CmForce - Measurement and analysis of placement forces

CmForce

CeTaQ GmbH has developed a measuring system for the determination of placement forces under real process conditions. This makes it possible to detect weak points at an early stage and prevent component damage during assembly. With only one measurement, the force and energy input of each individual nozzle cell is known. This enables maintenance, repair or optimization measures to be carried out in a targeted manner if necessary.

Example force-time plot
Example force-time plot. The first placement shows a distinct overshooting. This generates a high energy input.

Sensorboard

The central component of the measuring system is a sensor board with a triangular measuring surface of about 5000 mm². This allows a sequence similar to the assembly of real printed circuit boards. The necessary measuring electronics are integrated in the board. Forces acting on the sensor surface are recorded and analyzed by the CmForce software. The sensitivity and accuracy is constant over the entire measuring surface.

Example 12 nozzels before and after maintenance
Assembly head with 12 nozzels before and after maintenance

The sensor board can be fed to the placement machine like a normal PCB and processed by it. The measuring surface offers sufficient space for the assembly with real components in statistically relevant volumes. This means that all influences occurring during regular production are included in the result.

The sensor board allows the measurement of all common placement machines and functions completely independent of the manufacturer.

Example Nozzle 1 defect
Placement head with 12 nozzles with scattering on Nozzle 1.

Software CmForce

  • Live display of the force-time curve during loading
  • Analysis of the force-time curve in detail
  • Various peak search algorithms
  • Head/nozzle evaluation
  • Statistical evaluations
  • One click HTML protocol with all results
  • Calculation of capability characteristics
  • Export for CmCStat (CeTaQ Statistics Software) The most important task of the software is the analysis of the force-time progression of all placement processes. The following parameters can be determined:

  • Maximum peak force of the assemblies
  • Pulse force (dF/dt) - energy input into the component
  • Duration of placement
Example force-time plot
Example force-time plot. The stiff z-axis on the last head

Procedure of a measurement

Before the first measurement, a corresponding placement program must be available or created. We recommend to set at least 25 components per tool, if the program is available on the pick and place machine, the sensor board will be processed like a real PCB. Generally, components from production are used for this purpose. We recommend to use the relevant or interesting component types.

The required measuring time is essentially the same as the placement time, i. e. relatively short. After the measurement, the data is analyzed. The software allows to break down the measured values down to the individual nozzle cells. If the results show problems such as worn springs or stiff ones, they can be specifically corrected.

At the end, a report can be generated with one click to document the condition of the equipment.

Technical specifications

FMB-03 Wired system

  • Dimensions: 232 x 175 x 15 mm
  • Board thickness: 1,5 mm
  • Weight: ca. 1kg
  • Measuring range: 0.1 – 20 N
  • Measurement uncertainty (U): +\(\pm 0.03\) N
  • Assembly space: ca. 5000 mm²
  • Measurement frequency: 10 – 50.000 Hz

FMB-04 Wireless system

  • Dimensions: 257 x 210 x 25,3 mm
  • Board thickness: 1,5 mm
  • Weight: ca. 2kg
  • Measuring range: 0.1 – 20 N
  • Measurement uncertainty (U): +\(\pm 0.03\) N
  • Assembly space: ca. 5000 mm²
  • Measurement frequency: 10 – 50.000 Hz
  • Data transmission: W-Lan