Technical Library | 2008-10-15 20:16:12.0
Solder paste dispensing is usually considered a slow process. Due to the speed advantages, screen printing is used to apply solder paste whenever possible. However, screen printing is not always an option. Leveraging the high speed of piezo drive technology opens the door to a broad range of solder paste dispensing applications. The ability to dispense dots under 300-μm diameter, even as small as 125 μm, enables BGA rework, small geometry deposits for miniaturized passive components, electrical connections in recessed cavities, and RF shield attach for handheld devices.
Technical Library | 2012-12-17 22:05:22.0
Package on Package (PoP) has become a relatively common component being used in mobile electronics as it allows for saving space in the board layout due to the 3D package layout. To insure device reliability through drop tests and thermal cycling as well as for protecting proprietary programming of the device either one or both interconnect layers are typically underfilled. When underfill is applied to a PoP, or any component for that matter, there is a requirement that the board layout is such that there is room for an underfill reservoir so that the underfill material does not come in contact with surrounding components. The preferred method to dispensing the underfill material is through a jetting process that minimizes the wet out area of the fluid reservoir compared to traditional needle dispensing. To further minimize the wet out area multiple passes are used so that the material required to underfill the component is not dispensed at once requiring a greater wet out area. Dispensing the underfill material in multiple passes is an effective way to reduce the wet out area and decrease the distance that surrounding components can be placed, however, this comes with a process compromise of additional processing time in the underfill dispenser. The purpose of this paper is to provide insight to the inverse relationship that exists between the wet out area of the underfill reservoir and the production time for the underfill process.
Technical Library | 1999-08-27 09:24:56.0
Dispensing conductive adhesives in an automated factory environment creates some special challenges. A robust production process starts with understanding the adhesives in their fluid state and which important parameters must be controlled. Developing this understanding requires experience with a large number of materials and valves over time. Common uses of conductive adhesives in surface mount applications, die attach applications, and gasketing are addressed. As vendors of dispensing equipment, the authors see a constant stream of such applications. Dispensing requirements, techniques, and equipment resulting from this experience are discussed. Guidelines for optimizing quality and speed are given.
Technical Library | 2019-01-02 21:51:49.0
Failed solder joints remain a constant source of printed circuit board failure. Soldering is the bonding of metallic surfaces via an intermetallic compound (IMC). The interaction between thermal energy delivery, flux chemistry, and solder chemistry creates the solder bond or joint. Today, reliability relies on visual inspection; operator experience and skill, control of influencers e.g. tip geometry, tip temperature, and collection and analysis of process data. Each factor involved with the formation of the solder joint is an element of risk and can affect either throughput or repeatability. Mitigating this risk in hand soldering requires the identification of these factors and a means to address them.
Technical Library | 2018-02-22 10:56:36.0
As companies start to implement lead free soldering processes, hand soldering and associated techniques have been identified as key functions in the manufacturing process requiring additional research and development. Hand soldering tends to occur at the end of the process line where the circuit board has a high intrinsic value and so correct process control will have a significant affect on manufacturing costs and productivity.This paper discusses the fundamental aspects of the hand soldering process and discusses process adaptation requirements for successful lead free implementation.
Technical Library | 2015-04-23 18:48:18.0
Smart phones are complex, costly devices and therefore need to be reworked correctly the first time. In order to meet the ever-growing demand for performance, the complexity of mobile devices has increased immensely, with more than a 70% greater number of packages now found inside of them than just a few years ago. For instance, 1080P HD camera and video capabilities are now available on most high end smart phones or tablet computers, making their production more elaborate and expensive. The printed circuit boards for these devices are no longer considered disposable goods, and their bill of materials start from $150.00, with higher end smart phones going up to $238.00, and tablets well over $300.00.
Technical Library | 1999-05-09 12:51:38.0
This Technical Note outlines, step by step, the easiest ways to remove and replace surface mounted devices, using the lowest possible temperatures. This document discusses the following topics: Removal and replacement of discrete and passive components (capacitors, resistors, SOTs), Removal of two-sided components (SOICs, SOJs, TSOPs), Removal of quad components (PLCCs, QFPs), Replacement of quad components including fine-pitched devices.
Technical Library | 2020-03-01 23:06:45.0
For though hole soldering, no matter it's wave soldering or selective soldering, the process is same formed by fluxing,preheating,soldering. How these 3 process will change the soldering result? When you face the soldering defects, what could be the reasons caused these and how to debug them? With below information you may get some hints.
Technical Library | 2020-04-01 14:24:56.0
It happens much too often; manufacturing engineers are brought into a NEW product design phase at the very end of a design and are asked to provide input that should have been provided much earlier. One needs to understand how the circuit board design and quality of the manufacturing process not only effects assembly yield and product reliability, but how it could also affect the results of any testing that is done to circuit packs during prototyping. It is important that any circuit pack (including prototypes) that will be used in reliability, performance and functional testing be designed with the proper features and assembled with a manufacturing process that has been developed to produce a high-quality assembly. If not, the results of any testing might not represent the actual characteristics of the design and provide miss-guidance to future changes.
Technical Library | 2010-03-23 11:50:22.0
This document discuss how to design SMT stencil base on IPC-7525. Introduction: PCBA (Printed Circuit Board Assembly) is a segment of printed circuit board technology. This segment of printed circuit board industry is concentrated in assemble all the pieces of electronic industry to one piece before output them to market. This segment covers: interconnection technology, package design technology, system integration technology, board and system test technology