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Electronics Packaging by the Numbers

Fitting boards, sensors, cables and antennas into a mechanical product that seals, stays cool and survives the plant

Package electronics in a mechanical product with numbers: board mounting and vibration, heat paths, sealing and venting, cables, antennas, compliance, testing and release.

10 chapters · About 102 minutes · Free to read · Intermediate mechanical and product design

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KEVOS® LibraryENGINEERINGElectronicsPackaging by theNumbersKEVOS® ORIGINAL BOOK10 CHAPTERS

About this book

More and more mechanical products now contain a circuit board, a sensor, a radio and a cable. A pump reports its bearing temperature. A conveyor gearbox sends its vibration level to a phone. A water tank tells its owner how full it is. Each of these products is still a mechanical object that has to be bolted down, sealed against rain, kept within its temperature limits and assembled on a bench. The electronics designer can make the board work. Making it survive in the product is mostly a mechanical job, and it is the mechanical designer who gets the call when water collects under the lid or the radio drops out.

This book is for mechanical designers, product engineers and CAD users who are asked to package electronics. You will learn to turn an electronics brief into mechanical requirements. You will exchange board data with the electronics designer, mount a board so that it does not resonate, follow the heat out of the enclosure, seal and vent the housing, bring cables in, place an antenna and plan compliance and tests. Each chapter takes one decision, explains the physics, works the decision through the running case with real numbers and ends with an exercise and its worked answer.

It assumes basic mechanics, heat transfer at the level of a first engineering course and working CAD skills. It assumes no electronics design experience. Where an electronics concept is needed, the chapter explains just enough of it to make the mechanical decision.

The running case

The book follows a fictional gearbox monitor: a sensor node that bolts to the housing of the drive gearbox on an outdoor conveyor at a quarry in regional Australia. It measures housing vibration and temperature and sends summaries over the LTE-M cellular network. It has a die-cast aluminium base, a polycarbonate lid, a 4-layer circuit board 80 mm by 50 mm and an M12 connector bringing 24 V d.c. from the conveyor’s control cabinet 25 m away. The enclosure is 110 mm by 70 mm by 45 mm. It must be rated IP66 and IP67, and it must work with the gearbox housing at up to 75 °C and the air at up to 40 °C.

All dimensions, loads, temperatures, test results, quantities and money values are invented for teaching. This is an illustration. None of it describes a KEVOS® project, product or measured result. Money is in Australian dollars, and each example says whether GST is included.

How to use the book

Read the chapters in order the first time, because each one adds to the package decided in the chapters before it. Chapter 1 writes the brief, Chapters 2 to 7 settle the design and Chapters 8 to 10 prove and release it. Each chapter also stands alone as a reference when you meet the same decision on your own product.

Source limits and professional responsibility

A short industry eBook on designing smart connected products was supplied for this book. It was used only to choose the subject: it describes how sensors, boards, harnesses and antennas are changing the work of mechanical teams. The structure, case, calculations, figures and exercises here are original. Physical relationships are attributed to public references, and standards are named by number and scope only, without quoted values.

This book is educational. The calculations are simplified models with stated assumptions, and the material properties are illustrative unless a source is given. Products for hazardous areas, mining equipment under specific regulation, medical use, mains-powered equipment and safety functions carry requirements beyond its scope. Qualified review, the suppliers’ current data, an accredited test laboratory and the regulator’s own guidance govern real products.

Who this book is for

Mechanical designers, product engineers and CAD users who must put circuit boards, sensors, cables and antennas into an enclosure and make the result seal, survive vibration and heat, and pass compliance.

What you will learn

  • Turn an electronics brief into mechanical requirements for space, heat, sealing, mounting and connection.
  • Exchange board outlines, keep-outs and height zones with the electronics designer and catch clashes early.
  • Check board natural frequency, enclosure temperature, gasket compression and breathing with simple calculations.
  • Choose connectors, cable entries and antenna positions that keep the product sealed and connected.
  • Plan Australian compliance, prototype tests and a release package that production can build and test.

Inside this book

Chapters

  1. 01Write the packaging briefTurn an electronics idea into numbered mechanical requirements for space, heat, sealing, vibration, connection, radio, compliance and assembly before anyone draws an enclosure.
  2. 02Share the board with the enclosureExchange board outlines, mounting holes, height zones and keep-outs between electronics and mechanical CAD, check clearances with tolerances and catch clashes before prototypes.
  3. 03Mount the board for vibrationEstimate a circuit board's natural frequency, compare it with the excitation, place standoffs and sensors where they work, and couple a vibration monitor to the machine it measures.
  4. 04Follow the heat outBuild a simple thermal-resistance network for a sealed enclosure on a hot machine in the sun, find the internal temperature and choose a mounting that balances heat against vibration.
  5. 05Seal and vent the enclosureRead the IP code, size a lid gasket and its screw spacing, account for the vacuum a cooling enclosure pulls, and use a membrane vent so the seal is not fighting the weather.
  6. 06Bring the cable inChoose between a cable gland and a panel connector, check voltage drop on the supply run, route the cable and internal leads, and keep water from following the cable inside.
  7. 07Place the antennaUnderstand wavelength, ground planes and keep-outs well enough to place an embedded antenna in a metal-and-plastic enclosure, estimate what losses cost in range and prove it on site.
  8. 08Plan compliance in the designWork out which Australian regimes apply to a connected product, build EMC and safety features into the enclosure and cable entry, and pre-scan before the laboratory.
  9. 09Prove it on prototypesPlan prototype builds and tests from the brief, measure the thermal network on a heated plate, compare the sensor with a reference and read what a small sample can and cannot prove.
  10. 10Release a package production can buildAssemble one bill of materials across mechanical, electronic and firmware items, specify assembly and end-of-line leak and function tests, and control changes that cross disciplines.

Apply This in Practice

Use these KEVOS® tools to try the method from this reading with your own numbers.

References and source notes

The manuscript and worked examples are original KEVOS® writing. References inform particular concepts; their authors do not endorse this book. Web references were consulted on 26 October 2026.

  • Chad Jackson, Lifecycle Insights (LC-Insights LLC). The Engineering Handbook for Designing Smart Connected Products (2018). Supplied source, a 12-page industry eBook. Used only as a subject map: the new demands that sensors, circuit boards, harnesses and antennas place on mechanical teams and the need for close MCAD–ECAD integration. No text, figures or structure are reproduced; the case, calculations and method here are original.
  • Arthur W. Leissa, NASA. Vibration of Plates, NASA SP-160 (1969). Public-domain reference for the classical natural-frequency solution of a thin rectangular plate simply supported on all edges, used in Chapter 3 as an upper bound for a circuit board.
  • Frank P. Incropera, David P. DeWitt, Theodore L. Bergman and Adrienne S. Lavine. Fundamentals of Heat and Mass Transfer (multiple editions). Wiley textbook, named as the background for thermal-resistance networks and for the order of magnitude of free-convection coefficients in gases used in Chapter 4. No tables are reproduced; the coefficient used is a stated assumption.
  • International Electrotechnical Commission. IEC 60529, Degrees of protection provided by enclosures (IP Code) (current edition). Named by number and scope only. Chapter 5 explains the structure of the IP code and the headline meaning of the digits; it quotes no test conditions.
  • International Telecommunication Union, Radiocommunication Sector. Recommendation ITU-R P.525, Calculation of free-space attenuation (current edition). Reference for free-space path loss, used in Chapter 7 in its common form with distance in kilometres and frequency in megahertz.
  • Australian Communications and Media Authority. Know what you must do (supplier obligations) (current web page). Source for the supplier's duties summarised in Chapter 8: arrange testing, register as a responsible supplier on the national database, keep compliance records and label products.
  • Electrical Regulatory Authorities Council. Electrical Equipment Safety System: in-scope equipment definitions (current web page). Source for the statement in Chapter 8 that extra-low-voltage equipment, below 50 V a.c. or 120 V ripple-free d.c., is outside EESS scope but must still be electrically safe.
  • International Electrotechnical Commission. IEC 60068 series, Environmental testing; IEC 61000-6-2 and IEC 61000-6-4, EMC generic standards for industrial environments; IEC 61000-4-2, electrostatic discharge immunity test; IEC 61076-2-101, M12 circular connectors (current editions). Named by number and scope only, as the families a test laboratory and supplier would discuss. No requirements or test levels are quoted.
  • International Electrotechnical Commission. IEC 60028, International standard of resistance for copper (1925, current edition). Named as the basis of the annealed-copper resistivity of 0.017 241 Ω·mm²/m at 20 °C used in the cable voltage-drop calculation in Chapter 6.

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