When using pre-tinned devices and HASL (Hot Air Solder Leveling) or OSP (Organic Solderability Preservative) on PC Boards, using a very active rosin core solder is not necessary. Using a high activity level flux works well on heavily oxidized metals such as bare copper or other non-tinned or non-plated metals, but is not readily suggested for standard electronic assemblies. Use a flux that is designed for the metals that are being joined and keep the activity level to a minimum to help extend tip life.
Missed Weller’s first four tips?
Weller Soldering Tip 1
Weller Soldering Tip 2
Weller Soldering Tip 3
Weller Soldering Tip 4
If you are reading this, you probably have an idea of what ESD is. But do you know the common sources for ESD? There are three: human body ESD, machine ESD and charge device ESD.
I would imagine that human body ESD is thought of the most when the term ESD is mentioned, and rightfully so because humans probably cause the most ESD damage. Human body ESD is when a human transfers the electrostatic discharge to a part that is static sensitive. Some of the most damaging human errors include ungrounded employees walking around with static sensitive items such as PCBs, employees not wearing appropriate gloves or finger cots and employees walking around with ESD sensitive parts in open bags, bins, totes, etc… Human body ESD can be avoided with the use of a heel/sole ground or wrist strap; both are relatively inexpensive.
Machine ESD is the second cause of ESD damage. This source of damage is caused when an ungrounded part (conductive or dissipative) such as a machine or tool comes in contact with an ESD sensitive part. The solution to this problem is to simply ground the machine part, tools, etc…
The final source is charged device ESD. This type of ESD takes place when a part or device develops a charge and then comes in contact with a conductive item. Once the two parts touch there is a fast discharge which ultimately damages the ESD sensitive part. Ionizers are useful in this situation as they neutralize new charges and prevent build up of charges. Reducing movement of a part within the facility and having one common ground also helps combat charged device ESD.
Other things to keep in mind when protecting your ESD sensitive parts:
- Make sure your ESD bags and containers are not too old. Many materials lose their ESD protection over time.
- Have an ionizer? Make sure both emitters are working and make sure there is an equal balance of positive and negative ions.
- Store ESD sensitive parts in the appropriate containers. I know it seems like common sense but it’s important.
Fluxes containing a “high solids content” are one of the largest contributors to surface contamination, which leads to the blackening or charring of fluxes on a soldering iron tip. This in turn, can cause a tip to be rendered useless in a matter of hours, if not minutes. If proper research is done, solder manufacturer’s technical data sheets or MSDS sheets will indicate the % of solids. Extremely high temperatures will also accelerate the surface contamination process.
Soldering tip 1
Soldering tip 2
Soldering tip 3
RoHS (Restriction of Hazardous Substances) has been around for almost two years now. If you are not aware, RoHS is the ban on six substances (lead, mercury, cadmium, hexavalent chromium, polybrominated biphenyls and polybrominated diphenyl ether) in electronics equipment in the European Union.
According to an article on Purchasing.com, RoHS has cost the electronics industry over $32 billion, and that’s just getting started. It’s estimated to cost around $3 billion just to maintain compliance with RoHS.
Here are some things to keep in mind with RoHS:
- The cost of RoHS will continue to increase. With the possibility of adding more substances and getting rid of exemptions, compliance will just become more costly.
- About 29% of companies say they lost sales because of RoHS.
- On the more positive side of things, RoHS helped many companies reorganize by improving their supply chain process and reevaluating their product lines; some companies have even reported increased market share.
- Many electronics companies are reporting more inventory than usual. This is probably because many companies had to carry both RoHS compliant and non-RoHS compliant goods and now they are stuck with the non-RoHS compliant items.
The article on the cost of RoHS is pretty interesting, regardless of your involvement with RoHS.
Many solder manufacturers recommend that the wire cored solder should not be applied directly to the soldering tip. This is mainly in part due to the aggressive nature of the flux formulations used in the core. However, the tip has to constantly be “tinned.” Therefore the solder must be applied to the tips working surface to protect it from surface oxidation and contamination. Check with the solder manufacturer for a material that is compatible with hand soldering.
Soldering tip 1
Soldering tip 2