Dereks Tech Tips – Issue 3

How To Select The Best Soldering Tip For Your Application

When you 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.

Tip selection can often be a personal preference, but as we all know, there is always room for improvement and that is where HAKKO’s range of tips can really make a difference to improving soldering efficiency, being cost-effective and helping you speed-up your workflow. There are a number of 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 size, are all questions to base your selection on. To help you select the most pertinent tip for your application, let’s look at how we can make this process as straightforward as possible.

Tip Size

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 solder is easy, the setting temperature can be set to the lowest possible temperature, 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 workpiece. So, what size will transfer heat the most efficiently?

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. 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. Not selecting a correctly sized tip is a common mistake that is easy to make, as 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 amount of heat storage 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 of time will result in significantly reduced tip oxidation and longer tip life. Therefore, select a tip with the highest heat storage capacity possible if the size is the same. Additionally, reduce the size gradually considering various conditions such as narrow pitch.

Tip Shape

Now, let’s study how to select a tip with the appropriate shape by using the T15 series as an example. HAKKO’s T15 soldering tips are available in 13 different shapes and in a large variety of sizes, all of which are compatible with HAKKO’s FX951, FX952, FM203, FM204 and FM206 soldering stations.

Shape BC/C

The BC/C tips have a shape like a cone or column, cut at a slant, which allows users to select the cut surface size depending on the workpiece. These are ideally suited for drag soldering and pre-tinning of lead wires. The BC Tips are effectively cone shaped and the type C has a shape like a column. Both types are cut at either a 45 or 60 degree angle. Regarding the heat capacity of these tips, the BC series (with its conical shape) will have a higher thermal mass. Therefore, although these 2 types may have the same tip diameter, e.g. Φ1mm, the BC has a higher thermal capacity.

Shape BCM

Surface tension of solder in the indent of the BCM tip enables bridging to be corrected effectively. When the tip is placed on the PCB, solder present in the indent attracts solder from the solder bridge. The BCM Tip is ideal if the amount of solder on the bridge is small. However, if the solder contained in the bridge is large, we would recommend the use of shapes J and K. The BCM tip also prevents bridging from occurring when drag soldering. This is due to a higher volume of solder and thus greater surface tension offered by this tip as opposed to a BC tip for example.

Shape B

In general, the B shape tips are an excellent all round choice, which can be used from any direction and are easy to hold in any position, making it possible to solder any surface from small to large.

Shape D

Shape D is a very versatile tip, shaped like a flat-blade screwdriver (or double sided chisel). It is capable of soldering by applying the tip in 2 ways: line and face. You can select the size of tip suitable for the workpiece and it can be used for pretty much any type of soldering work.

Shape I

Shape I has a thin conical end and is an ultrafine tip, which is best suited for soldering fine pitch devices, rework, etc. It is the best tip for soldering micro components, such as 0603, and for repairing highly populated PCBs.

Shape J

Shape J differs from Shape B and I by offering a solder tip which is angled at 30 degrees.  It is capable of soldering by applying the tip in 2 ways: face and point, and is commonly used for drag soldering and correction of bridging.

Shape K

Shaped like a knife, Shape K is an extremely versatile tip. It is capable of soldering by applying the tip in 3 ways: line, face and point. It is used for soldering narrow pitch devices, correction of bridging and drag soldering.

SMD: Shape Quad

The SMD: Shape Quad tip is capable of heating plural pins or lead wires at once and is used for rework of SMDs. 
In particular, Quad Flat Packs (QFP’s).

SMD: Shape Tunnel

The SMD: Shape Tunnel tip is capable of heating plural pins or lead wires at once and is used for rework of SMDs, as well as the removal of Small Outline Packages (SOP’s).

SMD: Shape Spatula

The SMD: Shape Spatula tip is also capable of heating plural pins or lead wires at once as well as rework of SMDs.  However, this tip type is also suited to soldering for thermal compression of flexible PCB, RFI shielding cases, connectors, etc.

Shape R

Shape R has a groove at the tip end and is ideally suited to removing chip resistors/capacitors. It is also an ideal solution for fine-pitch soldering.

Shape SB

Shape SB is the perfect solution for fine-pitch soldering.

Special Applications

For special applications, 2 key Shape D products, T15-1603 (Shape-Long reach chisel) and T15-1605 (Shape-Long reach bent chisel) can be used in 2 ways of line and face. Both offer an excellent solution for fine-pitch soldering.

One of the most important things to bear in mind for effective tip selection, is that even though two tips may be similar in size, one may have a greater heat storage capacity, which will greatly contribute to improving the soldering process. Therefore, select a tip with the highest heat storage capacity possible as long as the size is the same (or similar) and still correct for the application. The difference in heat storage can be confirmed by the reduction in temperature for the comparative tips on the same application. If the temperature drop is small, the set temperature can be kept lower. It is unnecessary to set the temperature excessively high. This will reduce tip oxidation, tip replacement costs and, ultimately, the working time required to produce your solder joints thus increasing productivity.

We hope you found our advice on tip selection useful and that it has highlighted the versatility and variety of tips available from HAKKO for even better performance, reduced cost and improved work-in-progress. Look out for HAKKO Tech Tips next time, and in the meantime, feel free to contact us for any advice with your soldering or extraction equipment questions.