Implementation

1. Implementing Z-Fact0r in Microsemi

Microsemi, a wholly owned subsidiary of Microchip Technology Inc., is a partner of the Z-Fact0r H2020 project. Microchip is a multinational semiconductor company with a strong UK manufacturing base.

Microchip Technology Inc. is a leading semiconductor supplier of smart, connected and secure embedded control solutions. Its easy-to-use development tools and comprehensive product portfolio enable customers to create optimal designs which reduce risk while lowering total system cost and time to market. The company’s solutions serve more than 125,000 customers across the industrial, automotive, consumer, aerospace and defense, communications and computing markets. Headquartered in Chandler, Arizona, Microchip offers outstanding technical support along with dependable delivery and quality.

Increased miniaturization pushes the capability of standard electronic assembly equipment to the limits, particularly during the pre-volume ramp up period. Yield rates (the percentage of non-defective items of all items produced) in the first few months of new product tend to be lower until the process is stabilized.

The semiconductor components are a high value product, so a small percentage change in yield can make a significant difference to waste costs, particularly in early stage production ramp up where scrap costs can be several times higher than in volume production.

The process chosen to evaluate the Z-Fact0r system involves the placement and gluing of very small die/components (in the order of micrometres) with conductive paste into a laser cut cavity.

Assembly is a multistage process starting with visual inspection of the base printed circuit board (PCB), glue dot dispense, component placement and cure. The placement and deposition of the glue represents a crucial point in the process.

Microsemi expressed the need to be able to improve this process and finely control the amount of glue being dispensed into the cavity. Optical inspection along with trend monitoring, plus the prediction of the usability of the glue are all factors that help with improvements.

Use of the Z-Fact0r system and the introduction of optical sensors connected to the Z-Fact0r Artificial Intelligence (AI), was chosen to improve the yield and reduce waste, particularly in the early volume stage.

2. Implementing Z-Fact0r in Durit

DURIT develops and produces precision tools and engineers components made of tungsten carbide bonded with cobalt, with more than 30 years experience in this field.

DURIT is an intensive user of precision grinding, milling and turning operations particularly for the final stages of hardmetals’ wear tooling for numerous industrial applications. They have strict tolerances, down to +/ -1 micron. Surface finishing, including surface roughness, dimensional tolerances and structural integrity must meet precise standards which are met by continuous measuring and quality control.

The production process is based on powder metallurgy, so any non-quality is very costly particularly after the sintering stage because the recycling process can only done by specialised companies using chemical dissolution methods to recover the hardmetal components.

Typically, defective products account for about 3% of the overall production. Particularly, more than 70% of overall rejections registered are attributed to these operations, either from improper tool quality, improper operation strategy or from lack of properly done, time-consuming, measurements during manufacture.

In addition, there is not a production line but rather production “cells”, since the production strategy is for custom order, and a large quantity of different production orders can be performed daily at each one of these machines.

The objective, thanks to Z-Fact0r project, is to adopt and implement a predictive system to monitor online the quality of the parts, particularly, the dimensional tolerances, register the data and predict quality deviations resulting from systematic errors and improper machine operation. This system is based on optical sensors, comparing the true dimensional geometry and tolerances with the specified ones.

DURIT has two stages of production where we can apply the Z-Fact0r technology:

  • in pre-sintering conditions – green machining
  • in post-sintering operations – grinding and turning

DURIT produces normally batches in small quantities, but from of a very large number of different references. The Z-Fact0r system could be applied to many components, but for the project sake we focused specifically on:

  • a oil and gas prospection component
  • cutting/drawing dies
  • mandrels

as these products require very narrow dimensional tolerances and very high surface quality.

Thanks to the Z-Fact0r system implementation, DURIT is expecting to increase its productivity, enhance its quality and service level; hence to save costs related to the production process.