Technical Library | 2016-01-07 19:13:23.0
The purpose of this study is to investigate the effect of plasma surface modification to improve adhesion strength between polytetrafluoroethylene (PTFE) and electroless copper plating. PTFE is widely used in many industries because of its unique electrical, thermal, and mechanical characteristics. However, because of its low surface energy, it is difficult to acquire enough adhesion strength between PTFE and other substances without surface modification. Plasma is well known as one of the surface modification techniques that improve adhesion strength.
Technical Library | 2023-01-06 16:09:03.0
The 4-14 IPC Standards Committee recently created a revision to the IPC4552 specification for Electroless Nickel/Immersion Gold (ENIG) finished Printed Circuit Boards (PCB). Revision A brings a more comprehensive evaluation of metal layer thicknesses measurement, composition and introduces, for the first time, a quality aspect for nickel corrosion which has been historically connected to a defect called black line nickel or black pad.
Technical Library | 2012-12-13 21:20:05.0
First published in the 2012 IPC APEX EXPO technical conference proceedings. We investigated the micro-void formation of solder joints after reliability tests such as preconditioning (precon) and thermal cycle (TC) by varying the thickness of Palladium (Pd) in Electroless Nickel / Electroless Palladium / Immersion Gold (ENEPIG) surface finish. We used lead-free solder of Sn-1.2Ag-0.5Cu-Ni (LF35). We found multiple micro-voids of less than 10 µm line up within or above the intermetallic compound (IMC) layer. The number of micro-voids increased with the palladium (Pd) layer thickness. Our results revealed that the micro-void formation should be related to (Pd, Ni)Sn4 phase resulted from thick Pd layer. We propose that micro-voids may form due to either entrapping of volatile gas by (Pd, Ni)Sn4 or creeping of (Pd, Ni)Sn4.
Technical Library | 2013-01-17 15:37:21.0
A problem exists with electroless nickel / immersion gold (ENIG) surface finish on some pads, on some boards, that causes the solder joint to separate from the nickel surface, causing an open. The solder has wet and dissolved the gold. A weak tin to nickel intermetallic bond initially occurs, but the intermetallic bond cracks and separates when put under stress. Since the electroless nickel / immersion gold finish performs satisfactory in most applications, there had to be some area within the current chemistry process window that was satisfactory. The problem has been described as a 'BGA Black Pad Problem' or by HP as an 'Interfacial Fracture of BGA Packages…'[1]. A 24 variable experiment using three different chemistries was conducted during the ITRI (Interconnect Technology Research Institute) ENIG Project, Round 1, to investigate what process parameters of the chemical matrix were potentially satisfactory to use and which process parameters of the chemical matrix need to be avoided. The ITRI ENIG Project has completed Round 1 of testing and is now in the process of Round 2 TV (Test Vehicle) build.
Industry News | 2016-05-16 20:13:12.0
NEO Tech announces that it will showcase its high-reliability substrate and microelectronic assembly capabilities in booth 2143 at the 2016 IEEE International Microwave Symposium IMS 2016, which is schedule to take place from May 24-26 at the Moscone Center in San Francisco.
Industry News | 2017-07-19 21:09:38.0
STI Electronics is pleased to announce the acquisition of a new Fischerscope X-ray XDAL 237 energy dispersive X-ray fluorescence (EDXRF) system.
Industry News | 2019-11-05 22:19:03.0
> News-Blog > Guideline for wire bonding Guideline for wire bonding Tuesday,Jun 12,2018 There are two wire bonding processes that are used, Thermosonic (T/S) Gold Ball Wire Bonding and Ultrasonic (U/S) Aluminum Wedge Wire Bonding. Approximately 90% of all IC Assembly in Semiconductor Packages is manufactured using Gold Ball Bonding process, while Aluminum Wedge Bonding is used to produce about 10% of other Wire Bonding requirements on Printed Circuit Boards (PCB), Printed Circuit Flex (PCF) and other Packages.
Technical Library | 2014-08-07 15:13:44.0
Gold embrittlement in SnPb solder is a well-known failure mechanism in electronic assembly. To avoid this issue, prior studies have indicated a maximum gold content of three weight percent. This study attempts to provide similar guidance for Pb-free (SAC305) solder. Standard surface mount devices were assembled with SnPb and SAC305 solder onto printed boards with various thicknesses of gold plating. The gold plating included electroless nickel immersion gold (ENIG) and electrolytic gold of 15, 25, 35, and 50 microinches over nickel. These gold thicknesses resulted in weight percentages between 0.4 to 7.0 weight percent.
Technical Library | 2016-05-12 16:29:40.0
Advances in miniaturized electronic devices have led to the evolution of microvias in high density interconnect (HDI) circuit boards from single-level to stacked structures that intersect multiple HDI layers. Stacked microvias are usually filled with electroplated copper. Challenges for fabricating reliable microvias include creating strong interface between the base of the microvia and the target pad, and generating no voids in the electrodeposited copper structures. Interface delamination is the most common microvia failure due to inferior quality of electroless copper, while microvia fatigue life can be reduced by over 90% as a result of large voids, according to the authors’ finite element analysis and fatigue life prediction. This paper addresses the influence of voids on reliability of microvias, as well as the interface delamination issue.
Technical Library | 2021-07-06 21:20:38.0
The evolution of internet-enabled mobile devices has driven innovation in the manufacturing and design of technology capable of high-frequency electronic signal transfer. Among the primary factors affecting the integrity of high-frequency signals is the surface finish applied on PCB copper pads – a need commonly met through the electroless nickel immersion gold process, ENIG. However, there are well-documented limitations of ENIG due to the presence of nickel, the properties of which result in an overall reduced performance in high-frequency data transfer rate for ENIG-applied electronics, compared to bare copper.
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