Description The research discussed in this paper uses an innovative enhancement technique for printing High Density substrates. The technique takes advantage of high frequency low amplitude vibrations applied to the stencil at the time of the stencil/substrate ... read more

Description Recently,wafer bumping using solder paste with very fine solder powder has come into focus as more cost effective than conventional sputtered or plated methods. This additive method revolves around a stencil printing process similar to ... read more

Description SPC data has shown that the solder paste printing process is the primary source of soldering defects in SMT assembly. Consequently,verification of the specified printing properties of solder paste is of paramount importance in the pursuit of ... read more

Description As Electrostatic discharge,humidity can have a bad impact on assembly quality. It requires environmental conditions and process controls but also risks knowledge. To overcome humidity issue,parts (PCB or components) need to be baked to ... read more

Description The SMT (surface mount technology) assembly process for 0.4 mm pitch CSP (chip scale package) components was studied in this work. For the screen printing process,the printing performance of different solder pastes,aperture shapes and sizes ... read more

Description In order to understand the reaction mechanism of an auto-catalytic type gold plating bath,it is necessary to recognize the following reactions --- oxidation of reducing agent,gold deposition and dissolution of the underlying nickel deposit. ... read more

Description A novel electrochemical plating process for depositing gold and silver surface finishes using environmentally benign, organic-based solutions as the plating bath is being investigated. The plating bath solution consists of an extractant and a ... read more

Description Process,Process,Process – these words must ring loudly in our ears,and must be at the forefront of lead free implementation. The smaller process windows dictated by lead free alloys are going to put greater demands not only on ... read more

Description The popularity of low voltage technologies has grown significantly over the last decade as semiconductor device manufacturers have moved to satisfy market demands for more powerful products,smaller packaging,and longer battery life. ... read more

Description Evaluation of printed wiring boards (PWBs) for thermal reliability during assembly and rework operations by Thermal Mechanical Analyzer (TMA) “T-260” testing has been an accepted practice for many years. Test procedures are specified in ... read more

Description Non-destructive testing during the manufacture of printed wiring boards (PWBs) has become ever more important for checking product quality without compromising productivity. Using x-ray inspection,not only provides a non-destructive test ... read more

Description The behavior of BGA solder joints under dynamic loads has become more significant in recent years. This work explored test methodologies for solder joint failure evaluation under dynamic loads. The objectives of this study were ... read more

Description Industry cost control pressures and technology drivers demand more powerful 3D AOI machines for control of solder paste printing. Here is an inside look at the factors potential purchasers of these systems should take into consideration. ... read more

Description The electronic industry trend of smaller component packages and tighter spacing has put greater demands on manufacturing for process control and product verification. Defects must be caught earlier in the process to provide feedback to the process. ... read more

Description Conductive adhesives (CAs) have been an important problem-solving class of assembly materials for decades,but primarily as die attaches products,ever since they replaced metallurgical systems. Renewed and intensified interest in lead-free (L-F) ... read more

Description Quantifying SMT adhesive dispensing performance has typically been attribute analysis via a microscope. Individual adhesive deposits were inspected for strings or tails,extra dots,missing dots and dot diameter. These attributes were typically ... read more

Description Higher I/O Ball Grid Arrays (BGAs) are high speed,high pin count,and high performance array packages. These BGAs are also more complex in structure than “standard” BGAs and are generally targeted toward network and server class products. ... read more

Description With the function of today’s electronic devices become more and more complicate,the high I/O flip chip ball grid array package (FCBGA) is used more popularly in recent years. The FCBGA package is always subjected to thermal loading when ... read more

Description In recent years,Wafer Level Chip Scale Packages (WLCSP) are used not only in the hand held devices but also in high-end networking and telecommunication products. Due to their small footprint and the bare die structure,long-term board level ... read more

Description The trends of increased functionality and reduced size of portable wireless products,such as handsets and PDAs,are demanding increased routing densities for printed circuit boards. The handheld wireless product market place demands ... read more

Description The objectives of the present study are to design,fabricate,and test various configurations of micro-vias over military thermal environment,and then evaluate the impacts of micro-via design/manufacturing process variables on the thermal ... read more

Description In the present as in the past,printed circuit board conductors are sized using simple charts that are a function of cross-sectional area,current level and conductor temperature rise. These charts do not distinguish between copper ... read more

Description Various Ag-filled epoxies were subjected to a current carrying capability study in which current was applied to the epoxies at temperatures of up to 170°C for 1008 hours. Test devices with Ag epoxy joint diameters ranging from ... read more

Description Horizontal conveyorized spray processing is the most prevalent method for the production of circuit panels in the industry today. However,as line and space requirements fall below 4 mils (100µm),the difficulties in producing ... read more

Description Predicting printed circuit board (PCB) thickness has not historically been a difficult task. With lower layer count boards you can afford for the prediction per layer to be wrong by a relatively large amount and still meet thickness ... read more

Description Customer demands concerning thermal stability of PCB base materials are increasing. Rising complexity of printed circuit boards requires an improved quality of the dielectric in terms of cleanliness. ... read more

Description In order to evaluate the relative merits of halogenated and alternative flame-retardants used in PWB’s,a comparison between several different PWB’s each having different flame-retardant packages has been made. The study examines ... read more

Description Combination grid-prober (CGP) testing is being employed with increasing frequency as the density of SMD lands on boards continues to increase. A number of factors are at work. Grid testers,as a stand-alone test methodology,provide a fast and ... read more

Description Increasing global interest in environmental protection is leading to a higher demand for halogen-free materials that can be used as the base materials for the printed wiring boards (PWBs) in electronic equipment. These halogen compounds are ... read more

Description In the best selling book “Who Moved My Cheese”, author Spencer Johnson tells the story of four characters—mice named Sniff,Scurry,Hem and Haw--who are in search of cheese within a maze. Once they find it,they happily stay put. But one day ... read more

Description This paper discusses the results of Conductive Anodic Filament (CAF) testing of three types of reinforced microvia dielectrics using a CAF test specific Printed Circuit Board (PCB). Quantitative results are presented for two CAF ... read more

Description Copper migration such as conductive anodic filaments (CAF) has become a serious problem for printed wiring boards (PWBs). As the relation between CAF and matrix resin properties is not clear,the relation has been ... read more

Description BGAs are usually solder-reflowed on substrates,which are frequently made of a different material than that of the BGAs,which results in a TCE Mismatch between the components. If such an assembly includes a large size BGA, ... read more

Description The IPC-PCQR2 (Process Capability,Quality and Relative Reliability) program has developed a library of process capability panel designs,and a database that details the manufacturing capability,quality,and reliability of printed ... read more

Description The information age has arrived. A growing percentage of the Earth’s population now has access to pagers,cellular phones,computers,personal digital assistants (PDA’s),and a host of other electronic devices. We can now instantly ... read more

Description There are a number of organic,inorganic,and hybrid inorganic waveguide materials that are currently being used for a wide variety of optical interconnect applications. Depending upon the approach,waveguide formation is ... read more

Description Multiple soldering assembly steps are essentially standard for PWBs based on current technologies and needs. A variety of tests are currently in use to evaluate the performance of finished PWBs,and indirectly,the materials and material performance of ... read more

Description A new oxide chemistry has been developed which solves many of the annoying properties of the currently available alternate oxides. The process is simple to operate,even simpler to maintain,requires less chemistry,manages to be easier on the ... read more

Description Solder is used in polyimide-based flexible circuits for interconnect applications. But it cannot be used with polyester and epoxy based substrates because of the low temperature tolerance of these substrates. Conductive adhesives offer ... read more

Description Adhesiveless copper on polyimide substrates are used extensively for high density,flexible circuit applications. A typical construction includes the polyimide substrate,a thin vacuum deposited metal tiecoat,a copper seedcoat,and ... read more

Description Failure analyses of the leadfree and SnPb solder joints of high-density packages such as the PBGA (plastic ball grid array) and the CCGA (ceramic column grid array) soldered on SnCu HASL (hot-air solder leveling) ENIG ... read more

Description Temperature cycling test and statistical analysis of various high-density packages on PCBs with SnCu HASL,NiAu, and OSP finishes are investigated in this study. Emphasis is placed on the determination of the life distribution and ... read more

Description The lead-free solder-joint reliability of the high-density packages,256-pin PBGA (plastic ball grid array),388-pin PBGA,and 1657-pin CCGA (ceramic column grid array),on PCB (printed circuit board) subjected to temperature ... read more

Description The High Density Packaging Users Group (HDPUG) has conducted a substantial study of solder joint reliability of high-density packages using lead-free solder. The design,material,and assembly process aspects of the project are ... read more

Description With the advent of hard die coated microelectronic assemblies; the ability to perform visual inspections for quality control and failure analysis has been seriously hindered. Analysts have had to utilize X-ray inspection,cross sections,and chemical ... read more

Description During the last years Flip Chip Technology has been widely accepted as a means for maximum miniaturization of microelectronic assemblies. As an example the use of Flip Chips in advanced products as cellular phones,GPS ... read more

Description The Information and Electronic Warfare Systems business of BAE SYSTEMS Information and Electronic Systems Integration,Inc. (“BAE SYSTEMS IEWS”),a subsidiary of BAE SYSTEMS North America,is involved in the manufacture of a ... read more

Description All areas of manufacturing worldwide are impacted by the lead free initiative; none more than the reflow process. The higher melt temperatures and soak duration of leadless solder formulas require a change in the way reflow management is handled. Time ... read more

Description This paper discusses some of the new challenges associated with MSD Control in PCB assembly plants and offers a solution to reduce manufacturing costs and improve quality by automating this critical aspect of quality control. ... read more

Description The Final assembly and packaging area experiences similar integration issues as the Printed Wiring Board – PWB manufacturing industry. Communications between production equipment is based on different standards ... read more