Design for Manufacturability/Assembly/Testing

It is trying to get it right the first time, when the products are taken for the mass production, the product works, and you have the confidence it's been de-risked and testable.?Some of the unreliable products gets shipped to the field, which needs to be recalled, leading to of huge revenue losses.

Top Benefits of DFx:

1.??????Improved production yields – meeting 6 sigma goals

2.??????Increased quality – Reduces Rework after assembly

3.??????Maximized testability – Reduced test times

4.??????Improved product cost

5.??????Reduced time to market

6.??????Enhanced customer satisfaction

7.??????Minimised product risk

8.??????Improved overall operational efficiencies

?With DFx you would have a 99% confidence, that the product would meet “perfect product launch” and TTM requirements

Generally, traditional engineering methods do not concentrate on the alignment between a product's design teams and its production and supply chain teams. The DFx process brings in different people, talents, and resources when there is a challenge designing for a customer. DFx captures everything before production and becomes the liaison between the customer and the design teams. It's a process that takes place in the early design phase with much collaboration between all involved.

?Early Product Design Engagement

Since the decisions made during the new product development cycle account for 75-85% of products cost, it is vital that product cost management begins with the onset of product development.

There can be hidden costs associated with omitting early DFx reviews. These costs are associated with re-design, as in re-layout, PCB re-tooling, and re-build costs (which include materials and labor). Other hidden costs are time to market delay, validation testing, re-qualification, management of new build, and obsolete materials.

Product design can determine the defect rate of a product. The higher the yield, the lower the cost. The defect rate is recognized in the product design phase, not in the manufacturing process. Statistically, a process using DFx, and Six Sigma is expected to be free of all defects in 99% of all opportunities.

By engaging at an early design phase, manufacturers can prevent unnecessary design and production delays due to PCB fabrication errors, tests access issues, and out of date material. Adding in a vital component review, BOM checks, test review, and final DFx checks delivers cost benefits and overall product success.

?Below is a suggested process flow towards an error-proof approach using DFx.

Part of Zettaone Product design services, we adopt “Early Engagement - Model”, where we early engage with the Engineering teams and do the risk mitigation with below steps and actions

?Suitable component selection with Low supply chain risk with low FIT values and High MTBF numbers for the product reliability

·??????Perform Technical BOM assessment for EOL and supply chain Risk parts

·??????PCB stack up and material selection for cost optimization

·??????Plan layouts for the optimization for Panel Utilization for cost optimization

·??????Create symbol, footprint and 3D model for critical parts

·??????PTH to PIH ( Paste in Hole) process or to SMT parts

·??????Ampacity for power related parts

·??????VIPPO / Non Vippo analysis

·??????BGA pad cratering analysis

·??????Back drill Analysis

·??????BGA/LGA reworkablility

·??????Thermal pads for overall copperage

·??????Cu dissolution for PTH reworkablility

·??????Thermal pad design for the QFN

·??????Selective soldering requirements

·??????Plan Design layouts to meet Ruggedisation requirements e.g., Conformal coating

·??????Board Mounting hole optimization – Mechanical static load Analysis

·??????Heat sinks mounting hole design selection

·??????3D part interference

·??????Plan Hard and soft tooling

·??????Perform reviews for the Tier down competitor products with the CFT teams

·??????Identify Areas for Value Engineering and phase wise plans for implementation

·??????Box Build testability

·??????Test coupons – RVC/BD

·??????Review any manufacturing challenges (BGA fine pitch pad stack analysis) and Work on the mitigate plans with DOE / Test vehicle / Fixture development

·??????Identify Technological parts and access the technical risk to support testing with the test fixture development

We provide DFM /A /T (Design for manufacturing / Assembly / Testing) services, for the PCB and PCBA, at all the critical stages of product design stages (i.e., are Pre-Placement/Final Placement/Routing/ Final Fabout). We also provide, BOM validation to the design layout with AVLs, which ensures all the MPN's specified in the BOM has being verified for its Circuit symbols/Footprint/3D modelling on the Physical a layout of PCB footprint designs). We can perform the Analysis for design conformance for the Reworkablility, 3D interference, mechanical strain analysis

The expectation from Valor PCBA DFA report, is as below:

The expectation from Valor PCB DFM report, is as below:

Here's an example where we engaged with our customer at an early phase of design

?The Issue reported:

Package mismatch, PCB footprint is not matching with component. This will be sudden surprise during NPI build at assembly house.

Recommendation:

Design modification with new right footprint and launch new build or ordering right component.

The Issue reported:

Via on SMD pads, would lead to Solder loss for the Ground pads. This may not meet the Thermal and power integrity and might lead to long term product performance issues and could have high field returns

Recommendation:

We suggested the manufacturer consider "plug and capped" via holes. In the plugged vias process, vias will be plugged with solder mask. Mask plugging is used to prevent solder from wicking away from surface mount pads (SMD) during assembly. We can also adopt VIPPO process to fill in the Via with metal, but at some extra cost.

?

The Issue reported:

SMD direct connection Gnd pad - SO.QFN, Most of the SMD pads are connected to copper shapes directly, which results poor solderability.

Recommendation:

Provide pad thieving/ Thermal reliefs

In Summary

Is your product ready for manufacturing?

It is essential to design for manufacturability, testability, supply chain, quality, and more before the actual production process for efficient processes and a reliable product outcome. Great engineering design practices start with careful consideration of the product requirements up front to reduce the delays and redesign costs later.

There are always variables to consider, but with DFx (design for excellence) you have confidence that the products are reliable, testable, and have a faster time to market. All equates to happier and satisfied customers.

?This approach avoids re-spins, meet up NPI to Ramp timelines with improved yield, cost, TTM (Time to market) and reliability.?

Zettaone Technologies India Pvt Ltd is an AS 9100, ISO 9001:2015 certified company and IPC member, operating out of Bangalore INDIA

?To know more on 3D DFM/A/T solution for PCB/PCBA visit - https://www.zettaone.com/

?Email - [email protected] / [email protected]

?Call us @ +91-9731395261 / +91-9742489111