This section defines how each solder machine parameter is measured and or calculated:
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•Preheat Max Temp: The temperature of the Top Foil Thermocouple at the end of the Thermal zone (Zone 1). This records the change in temperature imposed by the preheat system on the top foil of a typical circuit board.
•Delta T: The maximum overall temperature seen on the Top Foil T/C after the Thermal Zone (Zone 1) minus the the Preheat Max Temp. This records the change in temperature imposed by the fountain on the top foil of a typical circuit board.
•Fountain Temperature: The maximum temperature seen on the Solder T/C within the Thermal Zone (Zone 1).
Dynamic (Fountain Measurements):
•X/Y: The center of the fountain’s contact diameter in cartesian coordinates using the equation below. This tell you how accurately the selective machine located its fountain relative to the X/Y sensor center.
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•Diameter: The diameter of the fountain’s contact area on the bottom of the X/Y sensor using the equation below. This is a measure of the fountain “spread” as it touch the bottom of the board.
•Height: The highest point the fountain could reach as measured from the bottom of the pallet. This measurement tell you how much higher the fountain reaches beyond the bottom of the board if not impeded.
•Dwell: The amount of time the fountain stays in contact with the Process Origin sensor. The fountain overall contact (dwell) time vs the programmed time varies with fountain height; the higher the fountain, the sooner it will contact the bottom of the board as it is raised into position and then lowered.
| The Fountain Dynamic location in X and Y and its Diameter are calculated from the fountain’s contact points on the X/Y Sensor. The SelectiveRIDER software uses the 3 largest (absolute) values of the 4 possible contact points. Two or less contact points reduces the measurements the software can calculate. However, given any 3 points of contact: x1/y1, x2/y2, x3/y3 on the X/Y sensor’s cartesian coordinate array, a circle that intersects the 3 points and its center can be calculated using the following coefficients and equations: |
| Coefficients: |
oA = x1*(y2-y3)-y1*(x2-x3)+x2*y3-x3*y2
oB = (x1^2+y1^2)*(y3-y2)+(x2^2+y2^2)*(y1-y3)+(x3^2+y3^2)*(y2-y1)
oC = (x1^2+y1^2)*(x2-x3)+(x2^2+y2^2)*(x3-x1)+(x3^2+y3^2)*(x1-x2)
oD = (x1^2+y1^2)*(x3*y2-x2*y3)+(x2^2+y2^2)*(x1y3-x3*y1)+(x3^2+y3^2)*(x2*y1-x1*y2)
Fountain Accuracy (X/Y location and Diameter):
•X = -B/2A
•Y = -C/2A
•Diameter = 2*sqrt((B^2+C^2-4*A*D)/(4*A^2))