Homemade LCD flat cable with your own hands. Soldering damaged flexible cable tracks. Tools and materials

Modern internal interfaces for connecting individual nodes within digital technology are almost impossible to imagine without loops.

These multicore connections act as a movable joint for electrical boards, individual models and other circuit assemblies.

The most common types of loop connection include:

1. Soldering (one of the most reliable methods, but it requires a certain technological process and equipment, overheating of the circuit elements during soldering can disable them).
2. Various mechanical joints (clamps, inserts, etc., it is very simple to make such a connection, no additional equipment or skills are required, the disadvantages include low reliability - the cable may not fully press in, contacts oxidize over time, etc.) ...
3. Sticker on conductive glue / adhesive tape (we will dwell on this method of connecting loops in more detail).

What are the types of conductive adhesive for the loop

Initially, adhesive technologies were used to mount a chip on a substrate using a special conductive paste. In this case, no soldering (that is, heating) was required, the paste solidified, providing the necessary heat dissipation and conduction of electricity.

Later, the technology was adopted to connect various kinds of displays and other digital technology nodes.

Conductive adhesives provide reliable and fast adhesion with minimal dimensions (since there is no need for special connectors).

Modern conductive adhesives can be:

• Isotropic. They differ in that there are no restrictions on the direction of propagation of the current inside the conductive material, the medium is homogeneous. These can be ICA (isotropic adhesives) or ICP (isotropic pastes).
• Anisotropic. Inside a conductive material, the current travels only in a certain direction. This group includes ACA (anisotropic conductive adhesives) and ACF (anisotropic conductive films).

The latter are most widely used in household appliances. So, with ACF you can glue the ribbon cable to the LCD TV matrix... The current will flow between the connected contacts strictly perpendicular to their surface inside the anisotropic adhesive tape.

The use of any adhesive mixture is associated with certain restrictions. Various ACF films (scotch tapes) are designed to bond certain types of materials, require compliance with temperature and humidity conditions, the absence of dust and other small particles that impede adhesion, as well as certain conditions for pressing the glued surfaces (minimum force, heating, etc.).

An important indicator of the use of ACF is the minimum required gap between the contacts (each type of film has its own).

VIDEO DESCRIPTION

How and how to glue the cable to the board

Most modern boards for digital technology use a mechanical method of connecting loops, however, in some cases, anisotropic conductive films (tape) or adhesives can be used.

To glue the flex cable to the board in the case of ACF, it is necessary:

1. Clean up any remaining compound / tape with isopropyl alcohol.
2. Take an anisotropic adhesive tape (for example, 3M Z-Axis 9703 is suitable, before use, be sure to make sure that the distance between the contacts does not exceed 0.4 mm, since a short circuit can be obtained with a smaller size).
3. Remove the first protective layer and stick the film on the board.
4. Remove the second protective layer from the ACF foil.
5. Correctly match the contacts of the ribbon cable and the contacts on the board, attach the ribbon cable and evenly press down to the surface of the board with sufficient force.

When carrying out work, be sure to take into account that there should be no dust and small particles in the air (if the sticker is made in a domestic environment, work can be carried out in the bathroom).

The room temperature must be between + 20 ° C and 38 ° C (but never lower than + 10 ° C).

How to glue a ribbon cable to the display - method description

The technology for mounting loops with conductive adhesive tape is identical to the process of connecting a loop and a board.

Differences may be only in the materials supported (for example, Axis 9703 tape is not recommended for mounting on glass surfaces, only 5352R and 5552R films from the same manufacturer are suitable) and the minimum recommended gap between contacts (for example, 3M Z-Axis 5552R film can be used for distance between contacts less than 100 microns).

Some conductive films or adhesives may require heat or a lot of force on the bonding surfaces during installation.

Before purchasing, it is imperative to familiarize yourself with the specification of the film / adhesive. Clarify the order of application.

Restoration of torn loops with conductive tape

It often happens that in the process of disassembling displays or other complex equipment, when unsticking the cable, excessive force is applied and it breaks.

The purchase of such a seemingly simple element can become an almost impossible task, since you cannot find similar conductors on sale, as well as donors (broken equipment from which parts can be removed).

In this case, ACF film or glue will save the situation, regardless of the type of loop.

The procedure is as simple as connecting the ribbon cable to a board or monitor.

1. The damaged section of the train is cut out. For this, the conductor is completely cut at right angles in two places along the edges from the break (damaged area).
2. If necessary, the live parts are exposed at the butted section (if the conductors are insulated in the middle of the loop) and treated with alcohol.
3. The first layer of the protective film is removed from the ACF, and the tape is applied to the end of one of the tail pieces.
4. The second protective layer is removed and the second piece of the loop is applied.
5. Depending on the requirements of the film mounting technology, heating or sufficient compression force of the joint may be required (here it is important to take into account that heating is contraindicated for some types of loops, which means that the connecting film should be chosen with mounting without heating).

VIDEO INSTRUCTION

The disadvantage of this method of restoring the loop is the reduction in its length.

The train is an important and even irreplaceable component of many mechanisms. In computers, loops are used to connect hard drives, optical drives and other nodes to the motherboard. A mobile phone will not work without a loop, because it connects its moving parts and serves to transmit a signal from one part of the mobile to another.

Instructions

To glue the ribbon cable to the matrix, completely separate the damaged ribbon cable. Then rinse off the remaining conductive glue with acetone, with which it was originally glued. Apply flux liberally to the board and ribbon and tinker with a soldering iron using a small mini-wave tip. It will collect excess solder on its surface, and there will be no closed contacts. Wash off all flux. Small beads of solder should remain on the gold-plated contacts.

Do this carefully to get uniform beads. Apply a little of the same flux, align the contacts on the board and the ribbon cable, and evenly warm it with a thermal air. The solder will melt, the plume will float and, under the influence of the surface solder tension, will find its place by itself. In doing so, it softens and takes on an ideal flat contact surface.

Use conductive glue to glue the ribbon cable to the tracks. You can buy such glue at any specialized electronics store or car stores.

Fill the tracks with sealant - the result is almost the same as with glue, but in this case you cannot promise the same durability as in the case of special conductive adhesives.

Press down on your own train using an elastic band from other indicators. If you have a toy "Wait a minute", use it - there these rubber bands are big and very helpful in such situations. You can also glue the wires from the wire to the indicator, and in turn glue them to the restored tracks of the loop itself.

If the train on the calculator has come off, glue it by simply placing it on the contacts and ironing it through the paper. But it is better to practice on a penny calculator in order to "fill your hand" and not spoil everything. This method is more suitable for repairing small office equipment, and not computers and similar mechanisms.

The most common cause of a TV or monitor malfunction is the data loop. The main signs that indicate damage to this part are:

• flickering of the matrix (with different intensity or constant);

• ripples;

• geometric distortion of the image;

• stripes of various widths.

All of the above defects may be permanent or intermittent.

In the presence of damage to the matrix loop, there are two ways to solve the problem:

• repairs;

• replacement.

The first method is more complicated, but there is no need to purchase a new part. It is much easier to replace, but some models of TVs and monitors have long been discontinued, and it is rather difficult to purchase parts for them.

Replacing the loop

The process of replacing a loop must be performed with extreme caution. A tool is required to perform this operation. A number of items are required, such as:

• a set of Phillips screwdrivers;

• a set of slotted screwdrivers;

• hexagons and sprockets;

• knife or autopsy tool.

For small parts, screws and bolts, you should definitely purchase a separate container. Losing them is extremely undesirable; in the absence of important parts, assembly and normal operation of the device will simply become impossible.

To get to the monitor cable, you need to disassemble its case. This operation is performed in the following order:

After completing all of the above actions, you can proceed directly to disconnecting the loop of the screen matrix itself. To do this, you need to use the special latches on the sides. One end of this part is connected directly to the die, the other to the electronic board.

It is necessary to disconnect as carefully as possible, several rules should be observed:

• it is important to preserve the original shape of the loop - do not bend it, as this can lead to breakage of the conductors;

• when disconnecting from the board, it is important to do everything very carefully, without making unnecessary efforts - by pressing hard on the circuit, you can easily damage it.

When the old cable is disconnected, you need to install a new one in its place. This operation also has some peculiarities:

• when connecting the connector, it is necessary to perform the “male-female” connection as carefully as possible - by pressing hard when a skew occurs, the contacts can be damaged (this will lead to the need for complex repairs);

• you should make sure that the new cable will not interfere with the subsequent assembly - it is advisable to give it a shape similar to the one being replaced.

The assembly process is carried out in exactly the opposite order.

Matrix loop repair

Matrix loop damage is not uncommon. Most often they have the following character:

Repairing the matrix loop using a soldering station or a special hair dryer is quite complicated. That is why, if it breaks down or breaks, you can proceed as follows:

The glued foam acts as a sealing cushion. This method is relatively reliable: if the monitor is not moved, then in this state it can serve for a very long time.

You can restore the matrix loop by soldering. To perform this operation, you will need the following items:

If thin conductors are damaged, you can simply solder them, just heat the metal to a sufficiently high temperature. To get a tight connection, you should simply cut out the damaged area with scissors and ensure a sufficiently tight contact between the tracks. After that, putting the parts of the train on a special lining, you should simply heat them up, aligning the individual tracks with each other as accurately as possible.

The thickness of the conductors in some places is quite small, so you should use a magnifying glass. This item will allow you to minimize the likelihood of defects: adhesions of individual cores to each other or, conversely, the appearance of unsoldered places.

The following models of IR equipment are suitable for soldering:

• Scotle IR-PRO-SC;

• ACHI IR-PRO-SC;

• Tornado Infra-Red.

You can also use other equipment to accomplish a similar task. It is only important that it can solder the tracks with a mother-in-law of about 0.06 mm as accurately as possible - this is the size of the conductors located inside the loop.

If there is oxide or carbon deposits on the plume, its individual parts, it is necessary to remove them with distilled water or pure alcohol. After performing this operation, be sure to check the voltage at the contacts with the device turned on. Or simply ring the loop with a multimeter. In the presence of damage in the conductors, it is necessary to determine the location of the defect as accurately as possible, and then carefully examine it under a magnifying glass.

If the conductors are long enough to solder, you can simply connect them and heat them well with an infrared soldering iron. Or heat it up with a hair dryer. After completing this operation, you must again check the presence of voltage at the contacts.

When performing soldering, it is necessary to observe the temperature regime as accurately as possible. To do this, determine what metal is used in a particular loop and set the desired temperature on the soldering equipment. If the melting point is significantly exceeded, then the metal will simply spread over the surface. This will make the repair impossible. It is important to avoid delamination of the PCB from which the board is made.