Technical Library | 2009-09-30 23:12:29.0
Being involved in the electronics assembly industry for more than 23 years, specifically in the field of defluxing and cleanliness testing, I have seen my share of environmental regulations. Long before the debate over lead-free alloys, there was the Montreal Protocol.
Technical Library | 2014-07-24 16:26:34.0
Wire bonding a die to a package has traditionally been performed using either aluminum or gold wire. Gold wire provides the ability to use a ball and stitch process. This technique provides more control over loop height and bond placement. The drawback has been the increasing cost of the gold wire. Lower cost Al wire has been used for wedge-wedge bonds but these are not as versatile for complex package assembly. The use of copper wire for ball-stitch bonding has been proposed and recently implemented in high volume to solve the cost issues with gold. As one would expect, bonding with copper is not as forgiving as with gold mainly due to oxide growth and hardness differences. This paper will examine the common failure mechanisms that one might experience when implementing this new technology.
Technical Library | 2018-01-17 22:47:02.0
Fine pitch copper (Cu) Pillar bump has been growing adoption in high performance and low-cost flip chip packages. Higher input/output (I/O) density and very fine pitch requirements are driving very small feature sizes such as small bump on a narrow pad or bond-on-lead (BOL) interconnection, while higher performance requirements are driving increased current densities, thus assembling such packages using a standard mass reflow (MR) process and maintaining its performance is a real and serious challenge. (...) In this study a comprehensive finding on the assembly challenges, package design, and reliability data will be published. Originally published in the SMTA International 2016
Technical Library | 1999-08-09 11:09:42.0
Organic Solderability Preservatives (OSPs), also known as anti-tarnish, on bare copper printed circuit boards (PCBs) are becoming more prevalent in the electronics industry as the low-cost replacement to Hot Air Solder Leveling (HASL). Introducing the anti-tarnish alternative into the customer sites requires working closely with the coating supplier, assembler, and Original Equipment Manufacturer (OEM) to gain a mutual understanding of respective processing concerns and finished product requirements.
Technical Library | 2017-01-19 16:58:47.0
The biggest problem with designing rigid-flex hybrid PCBs is making sure everything will fold in the right way, while maintaining good flex-circuit stability and lifespan. The next big problem to solve is the conveyance of the design to a fabricator who will clearly understand the design intent and therefore produce exactly what the designer/engineer intended.Rigid-Flex circuit boards require additional cutting and lamination stages, and more exotic materials in manufacturing and therefore the cost of re-spins and failures are very much higher than traditional rigid boards. To reduce the risk and costs associated with rigid-flex design and prototyping, it is desirable to model the flexible parts of the circuit in 3D CAD to ensure correct form and fit. In addition it is necessary to provide absolutely clear documentation for manufacturing to the fabrication and assembly houses.
Technical Library | 2009-11-05 11:17:32.0
Head-in-pillow (HiP), also known as ball-and-socket, is a solder joint defect where the solder paste deposit wets the pad, but does not fully wet the ball. This results in a solder joint with enough of a connection to have electrical integrity, but lacking sufficient mechanical strength. Due to the lack of solder joint strength, these components may fail with very little mechanical or thermal stress. This potentially costly defect is not usually detected in functional testing, and only shows up as a failure in the field after the assembly has been exposed to some physical or thermal stress.
Technical Library | 2020-11-24 23:01:04.0
The miniaturization trend is driving industry to adopting low standoff components or components in cavity. The cost reduction pressure is pushing telecommunication industry to combine assembly of components and electromagnetic shield in one single reflow process. As a result, the flux outgassing/drying is getting very difficult for devices due to poor venting channel. This resulted in insufficiently dried/burnt-off flux residue. For a properly formulated flux, the remaining flux activity posed no issue in a dried flux residue for no-clean process. However, when venting channel is blocked, not only solvents remain, but also activators could not be burnt off. The presence of solvents allows mobility of active ingredients and the associated corrosion, thus poses a major threat to the reliability. In this work, a new halogen-free no-clean SnAgCu solder paste, 33-76-1, has been developed. This solder paste exhibited SIR value above the IPC spec 100 MΩ without any dendrite formation, even with a wet flux residue on the comb pattern. The wet flux residue was caused by covering the comb pattern with 10 mm × 10 mm glass slide during reflow and SIR testing in order to mimic the poorly vented low standoff components. The paste 33-76-1 also showed very good SMT assembly performance, including voiding of QFN and HIP resistance. The wetting ability of paste 33-76-1 was very good under nitrogen. For air reflow, 33-76-1 still matched paste C which is widely accepted by industry for air reflow process. The above good performance on both non-corrosivity with wet flux residue and robust SMT process can only be accomplished through a breakthrough in flux technology.
Technical Library | 2015-06-11 21:20:29.0
The use of bottom terminated components (BTC) has become widespread, specifically the use of Quad Flat No-lead (QFN) packages. The small outline and low height of this package type, improved electrical and thermal performance relative to older packaging technology, and low cost make the QFN/BTC attractive for many applications.Over the past 15 years, the implementation of the QFN/BTC package has garnered a great amount of attention due to the assembly and inspection process challenges associated with the package. The difference in solder application parameters between the center pad and the perimeter pads complicates stencil design, and must be given special attention to balance the dissimilar requirements
Technical Library | 2018-05-23 12:12:43.0
Driven by miniaturization, cost reduction and tighter requirements for electrical and thermal performance, the use of lead-frame based bottom-termination components (LF-BTC) as small-outline no-leads (SON), quad-flat no leads (QFN) packages etc., is increasing. However, a major distractor for the use of such packages in high-reliability applications has been the lack of a visible solder (toe) fillet on the edge surface of the pins: because the post-package assembly singulation process typically leaves bare copper leadframe at the singulation edge, which is not protected against oxidation and thus does not easily solder-wet, a solder fillet (toe fillet) does not generally develop.
Technical Library | 2023-09-18 14:10:01.0
As with many advancements in the electronics industry, consumer electronics is driving the trends for electronic packaging technologies toward reducing size and increasing functionality. Microelectronics meeting the technology needs for higher performance, reduced power consumption and size, and off the- shelf availability. Due to the breadth of work being performed in the area of microelectronics packaging/components, this report limits it presentation to board design, manufacturing, and processing parameters on assembly reliability for leadless (e.g., quad flat no-lead (QFN) or a generic term of bottom termination component (BTC)) packages. This style of package was selected for investigation because of its significant growth, lower cost, and improved functionality, especially for use in an RF application.
Golden State is a contract manufacturer that makes wire harnesses, electromechanical assemblies (box builds, subassemblies, PCBAs, kits, etc.) and services (sorting, rework, value additive manufacturing engineering)
18220 Butterfield Blvd
Morgan Hill, CA USA
Phone: 5102268155
winsouce.jpg)
.gif)
