A Guide to Using LOCA Glue Replacing LCD Screen Glass

Loca glue, also known as UV glue, is an optically-clear liquid adhesive. This type of glue is used on a wide range of electronic equipment, especially with touch panels found in today’s smartphones. Today, we would like to let you know why and how to use LOCA glue to replace LCD screen in Mobile Phone Repairing.

Table of Contents

• I. What is LOCA Glue?
• II. Advantages of LOCA Glue over Other Adhesives?
• III. How to Use LOCA Glue to Replace LCD Display Screen Glass of Mobile Phone？

I. What is LOCA Glue?

LOCA or Liquid Optically Clear Adhesive is kind of special UV glue or sealant used to bond display / LCD Screen and touch screen panels. It is also called UV Glue. Most technicians prefer to use LOCA Glue or UV Glue over other glue or sealants because it improves contrast by many times.

It also prevents loss of light from the display and hence increases the life of Mobile Phone Battery. LOCA Glue is available in both acrylic-based and silicon-based.

The Introduction of LOCA Repair

Earlier, if a smartphone got cracked, repair shops would simply switch out the screen assembly. The problem with this was that in most cases the LCD was not damaged at all. Yet, it was impossible to separate the cracked glass from it.

The introduction of LCD separator machines allowed an even disbursement of heat that a heat gun could not achieve. Profits from glass only repairs were almost double of what one would make if they just switched out an assembly.

II. Advantages of LOCA Glue over Other Adhesives?

Main advantages of LOCA over other adhesives are:

1. Rework ability – If required, LOCA Glue can be removed for rework / repairing.
2. It offers excellent adhesion to even non-even surface.
3. Offers excellent optical properties.
4. It is very durability.

III. How to Use LOCA Glue to Replace LCD Display Screen Glass of Mobile Phone

In order to replace a faulty, broken or damaged glass / touch panel (PDA) of LCD Screen of a mobile phone or smartphone, you will need following Mobile Phone Repairing Tools:

1. Hot Air Gun or HOT Plate or LCD Separator Machine
2. Goof Off / or Hot Blade (A Soldering Iron with a Wide Flat Tip)
3. Putty Knife
4. Infrared Thermometer
5. UV Lamp
6. Illuminated Magnifier / Magnifying Lamp
7. LOCA Glue in a Syringe
8. New Screen / Glass for Replacement
9. Metal Spudger
10. X-acto Knife

1. Separating the glass from the LCD

Separating the glass from the LCD should be done very carefully to avoid any unwanted damage. Special care must be undertaken if the glass is cracked.

The glass and LCD are strongly bonded together with LOCA glue. The glue must be heated to loosen the bond. It can be done using a Hot Air Gun / Heat Gun. Technicians with some practice can easily do it.

However, in most authorized service centers and professional service centers, they use LCD separator machine.

How to Separate Glass from LCD Display

Use a Hot Air Gun or LCD Separator Machine, to give heat to the LCD to Loosen the bond of the LOCA glue. In both cases, a temperature of 200-300 Degree C is OK.

1. Gradually and evenly heat the front side of the phone. Use the Infrared Thermometer to check the temperature before trying to remove the glass. Make sure there is neither too much heat nor too little heat. Too much heat will burn the LCD screen while too little heat might crack it.
   
   
2. Start removing the glass from the top of the screen where speaker is located. Use the metal spudger to carefully separate the glass from the LCD screen. Move the spudger along the top edge and make enough space for the putty knife to slip in.
   
   
3. Reheat the surface and using the putty knife, carefully pry the glass away. After removing the Glass, use the Goof Off  or Hot Blade to remove existing melted LOCA glue and clean the LCD screen using lint-free wipes.
   
   
4. Some phones have “HOME” and “BACK” sensors attached to one end of the glass.  Carefully remove the connectors using the X-acto Knife.
   

Most professional technicians repairing iPhone and High-End Samsung Smartphone use LCD Separator machine.

2. Apply LOCA Glue

LOCA glue is available in the form of liquid. It is not as thick as other adhesives. Apply just enough glue on to the screen in a “X” pattern with a “-” in the middle of “X”. Make sure not to apply too much or too little glue and see that there is no air bubble.

The adhesive will gradually spread across the screen and to the edges on its own without you having to apply any pressure. If there is any bubble, apply gentle pressure on the LCD and guide the bubble to the edge.

3. Cure or Dry LOCA Glue

LOCA Glue do not cure or dry on its own. You have to dry it using UV light. Always Use a branded UV light that is about 30 to 40 Watts. You can also use a UV nail dryer. But do not use Flashlight UV lights.

Curing or Drying time of the Glue is generally 1 to 2 minutes. It also depends on the Wattage of the UV light source and the distance between the UV light source and the LCD Screen or Glass.

I hope now you know how to use LOCA glue to repair a broken LCD Screen / Glass of a mobile phone / smartphone. If you still have any question on how to use LOCA glue then do not hesitate to ask Phonefix question via comment.