Technical Library | 2013-08-08 15:23:11.0
In this project Machine Vision PCB Inspection System is applied at the first step of manufacturing, i.e., the making of bare PCB. We first compare a PCB standard image with a PCB image, using a simple subtraction algorithm that can highlight the main problem-regions. We have also seen the effect of noise in a PCB image that at what level this method is suitable to detect the faulty image. Our focus is to detect defects on printed circuit boards & to see the effect of noise. Typical defects that can be detected are over etchings (opens), under-etchings (shorts), holes etc...
Technical Library | 2015-12-23 16:57:27.0
The onset of copper barrel cracks is typically induced by the presence of manufacturing defects. In the absence of discernible manufacturing defects, the causes of copper barrel cracks in printed circuit board (PCB) plated through holes is not well understood. Accordingly, there is a need to determine what affects the onset of barrel cracks and then control those causes to mitigate their initiation.The objective of this research is to conduct a design of experiment (DOE) to determine if there is a relationship between PCB fabrication processes and the prevalence of fine barrel cracks. The test vehicle used will be a 16-layer epoxy-based PCB that has two different sized plated through holes as well as buried vias.
Technical Library | 2016-11-17 14:58:02.0
Since 2006 RoHS requirements have required lead free solders to take the place of tin-lead solders in electronics. The problem is that in some environments the lead free solders are less reliable than the older tin-lead solders. One of the ways to solve this problem is to corner stake, edge bond or underfill the components. When considering what mitigation technique and material to use, the operating conditions must be characterized. The temperature range is important when selecting a material to use since the glass transition temperature (Tg) and coefficient of thermal expansion (CTE) are important properties. If improperly chosen, the mitigation material can cause more failures than an unmitigated component.
Technical Library | 2016-09-08 16:27:49.0
In this investigation a test matrix was completed utilizing 900 electrodes (small circuit board with parallel copper traces on FR-4 with LPI soldermask at 6, 10 and 50 mil spacing): 12 ionic contaminants were applied in five concentrations to three different spaced electrodes with five replicas each (three different bare copper trace spacing / five replications of each with five levels of ionic concentration). The investigation was to assess the electrical response under controlled heat and humidity conditions of the known applied contamination to electrodes, using the IPC SIR (surface insulation resistance) J-STD 001 limits and determine at what level of contamination and spacing the ionic / organic residue has a failing effect on SIR.
Technical Library | 2015-12-01 20:36:48.0
On January 1, 2015, nine months from APEX 2014, the production and use restrictions on HCFC-225 will be in effect throughout the United States. This phase out is encompassing in scope. This phase out will have significant technical, performance, and economic implications for the electronics industry. The regulatory situation remains fluid. A number of alternative solvents have been or are in the process of being developed. We discuss the options for assemblers and component manufacturers.
Technical Library | 2019-04-15 22:18:13.0
The choice of supplier, first of all, is to choose the products offered by suppliers in the market. Since materials that meet certain product functional requirements are not unique, there are many alternatives. There are many factors to consider when purchasing, such as product quality, supply capacity, price, delivery time, reputation, supplier strength, after-sales service and other factors, but specific to the procurement of shipping tubes, we feel the following four points need special attention:
Technical Library | 2019-08-19 23:55:20.0
Electronic dry cabinet for MSD storage Humidity is one of the key reasons for rejected products, many manufacturers are taking measures to control the humidity to increase production efficiency and save cost. In semiconductor and electronic industry, the key section of rejected products mostly happen during SMT heating process, Climatest Symor® auto dry cabinet is a superior solution to avoid the cracking. Warranty: two years with lifetime technical support
Technical Library | 2008-03-18 12:36:31.0
This paper examines the construction of a notebook mainboard with more than 2000 components and no wave soldering required. The board contains standard SMD, chipset BGAs, connectors, through hole components and odd forms placed using full automation and soldered after two reflow cycles under critical process parameters. However, state of the art technology does not help if the process parameters are not set carefully. Can all complex BGAs, THTs and even screws be soldered on a single stencil? What will help us overcome bridging, insufficient solder and thombstoning issues? This paper will demonstrate the placement of all odd shape components using pin-in-paste stencil design and full completion of the motherboard after two reflow cycles.
Technical Library | 2013-08-13 09:49:53.0
One of the common issues I’ve noticed when visiting shops that use crimp force monitors (CFMs) is that the CFMs are usually turned off, regardless of the brand, because engineers and operators are not using them properly. Why, with all of their benefits, are CFMs not being used regularly by employees? One of the biggest problems is the lack of understanding of the variables affecting the CFM’s ability to detect variations. Crimp quality detection is similar to baking a cake. There are a lot of ingredients and if one ingredient is missing or of bad quality, you likely are not going to achieve your desired result. This article will go back through the basics of a crimp quality detection system and discuss what ingredients or variables you need to consider before switching off that CFM.
Technical Library | 2014-09-25 18:16:47.0
For the past few years there has been a shift in the Lighting Industry that has carried over to the surface mount technology assembly line. What is this shift you may ask? Well it is the LED revolution. This revolution or change in lighting has some very promising results already in practice and many more companies looking to implement the LED technology into their product portfolio's. With a number of companies looking to expand their portfolio to include LED fixtures there has been an increase in the number of companies that have started their own SMT lines, as well as a significant number of contract manufacturers to meet this new industries demands (...)This presentation will discuss some issues in the pick and place process for LEDs and presents a method to troubleshoot and resolve these issues.
