A exceeding consumer electronics society tasked one of its North American facilities to perform a month-long peruse to assess the importance of dwell generation wave solder optimization and repeatability. The meeting with the greatest volume, representing 19% of all the boards produced at that location, was selected for the study.

For this purpose, an electronic slogan was used with plain board-wave contact sensors. Capable of performing four runs in a row, the device offered the convenience of beguiling multiple readings before downloading the information to a PC. Also, the device's LCD expo allowed the reading of news straightaway upon its way out from the wave machine. Another big-league capability: Administer measurement of immersion depth. The consequent steps were performed:

Method 1.) Parallelism was measured and established.

Transaction 2.) Measurement of the board's happening dwell time, which was 1.0 seconds.

Action 3.) Measurement of the board's now immersion depth, which was 24 mil.

System 4.) Assessment of board quality, showing a defect degree at 312 ppm, a comparable considered standard at the absence in spite of the bigness of rework growth performed, and distinctive by production standards.

Process 5.) Steps 1 fini 3 was easily performed for three shifts in a row, twice per shift, on account of all info was obtained in a unmarried flow of the device concluded the wave machine. Operation four was performed at the deadline of everyone shift.

If, prior to running the assembly, measurements showed a disparallelism, or a dwell allotment also than 0.1 moment outside from 1.0 seconds, or an immersion profundity other than 24 mil, adjustments to the wave solder tool were prepared and fresh measurements were taken to confirm that the desired board-wave familiarity was occurring. Areas unrelated to board-wave interplay were maintained throughout. These include, for example, flux types, preheat settings and solder temperature.

At the butt end of each shift, a ppm roll was made. ppm's for this board were consistently at the 312 range. Hence, repeatability of board constitution was achieved.

Dwell Clock Interpret Methodology

The later intention was to dispose provided the board's defect standard was affected by running it at contrary dwell times. This was achieved by running the equivalent board type at contrasting dwell times in half-second increments, from 0.5 seconds to 5.0 seconds, and correlating each dwell eternity with the defect proportion it produced. Steps 1 completed 5 above were followed at each dwell time.


The glum border of figure 3 shows the results. It was brick wall that the dwell bit which produces the lowest defect scale for this specific board was between 2.5 and 3.0 seconds. Extremely read of this board was then performed. It was bent that defects are consistently lowest at 2.8 seconds. As a result, this board is instantly particular drop at the 2.8 second dwell date with 24 mil immersion depth. Engine settings are promptly incidental regardless of the wave soldering machines existence used. Wave solder Optimization of dwell lifetime was achieved, as was the flexibility to produce the board on practically any wave apparatus with predictable quality.

For the consumer electronics company, this has meant valuable wave solder means documentation, clearer directions to operators, preferable flexibility owing to the board can any more be canter reliably wrapped up any wave machine, fewer spikes in the evolution state chart in that measurements are mythical before boards are run, less downtime, higher throughput, reduced energy on formation engineers and happier management. As we all know, these are the general results whenever particular development improvement procedures are successfully implemented.

Other observations:

1.) What was discovered to be the optimal dwell interval was significantly discrepant than that which had been occurring however was heretofore unmeasured?

2.) Defect rates vary sharply with contradistinct dwell times.

3.) Controlling immersion depth was critical to this study, thanks to varying immersion depths miserly varying contact lengths and, as a result, uncontrolled dwell times.