Hybrid solder joints were formed by soldering SAC305 components with a Bi-Sn LTS solder paste at peak reflow temperatures of 175 C and 190 C. The component test vehicles were a 192-pin chip array BGA (192CABGA) and an 84-pin thin core BGA (84CTBGA). Thermal cycling was done using a daisy chained printed circuit board and two daisy chained ball grid array (BGA) test vehicles. This study used accelerated temperature cycling (ATC) to assess thermal fatigue performance of heterogeneous or hybrid ball grid array (BGA) solder joints formed with a Bi-Sn LTS and SAC305 (Sn3.0Ag0,5Cu) ball. The Bi-Sn eutectic alloy is the preferred base solder alloy to achieve targeted soldering temperatures below 200 o C. We recommend starting at a lower air flow and moving up as your needs require.Various technical, reliability, and environmental factors are driving the demand for development of low melting point or low temperature solders (LTS) for electronic assembly. If your air flow is turned up too high, it is quite possible that you will start seeing small projectiles shooting away from your board. A last resort is getting a replacement heating element. Last resort is getting a replacement heating element. Try checking the connections to see if the heating element needs to be re-seated. It might be that there is something with the heating element failing or not connected properly. Units displaying the “H-E” usually means there is a heating error. This results in fooling the controller into thinking the heater has failed. Another tech support rep thinks it’s oxide building up on the connections. The rework station might be able to be revived by removing and re-attaching the heater. Other times it indicates that the heat sensor is failing. Sometimes it goes away after messing with the dial and the temperature will display properly again. With the nozzle, you will get more air flowing through the hot-air rework station’s handle. If you are getting low airflow when the “Air” Dial is turned up, make sure that you have the nozzle securely attached. Troubleshooting Low Airflow when "Air" Dial is Turned Up Hot-air can sometimes be used in conjunction with a flux pen to remove these pesky buggers. Unintentional Solder Jumpers - If too much solder or solder paste is used, the result can be jumpers on one or more of your surface mount IC's legs. Hot-airing a new part in its place is a snap with this rework station. This can happen before or during reflow, resulting in a spot where something should be, but isn't. Missing Components - The smaller the component, the easier it is for it to disappear. Hot-air is great for replacing these bad parts. These ICs are then placed on perfectly good PCBs. Removing Defective Parts - Sometimes, during the IC manufacturing process, errors can arise and go unnoticed. The part usually sticks strait up resembling a tombstone.Ĭold Joints - This is similar to a tombstone except the parts might not be sticking strait up, making it harder to see the connection that is not being made. Tombstone Parts - This is when a part (usually a resistor or capacitor) reflows only on one side. These include ICs, diodes, some capacitors, connectors, etc. Polarized Components - Parts that have been placed incorrectly (backwards, shifted x degrees off). Just think of it as doing any work to the board that wasn't involved in the actual production process. The term rework just means you are refinishing or repairing an already reflowed board, and it is a term commonly used in the electronics world. As mentioned above, they are a crucial tool when it comes to reworking a board. Hot-air rework stations can be very handy. The bigger nozzle is great if you are trying to focus hot air around a big area on the board. The smaller nozzle is good for focusing the hot air on smaller components. Nozzles - The 303D comes with 2x changeable hot-air nozzles. The indicator in the temperature box will twinkle when the desired temperature is reached. The LED output will display the setting temperature for 3 seconds and then return to the actual air temperature of the nozzle. You can adjust the working temperature by turning the temperature setting knob. Temperature Range - Output temperatures range from 100° ~ 480° Celsius. The LED output will display the setting air flow grade for 2 seconds and then return to the current air temperature of the nozzle. You can adjust the air flow by turning the air setting knob. By default, the display will show your current temperature in degrees Celsius.Īir Flow Grade - Air flow grades range from A25 ~ A99. Note: Temperature scale (Celsius vs Fahrenheit) is set during the manufacturing stage.
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