THINKING 3-D WILL HAVE YOU FLIPPING
Thanks to the wonder of gravity, you can rely on stuff staying in a box when placed there. And if the stuff fits well in the box, only the top is accessible. It’s pretty much the same for components in a tray. Parts that fit precisely in tray pockets make processing a two dimensional activity unless you have discovered flipping.
When BGAs (Ball Grid Array packages) first hit the market the need for accessing the balls was not recognized. Once it was recognized, R H Murphy Company responded quickly with “flippable” trays. R H Murphy invented BGA trays that can be inverted, unloaded, reloaded, and restacked while the parts remain contained and protected. This makes inspection, rework, repair, even some level of testing possible without removing parts from the trays. This same principal is readily applied to other device types.
There is more to having flippable trays than just putting pockets on the bottom of a tray. Managing the alignment and exposure of the parts in both orientations is critical. Insuring that trays being stacked pre-align before engaging the parts requires unique features. Eliminating device terminals, leads, or pins from being the point of first contact means the difference between a tray the protects and one the damages parts.
The key to successful flipping is interengagement. By building features that overlap, trays capture the components from the top and bottom simultaneously. This provides a secure hand-off between trays and the components remain contained and protected in all orientations.
R H Murphy has been doing all this while giving you the performance you count on: ESD protection, mechanical integrity, thermal stability, JEDEC alignment features, and value above all else. Don’t let yourself be limited to a two dimensional process. Add a third dimension with flippable matrix trays from R H Murphy Company.
A Case Against Standards: Interface components need real specifications
JEDEC, the Joint Electron Design Engineering Council, originally started in 1958 as a division of the Electronic Industries Association and became an independent association, JEDEC Solid State Technology Association, in 1999.
Since many of the standards developed by JEDEC cover devices from many manufacturers, the "standard" dimensions are too general to be used as specifications. In most instances, the JEDEC standards have been developed to create interchangeability among multiple sources of the same component type. This has worked pretty well for PCB manufacturing because variation of the mounting footprints have been kept to a minimum.
But before the assembly to the PCB takes place, most processing is done with the goal of not contacting the terminals/leads. This goal makes it necessary to support the component by its body and here’s where it gets problematic. There are many variations in material, assembly technology, and tooling for the body. Rather than exclude any designs, the standards typically use reference dimensions or large tolerances for body dimensions.
When trying to build “standard” interface components and tooling for a standardized component, building to accept the full range of the standard specification will not work. Build for the biggest parts and the small ones will be too loose. Build for the smallest and the big ones get crunched.
In the following example from JEDEC Registration MO-082 for .025”pitch ceramic quad flat packs (CQFP), the body dimensions are allowed to vary by 1mm while the formed leads may start to bend at 0.64mm. Features accepting the largest body size will make contact with the leads of devices whose body dimensions are in the middle or lower range of the specification.
The good news is that most components produced by a specific set of tooling have much less size variation than allowed by the specification. That means that manufacturers can usually provide component specifications that are precise enough for safe handling without damage. When good dimensions are not available, measuring a sample is a good alternative.
The moral of the story is that it’s best to get manufacturers’ specifications for components rather than working with standards. Be wary of handling material that claims to be for “standard” packages, particularly when working with delicate SMT devices like QFPs, BGAs, and CGAs.
Trays are trays, right? Wrong! There are obvious differences and subtle ones, too. Beyond the specifications, here are a few question to ask your JEDEC tray supplier that will tell you what need to know before you invest your time and money.
Do your trays comply with the JEDEC outline dimensions and tolerances?
It’s important that trays meet the specification to work properly with automation equipment, fixtures and tooling. Don’t be misled by generic descriptions that don’t include tolerances.
RH Murphy Co. trays are manufactured to the same tolerances as the JEDEC standard.
Do you guarantee tray flatness at the maximum rated temperature?
Temperature ratings should be for continuous exposure and the trays must stay flat and functional. Some manufacturers are rating their trays based on deceptive testing. It’s not good enough that the tray doesn’t melt.
RH Murphy Co. tests trays at temperatures above their ratings to make sure trays will perform as promised.
When trays don’t meet their ratings
Do you use carbon powder in your trays? The best answer is no!
Carbon powder is a low-cost, electrically conductive filler for plastics used by some matrix tray companies. When enough is added to make trays static-dissipative, it rubs off the plastic (called sloughing). Now you’re putting dirty, conductive contaminants into your equipment, onto your parts, and your customers’ parts. You need to know whether you’ll be taking this risk.
RH Murphy Co. uses carbon fiber in NoStat® ESD-safe polymers. It’s non-sloughing and it makes the trays stronger.
NoStat® high performance composite polymers
How do you measure antistatic properties?
If a tray manufacturer claims to make antistatic trays, they should be able to measure it. Surface resistivity is the way to do it because it’s a property of the material that relates to the tray performance. Other methods can vary based on the geometry of the part being tested.
RH Murphy Co. measures surface resistivity with a simple-to- use meter – the same equipment used by the raw material suppliers, and easily used by customers.
Resistivity meters confirm anti-static tray performance
Are you the tray manufacturer or a distributor?
Distributors provide valued services. But being in the middle, they can also complicate communications and add cost. You need to be aware of the role of the company acting as your JEDEC tray supplier. You can save time and money working directly with the people designing and building your trays.
RH Murphy Co. sells direct to all customers. All our customers buy factory-direct, including value added resellers (VARs).
In the early days, trays were often referenced by the JEDEC tray manufacturer and you may still find people using names like peak trays, shinon trays, kostat trays, daewon trays or murphy trays. There are even references to trays from matrix tray companies that no longer exist like AMS, Fluoroware, or Camtex. If you want JEDEC matrix trays (sometimes misspelled as JDEC or JADEC) to protect your parts and work properly with handlers and automation, you must be specific about your requirements.
JEDEC matrix trays are not generic. All share the JEDEC outline which ensures the trays will work with standardized process equipment, but how they hold the parts is the decision of each manufacturer. Trays from different manufacturers shouldn’t be mixed. There are no “standard” trays. Each tray is designed for a specific device (not just package type). Get exactly what you need, without surprises. You put a lot of value into your parts. Make sure all that value reaches your customer.
JEDEC Trays – “Can I get special colors?”
Is buying JEDEC trays like buying a Model T Ford – you can have any color you want as long as it’s black?
JEDEC Trays are molded from a variety of plastic materials, and we all know that plastics come in almost every color imaginable. Why is it that most JEDEC trays are black? The short answer is: CARBON.
JEDEC trays are used to transport, process, and store many types of components, many of which are sensitive to ESD, electrostatic discharge – getting zapped by static electricity. One of the best ways to make the trays ESD-safe is to mix some form of carbon with the plastic. Carbon is black and, when mixed with plastic, it makes the plastic black. So, the easiest way to make ESD-safe JEDEC trays results in black trays. Trying to change a black, carbon-loaded plastic into some other color requires adding pigment. The pigment has special properties to make it disperse well and those properties are not ideal for trays so you don't want to add too much.
But what if you really don’t want black trays? What if you want different colors for different uses? Maybe you want to use a bright colored tray for parts that failed a test or use different colors to indicate which processes have been completed. Do you have options?
The good news is that there are options. There are a few colors that can be produced in carbon-loaded, ESD-safe plastics. An example is NoStat® C60 whose standard color is blue. The colors available for carbon-loaded plastics are not vibrant, decorator colors but they are definitely not black. For low-temp, non-bakeable trays there are additional options that use alternatives to carbon-loading to get ESD protection. Without the carbon, bright, lush colors are possible. Currently these non-carbon, ESD-safe options are not available for high-temp, bakeable trays.
There are costs for custom colors that may seem high if tray quantities are going to be low. The startup cost to mix a special batch of material, test it, and set up to mold trays is about the same for 10 or 100 trays as it is for 100,000. Standard color trays are more likely to be in stock and cost less. For these reasons, standard colors are used for most low volume applications.
Copies and Counterfeits
R. H. Murphy Co. sells directly to all our customers. If you purchase directly from R. H. Murphy Co. you are assured of getting genuine products at the lowest prices. There are no “Authorized R. H. Murphy Co. Distributors”. Several of our customers resell R. H. Murphy Co. products along with additional products and services, thereby adding value to their product offerings. Customers pay extra, presumably getting additional benefits from the reseller. Please understand that R. H. Murphy Co. has no control over the product after it is shipped and the resellers assume the responsibility for product condition and performance. This is particularly important when the reseller is also a recycler.
Copies of R. H. Murphy Co. product do show up from time to time. These may use low cost materials with inferior mechanical, electrical, and thermal properties. It is unfortunate when companies put their valuable components at risk of damage when losses can quickly overwhelm any potential savings promised by cheap copies.
Counterfeit products are similar to copies except they are disguised as genuine R. H. Murphy Co. products. We have seen poor quality counterfeits with duplicated markings. But the results have been catastrophic for customers who used what they thought were R. H. Murphy Co. high-temperature JEDEC Matrix Trays purchased at a “better” price.
Here is an example of a tray sent to us by a company asking why their “R. H. Murphy Co.” tray melted. They had purchased components that were shipped to them in trays that looked like the real thing, except they were underweight and the material was too shiny. Upon examination, the trays were marked just like R. H. Murphy Co. trays but with some misspelled engraving. When baked, the trays melted, damaging the expensive components. That’s not a great way to save!
How can you avoid these problems? Don’t settle for copies. If you are purchasing directly from R. H. Murphy Co. there are no worries. If you are getting trays or carriers from a reseller or component supplier, you can ask for confirmation. Work with companies you trust and don’t get mislead by false claims of savings. R. H. Murphy Co. has succeeded for more than 30 years by protecting the value your product. If you can get by with a low cost option, we will work with you to find the best option. But remember the wisdom of the ages, if it seems too good to be true, it probably is!
Old, Obsolete, Legacy or Vintage?
We support Electronic Immortality!
It was announced last summer that Funai Electric1, reportedly the last manufacturer of VCRs, was ceasing production of the video tape machines. Intel2 has been changing its emphasis away from PCs with a focus shift to IoT and cloud-based computing. It is a seemingly inevitable cycle where new becomes old and, eventually, obsolete. As a consumer, should I stock up on old hardware so I can view my library of tapes or pay to have them converted to digital media (and try to avoid the next one slated for obsolescence)?
But what about businesses that need to continue to operate with “obsolete” technology when costs or risks associated with upgrades are too great to abandon the old, but functional, technology? Finance, defense, and air traffic control are just a few well known markets where processes, systems, hardware, and software have been kept in use long after they have been declared obsolete. Some products have even made the transition to vintage, enabling them to command high prices – quite a change from old and cheap, or obsolete and worthless! As the song goes, everything old is new again.
A quick search brings up pages of companies offering everything from new-old-stock to modern packaging of legacy die-bank inventory; refurbs and restorations to replications. If you like what you’ve got, or just need to extend the life of your current platform, there’s hope.
Being in the business of providing custom products to handle and protect components, we see a steady flow of business from companies working with legacy products. We are able to help bridge old and new by providing interface products that let you handle all types of components, old and new, in your current manufacturing process. If you are digging those parts out of cold storage or a sacred vault, you don’t need a time machine to build with them. Sometimes old really is new!
“3D printing” and “rapid prototypying” seem to be in every other headline we read today. I know this is an exaggeration but the number of companies offering services or equipment is growing enormously with Forbes reporting the compound annual growth rate over the last 3 years for equipment manufacturers to be 33.8% (Forbes 6/30/2015). Computerworld reports “3D printer shipments are forecast to more than double every year between 2016 and 2019” (Computerworld 9/30/2015). More accurately described as additive manufacturing, there appears to be a manufacturing revolution in progress.
The beauty of additive manufacturing is its directness, going straight from a digital file to a part. Gone are the expenses of tooling, multiple setups, and the highly skilled individuals spending hours or weeks crafting parts. It sounds like you’re screwing up if you’re still wasting time and money machining and molding parts. With machines popping up in schools, libraries, street corner u-build-it shops, and many homes, everything else is obsolete! Well… maybe not.
Additive manufacturing typically builds an object in layers. This enables the creation of hollow geometry and blind undercut features that cannot be readily manufactured by other means – think of building a ship in a bottle with the cap still on the bottle! Some processes allow changing materials mid-stream giving multi-color or multi-hardness in a single, continuous part.
“If you can make it using conventional processes, 3D printing probably isn’t going to be the best way.”
This was what I heard from an industry expert giving a seminar on additive manufacturing, the over-arching description for 3D printing, stereo lithography, fused deposition modeling, and a handful of other technical sounding process names. The underlying message was far from discouraging; it was liberating!
Some equipment manufacturers are recognizing the limitations of these processes. Tight tolerance requirements have prompted them to offer hybrid machines that combine additive processes with precision CNC machining. (one-machine-to-rule-them-all) The tolerances achieved through traditional machining are more precise and the throughput is greater as well.
When seeking to fabricate an object whose geometry can be generated by subtractive manufacturing, such as machining, with a single setup, the machining process may well be faster and more accurate. Depending on the complexity of the programming and labor involved, machining may be less expensive and multi-part runs will increase any advantage.
Material properties can be a game-changer. Additive manufacturing encompasses multiple processes, each with its own material constraints. 3D printing dispenses material in liquid form which then solidifies and sticks to the surface or layer upon which it has landed. Material for 3D printers must be a low viscosity fluid that can be formed into tiny droplets.
Stereo lithography (SLA) utilizes a liquid pool upon which a focused light beam polymerizes a thin layer into solid material. It literally draws the object on the surface of the pool, lowers the new solid layer into the pool and draws the next layer on top, repeating the process over and over. The materials for this process are very specialized.
Laser sintering is similar to SLA except it starts with a powder, either spread in layers or dispensed in a stream, which gets heated and fused by a laser beam. The fused layer is lowered and additional powder is spread on top or dispensed, providing the basis for the next solid layer. Laser sintered materials must melt and solidify while retaining their properties. A variety of thermoplastics and metals are used in this process, providing a broad range of capabilities. For a nice overview of the various processes, check out the Stratasys white paper 3D_MATERIALS.PDF
In contrast, material options for a machined prototype are numerous. Most metals and many polymers are available in plate, sheet, rod, and tube form. (machinable polymers) And there is one category of material that is currently not an option for the additive manufacturing processes; fiber reinforced composite polymers. Fibers of glass, carbon, and aramid are widely used to add strength, stiffness, toughness, electrical conductivity and thermal conductivity to a wide range of polymers. The high aspect ratio of fibers that make them so valuable as a reinforcing additive also make them incompatible with additive processes. If the reinforced materials are pulverized or granulated small enough to use in the sintering process, the benefits of the fibers are lost.
A further variation that can provide very cost-effective rapid prototyping combines the benefits of injection molding or extrusion with machining. Injection moldable and extrusion grades of most polymers are the least expensive forms. By creating some useful “blank” forms in high volume, and machining details into the existing geometry, machining time and material waste can be dramatically reduced. This process is used by R H Murphy Company to produce RapidTray® Machined Matrix Trays with lead times comparable to the additive processes. Using molded blanks reduces the material cost by over 90% compared to stock shapes and offers the material performance that is simply unavailable from additive processes.
To learn more about combining molding and machining for value and efficiency call 603-889-2255.