Ron, when if comes to SMT printing of solder paste, why do some people use the
five-ball rule for rectangular apertures and the eight-ball rule for circular
“Five Ball Rule” is another metric that SMT assembly industry leaders believe,
but it is difficult to find its origin. It states that when selecting a solder
paste, five of the largest solder balls should be able to fit across the width
of the smallest rectangular stencil aperture. See Figure 1a for a 0.2mm wide
the largest solder ball diameter is assumed at the 90th
percentile. See Figure 2. So, in this example, a type 4 solder paste would fit
the five ball rule as the largest solder ball is 0.038mm. Five times 0.038 is 0.190mm,
just a little less than the aperture width of 0.2mm. It should be remembered
that this is a “rule.” not a “law.” So let’s say you had
4.5 balls across the aperture with instead of 5, it would most likely be
comparison of the Five and Eight Ball Rules
generation ago, the advent of circular apertures to support BGA and CSP
packages necessitated a new “rule.” Figure 1b shows why the five-ball rule is
inadequate for circular apertures. Although five type 3 solder balls fit along
the 0.275 diameter, off the diameter, there is not enough room for many
solder balls. Hence, an insufficient amount of solder paste would be
the same aperture, if a type 4 paste is used, 7 or 8 solder balls span the
diameter and the amount of paste printed would be much closer to the volume of
One of the first things I heard when I arrive at AltiumLive last week was was how much they loved the recap of the event my colleague Chelsey Drysdale wrote last year. They added that Chelsey truly captured what AltiumLive is about. Talk about pressure!
Let’s start at the beginning.
Drinks are on Them. The week (well, three days, but they really pack a lot in!) kicked off with a great reception on an outside terrace at the Loews Coronado Bay Resort. Dave Starkey, the engineer who designed and built the Piano Arc — the circular piano used by Lady Gaga’s pianist, among others — was there. So was the pianist. They displayed the unit, a 360-degree custom keyboard, with one of the panels removed, exposing the PCBs. Altium director of community engagement Judy Warner met Dave at a user group meeting in San Diego, heard his story and recruited him for the event. In case anyone wants to know the piano has 288 keys, a total of 12 circuit boards and only cost $57,000.
I saw our customary PCB West speakers Suzy Webb, Rick Hartley, Gary Ferrari and Eric Bogatin and met a lot of engineers.
Getting Younger. One of the things you note about AltiumLive is the demographics. It’s a younger crowd than you typically see at industry events. Eric Bogatin noted this in the first keynote (AltiumLive had not one, not two but three keynotes). He brought some of his students, had them stand up for recognition and encouraged hiring companies to talk to them. That drew a good laugh from the crowd. In his talk, he pointed out that while many designers will be retiring in the next 10 years, AltiumLive gives us reason to think a new generation is coming on strong.
Keynote #2 featured a celebrity from outside our industry. Jor Grand of Grand Idea Studio has a short-lived TV show called Prototype This! on the Discovery channel. The concept, which was similar to Mythbusters, was about the viability of gadgets and technology and how engineers feel a since of winning when a product doesn’t work the first time, but they don’t give up until their creation finally works successfully. While the show lasted only one season, Grand shared several clips and generated lots of laughs.
Finally, the main event: Altium rolled out its much-anticipated Altium Designer 20 ECAD. VP of marketing Lawrence Romine detailed the new “push and shove” capabilities that enable routing of complex HDI boards and ramp up design times over 20%. (For more on the tool, click here.)
Cloud in their Eyes. This was the third year of AltiumLive, and the multi-city event (another is being held in Frankfurt this week) draws 500 designers. The company grow is equally impressive. Last year 2018 Altium saw over 8,000 new users for its Designer PCB CAD tool, and on average Altium users do over 10 designs a year.
Looking ahead, Altium wants to move toward the cloud, something the industry has been avoiding for years. Its has added real-time collaboration, and hopes to bridge the gap between manufacturers and designers.
Not surprisingly then, AltiumLive focused as much on tomorrow as on today. The highlight of the event was the Robot Build and Battle. Attendees split into teams of six or more. Ours had nine; eight engineers, from all of the country, and me. I was cheerleader, motivator and general handyperson. (They said I sounded like each of their bosses … I beg to differ!) Team Sierra beat last year’s record, but we weren’t far behind. Amit Bahl of Sierra Circuits told me he didn’t realize just how geeky our industry was until the robot build. Such a fun and educational event!
Brooke Anglin is senior sales associate with PCD&F/CIRCUITS ASSEMBLY.
This coming February will be my third SMTA Pan Pac. Pan Pac is a very enjoyable and rewarding conference. It is small enough that you can get to know all of the speakers, yet large enough that there is a full venue. For those of us in the northern part of the US, it is also a nice break from the winter weather. The first time I went I was surprised that it wasn’t very expensive. For this coming conference, air tickets from Boston are as low as $600 and the hotel is about $200 per night.
The conference will be held on the “Big island” of Hawaii. If you come early or stay late there are many interesting attractions, including the active volcanoes and the Mauna Kea Observatories. So for sure come to the conference, but why not submit an abstract to be a speaker? If interested in submitting an abstract go to this site.
In his most recent monthly column my friend Gene Weiner pointed out the irony of calling a printed circuit board a commodity. “When did printed circuits become mass-produced unspecialized products?” he asks.
As I told Gene, it’s true PCBs are custom, but in some (many?) instances they are highly mass-produced. Think residential LED lighting, or game consoles or the most popular phones, etc. My sense is that calling them “commodity” or “custom” is a bit of a red herring. Large OEMs call PCBs commodities even though they know each is specific to a particular program. I think to most its a catchall word for “volume procurement.”
There is real tension on costs between customers and suppliers, and without artificial price bottoms I can see no reason that won’t continue. I think it’s highly unlikely sellers will be able to change the pricing model as long as the process technology remains essentially the same. It’s too entrenched, and often the buyers (which more and more often are EMS companies) have lower margins than the fabricators, so there’s no incentive for them to switch to a pricing model that will cost them more. A move to a different process technology (3-D/additive manufacturing) might well change the pricing curve.
It’s not that simple, of course. As double-Ph.D. and former CTO of Multek Craig Davidson once said, “Never underestimate the tenacity of incumbent technology.” It’s perhaps the best quote on technology adoption I’ve ever heard.
I used to think that with the many brilliant minds in our industry, we would successfully disrupt ourselves — in other words, the ideas that obsolete our current ways of doing things would be conceived and implemented by one of our own — maybe some genius in the basement of Apple or Intel or IBM. I’m less confident of that now.
I now lean toward the notion that the true disruptive change will come from someone outside our industry who has knowledge of both hardware and software and who uses a truly novel process to develop a widget that the public embraces. The mass appeal of the product (not the process, to which the general public is ambivalent) will be the proof of concept. And the investment money will follow.
You are putting in a new assembly line to assemble some large boards for which your company just received a three-year contract. The boards are 45cm long and you expect the cycle time from the component placement machines to be 40 seconds per board. Your boss is pressuring you to get another 5-zone oven, as they are cheaper and take up much less space than a 7- or 10-zone oven. But, you are concerned that a 5-zone oven may not have the capacity that is needed to keep up with the component placement machines. Let’s make some calculations and see if your concerns are justified.
Table 1 shows some typical reflow oven metrics:
Let’s assume that you will be using a typical modern SAC solder paste. By studying the reflow profile above, we see that the amount of time needed in the heated zone is about 4.5 min. or 270 sec.
So if we choose the 5-zone oven the belt speed will be:
Belt Speed = BS= Heat Tunnel Length/Time in Heated Tunnel = HTL/Time = 180 cm/270 sec. or 0.66 cm/sec
The component placers will be presenting a 45cm board every 40 sec., so the belt speed needs to be:
It brings to a close one of the stranger stories in recent EMS memory. Cemtrex grew through acquisition, buying up a German EMS company, and later another, and green-fielded plants in Romania and India.
Then there was bewildering and lame hostile takeover attempt of Key Tronic, at the time a Top 50 EMS in terms of revenue. In offering a 1:1 stock swap, Cemtrex called out the larger EMS for its seemingly underwhelming profitability. Key Tronic’s response — at once clinical and dismissive — was one for the ages: “Our initial research shows [Cemtrex] reports approximately $45 million of EMS revenue. In our opinion, this does not qualify [Cemtrex] to make any statements as to how it might operate an EMS business like KeyTronic which is over 10 times [its] current size in terms of revenue.”
Cemtrex never filed the paperwork for a potential acquisition and the proposal quietly vaporized. And today, so did its aspirations of EMS supremacy.
I don’t have all the details, but the industry icon Ralph Morrison passed away Aug. 2.
Ralph spent more than 50 years in the electronics industry. He was responsible for teaching thousands of engineers all about the fundamentals of how voltage and currents work. Up until about eight years ago, he was a constant presence at the PCB West design conferences.
He wrote several books, including Solving Interference Problems in Electronics, Grounding and Shielding Techniques in Instrumentation, and The Fields of Electronics: Understanding Electronics Using Basic Physics.
I didn’t know Ralph in his prime, but we developed an amiable relationship over the past 18 months as he did some writing for us. I truly enjoyed him — he had an economy with words that I will always strain to achieve.
According to longtime friend Dan Beeker, a memorial service will take place in October. I will miss his emails and occasional phone calls, and most of all, his kind words about the role we editors play in helping designers and engineers better understand their craft.
For years, manufacturers have insisted on putting factories in the greater San Jose area. The CIRCUITS ASSEMBLY Directory of EMS Companies lists hundreds of entries with Silicon Valley zip codes. Damn the costs — siting near customers — actual or desired — takes precedence!
Ironically, industrial space rents, while climbing, are a relative bargain. The average rent was $1.27 per sq. ft. in the March period, more than twice that in 2010 ($0.60 per sq. ft.), but well below the national average. That comes to more than $381,000 in rent a year for a modest 25,000 sq. ft. factory. But tack on energy, and labor costs — unemployment rates are not only lower than the national average, but workers earn a small fortune — and it all adds up to a very expensive enterprise.
Today the pendulum is shifting, if only bit by bit. We are seeing furloughs, layoffs and even some big names starting to blink. Jabil,Creation Technologies, and this week, Benchmark are among those closing factories in Silicon Valley.
Will more follow? In an industry where margin and cash flow often make all the difference, it won’t be a surprise if more players head for lower-cost pastures.
The US-China trade war shows no sign of abating. And as predicted, it is wreaking havoc on the electronics supply chain. While OEMs like Huawei get most of the headlines, suppliers of semiconductors are feeling the pain.
Less publicized, but perhaps just as crucial, is the ongoing spat between Japan and South Korea. The Asian nations are locked in a dispute over a group of uninhabited islands located in the straits between the two countries. Relationships are further frayed over issues of war reparations dating to World War II. Japan has struck first, taking steps to put controls on exports of key semiconductor fabrication materials to South Korea for fear they could be used in military applications. South Korea has not publicly countered, but the nation is home to two of the three largest memory device makers.
The tension between Japan and South Korea further complicates an already cloudy memory market picture. DRAM prices are already threatened by a global inventory glut, leading Gartner to forecast a 4% price drop this year. By choking materials supplies, Japan could inadvertently help lower inventories and boost margins. But there’s a point where parts availability could tip the wrong way, ratcheting up lead times and leaving buyers scrambling for sources.
By sales, Samsung and SK Hynix manufacture about 23% of the world’s memory chips. Their combined sales last year topped $110 billion. But there’s no simple answer. Japan is in many cases a sole source of many of these critical materials. How long will South Korea be willing to suffer? And what lengths will it go to to protect its semiconductor dominance?