I have a problem with my golf4 v5 engine sparking coil ..one phase of the coil not working it was confirmed that is dad ...what may cause it burn at of 5 coil

You'll need to verify spark at the ignition coil secondary (coil wire that goes to the ditributor). If you dont have a spark tester, remove plug from cylinder 1, disconnect coil wire from distributor and connect to the plug you removed and ground plug to engine steel, have someone crank engine and observe spark.

Before you remove spark plug, crank engine for a few seconds, then promptly remove plug. If its wet with fuel then at least you know injectors are working. If dry, then likely injectors are not activated by ECM. Go ahead and confirm spark and then figure out why no fuel from injectors.

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Ignition coils fail due to bad spark plugs or plug wires. Another potential cause is heat and vibration, which can damage the ignition coil's windings and insulation. If an engine is experiencing repeated coil failures, the underlying cause may be resistance from worn spark plugs or excessive spark plug gap. And in rare cases, the failure may be due to a lean fuel condition caused by leaky valves.

With coil on plug (COP) type coils, the rubber insulation dries up (over time and heat from the engine) and cracks and will arc across the engine's metal- shorting out. (Electricity seeks the path of least resistance)

By design, coils take low voltage energy from the battery (12-Volts dc) and transform that energy into a very high voltage charge (in the range of 30,000 to 35,000 volts) to energize the spark plugs which in turn ignites the fuel.

If a spark plug or plug wire is open or has excessive resistance, the ignition coil's output voltage can shoot higher (above the max threshold of 35,000 volts) and burns through the coil's internal insulation, causing a short.

When a coil failure occurs, the coil's voltage output drops, and the engine may not start or may misfire badly when under load.

Extreme caution should be exercised when handling coil packs that are energized- a lethal dose of voltage can arc across the air into the body. So don't touch them when the engine is running!

As stated earlier, if you need to replace the COP, replace the spark plug too, make sure the spark plug is properly gapped.

You can read more about coils here:

Ignition Coil High Voltage Display

for coils to burn or melt indicates excessive current flow through them
have voltage checks done wiring as there may be a problem in the ignition module that is allowing excessive current to the packs

Your distributor may be installed backwards, or maybe just out of phase.
If backwards, you will probably never get it to start and, of course the solution is relatively simple.
If out of phase, the spark may be jumping to a different terminal inside the distributor cap and completely disrupting your ignition timing. See the attached video for an explanation of phasing and how to correct it on your car. (you will need an old distributor cap to drill a hole into so you can confirm spark)
It also occurs to me that the coil you have may not be compatible with your system.

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NEW SPARK PLUGS NEEDED

Very much so. They have a belt on the timing and it can slip, loose a couple of teeth or break. You have a no tolerance engine, so I recommend you get it fixed. If the belt breaks, the pistons can slap and bend the valves. Alot more work and money.

Subaru engines (including Legacy and engines of many other automobiles, GM, etc.) have returned to so-called wasted spark ignition systems since advent of the electronic distributor-less ignition (having been used historically in early engines with magneto ignitions). With this approach, the ignition systems are less expensive and usually quite reliable. At the same time, however, a shorted spark plug (cracked or carbon clogged, etc.) (or bad ignition spark plug wire) grounds both the ignition spark and the false spark being used. This means that it also grounds the corresponding respective ignition spark of the other 180 degree out of phase cylinder (that uses the same the same coil because the spark current is connected to the spark plugs of two cylinders). Since such a defect allows more current to flow in the spark coil to two plugs when the resistance of the spark plug gap disappears due to a cracked plug, etc, it seems likely to hasten coil burn out if the spark plug/plug wire defect is not corrected before installing the new spark coil.

To explain further, wasted spark means that when a cylinder is ready to fire, it gets a spark to its spark plug while part of the spark (from the same coil and current) as a sort of copy is also sent to another cyclinder at the same time but when the piston in that cylinder is exhausting its ignited gases 180 degrees out of phase from when its spark is needed. When the second cylinder is ready to fire and receives its "spark, the first cyclinder the also receivesa "wasted" spark "copy" of the one needed by the second cylinder. Economy is achieved in manufacture because otherwise electronics would have to turn on and off four different spark coils to distribute four different sparks as needed to the four cylinders. With wasted sparks (which are cheap), because the spark current of one coil is connected (internally in the ignition coil unit) to two cylinders that are in the same position but 180 degrees out of phase in firing, the system can turn on and off two spark coils twice as fast with half the electronics and fire two cylinders that are 180 degrees out of phase. A four cylinder engine thus uses only two coils, a six cylinder engine, three coils, etc., in a wasted spark system.