Choose a compact purpose-built enclosure when its drawing matches your exact display, button arrangement and assembled depth. Specify a custom enclosure when available cases waste space or force awkward mounting and cable routing. A 20x4 LCD designation describes twenty characters across four rows; it does not define the board outline or mounting pattern. The closest-fitting box is therefore the smallest one that accommodates the complete interface, not just the illuminated display area.
Decide whether the purpose-built case actually fits
A case described as suitable for a character LCD still needs a dimensional check against your module. Different modules can have different board widths, mounting holes, connector positions and backlight assemblies.
Start with the display manufacturer's mechanical drawing and the enclosure's dimensioned drawing. Compare the complete board outline, usable front-panel area and internal mounting features. Check whether the case accepts your exact module without trimming its board or loading the display glass.
Choose the purpose-built case if it provides all three essentials:
- A front opening or window that exposes the required viewing area without revealing unwanted internal parts.
- Mounting points that support the module and buttons without improvised packing or structural adhesive.
- Enough usable depth for connectors, wiring and closure without pressure on the electronics.
Specify custom dimensions when one of those conditions fails or a large keypad area serves no purpose. Custom fabrication solves an envelope problem; it does not remove the need for a verified layout. The custom enclosure specification guide covers the broader information needed for a buildable specification.
Let the environment set the enclosure requirements
For a dry indoor interface, protection against accidental contact and ordinary dirt may determine the enclosure choice. A compact case with exposed button gaps should not be assumed suitable for coolant, cleaning spray or outdoor rain.
Identify the actual exposure before reducing the box dimensions. Include dust, water direction, cleaning chemicals, direct sunlight and the highest surrounding temperature. Also consider moisture entering through cable routes or collecting during temperature changes.
Compactness can conflict with protection. A sealed display window needs a continuous sealing land around its opening. Panel-mounted buttons need room for their seals, retaining hardware and electrical connections. Those requirements may set the minimum face size before the LCD board does.
If outdoor operation is required, verify the display's temperature range and sunlight visibility separately. An enclosure cannot correct an unsuitable display specification.
Choose the rating before choosing the openings
For custom designs, Type 1 addresses indoor general-purpose use, while Type 12 addresses indoor dust, dirt and dripping liquids. Type 4 addresses hose-directed water, and Type 4X adds corrosion resistance. Choose the required type from the actual exposure and project specification, rather than automatically selecting the highest number.
Our enclosure ratings are manufacturer ratings for the specified design; the enclosures are not UL listed. Confirm any project requirement for third-party evaluation before ordering.
An enclosure rating does not transfer automatically to an exposed LCD board or a homemade button arrangement. Specify the window, operators and cable entries as part of the completed enclosure design. Their installation must preserve the required protection.
A bare character LCD normally needs a separate protective interface rather than relying on its circuit board as a seal. The bonded bezel display mounting and sealing article explains the separate mechanical and sealing roles around a display opening.
Match the material to the application
For indoor washdown and many outdoor applications, 304 stainless steel is a suitable starting point. Consider 316L stainless steel where salt air, brine or chlorides make corrosion resistance more demanding. Neither choice replaces a chemical-compatibility check for the actual cleaning solution and exposure temperature.
Powder-coated carbon steel suits indoor and sheltered industrial panels. Aluminum can suit weight-sensitive builds, provided the finish, environment and mounting arrangement are appropriate.
Nonmetallic construction may suit a small interface, but its manufacturing route affects how closely the enclosure follows your layout. Our custom polycarbonate and fiberglass options use standard molded sizes cut to your layout. Do not assume those options provide arbitrary outside dimensions.
Use the custom enclosure options to specify the material and dimensional requirements together. Material alone does not establish the enclosure's environmental protection.
Size the face around the board and buttons
Keep three outlines separate: the visible display area, the complete module board and the enclosure's usable mounting area. A small viewing opening can hide a much larger board behind the panel.
Use the LCD keypad panel cutout checks for the opening details. The selection decision here is whether the surrounding enclosure has enough room after those details are fixed.
For an illustrative layout, assume a module board measures 3.86 × 2.36 in [98 × 60 mm]. These are example dimensions, not a universal LCD footprint or a catalog enclosure size.
Allowing 0.25 in [6.4 mm] clearance at each side produces a minimum usable width of 4.36 in [111 mm]. That allowance must still accommodate actual mounting hardware; it is not a prescribed clearance.
Below the board, suppose the buttons require a 0.75 in [19 mm] service band. Adding a 0.25 in [6.4 mm] separation and equal top and bottom margins produces a usable height of 3.86 in [98 mm]. Increase this if the operator bodies or connectors extend beyond that band.
These are internal layout dimensions, not finished external dimensions. Wall construction, corner features, seals and closure hardware require additional space. The compact electronics enclosure layout article helps resolve those competing footprints before fixing the outside size.
Check usable depth and heat before shrinking further
Nominal enclosure depth is not the distance available behind the display. Subtract the space occupied by the front construction, rear closure, mounting features and any internal plate.
Build a side-view stack using the actual assembled parts. Include the LCD, interface adapter, connector housing, cable bend and access needed to disconnect it. A connector that fits only before the lid closes is not a workable service arrangement.
For example, assume the electronics project 0.80 in [20 mm] behind the panel's inner surface. If the connector and cable require another 0.60 in [15 mm], with 0.25 in [6.4 mm] rear clearance, the usable depth requirement becomes 1.65 in [42 mm]. This example assumes those features stack directly behind each other; a relocated connector may change the result.
The display module enclosure fit checks cover the assembled envelope rather than the display diagonal alone.
Also total the internal heat losses from the display, backlight, controller and power conversion. Compare the expected internal temperature at maximum ambient with each component's operating limit. A smaller sealed box has less heat-dissipating surface area, so dimensional fit alone is insufficient. Do not add ventilation openings without revisiting the protection requirement.
Make mounting and sealing part of the selection
A purpose-built enclosure wins when its supports already match the module and its closure remains accessible after wiring. A custom enclosure wins when it provides deliberate mounting locations instead of forcing electronics into leftover spaces.
Support the module at its intended mounting points. Avoid using the LCD glass, ribbon connection or button plungers to carry assembly loads. The LCD mounting and standoff article covers the mounting details separately.
Decide whether buttons will be panel-mounted operators or board-mounted switches behind a designed actuator arrangement. Panel-mounted operators need clearance for retaining hardware and terminals. Board-mounted switches need controlled actuator travel and alignment; a button cap alone does not establish a water seal.
Check cable entry positions against both the electronics and the mounting surface. Bottom entries may help cable routing, but the gland body and cable bend still occupy space. Provide strain relief so cable loads do not reach the display connector.
For a metal enclosure, include the required bonding arrangement in the design. Keep any mains wiring appropriately separated from accessible low-voltage interface electronics.
Put the verified envelope on the order
Order against a dimensioned assembly layout, not simply a request for a box to fit a 20x4 display. The specification should distinguish required usable space from proposed outside dimensions.
| Item | What to specify |
|---|---|
| Display | Exact module identifier, mechanical drawing and complete board outline |
| Viewing area | Required visible area, protective window arrangement and orientation |
| Buttons | Quantity, spacing, operator drawings and rear hardware envelopes |
| Material | Selected grade or material, finish and relevant chemical exposure |
| Protection | Required manufacturer-rated enclosure type and any project evaluation requirements |
| Dimensions | Width, height and depth, clearly identified as external or usable internal dimensions |
| Mounting | Module hole pattern, supports, enclosure fixing method and service access |
| Depth stack | Electronics projection, connectors, cable bends and rear clearance |
| Thermal conditions | Maximum ambient temperature, internal heat loss and component temperature limits |
| Openings | Face, location, dimensions, tolerances and sealing method for every opening |
Use the cutout designer to locate display openings, buttons and cable entries on the selected faces. Include rear component envelopes in the supporting drawing because front-view spacing alone cannot prove fit.
We build custom enclosures in quantities starting at one, with the material, dimensions and cutouts specified for the design. Approve the returned drawing only after checking the complete assembled interface. Custom enclosures are delivered in 10 business days, counted from your approval of the drawing.
Enclosures for this job
Catalog sizes that suit the job this article answers, picked from its subject; open one for its full specifications.
| Enclosure | Material | Outside H x W x D / display | Rating |
|---|---|---|---|
| 12 × 10 × 6 in | 304 stainless | 12 x 10 x 6 in | Rated NEMA 4X / IP66 by the manufacturer; not UL listed |
| 16 × 14 × 8 in | 304 stainless | 16 x 14 x 8 in | Rated NEMA 4X / IP66 by the manufacturer; not UL listed |
| 20 × 16 × 8 in | 304 stainless | 20 x 16 x 8 in | Rated NEMA 4X / IP66 by the manufacturer; not UL listed |
Questions
Will any enclosure labeled for a 20x4 LCD fit my module?
No. The designation describes the character arrangement, not the mechanical footprint. Board dimensions, mounting holes, connectors and display assemblies can differ. Match the exact module drawing to the enclosure drawing before deciding that a purpose-built case fits.
Should I choose a purpose-built case or a custom enclosure?
A purpose-built case is preferable when its mounting features, display opening and usable depth already match your assembly. Specify a custom enclosure when available cases waste substantial space or require compromised mounting, button placement, cable routing or sealing.
How much depth should I allow behind the LCD?
There is no reliable universal allowance. Measure the complete assembly behind the front panel, including adapters, mating connectors and cable bends. Add the clearance needed for closure and service, then verify that space against usable internal depth rather than nominal outside depth.
Can a compact LCD enclosure include a few buttons?
Yes, if the layout accommodates their front spacing and rear hardware. Panel-mounted operators need room for seals, retaining hardware and terminals. Board-mounted switches need aligned actuators and controlled travel. Any water-protection requirement must cover the complete installed button arrangement.
Does adding a sealed window make the whole enclosure suitable for washdown?
No. A protective window addresses only part of the assembly. Its seal, the enclosure closure, buttons, cable entries and mounting penetrations must all support the specified protection. The display's own temperature and humidity limits also remain applicable inside the enclosure.
