Maximizing PCBs For Better Wave Soldering

Relying on wave solder machines during PCB assembly can save time, money, and produce more reliable printed circuit boards. In order to get the most out of this process, however, you might have to take a closer look at some of your manufacturing processes. Let’s take a closer look at 8 ways to maximize your PCBs for better wave soldering results.

  1. Check Pad Spacing
  2. Check Lead Lengths
  3. Check Thermal Tolerances Components
  4. Check Component Direction
  5. Include A Solder Mask
  6. Apply Spray Or Foam Flux
  7. Set The Correct PCB Height
  8. Preheat Your Boards

1. Check Through-Hole & SMT Pad Spacing

When designing your PCB layout, you’ll want to keep pads from ending up too close together. Solder will flow between cramped points, causing unintended connections. If you are experiencing multiple pad shorts or entire board short circuits, pad spacing might be the issue.

2. Check Through-Hole Lead Lengths

Your leads should extend just past the pad for soldering. Whether you cut your leads in-house or outsource this process, getting the lengths right is essential. Tips that are too long may get pushed out by the solder wave and lift components. Excessively long leads can also collect excess solder.

3. Check Thermal Tolerances Of Board Components

You’ll want to check the thermal tolerance of your PCBs and the different components on each board. Different components can have a variety of temperature demands that you need to be aware of to prevent lifting, malfunctions, and permanent damage.

4. Check Component Direction

Did you know that PCB components of the same type should all be facing the same direction on the board before going through a wave solder machine? Having the same types of components face different directions is another way to increase your risk of excess solder.

5. Apply A Solder Mask

Applying a solder mask or layer of solder resistance helps protect and insulate your circuit pattern. Only the non-coated areas are available for creating electrical connections and mounting components. A thoughtfully designed resist application can also prevent solder balling, a common headache for many PCB manufacturers.

6. Apply Spray Or Foam Flux

Maximizing your PCBs for wave solder includes ensuring your boards are clean and free of oxidation. This is where flux comes in. Spray flux application is a fine mist that is followed up by compressed air to remove excess material. Foam flux coats the bottom of your printed circuit boards.

7. Set The Correct Board Height

Before sending your boards in for preheating, you will also want to check how much of the PCB will be exposed to the wave at any one time — the board height. A good rule of thumb is to have at least half the board thickness running through.

Board height checks are especially important in through-hole assembly. Insufficient board height can prevent solder from filling drilled holes.

8. Preheat Your Printed Circuit Boards

Preheating PCBs is another safeguard and maximizing step. To prevent thermal shock, you want to make sure your boards slowly reach the high temperatures required for wave soldering.

Exposing your printed circuit boards to thermal shock can result in reduced performance, loss of structural integrity, disrupted circuit lines, and oxidation.

Upgrade Or Replace Your SMT Equipment

If your SMT equipment cannot maximize your PCBs or needs replacing, we invite you to explore the inventory of used wave solder equipment at Capital Equipment Exchange. Contact us today to place your order or get the latest information about what’s in stock.