Technical Library | 2016-05-05 15:19:39.0
For many years, manufacturing has sought to increase competitiveness by moving off-shore to countries with lower labour costs. Electronic manufacturing services (EMS) companies provided an essential element to make off-shore transfer happen more quickly, offering further cost reduction opportunities from load balancing. Fierce arguments were put forward to protect the loss of local jobs, although the result was, in almost all cases, inevitable. Today, however, the whole market of PCBbased electronics products has changed significantly. The "pros" of off-shoring are no longer what they once were, and the "cons" are becoming more significant because off-shore manufacturing can no longer satisfy the needs of the market. In this paper, we expose the real costs of off-shore manufacturing, and put labour cost differentials into perspective. We demonstrate how practically, using existing technologies, re-shored manufacturing can yield better business return, either for an OEM, or through EMS providers.
Technical Library | 2015-12-31 15:19:28.0
Today's consumer electronic product are characterized by miniatuization, portability and light weight with high performance, especially for 3G mobile products. In the future more fine pitch CSPs (0.4mm) component will be required. However, the product reliability has been a big challenge with the fine pitch CSP. Firstly, the fine pitch CSPs are with smaller solder balls of 0.25mm diameter or even smaller. The small solder ball and pad size do weaken the solder connection and the adhesion of the pad and substrate, thus the pad will peel off easily from the PCB substrate. In addition, miniature solder joint reduce the strength during mechanical vibration, thermal shock, fatigue failure, etc. Secondly, applying sufficient solder paste evenly on the small pad of the CSP is difficult because stencil opening is only 0.25mm or less. This issue can be solved using the high end type of stencil such as Electroforming which will increase the cost.
Technical Library | 2017-02-28 12:39:50.0
During the last 5 years mobile phones and other portable consumer electronics have been extremely popular and spread all over the world in different climate zones in very high volumes. At the same time the mobile phone terminal for many people has become a necessity that is brought with them in any activity they practice. These changes in user behavior have heavily changed the impact on handheld terminals from moisture, sweat, corrosive atmospheres and mechanical drop. As a result of this the requirement to solder joint reliability, corrosion stability and wear resistance are heavily increasing to keep a high reliability of the terminal.Immersion Ni/Au has been the overall dominant surface finish on Printed Wiring Boards (PWB's) for the last 10 years, but a paradigm shift to avoid use of this thin and porous surface finish is ongoing nowadays because it can’t address these challenges in a satisfactory way.In today's handheld terminals, Organic Solder Preservative (OSP) has replaced Immersion Ni/Au on solder pads. Carbon surface finish for Key- and spring contact-pads, combined with the right concept design can make use of Immersion Ni/Au unnecessary in the near future. The result will be higher reliability with less expensive and simpler processes.This paper will discuss the various considerations for choice of surface finish and results from the feasibility studies performed.
Technical Library | 2018-04-05 10:40:43.0
The miniaturization of microchips is always driving force for revolution and innovation in the electronic industry. When the pitch of bumps is getting smaller and smaller the ball size has to be gradually reduced. However, the reliability of smaller ball size is getting weaker and weaker, so some traditional methods such as capillary underfilling, corner bonding and edge bonding process have been being implemented in board level assembly process to enhance drop and thermal cycling performance. These traditional processes have been increasingly considered to be bottleneck for further miniaturization because the completion of these processes demands more space. So the interest of eliminating these processes has been increased. To meet this demand, YINCAE has developed solder joint encapsulant adhesives for ball bumping applications to enhance solder joint strength resulting in improving drop and thermal cycling performance to eliminate underfilling, edge bonding or corner bonding process in the board level assembly process. In this paper we will discuss the ball bumping process, the reliability such as strength of solder joints, drop test performance and thermal cycling performance.
Technical Library | 2018-05-17 11:14:52.0
Intermetallic compound (IMC) growth is being studied in earnest in this past decade because of its significant effect the solder joint reliability. It appears that from numerous investigations conducted, excessive growth of IMC could lead to solder joint failure. Leading to this, many attempts has been made to determine the actual IMC thickness. However, precise and true representation of the growth in the actual 3D phenomenon from 2D cross-section investigations has remained unclear. This paper will focus on the measuring the IMC thickness using 3D surface profilometer (Alicona Focus G4). Lead free solder, Sn3.0Ag0.5Cu (SAC305) was soldered onto copper printed circuit board (Cu PCB). The samples were then subjected to thermal cycle (TC) storage process with temperature range from 0 °C to 100 °C for 200 cycles and up to 1000 cycles were completed.
Technical Library | 2018-09-26 20:33:26.0
Bottom terminated components, or BTCs, have been rapidly incorporated into PCB designs because of their low cost, small footprint and overall reliability. The combination of leadless terminations with underside ground/thermal pads have presented a multitude of challenges to PCB assemblers, including tilting, poor solder fillet formation, difficult inspection and – most notably – center pad voiding. Voids in large SMT solder joints can be difficult to predict and control due to the variety of input variables that can influence their formation. Solder paste chemistries, PCB final finishes, and reflow profiles and atmospheres have all been scrutinized, and their effects well documented. Additionally, many of the published center pad voiding studies have focused on optimizing center pad footprint and stencil aperture designs. This study focuses on I/O pad stencil modifications rather than center pad modifications. It shows a no-cost, easily implemented I/O design guideline that can be deployed to consistently and repeatedly reduce void formation on BTC-style packages.
Technical Library | 2020-01-15 23:54:34.0
Flexible electronics has significantly advanced over the last few years, as devices and circuits from nanoscale structures to printed thin films have started to appear. Simultaneously, the demand for high-performance electronics has also increased because flexible and compact integrated circuits are needed to obtain fully flexible electronic systems. It is challenging to obtain flexible and compact integrated circuits as the silicon based CMOS electronics, which is currently the industry standard for high-performance, is planar and the brittle nature of silicon makes bendability difficult. For this reason, the ultra-thin chips from silicon is gaining interest. This review provides an in-depth analysis of various approaches for obtaining ultra-thin chips from rigid silicon wafer. The comprehensive study presented here includes analysis of ultra-thin chips properties such as the electrical, thermal, optical and mechanical properties, stress modelling, and packaging techniques. The underpinning advances in areas such as sensing, computing, data storage, and energy have been discussed along with several emerging applications (e.g., wearable systems, m-Health, smart cities and Internet of Things etc.) they will enable. This paper is targeted to the readers working in the field of integrated circuits on thin and bendable silicon; but it can be of broad interest to everyone working in the field of flexible electronics.
Technical Library | 2020-07-22 19:39:05.0
The PWB industry needs to complete reliability testing in order to define the minimum copper wrap plating thickness requirement for confirming the reliability of PTH structures. Predicting reliability must ensure that the failure mechanism is demonstrated as a wear-out failure mode because a plating wrap failure is unpredictable. The purpose of this study was to quantify the effects of various copper wrap plating thicknesses through IST testing followed by micro sectioning to determine the failure mechanism and identify the minimum copper wrap thickness required for a reliable PWB. Minimum copper wrap plating thickness has become an even a bigger concern since designers started designing HDI products with buried vias, microvias and through filled vias all in one design. PWBs go through multiple plating cycles requiring planarization after each plating cycle to keep the surface copper to a manageable thickness for etching. The companies started a project to study the relationship between Copper wrap plating thickness and via reliability. The project had two phases. This paper will present findings from both Phase 1 and Phase 2.
Technical Library | 2019-07-02 23:02:05.0
The introduction of lead-free solders resulted in a selection of different chemistries for solder pastes. The higher melting points of lead-free alloys required thermal heat resistant rosin systems and activators that are active at elevated temperatures. As a result, more frequent maintenance of the filtration systems is required and machine downtime is increased.Last year a different method of cleaning reflow ovens was introduced. Instead of cooling down the process gasses to condensate the residues, a catalyst was used to maintain the clean oven. Catalytic thermal oxidation of residues in the nitrogen atmosphere resulted in cleaner heating zones. The residues were transformed into carbon dioxide. This remaining small amount of char was collected in the catalyst. In air ovens the catalyst was not seen as a beneficial option because the air extracted out of the oven was immediately exhausted into the environment. When a catalyst is used in an air environment there is not only the carbon dioxide residues, but also water. When a catalyst is used in an air reflow oven the question is where the water is going to. Will it condensate in the process part of the oven or is the gas temperature high enough to keep it out of the process area? A major benefit of using a catalyst to clean the air before it is exhausted into the environment is that the air pollution is reduced dramatically. This will make environmental engineers happy and result in less pollution of our nature. Apart from this, the exhaust tubes remain clean which reduces the maintenance of air ovens.This paper will give more detailed information of catalyst systems during development and performance in production lines.
Technical Library | 2019-11-20 22:44:25.0
Salt spray test chamber is used to test teh salt corrosion resistance ability of hardware, metal and other auto parts,the chamber can quickly detect the corrosion resistance degree of products in the temperature, humidity and salt spraying environment, which can effectively improve production efficiency. So what is the reason why such a salt spray test chamber does not spray? As per our past maintenance experience,there are below reasons,customers can have a look,hope it is helpful: 1, the spray tower is blocked; 2, water pipes clogged, water flow can not go in; 3, the air compressor stops running,pls open the air compressor button; 4, main switch of the air compressor outlet is not turned on,pls turn on. 5, the solenoid valve fails, the pressure meter is broken or the pressure is too low, pls check with Climatest and repair it. 6, when the nozzle is clogged, the nozzle should be carefully removed and cleaned,because it is fragile. 7, if the spray pressure is normal, the position of the nozzle glass is also correct, but what is the reason for not spraying? In this case, it is necessary to carefully observe whether there is dirt at the contact surface of the nozzle. If so, clean up the dirt and the spray can be carried out normally. That‘s all we‘re going to talk about today. If you have any questions, follow us on facebook, Please feel free to ask us questions.
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