Benefits of Robotic Soldering in Increasing Your Productivity

Automation and robotics technology is helping to improve the soldering process by reducing the time it takes to produce assemblies and manufacture electronic devices and gadgets. Robotic soldering is particularly beneficial to the PCB (printed circuit board) manufacturing industry as it makes soldering more cost-effective, easier, and faster, thus boosting productivity and minimizing rework. Robotic soldering enabled producing higher-quality electronic products with minimal issues and problems in the manufacturing process. Soldering can be tricky, if not performed precisely, due to the soldering defects that can occur in the process such as spattering and bridging. With manual soldering, there is a greater chance for soldering defects to occur. By incorporating robotics technology in your soldering process, t human errors can be reduced and a faster and more efficient PCB manufacturing process can be ensured.

Robotic soldering is recommended in large scale and high-speed assembly processes. Robots can be designed to take up less space which reduces the need for bigger facilities to manufacture and assemble electronics. With robots, the need to hire more manpower can be reduced, overhead costs can be minimized and human resources can be utilized to focus on more crucial aspects of your electronics development and manufacturing.

To make robotic soldering work more efficiently, you may need to invest in better equipment and materials that are compatible with robots and the advanced machinery that is required. Flux cored wire can be formulated to work with a wide range of automated soldering processes, including those that are administered via robots. The flux cored wire provides excellent and consistent solder joint integrity to ensure higher yields and throughput, and minimal consumption with its low-flux spatter, fast wetting, and electro-chemical reliability. The wire produces minimal fumes and a non-tacky, clear residue, and possesses high electrical reliability with environmental compliance.

Creating High-Quality Solder Joints with No-Clean Solder Paste

Solder paste is used in PCB assembly and prototyping, and it is particularly helpful when the reflow soldering method is involved. It is typically composed of solder spheres and a specially formulated flux. Solder paste is applied on the surface of a PCB to create a physical and electronic bond between components and the printed circuit board. However, the process of soldering typically leaves a residue, which needs to be cleaned to maintain a seamless appearance. No-clean solder paste is formulated to help minimize or completely eliminate the need to clean via scrubbing or using a vapor degreaser or petroleum solvent.

No-clean solder paste can be handy in reflow and fine feature printing applications. It can be used in the most demanding manufacturing processes where soak reflow profiles are exposed to nitrogen and air. The excellent reflow process window of a lead-free and no-clean solder paste ensures excellent soldering on applications like lead-free HASL (hot air solder leveling) and ENIG (electroless nickel immersion gold) surface finishes, immersion Sn, Immersion Ag, and OSP-Cu. When choosing this type of solder paste, make sure that it complies with IPC Class III voiding classifications and ROLO IPC to ensure maximum product reliability in the long run. It’s also important to make sure that it complies to environmental standards, like RoHS (Restriction of Hazardous Substances).

Using a no clean solder paste can help speed up the assembly process. Excellent paste-in-hole or pin-in-paste performance has been proven for pin transfer or dispensing applications and printing. The long stencil life ensures consistent performance for a minimum of six hours of continuous printing, even if you do not apply new paste, and up to 24 hours in SMT production from 20°C to 32 °C in harsh environments. The paste is formulated to stand up to difficult wetting requirements in lead-free components, like QFN and CSP on various lead-free board finishes.

Why Use a Lead-Free Solder Alloy?

The RoHS (Restriction of Hazardous Substances) directive changed the way most electronics and electrical equipment are manufactured, and one of the most important changes is the use of lead-free alloys in making solder joints. Wave soldering is still one of the preferred methods for mass-production of printed circuit boards, but traditionally, the alloy used was tin/lead (Sn63/Pb37). Now, with the increased availability of lead-free solder bar options, it is possible for manufacturers to conduct lead-free soldering more easily and economically. Solder typically has a melting point that ranges from 90 °C to 450°C for most sheet metal work and electronics. However, lead-free replacements for 63/37 and 60/40 tin-lead solders can melt between temperature ranges of 5°C to 20°C or higher.

Tin-silver-copper (SAC or Sn-Ag-Cu) solders are preferred by some manufacturers for wave soldering and reflow because of the reduced melting point, which is around 217°C for SAC alloys. Sn95.5Ag4Cu0.5 and Sn96.5Ag3Cu0.5 are some of the best lead-free alloys to replace the Sn63 alloy in wave soldering processes. Depending on the conditions of the process, those SAC alloys may reduce or stabilize the copper content in a wave solder bath. A high-quality lead-free solder alloy is created using a specialized process to eliminate oxides and other impurities.

Lead-free solder alloys have a range of features that can make it beneficial for lead-free soldering. One of its most notable benefits is the best in class yield that outperforms other materials that are based on Sn/Cu. The solder possesses faster wetting speeds (at only 0.65 seconds), which was tested against Sn/Cu-based materials (1 second), making it highly solderable. The way the alloy is manufactured and conditioned helps reduce dross generation. The solder bar promotes excellent drainage, too, so it lowers the chances of bridging while delivering excellent performance when used on different flux technologies.

Using Solder Paste for Electronic Components

Solder paste is used for printed circuit boards assembly. That solder paste material is used to link surface mount components to the pads on PCBs and keeps those parts in place. Its main purpose is to form a mechanical bond between the parts and the board and to also form an electrical connection between the circuit board and electronic components. Paste is applied to a PCB, and the parts are placed manually or by using a pick-and-place machine. There are a variety of solder pastes available for various soldering applications.  It is important to have proper equipment and tools for applying the paste on the PCB to avoid soldering defects.

Most of the defects and issues in circuit board assembly are the result of either using a defective solder paste, using the wrong type of solder paste or the improper application of the solder paste. One of the more common soldering defects is bridging, which occurs when the solder melts over more than one joint and forms unintended connection. Too much solder, or insufficient/poor wetting can also result in soldering defects. Conventional solder pastes are formulated with lead, but lead-free variants, which, when used improperly, may cause head-in-pillow defects, solder paste deposits, and incomplete coalescence of BGA (ball grid array).

Solder paste particles are traditionally made up of lead and tin. Lead-free solders can be formulated from SAC alloys for HiP reduction and miniaturized electronics to ensure high throughput and reliability. Low temperature reflow lead-free solder pastes are designed to enhance the performance of the solder joint for thermal cycling and drop shock to create better joints with improved cosmetics and mechanical properties. Universal, high print speed electronic solder pastes have a no-clean formulation for a wide range of applications, especially those that require repeatability and high throughput.