... (SnAgCu) and, more recently, stabilised tin/copper (SnCuNi). Although the level of efficiency of both systems is not yet completely clear, the following presents the | PCB FAB | latest information: SnAgCu There is more experience in the field of silver systems. Here, differentiation is made between the Sn-3.5Ag-0.7Cu, Sn-4Ag-0.5Cu and Sn-3Ag- 0.5Cu systems | PCB FAB | which vary in use from continent to continent. However, the agreed expert opinion (IPC/Soldertech-Conference Brussels 2003) is that the technological differences between the three systems | PCB FAB | are negligible. Sn-3.5Ag-0.7Cu is the most common alloy in Europe. SnCuNi Although there are even fewer field results for the stabilised tin/copper system Sn-0.7Cu- 0.1Ni, | PCB FAB | it shows a lot of potential. It is called “stabilised” because the addition of nickel is said to show an improved hardening reaction in soldering. | PCB FAB | The creation of needle-structured crystals is said to alter to rounder structures, achieving an improved soldering flow for wave ...
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... metal deposition on an unclad substrate with electroplating or with etching, or with both | SMOBC SOLDER MASK OVER BARE COPPER. | A method | PCB FAB | of fabricating a printed wiring board which results in the final metallization being copper with no other protective metal but the non soldered areas are | PCB FAB | coated by a solder resist, exposing only the component terminal areas. | SOLDER LEVELING |The process of dipping PCB's into hot liquids, or exposing them | PCB FAB | to liquid waves to achieve fusion. First, flux is applied to the board by dipping or brushing. Then the board is preheated in a liquid | PCB FAB | (maintained at 250 F). Next, the board is immersed in fusing liquid at 430 - 500 F. Finally, it is dipped in another 250 F | PCB FAB | liquid to cool it and reduce thermal shock. Thin fused coatings can be applied. | SOLDER RESISTS (SOLDERMASK) | Coatings which mask off and surface | PCB FAB | insulate those areas of a circuit where soldering is not desired. | STEP AND REPEAT | A method by which successive exposures of a ...
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... personal digital assistants, and notebook computers, the PCB industry is experiencing an overwhelming rise in demand for high-density interconnect structures (HDIS). The demand for | PCB FAB | HDIS translates directly into a vigorous market for the microvias used in many of these multilayer substrates as well as in conventional PCBs. In 1998, | PCB FAB | for example, the worldwide microvia market made up about four percent of the total multilayer PCB market. By 2007 that market share is expected to | PCB FAB | expand to nearly 30 percent Worldwide, | THE TOTAL MICROVIA MARKET | approached $4 billion in 2000 - up 63 percent over 1999 (Figure 2).1 | PCB FAB | By the end of 2001 the market should reach $5.6 billion - up another 50 percent over 2000. These same data show Japan as the | PCB FAB | microvia leader, followed by Europe, Asia, and North America. Several factors contribute to this remarkable expansion, the most important being the steadily increasing interconnect density | PCB FAB | of PCBs. Microvias have become an attractive interconnect ...
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