HAKKO Tech Tips Soldering Tips: How Certain Decisions Impact On Your Solder Tip Life And Performance

 For the majority, tip selection is largely a personal preference, however, there is always room for development and that is where Hakko’s range of soldering tips can really transform a soldering process, helping you get through your workflow faster and more efficiently whilst remaining cost effective. There are several factors to take into consideration when selecting the most appropriate tip for your application and equipment. For instance, the type of soldering to be done, the Hakko soldering station and tip series that you are using, as well as the tip shape and diameter size. When you first start using your soldering station, you will probably only use the soldering tip that comes with your iron, which will be perfectly suitable for general purpose use. However, Hakko has designed a range of soldering tips that make quick and easy work of different soldering applications, which not only improve the soldering environment but also reduce costs. In this month’s edition of Hakko Tech Tips, we will be exploring some of the most frequently asked questions fielded by our Technical Support Team regarding soldering tips. We will also take a closer look at some effective troubleshooting tips to help you maximise your soldering process. 

What is the best way to make solder tips last longer?

 The best advice we can provide is to regularly maintain the cleanliness of your soldering tip. This will really help with having to replace your tips so frequently.  If the oxidisation on the tip is not too severe, simple maintenance can be carried out by using Hakko’s 599B wire Tip Cleaner. The 599B is made up of brass wire so you can easily work the tip to remove most of the oxides. The brass wire can also be easily replaced once they have been well-used. For re-tinning soldering tips and removing oxidisation, the Hakko FS-100 chemical paste is an essential workstation companion. Heat the oxidised tip to 350°C, then tin the soldering tip with the FS100, clean off the paste with any Hakko tip cleaning sponge or the Hakko 599B cleaning wire. Check if the tip surface wets or not. If not, then this process may need to be repeated numerous times until the tip surface wets. When re-tinning is complete, to prevent further oxidisation, it is always advisable to apply sufficient new solder to the tip when soldering work is completed. 

What are the benefits of using the Hakko Cleaning Wire rather than the traditional damp sponge for tip cleaning? 

Traditionally, for Tin/Lead soldering the cleaning a solder tip with a damp sponge is perfectly adequate. However, in the advent of Lead-Free Solders, the water in the sponge increases the rate of oxidation of the soldering tips, which is already high due to the absence of the Lead content in the alloy. The Cleaning Wire is much more abrasive and contributes to removing the oxide layer before it becomes a hindrance to the soldering process.

What is the purpose of calibrating the solder tip temperature? 

All soldering equipment is subject to variation in set-point temperature. This will be due to inherent equipment design and thermocouple tolerances. Oxidation build up and even operator error are also likely to be contributory factors. To ensure that the temperature of the solder tip is as shown on the display, use of a separate Digital Thermometer, such as the Hakko FG100B, is required. This will provide an accurate comparison so that a temperature offset can be programmed into the solder station to ensure that the display temperature is actually the true temperature of the tip. The aforementioned is especially important in high reliability applications such as MoD, Aerospace and Medical assemblies.

What tip size transfers heat the most efficiently? 

Smaller tips are more versatile and easier to use for numerous different applications, however, they will tend to cool down when presented to a large contact area. The larger sized tips have a higher thermal capacity and will maintain their temperature better when working on large contact areas, however, they will be too big for many applications. Not selecting a correctly sized tip is a common mistake that is easy to make. Choosing a tip that’s too small will result in insufficient heat being transferred whilst choosing an oversized tip could result in damage to the PCB and/or component. As a rule of thumb, selecting a tip with the largest thermal mass at the appropriate size will, importantly, eliminate temperature reduction of the tip during soldering and facilitate operation at a lower temperature set point. Potentially, this could also reduce the time taken to produce a good quality solder joint. For instance, a lower set point for a shorter period will result in significantly reduced tip oxidation and longer tip life. Therefore, select a tip of the correct size with the highest heat storage possible. 

 What are the real benefits of correct selection of the optimum tip?

Selecting the most accurate size of tip will significantly improve soldering performance and reduce costs. There are numerous benefits to getting the right-sized tip. Firstly, heat will be more efficiently transferred to the workpiece, which offers easy wetting by the solder. When wetting by the solder is easy, the set temperature can be set to the lowest possible, which in turn prevents tip oxidation and potential damage to your product. This will consequently prolong the service life of the tip and keep manufacturing costs down in the long-term. The size of the tip changes the contact area with the workpiece and the contact area determines how efficiently heat is transferred to the assembly. 

What is the best temperature for soldering? 

Quite simply, there is no “one size fits all” answer to this question!! The set temperature of a soldering iron is very much dependant on the solder alloy being used and thermal characteristics of the component and PCB being soldered, i.e. The higher the thermal demand the higher the set point may be. Care should be taken to still use the minimum heat possible whilst preventing prolonged contact, excessive heat and potential damage to the assembly. Most solder manufacturers would recommend a tip temperature of between 340°C and 420°C. Given full control, most operators will set pretty much any programmable soldering equipment to the maximum temperature possible. This is only for the benefit of speed and offers no advantage in terms of the integrity of the solder joint produced but will significantly reduce the life of the solder tip. The whole process of soldering is reliant on three main elements, i.e. The transfer of heat from the solder tip to the componentry to ensure that both parts are at the optimum temperature, which will then apply and activate the flux in the solder wire. This process allows the surfaces to be joined to be cleaned and prevents any further oxidation, enabling the solder alloy to melt and flow producing the solder joint.

We hope this month’s tech tips are helpful and interesting. We welcome feedback from our customers and potential new customers, so please do talk to one of our team if you have any questions. Look out for next month’s Hakko Tech Tips where we will be providing more advice on how to get the best performance from your Hakko equipment.

For further information about Hakko, please visit www.hakko.co.uk.