Recommended Products

Looking At The Reflow Soldering Oven

The world today is full of electronic devises that help you live an easier life. They come in the form of smart phones, tablets, lap top computers and too many other things to list. The thing most of these items have in common is they all use circuit boards to help maintain continuous service. The reflow soldering oven is one of the machines used to create the circuit boards that are so vital to the communications industry.

This machine is used to permanently solder two flat components together. The process uses a powdered solder mixture that is placed at critical locations on the board and circuits to be soldered. The prepared board is then heated to the point of melting the solder to permanently affix the two components together. There are four stages in conventional processing typically called zones.

The beginning zone is called a preheat period. As the name implies it serves to find the proper temperature needed to complete the task. The ramp up rate is important because if the temperature is too hot or too cold it will create problems with the finished product. When the heat rises too fast or too high it can cause solder to crack or spatter and too low or slow can create problems with the melting process of solder leaving it dull or brittle.

A thermal soak zone is next in the process. This soak usually lasts no longer than two minutes and is designed to remove paste volatiles and activate the flux components to begin oxide reduction on leads and pads of circuits. Again the temperature must be precise to prevent spattering or balling of solder from heat that is too high. When the soak is complete a thermal assessment of the entire board is required before it moves to the next zone.

The reflow zone is also called the time above liquidus or TAL. This is the point where the highest temperature is reached. This is a very important component because it must not surpass the highest temperature that can be tolerated by the part most sensitive to thermal damage. The process takes approximately one minute and should be closely monitored to ensure the temperatures do not surpass the limit set for the piece.

The final step is the cooling zone. This is a slow process that gradually cools the board and causes the liquid solder to become solid. When done properly it can help to prevent excess thermal shock to the boards and their components. Many companies pay little attention to the cool down rate because it is less critical than the ramp up rate but a cooling rate of four degrees Celsius per second is recommended.

Having a window to watch the entire process is one of the ways the manufacturer helps the operator. Most of the machines are computerized and can be pre-programmed to do the work without human assistance but being able to see what is happening is important especially on a new run. Many have USB connections so the operators can view them on their computers.

These ovens come in many different sizes. They may range from small units that can be placed on the surface of a bench to units that are longer than six feet. The importance of them is demonstrated everyday in products used to communicate with others as well as for mobile intelligence and gaming. They help to make the world smaller with each new devise they help to create.

Read more about Looking At The Reflow Soldering Oven.

Leave a Reply

Recommended Products