Flexible Thinking: The Key to a Successful Flex Circuit Design Transfer
Happy’s Tech Talk #29: Bend-to-Install Semi-flex FR-4
Modeling an SMT Line to Improve Throughput
June 6, 2018 | Gregory Vance, Rockwell Automation Inc., and Todd Vick, Universal Instruments Corp.Estimated reading time: 5 minutes
Table 2. Sample range of placements per panel versus count of assemblies and forecasted panel volumes.
The idea of using simple regression to develop a model of “placements per panel” to CPH began to develop. This relationship was first studied using production history.
Machine Mathematical Model for CPH
A report was available that contained panels built and total time to build a work order. This report was used to calculate the average CPH per panel for an SMT machine model. A scatter plot with a smoother line was used to view the relationship between the variables for a machine model. The smoother line is a line fitted to the data to explore the potential relationships between two variables, without fitting a specific model, such as a regression line.
There is a relationship between “placements per panel” and CPH but there are points that do not follow the smoother curve. The other observation is that actual CPH values vary greatly compared to the specification value the manufacturer stated.
Since production data was used to model this relationship, all the problem areas outlined earlier represent part of the performance and added noise in the model. Another idea was to use generic product simulation data from the manufacturer. The product simulation information included:
1. Quantity of placements per panel
2. Simulated cycle time for a SMT machine
3. CPH (calculated)
This would filter out the noise from production and machine configuration issues and could then be used to establish a realistic CPH equation. With the simulated cycle time data, the relationship between “placements per panel” and CPH was then studied.
The scatter plot revealed a relationship between “placements per panel” and CPH. Using the Pearson Correlation Coefficient, the strength of the relationship is assessed. At 0.536 it is considered moderate and P-Value of 0.000 means the relationship is statistically significant. This indicates that “placements per panel” is a good predictor of CPH.
To read the full version of this article, which appeared in the May 2018 issue of SMT007 Magazine, click here.
Page 2 of 2Share on:
Suggested Items
Winners of 2025 IPC Masters Competition China Announced
04/02/2025 | IPCOn March 26-28, the IPC Masters Competition China was successfully held in Pudong, Shanghai. This year’s competition brought nearly 500 electronics industry elites from 18 provinces and municipalities.
IPC APEX EXPO 2025 Review: Shifting My Focus to the Show Floor
04/02/2025 | John Watson, CIDIPC APEX EXPO 2025 marked a significant milestone as it celebrated its 25th anniversary. (Personally, I don’t think it looked a day over 20.) If you didn’t attend this great event, why not? This was my 10th anniversary of attending, and it had a distinctly different feel. There was a celebratory atmosphere as both veterans, like myself, and first-time attendees, were drawn into a celebratory occasion marking the significant milestone of the 25th anniversary.
Real Time with... IPC APEX EXPO 2025: Advanced Silicone Solutions from CHT
04/01/2025 | Real Time with...IPC APEX EXPOCHT team members introduce themselves and share their roles, with Kate Sincerbox focusing on technical service and Lisa Stutzman on inside sales. CHT specializes in silicone materials for encapsulation, adhesives, and coatings, serving the automotive and aerospace sectors.
Real Time with... IPC APEX EXPO 2025: Tariffs and Supply Chains in U.S. Electronics Manufacturing
04/01/2025 | Real Time with...IPC APEX EXPOChris Mitchell, VP of Global Government Relations for IPC, discusses IPC's concerns about tariffs on copper and their impact on U.S. electronics manufacturing. He emphasizes the complexity of supply chains and the need for policymakers to understand their effects.
Real Time with... IPC APEX EXPO 2025: Revitalizing the U.S. Microelectronics Industry with PCBAA
04/01/2025 | Real Time with...IPC APEX EXPOPCBAA president David Schild discusses his experience in the PCB and aerospace sectors, focusing on the mission of the PCBAA and its collaboration with IPC. He highlights the decline in PCB manufacturing in the U.S. and the importance of public policy in restoring capacity.