The phrase "Design For Manufacture" strongly implies the use of manufacturing information while making of design decisions or,in other words,incorporating manufacturing knowledge during initial design. Unfortunately,most currently available PCB DFM tools don?t fit into the design work flow until the PCB design is already complete. There are three nasty consequences to the current approach:
1. Designers are forced to make under-informed design decisions during layout,when DFM is easiest and least expensive to design in to the project.
2. When DFM errors are inevitably identified,they require significant rework,engineering effort and additional money.
3. The additional rework to fix back-end batch DFM increases the risk that your project will miss the market window.
New,more interactive approaches to DFM are becoming available to designers. Rather than postponing DFM checks until the end of the design,for example,the methodology described here enables designers to be notified (almost interactively) of any manufacturability issues as they design. By attending to DFM issues from the onset,designers are not only able to „pass? DFM,but can also invest in optimizing the manufacturability of their designs even from the first prototype. The result can be a cleaner,more manufacturable design that qualifies for production faster and at lower cost,and that also produces higher yields in production.
In this paper,we present case studies and efficiency results,from their implementation of an interactive DFM model to support our manufacturing process.

We have developed a cupric chloride-hydrochloric acid based microetchant process. This process provides a unique roughened copper surface,which yields excellent adhesion for both solder mask and dry film photo resist applications. The process also yields excellent solder mask adhesion through subsequent silver,tin and nickel plating post solder mask application.
The amount of copper etched using cupric chloride-hydrochloric acid based microetchant is not as high as that seen typically in cupric chloride etching systems. Airborne oxygen is efficient enough to be used as an oxidizer in the system. Hydrochloric acid maintains the proper hydrogen and chloride ion concentrations. The cupric ion maintains itself throughout the process.
The chemistry and process are both easily controlled. The process operation is comparable to a mini cupric chloride etcher,whereby copper concentration is maintained by specific gravity and acidity can be controlled by conductivity. It is not necessary to control oxidation-reduction potential,hence the difference as compared to conventional etching processes.
This technology provides highly roughened copper surfaces for conventional acid plated copper such as PPR and DC,and standard regular copper clad,which offers great adhesion for solder mask and dry film photo resist. For solder mask applications,it is necessary to produce a rougher topography by controlling micro etching rate at 1.0-1.5 µm/m to get good adhesion between copper surface and solder mask when the final finish is involved in immersion or electroless plating process with tin or nickel. For dry film photo resist applications,the processed copper surface is rough enough to improve the adhesion at micro etching rate below 1.0 µm/m. The copper surface roughness should be controlled within a range to balance the adhesion and resolution when dryfilm photo resist is used for fine line boards.

An electrochemical device has been developed that deposits non adherent copper metal powder at the cathode,and generates chlorine gas at the anode. The chlorine is contained within the system,and is used to regenerate the etchant in a continuous closed loop process. Chlorine is generated only when the electrochemical process is underway. There is never any stored chlorine gas. The copper metal powder is deposited on rotating disc cathodes,and continuously and automatically removed and stored. The disc cathodes rotate through the recirculating etchant solution,and the copper powder is deposited approximately 750 amperes per square foot and 5 volts DC. The powder is continuously removed from the cathode disc by mechanical scrappers,and flushed into a collection bin by a recirculating water spray. The anodes are inert DSA anodes. The chlorine generated is continuously transferred to the etchant where it reacts to regenerate the etchant. The rectifier is automatically turned on only when the ORP is below a set point. The rectifier is turned off when the ORP reaches a preset upper ORP limit,thus ending the production of chlorine gas. In order to conduct this study the existing unit has been installed and operated and tested in a real production facility. Because of the chlorine production,the unit cannot be operated or tested unless it is connected to a working etching system. The current high price of copper metal has made this technology very economically viable.

Emerging technologies in the printed circuit board industry including smaller holes,higher aspect ratios,three-dimensional features,fine pitch,blind via holes,and new lead free materials continue to challenge standard manufacturing methods. With these new technologies,plasma has become the chosen method for cleaning carbon/resin from laser formed blind vias,treatment of flex materials prior to lamination and etching lead-free materials and composite material constructions. The processing demand of these technologies has required improvements to the vacuum gas plasma process often used for desmear applications. Additional requirements including processing the high value product at a lower cost per panel are directly opposed to this new performance expectation. The new technology requirements translate directly to improved uniformity specifications for the plasma system,where the high value lower cost proposition drive cost of ownership and equipment configuration specifications. New plasma technology is required to meet the technology and cost demands. This paper describes one aspect of the technology development critical for improved uniformity.

More and more political bodies (countries,states,and unions) are enacting legislation designed to protect the environment from the impact of manufacturing. One category of restrictive legislation is called Extended Producer Responsibilities (EPR). The EPR directive with the biggest impact on the electronics industry is the European Union’s (EU) Restriction of Hazardous Substances (RoHS) Directive,finalized in 2003. The RoHS directive restricts the importation into the EU of new electrical and electronic equipment containing six hazardous substances including lead. For manufacturers to successfully comply with RoHS and similar EPR legislation,they need the ability to exchange material content information. This information needs to propagate through the supply chain from the raw material suppliers all the way to the final producer. To deal with this problem,the National Institute of Standards and Technology (NIST) developed a data model to address the underlying material declaration. This data model was used in the development of IPC-1751 Generic Requirements for Declaration Process Management and IPC-1752 Materials Declaration Management. While IPC 1752 was created with a focus on EU RoHS,industry is now faced with a multitude of new environmental legislations and regulations. While many are variants of the RoHS legislation,several address entirely new areas of environmental awareness such as energy efficiency. To address this problem,NIST has developed an updated model for IPC 1752 version 2.0. This model has a larger scope and is more modular making it better suited to address regulations beyond RoHS and meet other supplier declaration needs. This paper looks at the data models used in both version of IPC 1752 and highlights the differences for application developers.

Companies not only need to understand the reliability issues with environmental compliance,but also how to comply with the various regulations from the business end. China is the second jurisdiction with formalized legislation on the restriction of hazardous substances for electronic products.

There has been a global trend towards legislation meant to encourage sustainable manufacturing and minimize the environmental impact of product manufacturing. In the global economy,with its distributed supply chain,local environmental laws may affect companies located anywhere in the world. Often,these laws are targeted at the finished goods manufacturer on the assumption that changes will propagate through the supply chain all the way to the raw material suppliers. Penalties for non-compliance may include monetary fines and/or trade restrictions. Compliance will likely require modifications to existing manufacturing processes,the use of alternative materials or chemicals,and new data systems to track relevant information. In order to be prepared,companies need to look ahead to identify new and future legislation and determine how it might impact their business. Companies will need to be prepared well before new legislation goes into effect. This paper takes a closer look at two upcoming European Union legislative acts that will have significant impacts on the future of electronics and semiconductor industries in Europe. Specifically,it gives an overview of the Registration,Evaluation,Authorization,and Restriction of Chemicals (REACH) regulation and Energy Using Products (EuP) Directive. REACH creates a mechanism for the registration of chemical substances manufactured or imported into the EU,a methodology for the evaluation of those chemicals and their associated safety risks,and finally establishes an authorization requirement for chemicals of high concern. Instead of concentrating on materials,the focus of EuP is on energy. EuP is part of the EU Energy Efficiency Action Plan and seeks to reduce energy usage. While these directives will affect companies within the European Union,due to global nature of modern industry,their impact will be felt far beyond the borders of the European Union.

Currently little data exists on temperature repeatability of BGA/CSP rework machine equipment. This is an issue especially for lead-free rework as the temperatures during lead-free BGA/CSP rework are likely to be higher than reflow soldering,leading to potential component and board temperature related issues. A series of evaluations was conducted on rework equipment from four rework machine equipment suppliers. The BGA/CSP rework machine repeatability and tolerance temperature study used a fixed thermal profile with temperature measurement output on equipment specifically designed for BGA/CSP rework machines. The temperature input was a lead-free rework profile developed by each supplier on a PBGA544 component on a 135mil (3.4mm) thick test vehicle board. This lead-free rework profile was run on the rework machine 10 times. Temperature peaks and durations were recorded at the 6 different temperature locations on the temperature measurement equipment placed within the rework machine.
In Phase 1 of the program each rework machine supplier recorded temperatures using its defined lead-free profile with a specific rework machine. In Phase 2,each supplier repeated these tests on a different machine of the same model. A comparison was then done to analyze the temperature and time data from Phases 1 and 2 to determine rework machine temperature repeatability and tolerances.

Wire soldering operations are still widely accepted in the electronics assembly industry. When a product or the parts within cannot withstand the heat of oven reflow,the localized heat provided by a soldering iron has been the traditional solution. In high-volume operations,this can often require large labor pools to keep up with more automated assembly processes upstream or downstream. Soldering with wire and iron also leaves process judgments up to individual operators,and can produce a wide variety of defects,scrap,or long-term quality issues.
Despite the many improvements in automated soldering technology through the years,many soldering operations are best suited to manual production methods,which produce inconsistent results. Whether in low-volume custom operations or large-scale manufacturing processes,the quality of hand-soldered joints will exhibit a high degree of variation. Defect,scrap,and rework rates can be excessive,even when using skilled employees.
Higher temperature lead-free operations present an additional challenge. Because of the higher temperatures required,these processes have even smaller operating windows. Visual inspection of lead-free solder joints also presents new difficulties,and since most hand soldering rework occurs 'on-the-fly,' actual defect rates are difficult to measure.
There are other process solutions available which involve very little capital expenditure,but can significantly increase operator output. These solutions are effective in eliminating many of the process defects associated with wire solder. They will usually result in a faster and more controllable process that reduces scrap and improves overall product quality. In many applications where wire solder was once a requirement,a more automated approach can often be achieved using solder paste and localized heating methods.

Repairing a PCB with a defective BGA,uBGA,or QFN is often a difficult and tedious task. The conventional method is to remove the defective device from the PCB; clean the pads on the PCB,then print solder paste on the pads with a mini-stencil. The stencil footprint needs to be small enough to fit into the area of the removed part,which is normally surrounded by other devices in close proximity.
This paper will describe an alternative repair method. Instead of printing solder paste on the PCB pads this system prints solder paste directly on the QFN pad or the BGA solder balls. The repair tool is simple and easy to operate. A package can be inserted in the tool,printed and placed on the PCB in about 30 seconds. The tool is made up of two components: a universal master tool,which can be reused for all packages and a unique component,which is designed for a specific package. The unique components consist of a stencil and a device holding fixture. Both are free standing metal foils with laser cut or electroformed apertures.