A large amount of embedded passive components can be embedded into printed circuit board inside of, we can shorten the length of lines between components, to improve the electrical properties, improve the efficient packaging of printed circuit board area and reduce the number of printed circuit plate board solder surface, thereby enhancing the reliability of the package, and lower costs.
Printing Circuit Board Co., Ltd. Shanghai Hua Senior Ma Mingcheng
With the portable electronics and digital products, high-speed messaging surge, high-density packaging technology increasingly shown its importance. Its main function is to make complex electronic products for small, lightweight, thin and high-performance, high function. In order to continuously meet the needs of this development, electronic components tend to be more ultra-small and thin, printed circuit boards are turning to high-precision graphics and thin multi-layered. Printed in such a large number of board space to install the surface of the component layout more difficult, at present, in general on the printed circuit board assembly of various electronic components in the majority of passive components, passive components and a number of source component count ratio (15 ~ 20): 1, with the improvement of IC integration and I / O to increase the number, the number of passive components will continue to increase rapidly. Therefore, a large amount of embedded passive components can be embedded into printed circuit board inside of, you can shorten the device length between the lines, electrical properties, improve the efficient packaging of printed circuit board area and reduce the number of Indian system board space of the weld, thereby enhancing the reliability of the package, and lower costs. So, is ideal for embedded devices form an installation and technical.
Passive electronic components usually divided into two major categories of components and active components. Embedded active components present, because the manufacturing technology is still in active development stage, there is a certain distance away from the practical, so this article only briefly embedded passive components (resistors, capacitors, inductors, etc.) related technologies.
Embedded passive components to active components increased degree of freedom
So-called "embedded passive components" manufacturing technology, combining the inner layers of technology to etching or printing method resistors, capacitors, inductors in the inner panel, and then by multi-lamination and board production process embedded board inside the panel to replace the passive components required for welding, assembly and wiring to the active components to increase flexibility.
Embedded resistor materials are high resistivity of the material, and can make a variety of shapes and surface resistance of different resistance values. Resistor material is nickel-phosphorus alloy, non-metallic materials (such as carbon, graphite, diamond powder), it can be of metal powder and non-metallic fillers (such as silica powder, glass powder) and resin adhesive, dispersing agents, slip agents modulation level formed slurry (ink) complexes.
More common now adopted the following only in respect of the embedded resistor technologies are presented.
1. Etching resistance of the metal alloy technology. This technology is the first use of electroplating or sputtering surface in copper foil resistor together form a metal layer (such as Ni-P alloy Nip, Ni-Cr alloy NiCr, tantalum nitride TaN, Cr-Si alloy CrSi, titanium tungsten TiW, etc.), then so that the formation of production and other media materials, the inner cover foil laminate. In the production line, the use of multiple exposure and etching techniques, the formation of a specific location in the film resistor required. The process is as follows:
Foil plate surface cleaning exposure develop etching etching copper nickel-phosphorus alloy (or NiCr, RaN, etc.) to film the second foil oxidation secondary exposure to the oxidation of secondary imaging Etching copper Secondary Secondary to film detection.
2. Printing embedded resistor technology. There are low temperature curing of the resistance of screen printing ink (such as toner, graphite and resin phenolic resin, epoxy resin, etc.) and embedded resistor paste printing low-temperature sintering method.
3. Electroplating and sputtering technology embedded resistors and vacuum sputtering using electroplating method of forming or embedded resistor, that is, the inner core board to complete the circuit in the graphics, the use of mask (corrosion, anti-plating agent ), exposed for electroplating deposition resistance of metals (such as nickel-phosphorous alloy) or vacuum sputtering deposition resistance of the material window, by controlling the plating parameters or vacuum sputtering parameters to control the resistance of layer thickness, plating, or sputtering of the embedded resistor size and shape through a "window" to control.
4. Inkjet printing embedded resistor technology, which in recent years developed an advanced technology that uses inkjet printer principle, using for the resistance of ink jet printing, print form embedded resistors. This technique has many strengths, particularly the processing does not produce chemical waste, is environmentally friendly new technologies.
On the embedded capacitor. Embedded capacitor technology have adopted the method of dielectric membrane, with the formation of thick or thin film dielectric permittivity of a large body of methods and use of high-temperature sintering thick-film paste method.
On the buried inductor. Embedded inductor is formed by etching copper foil or copper spiral, curved and other shapes, or use the Via layer to form helical multi-layer structure. Its features depends on the shape of the substrate structure and graphics. Inductance current share is only about tens of Namibia. Are still mainly of high frequency modules. Research and development is being ferrous salts such as resin and magnetic powder mixture consisting of nano-powder film and search using the possibility of low-temperature sintering.
Integrated passive components on silicon chips to market
Recent integration of passive components on silicon chips have been listed. The silicon chip (IPD: Integrated) is the use of semiconductor micro processing technology, the Si surface of the SiO 2 Capacitor insulation film formed on C, resistor R, inductance L. A single chip can integrate more than 30 passive components, the thickness of 50 m or even just to thinner, the resistance 1 ~ 100k , capacitance 5PF ~ 500PF, as embedded device applications.
Recently to solve the heat dissipation of embedded devices, has developed a hollow core, the embedded component substrates. This is the embedded devices and other electronic components (passive components, active components) embedded in copper formed within the hollow structure. Specific processing is core material in the substrate resin paste 2 electrolytic copper foil or rolled, electronic components embedded in the hollow formed by the lower copper foil and resin within the fixed wiring with copper to achieve the formation of embedded components and electrical connections . This embedded device substrate can improve the cooling performance and lower electromagnetic interference. In addition, because the use of copper interconnects for electronic components, the interconnection with the traditional way of comparison, the relative copper heat shock plastic strain is small, helps to ensure product reliability.
Built-in component based