Silex Microsystems Turns Onsemi Fab Buy Into Defense-Sector Wedge as Data Center Optics Demand Accelerates
Q2 2026 earnings call, July 17, 2026 — first results as a public company following June IPO
Silex Microsystems used its inaugural earnings call as a listed company to lay out a more expansive strategic rationale for its $40 million acquisition of Onsemi's Mountain Top, Pennsylvania fab than previously disclosed, framing the deal not just as a capacity play for existing customers but as a direct entry point into the U.S. defense and aerospace market. CEO Edvard Kalvesten told analysts the geopolitical backdrop has made a domestic manufacturing footprint a prerequisite for a new class of customer. "This opened up also other new opportunities like defense sector," Kalvesten said, later adding that the current environment "changes every day" and that having a U.S. fab has become "important" in ways it was not when the deal was first contemplated.
The disclosure matters because it reframes the U.S. expansion from a customer-accommodation story into a genuine addressable-market expansion. Kalvesten confirmed defense interest is coming from both large primes and startups, and while the near-term pipeline skews American, European defense conversations are also underway. This is new information for investors who had previously understood the Onsemi transaction primarily as a response to existing U.S. customers wanting local supply.
Deal Mechanics and Capital Intensity Clarified
CFO Maria Engstrom and Kalvesten provided the clearest breakdown yet of the economics behind the U.S. build-out. The total investment through 2030 is now guided at SEK 1.6 billion, of which roughly SEK 400 million is the purchase price itself, with the remainder split between clean-room buildout and, predominantly, new MEMS process equipment layered onto the facility's existing 200-millimeter CMOS infrastructure. Silex will pay $10 million at signing, with closing targeted for January 1, 2028, pending CFIUS approval, which management expects to take three to six months. Onsemi will continue running legacy production at the site in the interim while effectively serving as an outsourced manufacturing partner for Silex's own product development through 2026 and 2027, an arrangement that lets Silex start generating revenue from the asset well before it takes ownership or absorbs its cost base.
On phasing, management was more forthcoming than in prior disclosures but stopped short of a formal ramp schedule. Kalvesten said the fab's steady-state economics — both revenue and margin — should eventually resemble the Järfälla, Sweden fab's 2025 performance, which Engstrom clarified generated SEK 1.385 billion in sales. Analyst Ruben Devos of Kepler Cheuvreux pressed for a phasing curve into the U.S. asset's ramp, but Kalvesten declined to quantify beyond noting that meaningful revenue ramp begins in 2028 once Silex takes full ownership and availability of the site. Clean-room space, he added, will not be the constraint — Mountain Top has roughly 3,000 square meters in use today with capacity to add another 12,000 — leaving MEMS-specific tooling as the binding capital requirement.
Optical Circuit Switch Demand Still Early, Concentrated
The quarter's growth was disproportionately driven by North America, where revenue rose 85% of the total net sales increase, largely on optical circuit switch, or OCS, demand tied to data center buildouts beyond the initial hyperscaler cohort. Analyst Erik Lindholm-Rojestal of SEB pushed for detail on market maturity, and Kalvesten's answer is a useful data point for anyone modeling the AI infrastructure supply chain: Silex counts roughly 10 OCS customers in total, but only one is in high-volume production. "As per my knowledge and what is communicated on the market publicly, it's only one who has that in real scale," Kalvesten said of OCS deployment across data center operators, adding that other players — some Silex customers, some not — are still testing. That leaves the vast majority of Silex's OCS book in development stage, with an inherent churn risk. Kalvesten was candid that not all development customers will convert to production: "Not all of these customers will succeed. We have churn rate of the customers." The offsetting argument, which he made unprompted, is that as the leading MEMS foundry in this niche for a decade, Silex expects to retain most of the eventual winners regardless of which individual programs fail.
Margins Ahead of Target, But Gross Margin Normalization Is a Watch Item
Reported financials were strong across the board: net sales of SEK 393 million, up 27.3% year-over-year (31.8% at constant currency), and EBIT of SEK 134 million for a 34% margin, more than double the prior year's 18.1%. Adjusted EBIT margin came in at 34.5%. Engstrom flagged that SEK 19 million of the EBIT beat came from favorable foreign-exchange revaluation on the balance sheet, versus a negative SEK 4 million a year ago — stripping that out, underlying EBIT margin was still a healthy 29%, up from 19%. On a trailing-twelve-month basis, revenue reached SEK 1.5 billion against a 2030 target of SEK 2.5 billion, and EBIT margin of 32.2% is already running ahead of the company's own medium-term target of above 30%. Net debt to EBITDA sits at negative 1.6 times, reflecting a net cash position bolstered by the SEK 1 billion IPO raise and an undrawn SEK 750 million revolving credit facility.
Gross margin ticked down in the quarter, which analyst Simon Granath of ABG flagged as consistent with prior guidance but worth watching. Kalvesten declined to give forward guidance on the metric, saying only that current levels are "in line what we have seen historically and what we will see going forward," while conceding that fab purchase pricing dynamics could theoretically pressure gross margin even if the EBIT impact is muted. Investors should note this as one of the few soft spots in an otherwise clean quarter — management is not committing to margin stability with the same confidence it applies to top-line growth.
Engineering Headcount Remains the Real Constraint
Perhaps the most concrete operational disclosure was around capacity bottlenecks. Development revenue — which the company treats as an early indicator of the future production pipeline — grew SEK 61 million year-over-year, accounting for 73% of the total sales increase. But Kalvesten was direct that engineering headcount, not equipment or clean-room space, is the binding constraint on how fast that pipeline can be expanded. Silex has around 200 engineers currently and just added 25 more hires who are being trained, with some of that capacity being directed toward transferring MEMS processes to the new U.S. site. Kalvesten noted an unexpected tailwind from the IPO itself: "It seems we are more attractive, and we get very good talent when we're hiring people now when we are a public company." This is a useful signal that the public listing is functioning as a recruiting tool in a labor-constrained niche, though it also implies growth will remain throttled by hiring and training cycles rather than being purely demand-gated for the foreseeable future.
AR/VR Program on Track for 2028, Limited New Detail
Management reaffirmed a large augmented and virtual reality development program remains on its previously communicated timeline, with production start targeted for 2028. Kalvesten offered little incremental color beyond confirming the customer relationship and project intensity are unchanged, which suggests this program is progressing as expected but is not yet a near-term earnings catalyst.
Notably absent from the call was any formal guidance for the second half of 2026 or commentary on order backlog and booked capacity, a gap that Kepler Cheuvreux's Devos raised directly. Kalvesten's response — that the business "seems to continue in the same angle as it has done before" — leaves investors reliant on historical growth trends rather than forward bookings visibility, a limitation worth flagging given the size of the capital commitments now underway in the U.S.