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Electronics product manufacturing and EVT, DVT & PVT engineering validation processes

The Consumer Electronics manufacturing industry is involved in the manufacturing and distribution of electronic items, including televisions, telephones, video cameras, alarm clocks, stereo items, MP3s, VCRs, and DVD players

Consumer Electronics Manufacturing outlets today are characterized by high-quality consumer goods. For example, manufacturers have improved the quality of audio devices by utilizing digital radio technology in both home and car radios and releasing them to the market. On the other hand, there is development in cameras, where more advanced digital cameras that can digitally record videos are being released to the market. Today, you can watch your favorite TV program from your phone and your car; you can access satellite TV that will keep you posted on the status of traffic on your road.

After the executives of the company have confirmed the new product planning (NPP) by determining a market opportunity, a product positioning, doing a technology assessment, supply chain strategy, and resource allocation, the development process is typically laid in the hands of a product team that has to translate these into a product requirements document (PRD) and come up with viable concepts.

NPD: NPD stands for new product development, and is commonly referred to as simply “product development”. NPD is the overall process of conceptualizing, designing, planning and commercializing a new product.

NPI: NPI stands for new product introduction. The market launch or commercialization of a new product. NPI takes place at the end of a successful product development project.

 

Proof of concept (POC)

At first, proof of concept (POC) prototypes are used for the initial test of an idea, method, or product to show its potential and feasibility in real-world settings. These concepts are later converted into prototypes, which are working models of a product showing exactly how the product will function in terms of mechanics, design, user experience, and so on.

 

In the world of mobile app development, a POC is a simple project that validates or demonstrates an idea. The purpose of a POC is to check if an idea can be developed and won’t consume excessive resources or time. With a POC you essentially evaluate core functionality. If your app idea is complex, you can have many POCs to test each functionality.

 

You can build a POC to present your idea to investors to acquire seed funding for further development. Creating many POCs using different technologies can help you decide which technology stack is the most suitable for your project. This way, you’ll know early on what’s possible as you move forward and how to structure your product’s roadmap.

 

Prototype

A prototype is where your product’s design begins to take shape. If a proof of concept evaluates the technical side, a prototype aims to answer the question how the product will look.

 

A prototype is an instantiation of a product design that can be used to communicate and assess its value regarding certain requirements. Prototypes range from low-fidelity ‘soft’ models handmade of materials such as clay, cardboard, foam, and wood to high-fidelity functional prototypes 3D printed or made in the machine shop. Focused prototypes are meant to embody only a part of the product’s requirements and can be a ‘looks-like’ model, a functional ‘works-like’ model, or one that demonstrates partial form and function in order to test certain sub-functionalities. When a prototype incorporates all requirements and functionalities with the design, it is called the engineering prototype.

 

The device prototype is developed, assembled, and tested on an evaluation kit for the chosen target platform.  The selected hardware and software technology solutions are evaluated. The potential weaknesses in the context of technical feasibility, the platform’s performance, and other essential characteristics are also assessed. As a result of this stage, we can understand whether we chose the right platform and best engineering solutions. In many cases,  a limited functionality, ‘desk-type’ prototype of the device is also developed.

 

Prototypes help you figure out what UI elements should be included and how the user will interact with them. Prototypes can take many forms — from simple paper-based wireframes to interactive “clickable” versions developed in Figma. A prototype lets you ship your product to test users for initial feedback. User testing in this phase can go a long way to improving and helping you chisel out the design, with plenty of time to fix flaws.

 

Minimum Viable Product

An MVP is essentially a finished product, even if it lacks some of the features. With an MVP, you can start collecting user analytics and add or refine features in the next iterations. A prototype lacks the business logic of your product and addresses the questions of design and UX

The key to building an MVP is to start learning with a version of your product that contains only the core features but lets you validate your hypothesis. A minimum viable product helps you gauge the demand and product-market fit — whether your product attracts early adopters and satisfies them.

An MVP should contain the minimum number of features that still make your product marketable. Remember, the goal is to collect and analyze user-generated data and feedback.

 

Electronics product development

List of required components is specified during this stage and then PCB (print circuit board) is designed. Bill of Materials (a list of all parts) is also generated and accurate suppliers’ prices are acquired. HMI (human-machine interface), control, and information display units are also designed. Simultaneously, engineers design the interface, create concepts of controls, and build the functions tree.

 

Electronic design automation (EDA) and Electronic Manufacturing

Electronic design automation (EDA), also referred to as electronic computer-aided design (ECAD), is a category of software tools for designing electronic systems such as integrated circuits and printed circuit boards. The tools work together in a design flow that chip designers use to design and analyze entire semiconductor chips.

Printed circuit boards (PCBs) are the foundational building block of most modern electronic devices on which all of the other electronic components are assembled onto. A circuit card is a thin, flat piece of dielectric material that has conductive paths or traces etched on it. These conductive circuits – usually copper connect various electronic components by routing electrical signals and power within and between devices.

The first step in the CCA process is to create a circuit card design. This design is created using CAD (computer-aided design) software. Once the design is complete, it is sent to a CAM (computer-aided manufacturing) system. The CAM system uses the design to generate the necessary tooling paths and instructions for manufacturing the circuit card.

 

Simultaneously with the schematic development, the enclosure design is also developed. Solid model and mechanical design of the case based on a previously developed sketch and the HMI is created and then  PCB layout in the required form-factor is carried out. After defining the software architecture at the previous stage, it is further implemented and then adapt and elaborated.

 

PCB Fabrication

The blueprint of your PCB, usually in Gerber format, is used to fabricate the PCB. PCBs are made of non-conductive substrates with copper layers. The circuit layout is transferred onto the copper layer using exposure methods, such as lithography

The supplier uses chemical processes to etch the copper layers according to the Gerber files provided. Solder masks and silkscreen are then applied onto the PCB. Tests, like flying probe tests, are then conducted to ensure the circuits are properly connected and there are no short circuits on the PCB.

 

Design for Manufacturing

There are many different approaches to DFM, but some common considerations include:

Component placement — Components should be placed to minimize interactions between signals. This can help to reduce crosstalk and other forms of signal noise.
Routing density — Higher routing densities can lead to problems with etching and soldering. PCB design guidelines should aim for a balance between dense routing and clearances that allow for manufacturing tolerances.
Thermal management — Temperature gradients can cause components to expand or contract unevenly, leading to reliability issues. Proper thermal management ensures that components stay within their safe operating temperatures.
Signal integrity — High-speed signals are susceptible to crosstalk and other forms of signal degradation. Good DFM practices help to ensure that signals maintain their integrity throughout the PCB.

 

Components Procurement

At the same time, you’ll need to start sourcing the components from suppliers. Usually, shipment takes at least two weeks depending on the number of components involved. There are a number of things that can affect supply chains (like global pandemics), so be sure to plan ahead if expediency is required.

 

PCB Assembly

The various stages in the PCB assembly process include adding solder paste to the board, picking and place of the components, soldering, inspection, and testing. All these processes are required and need to be monitored to ensure that product of the highest quality is produced.

Both the fabricated PCBs and components are then consigned to the PCB assembly supplier for mass production. Before starting the assembly, solder paste stencils are produced for the PCB.

Solder paste: Prior to the addition of the components to a board, solder paste needs to be added to those areas of the board where solder is required. Typically these areas are the component pads. This is achieved using a solder screen. The process starts with applying solder paste to the pads of surface-mount device (SMD) footprints. Then, the SMD components are fed into the pick-and-place machines where they are automatically placed onto the PCB.

Pick and place: During this part of the assembly process, the board with the added solder paste is then passed into the pick and place process. Here a machine loaded with reels of components picks the components from the reels or other dispensers and places them onto the correct position on the board. After all of the components are mounted, the PCB is placed into the reflow soldering machine.

Soldering: Once the components have been added to the board, the next stage of the assembly, and production process is to pass it through the soldering machine. Although some boards may be passed through a wave soldering machine, this process is not widely used for surface mount components these days.After the SMD components are soldered, the assembler will manually solder any through-hole components.

Testing

All assembled PCBs must go through visual inspections. Inspection: After the boards have been passed through the soldering process they are often inspected. Manual inspection is not an option for surface mount boards employing a hundred or more components. Instead automatic optical inspection is a far more viable solution. Machines are available that are able to inspect boards and detect poor joints, misplaced components, and under some instances the wrong component.

Often, X-ray machines are used to detect short circuits, discontinuity, or solder defects. Then, functionality tests need to be conducted on the PCBs before they are ready to be deployed.

Tests are developed and performed for verifying the software operation and its correctness. They also establish program tests allowing checking both hardware and software operations. The electronic product development stage is a full package of the device’s design documentation and final preparation for the manufacturing of a pilot batch.

 

Assembly

At the assembly plant, the components are put together. A combination of machines and workers does this in the electronics manufacturing process. The workers put the components in the right place and solder pasting them together. The device is then tested again to make sure it works correctly.

CCA (Circuit Card Assembly) is the process of manufacturing circuit card assemblies. This process involves etching patterns onto a dielectric substrate, such as FR-4, and then adding electronic components to the substrate.

BOM: BOM stands for Bill of Materials. A BOM is the list of parts or items that make up a product assembly. A complete product BOM often includes subassemblies, which may represent different steps in the assembly process.

Config / Configuration: A configuration is a “recipe” on the Bill of Materials for a specific group of units. For example, in the same build, you might build a configuration of black units and a configuration of white units.  You might build a configuration that contains certain vendors or variations of components (also see, Stuff/Stuffed).  Configurations usually have names, sometimes as simple as “A”, “B”, etc — and they are defined as columns on a Build Matrix.

Box-build – Also called systems integration, box-build is the assembly work, other than printed circuit board (PCB) production, involving enclosure fabrication, installation of sub-assemblies and components, and installation and routing of cabling or wire harnesses.

 

Conduct Validation Testing

A product design is hardly ever production-ready right from the very first CAD model. Even a simple plastic item may turn out to have bad sink marks, flow lines, or weak areas due to heterogeneous cooling after the first series is molded. An area can turn out too small to incorporate the legally required labels. There might be tolerance issues with a mating part under certain conditions. Or a lead user group could come up with a new high-priority requirement forcing the designers into another round of development.

 

The design process continuously requires such alterations, refinements, and pivots, as well as studies into aspects like manufacturability, cost estimation, voice-of-customer (VOC), legislation, IP, and certification standards right from the onset.

 

As the process advances towards production, the cost of these iterations rises exponentially. Whereas a series of sketches and foam models done by a designer at the beginning of development will cost a company $50 in materials, a more refined rapid prototype based on 3D prints, buy-in parts, and a vacuum cast overmold might set the company back somewhere in the order of $500-$1,000. Tooling changes in the production phase may lead up to $50,000 in total cost and result in multiple weeks or months of delay.

 

Validation testing is essential to ensure that the status of the design meets the right set of requirements at a given stage. Gating each phase with clear exit criteria and deliverables ensures optimal use of resources and quality advancement.

Considering that your design is done, there are a few important steps for validating your freshly engineered product which is unique to hardware product validation – EVT, DVT & PVT.

Examples of industries that use EVT, DVT & PVT as a standard

  • Semiconductor companies before launching a new chip
  • Mobile phones
  • Medical devices

Engineering Validation Test (EVT)

The EVT build is an iteration of the engineering prototype in which all of the functional requirements are matched and the testing results meets the requirements outlined in the PRD. Units must be completely functional and testable and made from the materials intended for the final product. The final exit criteria for this stage is configuration of the design that meets the required standards for functionality, performance and reliability. The most common types of EVT include Functional Testing, Conformance Testing, Power Measurement and Electromagnetic Interference pre-scan.

For electronic products, high-end ‘hot stake’ PCBs are developed using industrial processes. This is to validate the PCB (Printed Circuit Board) itself and whether all of its components and functionality are working as expected.  The PCB for the hardware will be tested for thermal, power and EMI stresses.

EVT is performed on the earliest prototypes to ensure that the basic version complies with the design specifications and development goals. The engineering validation test (EVT) stage is all about incorporating and optimizing the crucial functional scope required for the product. Whereas the result of the prototyping stage was a limited ‘alpha’ prototype, here an engineering-level ‘beta’ prototype will be developed that houses a more complete set of functionalities, typically determined by a build matrix.

A make-buy analysis is performed for all components in the assembly, component engineering is done on custom parts and a bill of materials (BOM) is set up for RFQs towards contract manufacturers (CMs) so they can prepare for the first assembly line and first shots (FS) tooling.

The engineering prototype is a minimum viable version of the final commercial product, that is designed for manufacturing (DFM). It is used for lab-based user testing with a select group of lead users, to communicate production intent to tooling specialists in subsequent stages, and to act as a demonstrator in the first sales meetings.

Approximately 20 to 50 units are produced using high-precision processes such as additive manufacturing and CNC machining, or a series of casts based on soft tooling such as silicone or 3D printed molds. The overall objective is to develop the design with full production intent and end up with a small number of production-worthy engineering prototypes.

 

Design Validation Test (DVT)

The design validation test (DVT) stage is where a product truly starts becoming industrialized. Where EVT is all about architecture-level design for manufacturing, DVT is about getting the details right while moving towards the first mass production line. It is a stage marked by experimentation and optimization.

In this stage, all of the hardware is complete and your aim is to make sure that your product matches your requirements in terms of cosmetics and environment. Testing whether the product as a whole will withstand environmental stresses. The objective of the DVT is to evaluate the design standards with the actual components and materials to be used in mass production. Furthermore, the sample unit is tested for external factors such as climate.

This stage is also where tools are developed and inspected. You are aiming to teach the contract manufacturer how to build your product while at the same time identifying remaining DFM (design for manufacturing) issues. PCBs are iterated to perfection through debugging and denoising efforts. The CM will develop the first hard tool for every made part to verify mass production yields. Aluminum molds may be used to optimize the design in terms of surface finish, materials, tolerancing, mold configuration such as sliders and cams, joining methods, as well as process parameters.

You will be producing small batches of your product and putting it under real stresses such as dropping from a height, burning it or seeing if it is waterproof. While typically 50 to 200 units are produced, it is not uncommon to see over 1,000 units produced for large projects. These units are subsequently shipped back for in-house evaluations and implementing final engineering changes, whereas some are sent out as beta units to potential customers and expert reviewers.

The most common types of DVT include Usability Testing, Climate Testing, Environmental Testing, Mechanical Testing, Performance Testing and Mean Time Between Failure (MTBF). Also checks if the product is following the rules and regulations with proper certifications.

Lots of tests will be performed on the first production-level units: environmental chamber tests, thermal cycles, vibration, ESD, biocompatibility, chemical resistance, certifications such as FDA, FCC, UL, CE, EC, and RoHS, aging, radiation, cosmetic, wear, and drop tests, among others. Extensive user testing is done with a significant part of the population in a realistic context

 

Production Validation Test (PVT)

The production validation test (PVT) is the final phase before mass production starts.  If the sample qualifies for all tests here, it is internally certified to be taken to markets. The PV iteration will see tests of the manufacturing processes devised in the course of the EVT and DVT phases. This validates the production line process and is the time to optimize this process so it can be cheaper and quicker.

In PVT, the units you are building should be ready to sell to customers if they pass all of the test stations. A pilot production line will be established to check if there are any failures at any stage of the production line. At the end of the PVT, the hardware startup and contract manufacturer will decide whether or not to move on to mass production.

The objective of the PVT is to validate the production yields at different rates and verify if the production process is fully operational. Accordingly, if needed, the line is optimized as per the finished goods’ standards. The common types of PVT done are Prospective Validation, Retrospective Validation, Concurrent Validation and Revalidation. Efforts made in this stage are directed towards optimizing and stabilizing the production and assembly lines in terms of line speed, operator expertise, scrap rate, and daily yield. Hard tooling is fixed, meaning that no more changes to either the product design or production molds can be made. Jigs, fixtures, and test benches must be in place and validated for the production pilot (PP) to commence.

Potential risks like single-source supplies—when a component is restricted to be made by a single selected CM—will be identified through risk management protocols such as FMECA, QA/QC, and FAI. Electronics undergo their first boot as well as a firmware inspection, and the product packaging plus user manuals will be created in this stage as well. Most of the work in this stage will be executed on the side of the contract manufacturer.

A typical outcome of the PVT stage is 500+ units or at least 5% of the first production run quantity. The objectives are to verify mass production yields at mass production speeds and to create sellable products. This is where many companies will create a sales plan and start their operation with the early buyers. The PVT build is the last chance for a company to tweak the production process. It is sometimes stage-gated in terms of a red, orange, and green state, based on success according to key production metrics. When the green light flashes on, true mass production can start.

 

Packaging and shipping

After testing, the devices are sent for packaging and shipped to retailers. They are then sold to consumers

 

Quality Control

QC: QC stands for Quality Control. QC is the process done at the factory to ensure the product you’re assembling is free of defects. This often relates to the fixtures and test equipment.

QA: QA stands for Quality Assurance. QA is the process done before a product is set to ramp. Things like electrical validation and reliability are quality assurance procedures.

IQC: IQC stands for Incoming Quality Control. IQC is the process of ensuring quality in a product is up to par with expectations. This can be done in the form of different stations on an assembly line or disassembling a fully packed product to ensure assembly procedures have been followed.

IPQC: IPQC stands for In-Process Quality Control. IPQC happens during the process of assembly on the line. This can often be a line worker checking for defects caused by the assembly process at a particular point on the assembly line.

OQC: OQC stands for Outgoing Quality Control. OQC is often referring to the process that occurs to check for functionality and quality before they’re shipped to your factory.

 

Mass Production (MP)

The final stage in the evolution of product maturity is the ramp-up towards mass production (MP). It typically starts at a minimum quantity of 5,000 units but can lead up to several million units in the case of popular consumer products such as the PlayStation, iPad, iPhone, or the Rubik’s cube.

You still need to be actively looking for fixing issues in the design and manufacturing process. Over the following six to nine months, continue testing of your product at a high sampling rate and put ongoing reliability tests programs in place. As soon as you are certain that quality issues have been largely addressed, you can ramp up the production capacity to match your original unit forecast.

In this phase, the initial production line might be replicated to other lines to be run in parallel. A failure and yield analysis on a small percentage of units ensures consistent quality. The first returns will come in, and EFFA analysis will ensure that all failed units make it back to the engineering team.

FA: FA stands for failure analysis, the process engineers take to determine the root cause behind a failure mode.

EFFA: EFFA stands for Early Field Failure Analysis. In the first 6-8 weeks after shipping, manufacturing teams capture returned units back from the field in order to conduct failure analysis on them and try to implement changes to improve the product.

To further guarantee the quality, factories and vendors need to be supervised to make no unforeseen changes in tooling or process parameters leading to quality shifts. The overall focus is on yield improvement, cost reduction, and expansion where necessary. The marketing and sales team here can focus on developing collateral, advertising, as well as predicting sales volumes.

 

EOL: EOL stands for end-of-life and is often used by OEMs on products that they will no longer market, sell, or update – often after a newer model is released

 

 

References and Resources also include:

https://formlabs.com/asia/blog/validation-testing-product-development-poc-evt-dvt-pvt-mp/

https://instrumental.com/resources/factory/manufacturing-terms-every-mechanical-engineer-should-know/

https://ioterra.com/articles/the-different-engineering-validation-stages-in-a-nutshell-evt-dvt-pvt-6qs4ir3ngqfl/

 

 

 

Cite This Article

 
International Defense Security & Technology (December 1, 2022) Electronics product manufacturing and EVT, DVT & PVT engineering validation processes. Retrieved from https://idstch.com/technology/electronics/electronics-product-manufacturing-and-evt-dvt-pvt-engineering-validation-processes/.
"Electronics product manufacturing and EVT, DVT & PVT engineering validation processes." International Defense Security & Technology - December 1, 2022, https://idstch.com/technology/electronics/electronics-product-manufacturing-and-evt-dvt-pvt-engineering-validation-processes/
International Defense Security & Technology November 21, 2022 Electronics product manufacturing and EVT, DVT & PVT engineering validation processes., viewed December 1, 2022,<https://idstch.com/technology/electronics/electronics-product-manufacturing-and-evt-dvt-pvt-engineering-validation-processes/>
International Defense Security & Technology - Electronics product manufacturing and EVT, DVT & PVT engineering validation processes. [Internet]. [Accessed December 1, 2022]. Available from: https://idstch.com/technology/electronics/electronics-product-manufacturing-and-evt-dvt-pvt-engineering-validation-processes/
"Electronics product manufacturing and EVT, DVT & PVT engineering validation processes." International Defense Security & Technology - Accessed December 1, 2022. https://idstch.com/technology/electronics/electronics-product-manufacturing-and-evt-dvt-pvt-engineering-validation-processes/
"Electronics product manufacturing and EVT, DVT & PVT engineering validation processes." International Defense Security & Technology [Online]. Available: https://idstch.com/technology/electronics/electronics-product-manufacturing-and-evt-dvt-pvt-engineering-validation-processes/. [Accessed: December 1, 2022]

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