DFM What is design for manufacturing

DFM 2021 – What is Design for Manufacturing?

DFM – Design For Manufacturing means fully integrating manufacturing considerations in the design process. Manufacturing equipment & practices vary greatly from factory to factory, especially if that factory is in another country. It is very important to involve the factory as early as possible, to prevent expensive re-design cycles delaying the New Product Introduction process.

 

Read the 9 Key Principles of DFM, see the preview below

The DFM concept is applied throughout all of  the product development process stages but implementation varies widely.

 

Design for Manufacturing is abbreviated as DFM and sometimes also referred to as Design for Manufacturability, all three terms refer to the same concept, design something that is easy to manufacture.

What is Meant by Design for Manufacture?

Usually what is meant by design for manufacturing is the early engineering optimization of a product to make it ready for time-to-market and limit its manufacturing process production costs.

 

“Skillful improvements at the planning and design stage are ten times more effective than at the manufacturing stage.”

 

Implementing DFM will make product issues disappear before they leave the design stage.

 

This will reduce product development costs as it is the least expensive phase to solve issues, once in the manufacturing stage, product design issues are extremely expensive to fix.

 

DFM and product development

 

Since DFM is applied throughout the whole product development process, the engineering team in charge of implementing DFM has to deal with

  • Product components sourcing
  • Raw materials sourcing
  • Materials’ form, shapes, and finishing
  • Dimensional tolerances
  • Mold design and development
  • Firmware development
  • PCB design and development

 

The last two apply more to an electronics manufacturing product development process

DFM for Printed Circuit Boards PCB 

DFM in PCB development means that the electronics engineers must ensure the PCB will perform all of the functions specified in the Requirements Traceability Matrix.

 

At the same time, they must ensure the design won’t be in disconnect with the manufacturing process for the PCB (THT or SMT) and subsequent protective process such as conformal coating.

 

DFM and PCB design

 

This means the engineers must take into account the manufacturing capabilities and technology they use.

DFM for PCB Manufacturing  – 5 Basic Guidelines

  1. In a sheet metal design, it is essential to specify the size of the holes, the locations, and their alignment.
  2. The space between holes is essential. It must be at least twice the thickness of the sheet.
  3. In cases where the holes must be near the edge, the minimum space between the side and the holes must be at least the thickness of the sheet.
  4. Add Bends at edges to reduce the likelihood of metal tearing.
  5. Put chamfers at corners and beads on bends to increase stiffness and reduce the spring-back effect.

 

Click the following link to get other 33 DFM for PCB manufacturing guidelines

DFM for Integrated Circuits (IC)

ICs are the main component of every electronic device; they’re low cost, require low levels of power and have high reliability and high processing speeds  

 

Integrated circuit microcomputers are now used as controllers in applications that before required hydraulic,pneumatic, and mechanical controls.

 

Designing and manufacturing a new IC is a titanic task for the likes of Intel.

 

We wouldn’t advise you to design and manufacture your own, that goes against our second law of Design for Manufacturing DFM , Use Off the Shelf Components.

 

Any company designing a new electronic device will just have to buy the appropriate IC and program it accordingly, there’s no design and manufacturing rework needed.

 

DFM guidelines for Integrated Circuits is something companies like STM have to worry about.

 

DMF GUIDELINES FOR IC

 

Since IC technology is evolving, it’s difficult to come up with a set of specific recommendations, as what worked for a previous generation of ICs may not be useful anymore.

 

However, there are some things people tasked with IC design are aware they have to deal with.

 

  • Functional yield loss caused by printability or planarization problems.
  • Parametric design marginalities caused by fluctuations or environmental factors.
  • Test related yield losses caused by incorrect testing.

Basic DFM guidelines to fix IC design problems are 

  • Substituting higher yield cells where permitted by timing, power, and routability.
  • Changing the spacing and width of the interconnect wires, where possible
  • Optimizing the amount of redundancy in internal memories.
  • Substituting fault tolerant (redundant) vias in a design where possible.

DFM for Computer Numerical Control  Machining

CNC machining is used across different manufacturing industries.

 

DFM here is all about designing the product parts in a way that won’t require many “flippings” in the CNC machining process,  with the purpose of saving time and money. 

 

Most CNC machines can only approach a part from a single direction, meaning it can only work on one side of the part at the time.

 

If a second side of the part has to be worked on, then the part must be flipped manually.

 

DFM and CNC Machining

 

The more geometrical sides the part you designed has, and has to be worked on, the more flips will be made, this will make the part more expensive, adding to the overall cost of manufacturing your product.

 

Keep in mind that each flip of the part requires a set up time and time to create the NC program.

DFM Guidelines for CNC Machined Parts 

  • Minimize the number of flips required.
  • Use CNC machining for large manufacturing volumes so the set up costs can be amortized among all the parts.
  • Use aluminum, brass and other soft metals as material. Steel, stainless steel and titanium are harder and take much longer to machine.
  • For material forms, bar stocks are easier to machine
  • Design the parts as small as you can. The bigger the parts, the harder it will be to remove them and flip them back into the machine.

What are the principles of DFM?

Every product and its respective manufacturing facilities and technology are different, so coming up with DFM guidelines that can apply to all products is not possible.

 

However, there are a couple of things you should always keep in mind.

1 – DFM and the Manufacturing Process

 

The manufacturing process you choose must be the most adequate for the part, material and volume you’ll be working with.

 

For example, if you’re going to mass manufacture some sort of radio, injection molding is your best choice, injection molding will give you flexibility with surface finish and colors.

 

The thing about injection molding is that making the molds is expensive, this is why it is suitable only for mass production.

 

For lower manufacturing volume thermoforming or even 3D printing might be a better fit.

 

DFM Choose the best manufacturing process

 

If you’ll be working with hard metals, CNC machine manufacturing will be needed.

 

The manufacturing process you’ll need for your product must be clear early on in the design stage, and make sure your manufacturing partner has the capabilities for it.

2- DFM and the Product Design

 

You have to make sure the product design is as simple to manufacture as possible.

 

Things like a uniform wall thickness for a product part, avoiding unusual hole sizes that would require custom tools and avoiding similar shape product parts are all part of a good design for DFM.

 

For more DFM guidelines please click the following link DFM Guidelines 

3- DFM and the Material You’ll Use 

 

Metal or plastic and specifically, what kind of metal or plastic?

This is important as there are different and specific  DFM guidelines you should apply depending on what kind of material you’ll use.

DFM Guidelines for Plastic Injected Parts

DDM Guidelines for Metal

The material selection  depends on the requirements of the product.

 

metal or plastic material for DFM

4- DFM and the Environment of The Product 

 

The product requirement sheet or matrix will specify the kind of environment the product will have to withstand.

 

As you might expect, a device that is meant to work in extreme heat conditions will not be designed following the same guidelines as one that has to work, say, underwater.

 

Conformal Coating for PCB 

5 – DFM and Compliance/Testing

 

Your product won’t succeed unless you do all the proper testing before mass manufacturing.

 

Any kind of product you manufacture will have some safety and quality standards to comply with; knowing exactly which certifications a product will have to pass before it hits the market is  vital .

 

The certifications will have to be considered in the early design stages of the product or risk major drawbacks as, you’ll think, you’re nearing the end of the product development process.

 

DFM and testing

 

In electronics for example, if a device can not pass a certification due to a PCB interference signal, it could mean having to do a whole redesign of the PCB, pretty much going back to the first steps of product development.

 

There are other 9 principles, or laws as we prefer to call them we’d recommend you to read ; they were written by our CEO, Case Engelen who’s been in the electronics manufacturing industry  for over 20 years now.

 

You can read them here: 9 Laws for DFM .

Why is Design for Manufacturing Important?

DFM is important because it is the smart way to manufacture any product. 

 

When DFM is done right, you’ll ensure your product hits its market window when it has to and maximize profit, something that won’t happen if you design a product without taking into account the manufacturing plant capabilities and technology -a non DFM approach.

 

Breaking it down more thoroughly

 

DFM is important because 

 

  • It drastically reduces production costs.
  • It makes sure your product goes from Proof of concept to mass manufacturing.
  • It reduces set up time for the factory.
  • It leads to a shorter Time to Market.

 

Cost Reduction

 

Perhaps you’ve already heard this: Hardware is a Cash Flow Business; here at Titoma we back up that statement.

 

And it’s also backed up by statistics.

 

According to Cb Insights, 29% of new hardware ventures fail because they run out of money.

 

That’s not going to happen to my company; I have millions raised to develop and manufacture my product – you might be thinking.

 

Congrats on having all that money, but sometimes not even $118 million is enough to make it.

 

Airware, despite raising $118 million, ran out of money after trying to manufacture its own hardware.

 

The main reason for this failure- apart from poor leadership – was trying to develop and manufacture every single part of their hardware (a drone); they wanted to be proprietary owners of it all.

 

An ex-employee explained how, in Airware, nothing was good enough, so everything was invented. 

 

 

Why is DFM important (2) 

That was the perfect formula to make those development costs skyrocket through the roof.

 

And it was a decision that goes against one of the most basic laws of DFM.

 

Our CEO, in his 9 DFM Guidelines article says:

 

“Use off the shelf components parts wherever possible”

 

Standard components are key to developing a manufacturable product that meets functionality and costs.

 

Around 70% of the manufacturing costs of a product come from design decisions, that includes components and parts selections and manufacturing method. 

 

Notice how I wrote, “component and parts selection,” now what more if someone has the brilliant idea to manufacture all parts and components from scratch.

 

Still, somehow some Western companies wait eight weeks and pay a $250 K set-up fee for a custom LCD, when in China almost any display imaginable is readily available, mature, and at a little cost.

 

So remember, one of the reasons DFM is important is that it reduces product development costs by dictating you to use off the shelf parts. 

 

Scaling Up

 

Scaling up is when you go from one prototype that works to thousands of end products that deliver expected functionality and meet established costs.

 

At this stage, you have to deal with two things, your manufacturing partner’s capabilities and components availability.

 

When you’re doing a couple of dozen prototypes you can use any and as many components and parts as you want, but when the time comes to build thousands, they might turn out not to be the best choice regarding costs and lead time.

 

And what if on top of that, the manufacturing plant doesn’t have the capacity or technology to handle the components you chose for your design?

 

Take Juicero as an example.

 

It consisted of 400 custom parts and dozens of components and subsystems, it’s as if they wanted to make the device as difficult to manufacture as possible.

 

It was not DFM friendly.

 

Juicero failed by the way.

 

DFM and scaling up

 

Bottom line, if you designed your product without considering your manufacturing plant’s capabilities and components availability, you’ll have a hard time scaling up.

 

You’ll have to go back to the design board and start over.

 

Allow me to introduce another DFM guideline from our CEO.

 

“Involve key suppliers early in the design”

 

This way, you’ll ensure that each custom and non-custom part of your design is available in stock and compatible with the machines and capabilities of the factory you’re working with.

 

Setting Up Tooling 

 

This might be a little obvious but is still worth mentioning because many times it is overlooked.

 

The more components and parts your product has, the bigger the production line will be.

 

The more machines and work stations will need to be set up.

 

There’ll be more operations required per part.

 

DFM and tooling

 

The more workers will have to be trained, and in case the plant doesn’t have them, they’ll have to start looking for them.

 

If you follow a DFM approach to your product development process, you’ll end up with a product consisting of as few parts and components as possible.

 

This will significantly reduce the number of operations required per part and simplify assembly.

 

Now for the most important reason to use DFM.

 

Faster Time to Market

 

DFM aims at creating a smooth transition from prototyping to mass manufacturing.

 

That right there is the key to making it to the market before your competitors and making some serious profit.

 

Imagine you spend months or years developing a product just to realize that it’s not possible to mass manufacture it in a timely and cost-effective manner.

 

All that money and time wasted. Now you have to start over, that is, if you can afford it.

 

And now, after a redesign, even if you get to manufacture the product this time, you’ll realize that your entry to the market is late; your competitor already took your market share.

 

That’s a very dark scenario I know, but sadly, one that many new hardware ventures go through.

 

DFM and time to market 

Just Google hardware failures and you’ll see it for yourself.

 

In many instances, these hardware companies fail because they failed to embrace DFM.

 

It doesn’t matter if you’ve spent countless hours on the design of your product and is the best in the industry; if it’s not manufacturable, it was just a waste of resources.

 

DFM importance resides in making sure whatever you design is manufacturable, something way too many companies fail at.

What are the Advantages of DFM?

The advantages of DFM are

 

  • High quality products
  • Fast Time to Market
  • Lower production cost
  • Faster product development process
  • Smoother transition between prototyping and mass manufacturing
  • Smooth product manufacturing
  • Higher profits

How Long Does DFM Take?

DFM will take from 3 months to 6-9 months, this will depend on the expertise of your engineering team,how well they communicate with the manufacturing plant and the complexity of the product.

 

There’s something we’d like to make very clear, DFM is not a step that happens before, after or throughout the manufacturing process.

 

DFM is a design and manufacturing approach that happens along with every product development stage until the product reaches mass manufacturing and packaging.

 

how long does DFM take

 

With an experienced team, DFM for your first prototype will take 3 months, for a works-like-looks-like prototype DFM will take 6-9 months.

 

DFM will also be present throughout the final assembly stage.

 

DFM Guidelines for Assembly  

What are Design for Manufacturing Examples?

Here’s a clear example of DFM in a mass manufacturing setting


The Renault-Nissan-Mitsubishi Alliance produces 49 different vehicle models.

 

All their electronics, such as the displays, the radios, the safety devices, HVAC, etc., are 99% the same, the only difference is the logo, and sometimes a part of the housing and the firmware.

 

Here’s a possible scenario in your manufacturing process and a good DFM example.

 

You are using screws to fasten your PCB on the housing, a different screw type to attach a sensor on your electronic product, and another kind to fix a heatsink to a transistor.

 

Instead of having 5 type-A screws and 7 type-B, and 3 type-C, you will have 15 screws, but all of them type-D, improving your volume effect, your manufacturing logistics, etc…. And then reducing your product cost!

 

One more DFM example 

 

Sometimes, because it is more appealing to benefit from the volume effect, some brands install the same components for products of different tiers but restrict the lower tier ones by firmwaring it differently.

 

This is the case of some smartphones: In a mid-range smartphone, you can have the same camera as the high-end model, but its poorer firmware will limit the quality of its use. But both need cameras; then both use the same camera. “same need; same solution.”

What Factors Affect DFM?

DFM aims at making a product easy to manufacture while achieving high quality standards and lower manufacturing costs, these are the factors that get in the way of DFM. 

 

1- Product Complexity

 

The more complicated the product is, the more mechanical and electronic parts and components will be needed, this increases the difficulty of building an easy to manufacture product.

 

2- Product Variants

 

Typical example here, smartphones, every time Samsung Or Apple comes out with a new series of phones they have 2 or 3 tiers.

 

They come out with these variations because of market needs and different market segments they’re appealing to, it’s great from a business point, but manufacturing wise is challenging.

 

It’s challenging because you have to deal with 2 to 3 different production lines, this means having to source different components, developing different firmware or setting up different toolings, it will all depend on how different the product variants are.

 

Some solutions, using the same components, such as camera modules, to make assembly easier, but limiting functionality with different firmware.

 

3- Components Availability and Price

 

Getting all the electronic components you need to keep production lines running is a challenge.

 

Components’ lead times vary from days to weeks.

 

So if you designed your PCB with components you did not check lead times for, you might be in trouble when mass manufacturing comes.

 

The price of components it’s also something that may vary widely based on your suppliers.

 

4- Reusable Design

 

Whether a previous design is reusable or not will impact DFM, there’s a reason why every new iPhone looks a bit like its previous version, because the design was intended to be reused for ease of manufacturing.

 

If Apple wanted to come out with totally different phone shapes every year, they would have to invest heavily in R&D, tooling and molds; this wouldn’t be DFM friendly.

 

5- Regulatory Requirements 

 

Every product has to comply with quality standards and certifications depending on the environment where they’ll function and depending on country location.

 

So , if a product needs to work say, in underwater conditions, then conformal coating for PCB will have to be added to the design 

 

This means an  extra step in manufacturing, tie and costs will have to be calculated for this.

Learn DFM with Blogposts by Industry Experts

Do you already have an electronic prototype and you want to make sure is optimized for DFM?

Get in touch with us to discuss where your project is at and find out if we’re the right manufacturing partner for you.

Contact Us
CONTACT