Technical Library | 2019-08-08 10:23:51.0
High mix production is the mainstay of many electronics assembly plants. Lot sizes and board complexities vary and the boards are often mixed technology, comprising a blend of both surface mount and through-hole technology. Modularizing a production line enables a clear distinction between one type of assembly process and another. This article assumes a modern factory where a job can be routed to the selective soldering machine module, the hand assembly bench, or a combination of both. The decision rules of routing a circuit board through hand assembly versus automated selective soldering are discussed. Hand assembly soldering operations require no explanation.
Technical Library | 2019-05-29 23:10:30.0
There are times when a PCB prototype needs to be built quickly to test out a design. In such cases where it is known early on that there will be multiple iterations or that a "one and done" assembly will be made that there will be some SMT assemblers who choose to hand print solder paste onto the board using a "frameless" stencil. In such cases where hand printing is used, the consistency of the printing technique has typically been in question. Furthermore, the effectiveness of both the nanocoatings as well as the higher end stainless steel materials, which have been heretofore studied in controlled printing environments, will be evaluated for their impact on the hand printing process.The purpose of the study was to determine the effectiveness of select nanocoating materials as well as certain high end stainless steel stencil materials as they relate to the manual SMT printing process. A variety of nanocoatings were applied to SMT metal stencils and solder paste volume measurements were taken to compare the effectiveness.
Technical Library | 2008-03-31 21:35:36.0
While the situation varies from country to country, nearly one year after the EU RoHS Directive came into force implementation of lead-free solder is progressing steadily. For lead-free soldering to be considered successful it is not sufficient just to have dealt with the challenges of mass production. It is also necessary to establish that the soldered joints produced are at least as reliable as those made with Sn-37Pb alloy. In this context "reliability" means the length of time in service that the initial functionality of the joint can be maintained. In this paper we will discuss some of the issues involved in solder joint reliability through a comparison of the properties of two alloys that are widely used for lead-free wave soldering, SAC305 (Sn-3.0Ag-0.5Cu) and the Sn, Cu, Ni, Ge alloy SN100C.
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 | 1999-05-09 13:07:16.0
This paper will give the reader a general understanding of EOS and ESD phenomena. It specifically addresses hand soldering's role in EOS and ESD and how to protect against and test for potential problems. It discusses how Metcal Systems address EOS and ESD concerns and how they differ from conventional soldering systems.
Technical Library | 2012-11-27 14:06:48.0
Quality managers and line supervisors are routinely tasked with the responsibility of ensuring that the hand soldering process is under control. The method most commonly used is to measure the idle tip temperature of the soldering station and to use this reading as a benchmark of system compliance. This method, although popular is now being seriously questioned by many industry professionals as being irrelevant in qualifying true system process control. This document aims to present a practical view of what factors are important for successful hand soldering and to suggest an alternative procedure for qualification that is simple, repeatable and directly related to the effectiveness of the soldering station.
Technical Library | 2013-01-05 22:21:01.0
More and more countries legislate to forbib lead usage in solder material. However, the lead-free solder wire has higher melting point and soldering temperature, increase soldering iron temperature may damage the PCB or components. How to solve this problem?
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 | 2007-11-15 15:54:44.0
At the contractor level once a product is required to be soldered with lead-free solders all the processes must be assessed as to insure the same quality a customer has been accustomed to with a Sn63Pb37 process is achieved. The reflow, wave soldering and hand assembly processes must all be optimized carefully to insure good joint formation as per the appropriate class of electronics with new solder alloys and often new fluxes.
Technical Library | 2008-01-24 21:42:39.0
Although many through-hole components are being replaced by their surface mount (SMT) counterparts, printed circuit boards (PCBs) are still being designed with both types of components. Often, there are interconnect hardware, displays, or other components that cannot withstand the exposure to the high temperature involved in the wave soldering process. They are generally soldered by hand. The challenge is to determine the optimal method manufacturers can use to solder these boards populated with mixed technology.
