, flatness, copper foil peeling strength, bending strength and so on.
If CCL unsatisfactory performance in dimensional stability, it will deteriorate in the component mounting accuracy. CCL solder heat resistance is low, the wave soldering or reflow soldering process, since the substrate by thermal shock arising plate bulging, interlayer delaminating, blister copper and other quality problems. And deformation of the substrate is too large, decreasing the accuracy component mounting. The flux creep can also cause the site, resulting in poor connection. CCL after thermal shock, if the decline in copper foil peeling strength, it will result in the copper foil and mounted components together detached from the substrate. Due to the larger mass of the weight of the device on the substrate, the bending strength of CCL if small, will result in deformation of the substrate is too large. In recent years, micro-sized chip components adopt SMC, CCL also requires a higher surface smoothness.
Electronic products in the machine operational aspects of the CCL's performance requirements
In terms of running the whole electronic products, more emphasis is CCL electrical insulation properties, dielectric constant and dielectric loss
Consumption tangent, accuracy of plate thickness (in particular parts of the connector plate), reliability (ie low thermal expansion coefficient of resistance, heat resistance, heat resistance and other properties as to guarantee), mechanical strength, flame retardancy, environmental characteristics, thermal conductivity and other properties can.
To ensure the normal and stable operation, use, electronic products, the whole insulating substrate with an ion mobility cannot appear now Like occurrence. Because of this phenomenon, a direct impact on the reliability of the machine insulation resistance, voltage, or even appear Short circuit between the wires. In order to meet the characteristics of the impedance of the whole electronics high-precision control, high-speed signal transmission, must be on the dielectric properties of CCL's performance was excellent
(having a low dielectric constant, etc.). Especially at high frequencies, under high humidity conditions, it requires that its dielectric properties remain stable.
The plated vias of quality assurance and improvement is directly related to the long-term running of the machine's electronic product reliability problem. For this reason, it is closely related to the level of production quality vias with CCL thickness direction (Z direction) dimensional stability. For the level of production quality circuit pattern, but also with CCL plane direction (XY direction) associated with dimensional stability. This is also seen, with the development of electronic products, machine size and weight, making toward high-density printed circuit board wiring, fine-line, small aperture forward direction. This prompted the PCB to CCL dimensionally stable have increasingly high requirements.
CCL above three aspects of performance requirements, all have focused on the performance of the project. In the printed circuit board processing, The main focus on the dimensional stability of the substrate material, hole processing, electroplating, warped and distorted resistance, chemical resistance, etc. In recent years, it also appeared in the UV shielding, CO2 laser drilling and so on. In the installation components, the main focus line Coefficient of thermal expansion, thermal shock resistance, copper foil peeling strength, smoothness and other properties. In the operation of the whole product, more, the emphasis is on reliability of electrical insulation, dielectric constant and dielectric loss tangent, wet heat resistance, flame retardancy, particular environmental And other properties.