Developing the PCB for a Product Made in China – Part 6

Let’s keep going with the series of articles on new product development. This sub-step is dedicated to products that contain electronics.

PCB design

If your product requires a printed circuit board (PCB), this falls under the ‘hardware design’ element of this phase. We will not go into too much detail of how to design a PCB, but will however go over the basic steps behind best practices (Source: National Instruments tutorial 6894).

Step 1 of the PCB design starts with the understanding of what it is required to do and then goes onto researching each of the individual physical components (such as resistors, capacitors, transistors, diodes, ICs and other components). Part research and selection requires trial and error and a structured methodology to understand how each component works within the overall design of the PCB.

Step 2 is all about generating a schematic of the PCB design, also known as capture. The schematic capture uses a CAD design interface specifically for PCBs which have all the required product symbols of the circuit components. The schematic is a design representation in the form of symbols connected together by lines which is known as a net, an example of a schematic diagram is shown below:

PCB schematic

Step 2 also includes simulation. Once the schematic has been completed, simulation of the design can be run which can predict the behavior of a circuit and analyze the effects of various components and signals upon the design. This is an important step in the modern design process because it allows one to emulate the performance of a device before it is even physically built. A design topology can be tested immediately to see if it needs to be modified. Simulation can therefore save both time and money. Simulation can help uncover the most uncommon flaws quicker, and prior to costly prototyping.

Step 3 is where the PCB layout is completed. During the layout stage the actual integrated circuits (ICs) and components are placed onto the board, and connected via a current carrying conduit called a copper route (or copper trace). The final necessary step is creating a board outline which defines the form factor of the PCB (the form factor is important as it will ensure that the board fits the chassis, system or physical environment in which it will be eventually placed and operated from).

Step 4 is the final step in the validation of a PCB — prototype test. It is important in validating if the design meets the original specifications, while manufacturing test is important in making sure each device shipped to a customer meets the appropriate testing standards.

The prototype test analyzes the real-world behavior of a PCB and compares it to design specifications to benchmark these results. From a high-level perspective this stage requires a test engineer to take design specs from the designer and evaluate the PCB performance (thereby commenting on the success of the design). Based on this analysis the test engineer needs to either communicate to the designer if some form of design modifications are necessary on the board, or if it is ready for manufacturing.

How to Understand Quotations from Chinese Suppliers

Here areBest Quality & Sourcing Articles some interesting or useful articles that I found recently.

NOTE: A FEW DAYS AGO I HIT THE “PUBLISH” BUTTON INSTEAD OF THE “SAVE” BUTTON SO THIS MESSAGE WAS POSTED TWICE. SORRY ABOUT THAT.

Question your Quotes from China

Jacob Yount gives excellent advice about the way to understand and respond to quotations from Chinese suppliers. Good read, especially for purchasers with limited experience in China.

Restricted Substances: 5 Challenges when Buying from China

Fredrik Gronkvist has a knack for taking a complicated and boring issue and simplifying it. If you are curious about safety requirements such as REACH, ROHS, Cal Prop 65, and so on, this is a good article.

Retail Global Sourcing Report

CBX Software produces a report every quarter that includes many interesting data (labor rates, freight costs, currency moves, etc.) as well as some analysis of the latest trends.

Minimum Wages in China for the year 2014-15

Interesting database about minimum wages in China, with details per city.

‘Made in China’ Is Increasingly Becoming ‘Made in USA’

The American press keeps relating examples of a revitalization of American manufacturing. But the so-called vast “re-shoring” movement hasn’t happened.

What if 3D printing was 25 times faster?  

It seems like a new technology is going to allow 3D printing to become much, much faster. If this promise becomes true, it might impact the global manufacturing industry in a major way — especially in product lines where China is currently competitive (injection molding, metal machining).

Plastimake

I just discovered this fun product. Look into it if you need to make prototypes for certain types of hard goods.

Quality Issues in China: Planning for the Worst Case Scenario

I responded to this Q&A about the types of quality issues, what to do in case of minor issues, what to do in case of major issues, and what steps small buyers should take to avoid those problems in the first place.

Developing the Product – Part 5

This is the fourth in the series of articles helping you through the New Product Development process. We will actually break it into 12 separate articles.

Product_Development

In this post we’ll briefly go over the objectives of this phase.Objectives

During the product development phase the product is designed, built, tested and finalized ready for mass production. The main tasks in order to achieve this are listed below (obviously this is an example that needs to be adapted to your product):

  1. PCB / hardware design
  2. Physical mechanical parts design
  3. All parts to have a prototype built
  4. Product functional testing
  5. Design review iterations
  6. Build of pre-production tooling
  7. Initial product build
  8. Assembly review
  9. All safety and regulation requirements testing and approval
  10. Technical data pack including all engineering drawings and specifications.
  11. Also included in this phase are the design for the product packaging, user instructions, marketing materials and any other item requiring design input.

Many good articles are coming up soon…

Different Methods of Prototyping

When it comes to making hard goods (be it a plastic case for an electrical product, a new type of metal jewel, a new mechanical part…), making prototypes is an important part of the new product development process.

When the prototype is made by a Chinese manufacturer, the buyer should know what type of prototype will be made. There are many prototyping processes available for product development teams to choose from. Here is a list of the most common ones.

1. Conventional machining

Ideally, a 3D CAD design is received by the machining center and a prototype comes out at the end. The machines might be numerically controlled (CNC) or not — this is often a great way of getting a few prototypes that should look the same as mass production.

Advantages of Conventional machining

  • Mature technologies that can produce high-accuracy components
  • The material can be the same as mass production
  • Any testing carried out on this form of prototype will be fully representative of the production intent design, therefore any material or strength issue found at this stage can be addressed and design modifications made.

Disadvantages of Conventional machining

  • Parts tend to be machined out of solid blocks of material and there could be a lot of wasted material.
  • A number of different machining processes may be required to complete the part. Each of these processes takes time and would normally be completed by skilled machinists. All this adds up from a cost point of view.

2. Stereolithography (SLA)

SLA produces fast, accurate prototype models using an additive manufacturing technology which employs a vat of liquid ultraviolet curable photopolymer “resin” and an ultraviolet laser to build parts’ layers one at a time.

Advantages of SLA

  • Speed — within a day.
  • Accuracy within the tolerance of the thickness of each layer, which is typically 0.05mm (0.002”).

Disadvantages of SLA

  • Typical size of parts that can be produced are 500mm x 500mm x 600mm (20” x 20” x 24”). Large parts cannot be made with SLA. Note that several parts can be glued together.
  • The finished product can be quite brittle (made from cured resin only).

3. Selective Laser Sintering (SLS)

SLS is also an additive manufacturing technique. A laser fuses several materials (plastic, metal, or ceramic powders).

Advantages of SLS

  • Strong prototypes
  • Wide range of materials

Disadvantages of SLS

  • Less accurate than SLA due to the size of the powder granule.

4. 3D Printing

3D printing is yet another additive technique. An object is created by laying down successive layers of material.

Advantages of 3D Printers

  • 3D printers are inexpensive. You can have one in house.
  • You can run multiple iterations of new products at a low cost.

Disadvantages of 3D Printers

  • Size constraints: it is hard to find a 3D printer that can make large parts.
  • Material choice is relatively limited.
  • The surface finish can be highly textured (low accuracy)

5. Vacuum Casting

Silicone molds are created, and then the mold is used to create parts.

Advantages of Vacuum Casting

  • Multiple parts can be produced. Good for making small quantities of a certain product.
  • Parts are near perfect production quality.

Disadvantages of Vacuum Casting

  • Products are usually in rubber material.
  • Relatively high cost of producing the silicone mold and the parts.

A couple of precisions:

  • The methods listed above are all available in China from many suppliers.
  • Industries concerned are household products, office supplies, automotive parts, consumer electronics, medical devices, concept showcases, kitchen products, garden tools, industrial designs…

Three Different Types of Prototyping for China Manufacturing

When it comes to mechanical and/or electrical products, importers often wonder what level of perfection they should aim for when it comes to pre-production prototypes.

Chinese manufacturers can move very quickly for a few weeks, and then get distracted by another shiny project. And many projects get stalled after the buyer asked for one or two revisions that became obvious once prototypes were made. Therefore it sometimes makes sense to start with a very simple prototype version, to move fast and keeps the investment low.

There are three main types of prototypes you should consider:

  • Working Prototype or ‘works like’
  • Non-working Prototype or ‘looks like’
  • Works like / Looks like

Which one is the most appropriate to you? Well it depends on what your objective is.

Working Prototype (works like)

This type of prototype basically proves your concept in a working model, from moving parts to electronics; it will show you how the finished product would perform.

This prototype does not need to look pretty or polished as its main function is to prove functionality and performance. They are great for testing each subsection as well as the complete system integration of the entire product.

Non-working Prototype (looks like)

This type of prototype is all about looks, and ultimately could just be a non-working shell of your design. From a marketing and branding point of view, you could use these prototypes for photo shoots, website images; these could be used at exhibitions to show potential buyers and distributors the ‘next big thing’ you are releasing.

One advantage is that Chinese suppliers won’t be able to display it on their trade booth or in their showroom. Any potential customer will understand right away that there is still a long way to go before getting into production.

Works and Looks like Prototype

This is a fully functioning physical model of your concept, from both a functional and design point of view. This level of prototype is just one step away from full production and is normally produced once you are sure all the design features are finalized and everything has been verified and ready to move into production.

When should I use what type?

Throughout the New Product Development process you will need to verify your idea and concept, and as the product moves through the development stages you may need a number of different prototypes. The ‘Working Prototype’ will provide you with that platform to test and develop all the features of the product. At this stage you may not have the overall look or shape as you need to finalize the ‘working aspects’ of the product.

The non-working ‘looks like’ prototype can be commissioned once you have the layout complete and you know the overall size of the product.

You may need a number of iterations of both the working and non-working prototypes throughout the product development cycle, but ideally you would just need design of the fully functional ‘works and looks like’ prototype.

Any other tips to share?