How to Choose a Box Build Assembly Manufacturer

Disclosure: This guide is published by Cloom Tech. Cloom Tech is one of the seven companies listed below, and the decision block at the end is a sponsored, disclosed element that routes you to Cloom Tech.

Box build (sometimes called higher-level assembly, or HLA) is where a manufacturer takes populated boards, cables, enclosures and other purchased parts and turns them into a finished, tested unit. The company you pick affects how much of that integration work you still have to manage yourself, how consistently each unit is tested, and how well the documentation holds up if a customer or auditor asks for it later. This guide does not rank suppliers. It sets out the questions to ask and gives the same facts for each company so you can compare them yourself.

What should I check before shortlisting a box build assembly manufacturer?

Use these criteria for every company in this guide:

• Quality system: which certifications the company publishes, and at which sites.
• Where the box build happens: the company’s own stated locations. Some suppliers list a headquarters in one country and production somewhere else, or name a plant count without naming the plants.
• Scale and programme fit: facility count, headcount, and whether the company publishes figures that suit your volume.
• Is box build the main offer, or a secondary line? Some companies lead with box build and higher-level assembly; others treat it as one item on a longer services list behind PCB assembly or precision machining.
• Industry fit: which industries the company’s own site actually names, and whether that matches your end use (medical, industrial, automotive, telecom, and so on).

Figures below come from each company’s own website unless marked otherwise. Anything a company did not publish is left out, not estimated.

Which box build assembly manufacturers serve these buyers?

The seven companies are listed in alphabetical order. Order does not indicate quality or preference.

Cloom Tech (Hebei Cloom Electronic Technology Co., Ltd)

Cloom Tech is one of the seven companies in this guide. Its facts below are sourced to its own live pages, the same way as every other company in this guide.

• Founded: 2017 (homepage statistics panel, “Since 2017”).
• Locations: Shijiazhuang, Hebei, China (headquarters and factory, stated as 5,000 sqm “Factory Space” on the homepage); Cavite Economic Zone, Rosario, Cavite, Philippines (factory); Medley, Florida, USA (office).
• Scale (company-stated): 1,000+ cumulative clients since 2017 (homepage statistics panel).
• Certifications (company-stated): ISO 9001; states it meets the IATF 16949 standard (its FAQ page and certification badges say it holds/meets IATF 16949, but no certificate validity date is published on its own site as of this check); ISO 13485 specifically for its wiring-harness business (FAQ page). RoHS and REACH compliance also stated.
• Box build focus: its own box-build page describes “streamlined box build and wiring solutions” for OEMs, system integrators and end users, checked against quality, safety and operational requirements before shipment, with a stated 12-hour quote turnaround. Cloom Tech does not sell standalone connectors, does not sell standard or pre-built cables/harnesses, and does not offer design services — it consults and offers professional recommendations on a customer’s own design.

Trade-offs:

• Strength: states it meets the IATF 16949 standard and holds a dedicated ISO 13485 certification for its wire-harness business, from a stated 5,000 sqm factory.
• Limit: Cloom Tech builds in China and the Philippines and has a US office, so confirm where your box build would be produced and what that means for lead time and cost. It does not supply standalone connectors, standard/pre-built harnesses, or design services — only custom assemblies and wiring built to your own spec. Its own site doesn’t publish an IATF 16949 certificate validity date — ask for the current certificate directly.

Creation Technologies

• Founded: not published on the company’s own site as of this check.
• Scale (company-stated): 3,000+ employees; 12 manufacturing locations across 4 countries (U.S., Canada, Mexico, China). Corporate address given in the site footer: One Beacon Street, 23rd Floor, Boston, MA.
• Certifications (company-stated): ISO 9001:2015, ISO 13485:2016 and ISO 14001:2015 across its “certified facilities” (the company’s own quality page does not say which facilities hold which certificate); in-house testing stated as ISO 17025-certified. Its medical page also states its manufacturing execution system is validated to 21 CFR Part 11 and that its facilities are FDA-registered.
• Box build focus: an electronics manufacturing services (EMS) provider offering PCBA, Interconnect and Supply Chain solutions, plus “Full Box-Build capabilities” under its After-Market Services. Its deepest published line is medical and life-sciences manufacturing: Class I, II and III medical devices, biotechnology and pharmaceutical OEM work, clean-room manufacturing, and component- and product-level traceability. It also serves a “Tech Industrial” market covering communication, instrumentation, energy & environmental, and transportation customers.

Trade-offs:

• Strength: a certified, FDA-registered medical-device manufacturing line (ISO 13485, 21 CFR Part 11-validated MES) alongside general box build, PCBA and interconnect work.
• Limit: a large, multi-site EMS model spread across 12 locations in 4 countries, and its own site doesn’t say which specific plant holds which certificate — confirm both the certificate and the plant before assuming either for your build.

Incap Corporation

• Founded: not published on the company’s own site as of this check.
• Scale (company-stated): 3,000+ employees globally. Factories in Estonia, India, Slovakia, the UK, the USA, Germany and Romania, plus offices in Finland (Helsinki) and Hong Kong.
• Certifications (company-stated): ISO 9001, ISO 14001, ISO 45001, ISO 13485 and IATF 16949, listed in the site footer with no validity dates and no facility-by-facility breakdown.
• Box build focus: its EMS-production pages name Box Build, Control Cabinets, Cable & Wire Harness Assembly and PCB assembly, describing “scalable manufacturing covering cable & PCB assembly, box build, and full system integration.” It also names a “Fast Track” prototyping service in its navigation, without describing it further on the pages checked. Its own site names 13 industries; one names a sector this guide does not describe or link to, consistent with this guide’s style rule. The other 12 are: e-mobility and automotive, energy/power/charging, high-end consumer, industrial automation and robotics, IoT and smart-tech, med-tech and life science, metering, oil/gas/mining, railway and transport, scientific instrumentation, security and surveillance, and vending machines.

Trade-offs:

• Strength: a broad certification set (ISO 9001, 14001, 45001, 13485 and IATF 16949) across a seven-country factory footprint, plus a named fast-track prototype service.
• Limit: factories span seven countries and the company’s own site doesn’t say which certifications apply to which factory, so confirm both the build location and the certificate that covers it before assuming either.

Mekoprint

• Founded: 1954 (company “About us” page).
• Scale (company-stated): 750+ employees; headquartered in Denmark with 13 production sites across Europe (About us page). Its separate box-build page cites a different figure — “10 factories and over 20 production partners” — so the two pages do not agree on a single site count; ask the company which is current.
• Certifications: not named with a specific standard (ISO, IATF, etc.) on the pages checked. The company’s own site shows an EcoVadis Silver rating (2026) and UN Global Compact membership — sustainability ratings, not quality-management certifications — and says generally that it “complies with industry standards” without naming which ones.
• Box build focus: its box-build page pitches a single-source service covering electronic, mechanical and electromechanical components, moving from individual parts to a complete assembly so the buyer doesn’t have to manage separate suppliers. Cable and wire harness assembly is listed as a separate solution category. Its own site names 8 industries; one names a sector this guide does not describe or link to, consistent with this guide’s style rule. The other 7 are: medical and life science, manufacturing and automation, agricultural and heavy-duty machinery, green technology and energy, major appliances, automotive and transportation, and electronics and instrumentation.

Trade-offs:

• Strength: a broad European manufacturing footprint and more than 70 years in electronic, mechanical and electromechanical component manufacturing.
• Limit: no ISO or IATF certificate is named on the pages checked, so ask directly for the certificate covering whichever site would build your product; its own pages also disagree on the site count (13 vs. 10), so confirm the current figure too.

PEKO Precision Products

• Founded: the company’s own homepage says it has been providing machinery and assembly manufacturing “since 1966”; no separate incorporation date is published.
• Scale (company-stated): 400+ employees; a 375,000 sq ft campus described as nine plants, based in Rochester, NY (1400 Emerson Street). One additional site, a “Lee Road plant,” is named without a city or state.
• Certifications (company-stated): ISO 9001:2015 and ISO 13485:2016, “through ABS Quality Evaluations.” No validity dates are given.
• Box build focus: describes “complex, precision mechanical and electromechanical contract assembly manufacturing” and “high level assembly” rather than using the term “box build.” Capabilities named include a CNC machine shop (100+ machines), a New Product Introduction division, sheet metal fabrication, an assembly plant with a clean room, and a welding center. Its own site names 6 industries; one names a sector this guide does not describe or link to, consistent with this guide’s style rule. The other 5 are: renewable/clean/green energy equipment, industrial equipment and machinery, medical, semiconductor, and communications equipment manufacturing.

Trade-offs:

• Strength: a large single-campus footprint (375,000 sq ft, nine plants) with ISO 13485 alongside ISO 9001, useful if you also need medical-grade documentation.
• Limit: the company’s own site doesn’t use the term “box build” (it uses “high level assembly” and “systems integration” instead), and it names only one city (Rochester, NY) despite citing nine plants — ask for the other plant locations before assuming where your product would be built.

Sierra Assembly Technology LLC

• Founded: not published precisely. Its “About us” section cites “30+ years” of experience, while a site image filename references a “25th anniversary” — the two don’t agree, so treat the exact founding year as unconfirmed.
• Scale (company-stated): describes itself as “a small business at heart”; no employee count is published. It names one through-hole (PTH) and two surface-mount (SMT) assembly lines.
• Locations: Chino, California (14764 Yorba Court) — the only address published on the page checked.
• Certifications: none named with a specific standard or validity date on the page checked. The company claims RoHS compliance and conformal coating “in compliance with the IPC-CC-830B standards” — compliance claims, not third-party certifications.
• Box build focus: PCB assembly is presented as the primary line, with “cable and wire harness assembly, Box Build assembly, and many more” listed as additional services rather than the lead offer. Its own “Industries Served” menu names 19 markets; two name sectors this guide does not describe or link to, consistent with this guide’s style rule. The other 17 include industrial electronics, computer and business electronics, consumer electronics, LED, medical, telecommunications, wireless, automotive, automation, IoT, security, smart home, video camera, wearable devices, and others.

Trade-offs:

• Strength: an unusually wide published industry list, with in-house PTH and two SMT lines supporting PCB work alongside box build.
• Limit: a self-described small business with a single published site and no named certification — if you need a certified quality system, ask for the certificate before assuming one exists. Box build is listed as a secondary service behind PCB assembly, not the company’s primary offer.

TT Electronics

• Founded: not published on the company’s own site as of this check.
• Scale (company-stated): 3,500+ employees; 20 locations; £481.4M revenue (homepage “About TT Electronics” figures).
• Certifications: not published as a general, company-wide list on TT Electronics’ own manufacturing or quality pages reviewed in this pass.
• Box build focus: its Manufacturing Services pages name Box Build and HLA (higher-level assembly) as a distinct service line alongside PCBA, Cable and Harness Assembly, NPI and Engineering, Testing Solutions, Global Supply Chain Management, and High Volume Low Mix EMS. Markets named on its own site, outside the sector this guide excludes: healthcare (including medical device coils and power supplies), automation, and electrification.

Trade-offs:

• Strength: a large footprint (20 locations, £481.4M revenue) with box build named as its own manufacturing-service line rather than folded into general assembly.
• Limit: the manufacturing pages reviewed don’t publish a company-wide certification list or process specifics (clean room, prototype lines, etc.), so ask for the certificate and process detail covering the specific site that would build your product.

How do I choose between these box build manufacturers?

1. Match the certificate to your buyer. If you supply a regulated end customer (medical, automotive, industrial safety), ask for the current certificate for the specific site that would build your product, not a company-wide claim.
2. Confirm the build location. Several companies here name a headquarters or a site count without naming every plant — ask for the plant address in writing.
3. Find out if box build is their main line or a side offer. A company built around PCB assembly or precision machining may treat box build as an add-on rather than a core process.
4. Test the process, not just the pitch. Send the same drawing and BOM to two or three suppliers and compare lead time, questions asked, and how they document the build.
5. Check fit with your volume. Large multi-site EMS providers and small single-site assemblers serve different programme sizes.

Ready to request a quote?

Sponsored (Cloom Tech): If you want Cloom Tech to quote your box build, send your drawing, expected volumes and target certifications. Request a quote at the Cloom Tech contact page. See what Cloom Tech builds as a custom cable assembly manufacturer.