Bonding & lamination for displays, touchscreens, cover glass and films

Optimized bond­ing tech­nolo­gies such as opti­cal bond­ing(OCA bond­ing and LOCA bond­ing) and air gap bond­ing improve the image qual­ity, robust­ness and ser­vice life of your HMI and dis­play mod­ules — from indus­trial to med­ical tech­nol­ogy and out­door.

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Maximum read­abil­ity, shock­proof — ideal for out­door & indus­try — Made in Germany or Asia

Optical bonding

Full optical bonding — What is optical bonding?

Optical bonding

With opti­cal bond­ing, the cover glass, touch and dis­play are bonded together over the entire sur­face with­out an air gap. A trans­par­ent adhe­sive is applied between the glass and the dis­play — usu­ally OCA (Optically Clear Adhesive) or LOCA (Liquid Optically Clear Adhesive) — is applied between the glass and the dis­play. The result is bet­ter read­abil­ity in sun­light, fewer reflec­tions and higher con­trast. Optical bond­ing also increases the robust­ness of the dis­play, as the com­pos­ite is more resis­tant to shocks, vibra­tions and moisture.

Advantages of optical bonding

Robustness and mechanical stability

Very high robust­ness and impact resis­tance, ide­ally pro­tected for out­door envi­ron­ments and against van­dal­ism. Mechanical sta­bil­ity at its best! 

Robustness

Reflection reduction and brightness

Significantly reduced reflec­tions and improved read­abil­ity thanks to the elim­i­na­tion of the air gap as well as increased bright­ness and con­trast sta­bil­ity, even in direct sun­light, for con­sis­tently opti­mum dis­play per­for­mance.

Optical bonding

Condensation and impact resistance IK10

No con­den­sa­tion or dust inclu­sions in the entire air gap. Thanks to the opti­cal bond­ing and the match­ing glass, we achieve a degree of impact resis­tance up to IK10

Impact resistance

Cost-​efficient alternative — What is air gap bonding (lamination)?

With air gap bond­ing, the cover glass is attached to the touch or dis­play with double-​sided adhe­sive tape with­out com­pletely fill­ing the air gap. This cre­ates a nar­row air gap between the glass and the dis­play, which is suf­fi­cient for many indoor appli­ca­tions. Compared to opti­cal bond­ing, how­ever, reflec­tions, reduced robust­ness and con­den­sa­tion can occur in the event of large tem­per­a­ture dif­fer­ences. This con­struc­tion method is cheaper and eas­ier to imple­ment than opti­cal bond­ing, as no addi­tional adhe­sive is required. We can advise you on whether air gap bond­ing makes sense for your project — or whether opti­cal bond­ing offers clear advantages. 

Air gap bonding

Advantages of air gap bonding

Lower production costs

Cost-​efficient alter­na­tive to full opti­cal bond­ing — opti­cal bonding

Easier and faster production

The process is less com­plex and there­fore has a higher yield

Better repairability

As the lay­ers are not fully bonded, the glass or touch panel can be replaced more easily

Selection of technology

Description /​ Design

Air-​Gap

(Double-​sided spacer tape)

Dry — DOCA

(PVB, OCA,…)

Wet — LOCA

(sil­i­cone or acrylate-based)

Typical trans­mis­sion opti­cal bond­ing layer (with­out com­po­nent transmission*)

88%

95%***

95%***

Max. Temperature range (lim­i­ta­tion rather by components) 

-30° to +80°C

-30° to +80°C

-30° to +80°C

Protection against con­den­sa­tion between layers

No

Yes

Yes

EMC pro­tec­tion or other func­tions (polar­iza­tion foils etc.)

Only via components

Via com­po­nents or addi­tional layers

Via com­po­nents or addi­tional layers

Combination rigid with flexible**

No

Yes

Conditional

Combination of rigid with rigid

Yes

No

Yes

Combination Flexible with Flexible

Conditional

Yes

No

Bonding uneven surfaces

Conditional

No

Yes, (top­ping up possible)

Installation height

Up to 1mm

Up to 0.3mm

Up to 1mm

Cost effi­ciency

Very high

Medium

Medium to high

*Theover­all trans­mis­sion depends largely on the com­po­nents used. Additional anti-​reflective prop­er­ties can there­fore be achieved via the com­po­nents or addi­tional lay­ers.
**e.g. films or thin PMMA/​PC
***BenefitTransmission: Display must pro­duce 7–8% less bright­ness to give the same impres­sion to the user

Our rec­om­men­da­tion: Optical bond­ing for demand­ing out­door and indus­trial appli­ca­tions & air gap bond­ing for cost-​conscious indoor projects.

Terms & synonyms

Full-​surface bond­ing, Direct dis­play bond­ing, Optically clear bond­ing, Laminated dis­play unit, Display lam­i­na­tion, Air gap bond­ing, Air gap dis­play, Classic dis­play mount­ing, Indirect bonding

Manufacturing process

As an expe­ri­enced dis­play and HMI part­ner, we man­u­fac­ture opti­cal bond­ing and air gap bond­ing in a con­trolled envi­ron­ment and with high qual­ity stan­dards.

The process includes the selec­tion of the appro­pri­ate adhe­sive(OCA or LOCA), mate­r­ial prepa­ra­tion & clean­ing, pre­cise align­ment, lam­i­na­tion, degassing, cur­ing and final opti­cal and func­tional testing.

Frequently asked questions about bonding & lamination

Die Durchlaufzeit hängt von Displaygröße, Stückzahl und Testanforderungen ab. Typischerweise soll­ten Sie für ein Serienprojekt mit etwa 10–15 Werktagen ab Freigabe der Komponenten rechnen.
Je nach Projekt nutzen wir OCA-Folien oder flüs­sige LOCA-Systeme. Die Auswahl hängt von Displaygröße, Aufbau, gewün­schten optis­chen Eigenschaften und Umgebungsbedingungen ab.
Ja — das voll­flächige Verkleben macht das System deut­lich robuster gegenüber Schlägen und Vibrationen.
Ja — durch die Eliminierung des Luftspalts wird Reflexion stark reduziert und der Kontrast deut­lich erhöht.
Hochwertige OCA/​OCR-​Materialien sind für mehrere Jahre, oft 5–10 Jahre, UV- und alterungssta­bil ausgelegt.
Ja, beson­ders kapaz­i­tive Touchsensoren kön­nen ger­ingfügig an Präzision ver­lieren, da der Abstand zum Display größer ist.
Ja — beson­ders bei starken Temperaturwechseln kann sich Feuchtigkeit im Spalt sammeln.
Der Luftspalt verur­sacht dop­pelte Reflexionen, gerin­geren Kontrast und ein „ver­wasch­enes“ Erscheinungsbild.
In der Regel nein, da Reflexionen, Feuchtigkeit und gerin­gere Robustheit prob­lema­tisch sein können.
Für viele Indoor-​Anwendungen mit mod­er­aten Lichtverhältnissen und geringer mech­a­nis­cher Belastung ist Air Gap Bonding eine sehr wirtschaftliche Lösung. Wir prüfen gern gemein­sam, welche Variante für Ihre Applikation sin­nvoll ist.
Wir kön­nen eine große Bandbreite an Displaygrößen und ‑tech­nolo­gien ver­ar­beiten – von kom­pak­ten HMI-​Displays bis hin zu größeren Industrie- und Infotainmentsystemen. Sprechen Sie uns für konkrete Spezifikationen ein­fach an.

Project request

Briefly describe your project — we will get back to you with advice and a proposal.

  • Industry & oper­at­ing environment
  • Displaydiagonale
  • Outdoor or indoor


    Related components

    Touchscreens

    Displays

    Keys

    Carrier plates & housings

    EP Electronic Print GmbH

    Your part­ner for cus­tomized HMI solu­tions, opti­cal bond­ing, front foils and mem­brane key­pads.

    Contact us

    Phone: +49 (0)8142 /420896–0
    E‑mail: info@ep-electronicprint.de