OPTIMUM EMS HANDBOOK

Transcription

1 OPTIMUM EMS HANDBOOK

2 TABLE OF CONTENTS Introduction... Pricing Matrix... Step 1: Early Process Preparation... Step 2: Design Review... Step 3: Open Book Cost Analysis... Step 4: Lean Front Office Processing... Step 5: Manufacturing... Conclusion

3 Yes, we re different. First, we talk openly about price and recognize how vital it is to you. Second, we deeply respect the risk you take when selecting outsourcing partners. On this page we provide a detailed explanation of how we approach PCB assembly so you can decide if we might be right for you. We are low cost. How can a domestic contract manufacturer in Silicon Valley compete with Mexico and China on price? Competitors are watching, so you ll have to call us for that one, you ll like what you hear. But... We are not everything to everyone. We are a focused factory very good at volume SMT production and related system integrations. We have the very same capabilities as the biggest EMS companies (we used to work for them), the difference is we have the freedom to innovate new ways of driving down your costs. Optimum EMS Handbook 3

4 Speaking of prices, here they are... We know price is vital to you, so here you go. The non-optimum prices are tabulated from objective 3rd party data sources. Our approach is very different from what other EMS companies are doing. It isn t theory, and it s not sexy or showy. Mostly it s just hard work. It does require experience, expertise, and intelligence. But history has shown it s successful at reducing cost and improving quality time and time again. So we just do it, everyday. Optimum EMS Handbook 4

5 Step 1: Early process preparation. Early - as in before we do anything else. Applying lean principles to the early stages of a project is one of the factors most responsible for our phenomenal quality performance. When you request a quote from EMS companies their objective is to figure out a price (we know, we ve worked at all the big EMS companies). At Optimum, we don t just quote, we begin the process of preparing to build. More fully detailed in the pages that follow, by the time you receive a quote from us we have cross-checked hundreds of elements of each component. You need to......perform a BOM scrub...know about ECN s & PCN s...know if you re single sourced...know if your supplier has on-hand inventory...confirm your package types Optimum EMS Handbook 5

6 You need to perform a BOM scrub. A BOM scrub verifies that your manufacturer/manufacturer part number combinations are valid. This should always be your very first step. Enormous amounts of time are wasted when this isn t done, and without it your ability to take advantage of downstream automation tools is greatly restricted. We prefer SiliconExpert for this. We have partnered with them for years, and through a special arrangement we contract directly with SiliconExpert s component engineering team to conduct most of our BOM scrubs, which they do for us overnight. You need to know about ECN s & PCN s. We don t wait to hear back from suppliers that one of your parts is obsolete. We collect the life cycle status of each individual component, but here s what a summary chart of your lifecycle data would look like: Lifecycle Summary Report Optimum EMS Handbook 6

7 You need to know if you re single sourced. The percentage of your BOM that has multiple sources is a good barometer of overall risk. We provide you with line by line detail, but here s what a summary chart of your multi-source postion would look like: Multi-Source Summary Sometimes, you need alternatives. When you do, wouldn t it be nice to have comprehensive report of alternates, including any differences and the predicted life of the alternate? And how about a link to the datasheeet? Viola! Cross Reference Detail Report (source: SiliconExpert) Optimum EMS Handbook 7

8 You need to know if your supplier has on hand inventory. This is often one of the most vexing problems for small lot builds. Your supplier presents you with costs related to min/mults, but you think they should have the parts on hand from prior builds. Our systems automatcially checks each AVL d manufacturer part number for 3 types of on hand inventory: on hand under your internal part number, on hand consigned inventory for you, and on hand unallocated inventory under another customers internal part number. These checks are performed automatically by our custom designed cost analysis software. Descriptions are unreliable, your package types need to be confirmed. Package types are critical to understanding labor costs and workmanship standards, and capability requirements. We pull the package types automatically from two databases (SiliconExpert and Mentor Graphics VPL) which each reference over 3 million parts. Our software recognizes 300+ package types and further categorizes them into 12 types for labor analysis. Optimum EMS Handbook 8

9 Step 2: Design Review Design for Manufacturing (DFM) is a broad term with a range of meanings. We refer to design reviews as Design for Fabrication (DFF), and Design for Assembly (DFA). DFF is a tool set used to review the design of the PCB prior to fabrication and we discuss it in the PCB layout methods section. Here we ll review DFA, which looks for problems that may cause rejects or other quality issues during assembly. Often associated with NPI, we run DFA on all products new to our manufacturing floor, and after any significant ECO s. We use Valor. Mentor Graphics Valor software is a suite of products for manufacturing. One of the modules runs a series of checks against a set of rules specifically configured for the target manufacturing floor. Called the Design Rules Check file (.drc), there are hundreds of test performed on every component and on every individual solder joint. Valor divides the tests into 6 categories and reports concerns (in yellow) and violations (in red) as summarized here: Optimum EMS Handbook 9

10 Tens of thousands of solder joint checks. A typical 100 line item BOM might have 500 individual solder joint connections. We check each board for 242 solder joint rules, that s 126,000 tests (500 X 242). Here s some examples of what we check for you: You receive a detail report by line item. The Valor software reports a staggering amount of detail and can frankly be overwhelming. We have designed a custom report organizing the Valor output by prioritizing the issues. This is the report we provide to you. Optimum EMS Handbook 10

11 We handle the interpreting. In truth, you probably won t actually want the report above. Instead, you ll likely rely on us to review the report and let you know if there s anything you need to address (this is especially true if we designed the board). This is because we have in house design engineers, manufacturing engineers, test engineers, and world class PCB designers, so we have immediate access to the expertise necessary to interpret and act on the Valor DFA outputs. Optimum EMS Handbook 11

12 Step 3: Open Book cost analysis (not quoting) You need a partner, not an adversary. The partnership starts with working together to drive cost. We are big believers in the should cost approach, which means you should understand the actual manufacturing costs of the products your outsourcing, not just the top line price. Most OEM s lack the resources or training to conduct this type of analysis. Instead of just quoting you a top line price, we provide you with a full cost analysis so we can work together to drive out cost. Your costed BOM is the repository of your collected wisdom. OEM s are often a little surprised when we point this out, but consider it for a moment. Which manufacturer has the best price for each component? Which vendor (as in distributor) offers you the best pricing and terms? Which package/temp range/rohs/bulk or reel or tray or cut tape combinations is best for your circumstance? Have you leveraged your larger relationship to negotiate preferred pricing? The older the product, the more this type of knowledge accumulates in your BOM/AVL. This is especially true for custom items like cable assemblies, plastics, sheet metal, and machined parts. Optimum EMS Handbook 12

13 So... share your costed BOM. Apple, Cisco, and other leading outsourcers provide their costed BOMs. Why? Because it s dramatically more efficient and much more likely to lower costs. It s more efficient because we do not have to chase after low cost, highly custom, or poorly specified material. The odds of suppliers magically discovering lower material costs are actually quite low, especially for electronic components (see our article on how components are priced). We re much more likely to actually identify lower costs for you when we can focus our efforts on the cost drivers instead of chasing after every low value component. Where to collaborate, and where to compete. In most outsourced electronic assemblies materials account for about 80% of product cost and we are not the direct source. The other 20% is labor, overheard, and profit which we are the direct source. We are both equally interested in the lowest material cost, so we are doing our best work together when we collaborate on materials. Share information, sources, prices, etc. Labor/OH/Profit we do have differing interests (we want more, you want less!), so compete this part. Optimum EMS Handbook 13

14 Open Book Costing (we share too). Transparency in cost is the heart of a should cost partnership. Finding a contract manufacturer willing to provide open book costing is a foundation to cooperating on reducing costs, especially materials cost. We provide you the line item detail necessary to understand your product cost so we can work together to drive it as low as possible. It s a big world; prices will vary. Global component pricing is an ever changing riddle. Since our management team includes a former distibution executive we have a clear understanding of how component pricing really works. One of the fundamental problems is component pricing is often silo d inside the component suppliers. There is a nice person who prices United States procurements, a nice person who prices Asia, and another nice person who prices Europe. And they don t talk to each other. We often wonder if they even know each other, considering how widely prices can vary by global region. As a broad average, we believe component prices vary by about 20% around the world. Global component sourcing. Savvy buyers must know which region of the world is currently pricing their commodities the best, so that s what we do for you. We maintain a network of sources that allow us access to sourcing around the globe. This is often very sensitive, so we work closely with you to make sure any existing domestic supply chain relationships are honored. Optimum EMS Handbook 14

15 Cost reduction is an on going process, not an annual event. World class outsourcing OEM s don t treat cost reduction as a yearly excercise, or something that happens during NPI, or as any else special. It is part of the daily DNA. To get your best possible cost, you need a partner with a culture of cost reduction who works in cooperation with you to drive cost all year long. Customized cost report. Our cost analysis process collects a lot of data and you will likely only want to see part of it. All of our cost analysis reporting is custom formatted for your needs in Excel. We can provide whatever you can use, here s an example of how one customer likes to receive the data. Optimum EMS Handbook 15

16 Step 4: Lean Front Office Processing Front office processing refers to those steps we take to import your BOM, acquire your materials, and bring your documentation into our systems. Once you release your order, our front office processes begin. The steps we take here are crucial to delivering your product on time and have a substantial impact on quality by reducing common errors. In this section you ll learn about surprising process innovations we have made through the application of lean principles to office processes. Lean Insight 1 All powerful Program Managers. OEM s are often a little surprised when we point this out, but consider it for a moment. Which manufacturer has the best price for each component? Which vendor (as in distributor) offers you the best pricing and terms? Which package/temp range/rohs/bulk or reel or tray or cut tape combinations is best for your circumstance? Have you leveraged your larger relationship to negotiate preferred pricing? The older the product, the more this type of knowledge accumulates in your BOM/AVL. This is especially true for custom items like cable assemblies, plastics, sheet metal, and machined parts. Optimum EMS Handbook 16

17 Lean Insight 2 Dual BOM s. We know, this is heresy, but it s phenomenally successful. We use your BOM in our costing tool for the ERP import which drives material and planning (see instant BOM import below to understand why) and we pass your original documents to Manufacturing Engineering which uses them for programming the manufacturing equipment. The two BOM s meet at the kitting/feeder set up stage when the Picklist gets matched up with the Traveller. This is not only much more efficient, it creates a closed loop feedback channel that automatically double checks for simple errors, like data entry. Lean Insight 3 No dedicated document control function. More heresy. It turns out Program Managers and Manufacturing Engineers, who actually use the data, are the most efficient and effective at storing it. To be clear, we have strong document control practices, we just don t accomplish the task by passing the docs to a 3rd party for storage and access. Turns out that doesn t add value, in fact it induces error, and lean principles demand we eliminate such steps. Optimum EMS Handbook 17

18 Instant BOM import During the cost analysis process we collected and organized all the data necessary to import your BOM. In the process we identfied and resolved any issue that would prevent us from importing, like missing, incorrect, or mis-matching information. We accomplished the myriad little things, like customizing your part numbers to our nomenclature, addng vendor codes, adding package codes, etc. Because this was all done very early, once we receive your order we simply hit a button and your data is instantly imported into our ERP. Instant 100% ERP accuracy We re really very pleased with ourselves about this one. Items are at the core of all ERP systems. Items have many fields, usually around 25 that matter. Typical active contract manufacturing divisions have 10,000-20,000 active part numbers. That s 250,000 or more fields that have to be correct. We don t know of any other company that has the tools to make sure all the fields are correctly populated, but if they did they would have 25,000 or more errors to correct (we know because we ve done studies on these types of databases). We have built just such a tool and we know the moment your BOM is imported if there is any missing or out of parameter data. We belive we have the only ERP database in the industry that is 100% correctly populated 100% of the time. Instant procurement visibility We have aligned our internal procedures to allow any procurement or program management personnel to run ERP on the fly. Our ERP recalculates in about 15 seconds. So when your new requirements are loaded, purchasing sees them immediately. Instant = Efficient = Low Cost It s great that we can execute these processes instantly. But speed isn t the real advantage, it s cost. Fast means we are extremely efficient, and less time directly translates into less cost. Optimum EMS Handbook 18

19 The industry s best real time dashboard The screenshot below is a portion of our in house developed real time dashboard. It is connected in real time to over 50 database components of our ERP and Quality Execution systems, interogating the status of about 100 key operational metrics. In addition, we push key parts of the dashboard to our smartphones 3 times a day, so we are always aware of our operational status. This creates another remarkable efficiency effect. Our team doesn t have to stop and think about what to do next, the dashboard guides them. And because each department stays on top of their metrics, there is little need to cross expedite each other. Real Time KPI Dashboard Updates pushed to phones 3 times daily Optimum EMS Handbook 19

20 Step 5: Manufacturing Manufacturing defects are more commonly induced by human error than machine failure. So we trust automated processes, and double-triple check anything a human does. This simple philsosophy is the heart of how we approach manufacturing and achieve less than 25 solder joint DPMO. Double Check #1 Manufacturing Engineering starts fresh. Manufacturing engineers start with the original customer documents to create the files and documentation necessary to process the job. Additional information to process the job is passed from the Program Manager to Manufacturing Engineering via an internal checklist to ensure all the required docs and data are present for engineering. We ask a lot of our manufacturing engineers. They basically start with fresh eyes and review the entire job in detail. Double Check #2 BOM compare at kitting. At kitting we compare the Picklist BOM to the Traveller BOM. The Picklist is generated by our ERP and drives material. The Traveller is generated independently by manufacturing engineering. By cross-checking at this stage we verify correct BOM entry, including internal part number, quantity per, and AVL manufacturer part number, and packages. Optimum EMS Handbook 20

21 Then we set up the feeders. Ah, feeders. OEM s seldom realize it, but a contract manufacturer s investment in feeders can equal or even exceed the investment in SMT equipment. If you want to ask a savvy question next time you visit a PCB assembly operation, inquire as to how many feeders they have. You re probably looking for an answer of about 200 feeders per line. They need enough feeders to have each line running and a set up waiting for each line. If you want to know if they have enough feeders for your work, count how many SMT parts are in your largest BOM, times that by two, then times that by the number of SMT lines at the contract manufacturer, and that s how many feeders you need them to have (actually you should perform this calculation on the contract manufacturers largest build but for good reasons that s hard to know). Double Check #3 Now we do a full audit. Manufacturing engineers start with the original customer documents to create the files and documentation necessary to process the job. Additional information to process the job is passed from the Program Manager to Manufacturing Engineering via an internal checklist to ensure all the required docs and data are present for engineering. We ask a lot of our manufacturing engineers. They basically start with fresh eyes and review the entire job in detail. Post Feeder Setup QA Optimum EMS Handbook 21

22 Meanwhile, we re programming the equipment. This is another area we have eliminated a human step. We run your information through Valor to check for potential manufacturing problems, then we use Valor directly to program our equipment (most contract manufacturers use the equipment vendors software to program, meaning up to 4 different software packages to cover SPI, SMT, AOI, and AXI programming).we work very closely with Valor and the equipment manufacturers to support, streamline, and optimize this process. About 75% of programming time is related to developing a library of components for each equipment supplier. By working to integrate Valor libraries with equipment libraries we are pioneering an effort to greatly reduce programming time and improve optimization quality (this is a really big deal!). Our SMT line capacity is up to 4x the industry average. The capacity of SMT lines is expressed in component placements per hour (CPH). CPH ratings can be taken from manufacturer max rating, from an IPC standard rating, or from actual boards. The rating from actual boards is the only one worth paying attention to, and is derived from programming simulations of actual boards and verified with actual results down the line. Most industry SMT lines run two pick & place machines and have an actual CPH of about 15,000. We deploy a line with two Universal Instrument Fuzion machines, the line capacity is 60,000 CPH actual. Our other line deploys 3 Universal Advantis machines with a line capacity of 27,000 CPH actual. Put another way, we have the capacity of a 4 line SMT operation with half the overhead...more cost savings passed to you. The secret sauce: Printing & Oven... The manufacturing steps down an SMT line are solder paste printing, SMT placement, solder reflow oven, and wash. Of defects induced on a SMT manufacturing line, substantially all of them are related to either solder paste or the reflow oven. Exactly how we develop our printing processes and oven profiles is proprietary, but there are a few best practices we can share... Optimum EMS Handbook 22

23 Solder paste printing best practices % of SMT manufacturing defects can be traced back to paste printing. Keys to successful printing are selecting the most optimal paste and the best tools (stencil and squeegee blade). Solder paste consists of solder powder and liquid flux. The solder powder is comprised of metal alloys chosen for the specific application. The particle size of the solder powder varies, and the needle that dispenses the paste must be sized accordingly. The table below is best practice starting point for selection of solder paste/needle size combinations: Dispensing Needle Size Selection Guide For typical projects that contain fine pitch components, we consider laser-cut stencils with micro-etching to be best practice. Laser cut stencils are made directly from CAD data which improves process control and can produce aperture widths as small as with an accuracy of When appropriate, laser cutting can produce tapered apertures, an angle of about 2 is best practice for optimal solder paste release. Optimum EMS Handbook 23

24 ...and oven profile best practices. There are two approaches to oven profiles, ramp-to-spike profiles (also called ramp-to-peak or tent profile) and the soak profile. We utilize soak profiles on 9 zone ovens. There are four basic stages, preheat, pre-reflow, reflow, and cooling. During pre-heat the assembly s temperature is raised from ambient to a target temperature at a rate that can vary from 0.5 to 2.0 C per second. About 0.78 C per second is a good baseline best practice for average board sizes and densities. As the board moves between zones, a T (delta T) of 40 C is best practice. At pre-reflow, also called the soak phase, the goal is to bring the entire board to exactly the same temperature everywhere across the assembly. During this phase the component leads are prepared for bonding with solder by the flux activator, which removes surface oxide. The soak phase is critical to preventing voiding in all it s forms, and is especially critical for hidden lead packages (BGA, LGA, QFN, etc.). At the reflow phase, the temperature of the assembly is raised just high enough to cause the solder to liquify (the liquidus) and form a metallic bond with the component leads. Best practices are to raise the assembly s peak temperature to C above liquidus and hold it there for a TAL (time-above-liquidus) of seconds. During the cooling phase the objective is rapid cooling, because rapid cooling produces the most reliable long term solder joint by inducing a fine grain structure in the solidifying solder. However, if the cooling is too rapid solder joints will crack from thermal stress caused by different coefficents of thermal expansion between the component leads and the solder. Best practice is a cooling rate of 4 C per second. Post reflow first article inspection. Once the first assembly completes reflow, the line is stopped while independent quality auditors verify the process. The assembly is first visually inspected, then undergoes automated optical inspection (our latest AOI was installed in 2014 and is state-of-the-art). When needed we inspect the board with automated x-ray inspection (our latest AXI was also installed in 2014). When these steps are complete, the board undergoes a final visual inspection, then the line resumes production. Optimum EMS Handbook 24

25 Conclusion As this overview demonstrates, the Optimum Method is not about tips & tricks; it s a consistant process that covers a range of disciplines and is designed to lower your cost while improving your quality. We don t know any simpler, more effective methods of saving you time and money. What to do next... We make evaluating us further a breeze. You can easily review our cost model by requesting a price. Your quality team can review a 60 page IPC audit report at any time. We ll encourage you to speak with exisiting customers so you can get a feel for what it s like working with us. Our state of the art Quality Execution System is fully on line and easy to show via a Webex. And when your ready, we ll fly a team to your site to meet you personally. If you d just like to learn more... We have tons of helpful information published on our blog. Visit our website to view our most popular articles to get you started. Optimum EMS Handbook 25