Latest / Hardware Startups with Fexingo: Devices, Robotics, and Manufacturing Tech Companies / Hardware Startups Should Use HALT Testing Early
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- Lucas: You can spend months designing a board, get it assembled, run functional tests — everything passes — and then three months after shipping, units start coming back dead. The failure mode is something you never saw because you never pushed the product past where you thought it would ever go. Luna: That's the nightmare scenario for any hardware startup. And it's exactly what HALT testing is designed to catch before you ship. Lucas: Right. HALT — Highly Accelerated Life Testing. It's not the same as standard reliability testing where you simulate real-world conditions. HALT does the opposite. It deliberately over-stresses the product far beyond what it would ever see in normal use — extreme temperature, rapid thermal cycling, multi-axis vibration — to find the fundamental weak points. Luna: I've heard it described as 'torture testing.' And the goal isn't to prove the product lasts — it's to break it as fast as possible, so you can fix the design. Lucas: Exactly. The philosophy is: find failures in the lab where they cost a few hundred dollars, not in the field where they cost thousands in warranty, returns, and brand damage. A startup I talked to recently put their first production prototype through HALT and found a brittle solder joint on a power regulator that would have cracked open after maybe a thousand thermal cycles. They never would have caught it in standard functional test. Luna: And how many units would they have shipped before that failure showed up? Probably a lot. So HALT essentially saved them from a recall. Lucas: That's exactly what happened. They fixed the joint, re-spun the board, and went back into HALT. The second version survived three times the stress before any failure. They shipped with confidence. And the whole process — from first HALT to design fix to second HALT — took about three weeks. Compare that to discovering the issue six months after launch. Luna: So for a startup that's already cash-strapped and time-pressed, HALT sounds like an upfront cost that pays for itself quickly. But what does it actually cost to run HALT on a prototype? Lucas: Depends on whether you buy a chamber or rent time. A full HALT chamber — the kind that can do thermal and vibration simultaneously — runs anywhere from sixty to a hundred and fifty thousand dollars new. That's a lot for a startup. But most hardware startups don't buy one. They use service bureaus or shared-lab facilities. You can rent a day of HALT time for maybe fifteen hundred to three thousand dollars, depending on the facility and the complexity of the setup. Luna: And you'd typically need a few days — initial run, then a re-run after fixes. So maybe five to ten thousand total? That's not trivial, but compared to a recall, it's nothing. Lucas: Yeah. And some universities with engineering programs have HALT chambers that startups can access for even less. There's also a network of contract test labs — places like Intertek or Element — that run HALT as a service. For a hardware startup, renting a chamber for two or three days is the smart move. Luna: Let's get into the mechanics a bit. What exactly does a HALT profile look like? How do you actually stress the device? Lucas: Typically, you start with thermal step stress. You bring the chamber temperature up in increments — say, ten degrees Celsius per step, holding for ten minutes — until the device fails or hits the chamber limit, which is often around two hundred degrees Celsius. Then you do the same going down, below zero, sometimes as low as minus sixty or minus eighty. You're looking for where the product stops working. Luna: And you're not just looking for catastrophic failure — you're also monitoring for performance drift. Like, maybe the device still runs, but its accuracy or speed degrades. Lucas: Right. Then after thermal, you add vibration. HALT chambers use pneumatic actuators that deliver random six-degree-of-freedom vibration — up to fifty Gs or more. You ramp up in steps, and you're looking for resonances, loose components, solder cracks, anything that emerges. Then you combine thermal cycling with vibration simultaneously, which is where you really find the interactive failures. Luna: That combined stress is brutal. A component that might survive hot temperature alone, and survive vibration alone, can fail when both hit at once — because materials expand and contract while being shaken. Lucas: Exactly. And that's the kind of failure that shows up in shipping or in the field during seasonal temperature changes. A product might be fine in a climate-controlled warehouse but fail when it's shipped in a truck in the Arizona summer. HALT catches that. Luna: I want to talk about the 'accelerated' part — because HALT is not the same as a standard life test. In a typical life test, you might run the product at, say, fifty degrees Celsius for a thousand hours to simulate a year of use. But HALT is way more aggressive. Lucas: Yeah, HALT doesn't try to simulate actual use. It accelerates failure by going far beyond use conditions. The idea is to find the fundamental limits of the design — the 'operating margin' and the 'destruct limit.' You want to know at what temperature the product stops working, and at what temperature it actually breaks. Then you design so that your real-world operating range is well inside those limits. Luna: So you're building a safety margin. If your product needs to survive from zero to forty degrees Celsius, but HALT shows it fails at sixty, then you know you have twenty degrees of headroom. But if it fails at forty-five, you're too close — you need to redesign. Lucas: Exactly. And HALT also reveals what you should fix. It tells you the weakest link. Maybe it's a connector that pops off under vibration. Maybe it's a crystal oscillator that stops oscillating at high temperature. Once you know that, you can address that specific component or joint. You don't have to over-engineer everything — just the one weak point. Luna: That's the beauty of it: targeted fixes instead of blanket over-design. For a startup that's trying to hit a price point, that's gold. Lucas: Absolutely. You don't want to spend money on a military-grade connector if a commercial one works fine after you add a dab of adhesive. HALT tells you where to spend and where to save. Luna: Let's talk about when to do HALT in the development cycle. I've seen some startups do it too late — after they've already committed to tooling or production. Lucas: That's a mistake. The ideal time is as soon as you have functional prototypes — ideally before you finalize the PCB layout or injection mold tooling. Because if HALT reveals a fundamental design flaw, you want to be able to change the board or the enclosure without writing off expensive tooling. So the sweet spot is during the EVT — engineering validation test — phase. Luna: And ideally, you run HALT in iterations. Test, fix, test again. That way you converge on a robust design before you go into DVT — design validation test — and then production. Lucas: Right. One startup I know ran three rounds of HALT over six weeks. First round broke the product at forty-five degrees Celsius. They fixed a thermal interface issue. Second round pushed it to seventy degrees. They added a small heat sink. Third round survived ninety degrees with no failure. They shipped that design and had zero field returns related to thermal stress. Luna: That's the kind of story that makes HALT a no-brainer. And it's not just for electronics — I assume you can HALT mechanical assemblies too? Lucas: Yeah, absolutely. HALT chambers can accommodate fairly large products — up to the size of a small refrigerator or even a server rack. So you can test the whole assembly, including enclosures, cables, fans, displays. We've even seen startups HALT their entire product with packaging to simulate shipping stress. Luna: That's smart — because shipping is one of the most stressful things a product goes through. I've heard of products that pass all lab tests but fail in transit because of pallet stacking or forklift vibrations. Lucas: Exactly. So HALT with packaging can reveal if your foam inserts are adequate or if your box needs a different corrugation. It's all about catching failures before your customer does. Luna: Now, I want to ask about the flip side. Are there any downsides to HALT? I mean, if you over-stress a product, you might introduce failures that aren't representative — like you break something that would never break in real use, and then you over-design for a phantom issue. Lucas: That's a valid concern. HALT is not a pass-fail test. It's an exploratory tool. You have to interpret the results with engineering judgment. Just because a component fails at eighty degrees Celsius doesn't mean you need to make it survive eighty if your product only sees forty. But you do need to understand why it failed — is it a fundamental weakness, or just an artifact of the extreme test? A good HALT engineer knows the difference. Luna: So it's about using the data, not just the outcome. And you need a team that can analyze root cause quickly — which startups often have, since they're lean and close to the design. Lucas: Yeah. And the other downside is cost and time, but as we said, it's usually a fraction of the cost of a recall. Still, for a very early-stage startup with no funding, three thousand dollars for a day of HALT might be hard to justify. But there are ways to do low-budget HALT — like using thermal chambers and shaker tables separately, or even building a rudimentary thermal cycling chamber with an oven and a freezer. Luna: That's scrappy. Not as comprehensive as a full HALT chamber, but better than nothing. And it gets you in the habit of stress-testing early. Lucas: Exactly. The mindset is what matters. HALT is a philosophy: seek failure aggressively, learn from it, and fix it before your customer ever sees it. Luna: I think that's a good note to wrap on. If you're building hardware, get your prototypes in front of some stress — it's the best teacher. Lucas: And if you find value in these conversations about what it really takes to build hardware, consider supporting the show. It keeps things ad-free and helps us dig into topics like HALT that are practical and actionable. You can find us at buymeacoffee dot com slash fexingo. No pressure — just know that listener support is what makes this possible. Luna: Yeah, it really helps us keep the focus on the nitty-gritty that founders and engineers actually need. Appreciate everyone who's chipped in. Lucas: So to leave you with one thought: next time you're reviewing your prototype test plan, ask yourself — have I tried to break this today? Because if you haven't, someone else will break it for you later. Luna: And that someone is usually your customer. Good luck out there, and we'll catch you next time.