Research On Marching-on In-time Scheme And The Fast Algorithm Of Time Domain Integral Equation

With people's demand for the performance of electronic information products rapidly increasing,electronic information products are constantly developing in the direction of high integration,multi-function,small size and high reliability.These requirements need to rely on printed circuit boards?PCBs?,to achieve,and thus the design and manufacturing of PCBs also need to develop rapidly in the direction of high-density interconnected?HDI?.Therefore,in this dissertation,metal dots are constructed on the surface of organic matter as the seed layer for metalization of the insulating substrate,and a conductive pattern was formed on the seed layer by electroless plating or direct electroplating.The metal pattern had excellent conductivity,uniform thickness and strong bonding with the substrate,which can be applied the production of high-reliability electronic circuits for PCBs,provides a new technical approach for HDI PCBs manufacturing technology,which has achieved better results in actual production applications.The traditional electroless-plating process uses precious metals as the seed layer,resulting in high production costs.In addition,the precious metals are only adsorbed on the surface of the substrate during this process,so the deposited copper layer is easily separated from the substrate.In order to solve these problems,a new composite solution of copper ion and epoxy resin is proposed.The cured product of the composite solution is treated with a sodium borohydride solution,and the copper ions in the composite solution are reduced to copper,which serves as a seed layer on the insulating substrate to induce the insulating substrate to form conductive patterns.Due to the presence of epoxy resin in the solution,it has good compatibility with the insulated epoxy substrate and improves the bonding force between the pattern and the substrate.Therefore,the bonding force between the copper layer and the substrate was good,namely,no copper layer was peeling off,so as to ensure the reliability of the conductive pattern.Various chemical and physical characteristics of the composite layer formed by copper acetylacetonate and epoxy resin were analyzed and combined with the observation of the microscopic appearance,it is determined that the composite solution containing40%copper acetylacetonate after treatment,formed the copper layer was the best by electroless-plating and the corresponding copper deposition rate was 19.4?m/h.This method can be applied to the actual manufacturing of PCBs.However,in traditional electroless-plating,a large amount of formaldehyde is used as a reducing agent and a large amount of ethylenediaminetetraacetic acid is consumed as a complexing agent,which causes serious environmental pollution,and this method has a slow copper deposition rate.Therefore,conductive polymers are proposed as non-metal seeds for insulating substrates to form a conductive pattern by the direct electrodeposits copper,instead of electroless copper plating technology.Firstly,conductive polythiophene?PT?was formed on the epoxy substrate containing rolled coppe by a simple chemical oxidative polymerization,and the substrate was directly placed in the Harlem tank for electroplating,finally a conductive copper layer with excellent performance was formed on the conductive polymer.The copper electrodeposition rate of this method was fast and can reach 71.4?m/h,and the bonding force between the formed copper layer and the substrate is good,which provides a fast and efficient new method for PCBs manufacturing.In the experiment of using polythiophene as a seed layer to induce direct electrodeposition of metal copper on an epoxy substrate,it was found that the direct electrodeposition copper of polythiophene technology cannot be used on a fully insulated substrate,so nano-nickel particles?Ni NPs?which are simple in synthesis,low in cost and difficult to decompose in a strong acid electroplating copper solution,were introduced,and coated them on the surface of PT,and then electroplated copper,finally a conductive copper layer was formed on the insulating substrate.Moreover,the copper layer was dense,bright,and not easy to fall off from the substrate,and the corresponding copper deposition rate was 14.55?m/h.In addition,the role of Ni NPs in the direct electroplating process of polythiophene was further studied by SEM,energy dispersive spectrometer?EDS?and EDS mapping,which provided a reference for the application of other metal nanoparticles in the direct electroplating of conductive polymers on insulating substrates.The introduction of Ni NPs not only enables the PT on the insulating substrate to be directly electroplated,but also increases the conductivity of the PT,which can effectively increase the rate of copper layer on the PT surface,thereby it is applied to metallization of the high thickness-diameter ratios of through-holes?THs?,and filling of the miniature blind vias.Through the metallization of through-holes of different sizes and the comparison of the throwing power?TP?of THs,it was confirmed that Ni NPs can increase the copper electroplating layer in the holes during the through-hole metallization process,thereby improving TP of THs.the results of thermal shock test proved that the electroplating copper layer formed in the hole with the Ni NPs had strong binding force to the substrate.Additionally,Ni NPs was dispersed in the wall of the blind via with PT can also increase filling rate of the blind via during electroplating.These researches can be applied to the metallization of THs and blind vias to achieve the requirements for the preparation of printed circuit boards with small apertures and high hole density to form high-density interconnect structures.In order to prevent the separation between coated nano-metal and polymer to hinder the direct electroplating of polythiophene,a method of forming a metal-containing polythiophene composite conductive film on the surface of an insulating substrate is proposed in this dissertation.The key point of this method is that an acidic mixed solution of potassium permanganate and copper chloride acted as an oxidizing agent to oxidize the substrate and form an oxide layer containing manganese dioxide and copper ions.Manganese dioxide can promote the rapid formation of polythiophene from thiophene monomer in the polymerization solution,and copper ions can provide a copper source for the formation of copper.In addition,linear scanning test in electrochemistry verified that the conductive composite film containing PT and Cu had good electrochemical activity,which can perform electrodeposition copper reaction in electroplating copper solution.Moreover,the conductive composite film containing PT and Cu as a novel seed layer also explored some characteristics in its electroplating copper reaction,confirming the Cu²⁺and additive content in the electroplating solution and the initial voltage had an effect on the deposition copper rate during electroplating the conductive composite film.In addition,this composite film can also form electroplated patterns on textiles,and when the conductive textile was stretched to 50%,it still maintains conductivity,providing a method for the manufacture of flexible and wearable electronic components.