A materials study of high reliability electronics cleaning is presented here. In Phase 1,mixed type substrates underwent a condensed contaminants application to view a worst-case scenario for unremoved flux with cleaning agent residue for parts in a silicone oil filled environment. In Phase 2,fluxes applied to copper coupons and to printed wiring boards underwent gentle cleaning then accelerated aging in air at 65% humidity and 30 OC. Both sets were aged for 4 weeks. Contaminants were no-clean (ORL0),water soluble (ORH1 liquid and ORH0 paste),and rosin (RMA; ROL0) fluxes. Defluxing agents were water,solvents,and engineered aqueous defluxers. In the first phase,coupons had flux applied and heated,then were placed in vials of oil with a small amount of cleaning agent and additional coupons. In the second phase,pairs of copper coupons and PWB were hand soldered by application of each flux,using tin-lead solder in a strip across the coupon or a set of test components on the PWB. One of each pair was cleaned in each cleaning agent,the first with a typical clean,and the second with a brief clean. Ionic contamination residue was measured before accelerated aging. After aging,substrates were removed and a visual record of coupon damage made,from which a subjective rank was applied for comparison between the various flux and defluxer combinations; more corrosion equated to higher rank. The ORH1 water soluble flux resulted in the highest ranking in both phases,the RMA flux the least. For the first phase,in which flux and defluxer remained on coupons,the aqueous defluxers led to worse corrosion. The vapor phase cleaning agents resulted in the highest ranking in the second phase,in which there was no physical cleaning. Further study of cleaning and rinsing parameters will be required.

Although reflow ovens may not have been dramatically changed during the last decade the reflow process changes step by step. With the introduction of lead-free soldering not only operation temperatures increased,but also the chemistry of the solder paste was modified to meet the higher thermal requirements. Miniaturization is a second factor that impacts the reflow process. The density on the assembly is increasing where solder paste deposit volumes decreases due to smaller pad and component dimensions. Pick and place machines can handle more components and to meet this high through put some SMD lines are equipped with dual lane conveyors,doubling solder paste consumption. With the introduction of pin in paste to solder through hole components contamination of the oven increased due to dripping of the paste. The iNemi Roadmap identified seven key metrics for the reflow process: 1. Temperature delta performance 2. Inerting capability 3. Cooling rates 4. Flux management 5. Cost of operation 6. Traceability 7. Change over time. The current flux collection systems need to focus on improvements to minimize maintenance downtimes. Flux management and cost of operation will benefit from an efficient oven cleaning method. The filter and condensation systems that were successful running in SnPb processes have to be reviewed and new technology is introduced to have a more efficient removal of solder paste,board and component gasses.

Proper assembly of components is critical in the manufacturing industry as it affects functionality and reliability. In a heat sink assembly,a detailed manual process is often utilized. However,an automated fixture is used whenever applicable. This paper will illustrate the use of strain gauge testing and Finite Element Analysis (FEA) as a simulation tool to evaluate and optimize the heat sink assembly process by manual and automated methods. Several PCBAs in the production line were subjected to the manual and automated assembly process. Strain gauge testing was performed and FEA models were built and run. Results were compared with the goal of improving the FEA model. The updated FEA model will be used in simulating different conditions in assembly. Proposed improvement solutions to some issues can also be verified through FEA.

Electrical overstress causes damage to sensitive components,including latent damage. A significant source of EOS is high-frequency noise in automated manufacturing equipment. This paper analyses sources of such noise,how it affects components and how to mitigate this problem.

Press-fit technology is a proven and widely used and accepted interconnection method for joining electronics assemblies. Printed Circuit Board Assembly Systems and typical functional subassemblies are connected through press-fit connectors. The Press-Fit Compliant Pin is a proven interconnect termination to reliably provide electrical and mechanical connections from a Printed Circuit Board to an Electrical Connector. Electrical Connectors are then interconnected together providing board to board electrical and mechanical inter-connection. Press-Fit Compliant Pins are housed within Connectors and used on Backplanes,Mid-planes and Daughter Card Printed Circuit Board Assemblies. High reliability OEM (Original Equipment Manufacturer) computer designs continue to use press-fit connections to overcome challenges associated with soldering,rework,thermal cycles,installation and repair. This paper investigates the technical roadmap for press fit technology,putting special attention to main characteristics such,placement and insertion,inspection,repair,pin design trends,challenges and solutions. Critical process control parameters within an assembly manufacturing are highlighted.

Soldering has been a key process step in the manufacture of electronic assemblies since the earliest days of the electronics industry,it is also one of the most challenging processes to control and predict and a major source of defects and failure. For several years,the elimination of solder from the electronic circuit assembly manufacturing process has been suggested as a potential way to sidestep solder technology’s many short comings. Elimination of solder can in fact be relatively easily accomplished by simply reversing the manufacturing process. That is,rather than building printed circuits and then placing components and soldering to them together,it is here proposed that boards containing components,with the component’s planar terminations exposed on the surfaces of said component boards,have circuits applied to them using PCB buildup technologies which are now well established in the PCB industry. By bypassing the soldering process,the resulting assemblies offer significant benefits and improvement potential in terms of cost,reliability,security and environmental friendliness among others. While the manufacturing infrastructure to build such structures is fundamentally in place and ready to go,the design approach,mentality and some tools which are presently available are less ready. This paper will examine,by way of demonstration,the challenges associated with designing SAFE (solderless assembly for electronics) products. In the paper,a current product board is redesigned using all preferred case design rules which include,a fundamental grid pitch for all components resulting in a design which is substantially smaller than the original design and yet which are less challenging to the circuit manufacturer than most current leading edge designs. The paper will identify the limitations of current design tools relative to executing such designs and offer suggestions as to how those tools might be improved to make the manufacture of solder free electronic assemblies easier. It will also describe and suggest novel ways of integrating passive devices into such electronic assemblies to further conserve space and improve performance.

The embedding of components in electronic interconnection structures has been carried out for more than 30 years. It is regarded as the “poor men’s silicon device”. Different technologies have been developed and were technically successful,but history has shown that these embedding developments did not result in a sustainable success over a longer period of time. Replacement technologies have been developed after a short period of time by the so-called “Not in Kind” (NiK) technologies often called disruptive technology. (e.g. From the viewpoint of a PCB fabricator the use of an “Inorganic ceramic material is a = “Not in Kind”,while a standard FR4.0 or FR4.1 is considered as an Organic = “In Kind” technology). The paper will explain what is needed to avoid technology pitfalls that will lead to business failures in future. In addition,opportunities are discussed that enable development managers,design engineers and specialists to use the full benefits of embedding devices in automotive,medical and industrial applications. These ‘enabling’ manufacturing technologies will offer the opportunity to develop innovative product solutions in critical technical,environmental and business situations.

Embedding components within the PC board structure is not a new concept. Until recently,however,most embedded component PC board applications adapted only passive elements. The early component forming processes relied on resistive inks and films to enable embedding of resistor and capacitors elements. Although these forming methods remain viable,many companies are choosing to place very thin discrete passive components and semiconductor die elements within the PC board layering structure. In addition to improving the products performance,companies have found that by reducing the component population on the PC board’s surface,board level assembly is less complex and the PC board can be made smaller. The smaller substrate,even when more complex,often results in lower cost. Although size and cost reductions are significant attributes,the closer coupling of key elements can also contribute to improving functional performance. This paper focuses on six basic embedded component structure designs described in IPC-7092. The process variations define the structure,depending on whether components are passive or active,placed and/or formed and if they are on one side of the PC board base-core or both. The formed and placed components may be located on any number of layers,however,formed components are generally assigned to dedicated layers. The layering description actually becomes part of the type designation that is very similar in describing an eight layer (2-4-2) HDI board and the naming indicates whether the base-core represents a final assembly or is simply a mounting base onto which additional layers are sequentially added.

As a part of series of studies on X-Ray inspection technology to quantify solder defects in BGA balls,we have conducted inspection of 3 level POP package by using a new AXI that capable of 3D-CT imaging. The new results are compared with the results of earlier AXI measurements. It is found that 3D measurements offer better defect inspection quality,lower false call and escapes.

In a typical mechatronic manufacturing functional test setup,actual load simulations are usually done by connecting the DUT outputs to power or ground in order to establish either a high or low side driver. Each output is connected with different load and the test will either be sequential or concurrent. At lower power levels,these can usually be managed with general purpose switches. However,when it comes to higher power levels of currents more than 5 amps,such switching and loading might pose a greater challenge. Furthermore,critically in the manufacturing line,the tradeoff between cost and test time would have a great influence on the test strategy. This paper will present some key points to design a cost effective high power switching and load management solution. Firstly,we will discuss the selection process for the types of relays to be used in the switch methodology. Next,for automotive testing where high current measurements are typically done at the output channels,we will look into how this measurement is done; with or without loads and by instantaneous or continuous measurements. Then,we will discuss single load or multi load connections and explore different approaches. These connections provide simulation at different loading conditions. A typical example would be to emulate the steering wheel audio control button with different resistive loads. Subsequently,we will also discuss voltage protection and temperature cooling which are essential in such high power applications. Finally,we will give a bird eye’s view on the complete high level architecture of the combination of switch and load box,where usually the right solution is more than the sum of the parts. By providing the reader with guidance and tips on which design and methodology to adopt for the high power switch and load solutions,a cost effective while robust solution that promotes reusability of the test system in high mix test environment would be at your fingertips.