CLUSTER BOMBS: The term "cluster bomb" is generally used to refer to a bomb that contains submunitions. When the bomb casing breaks open, the submunitions are released and scattered, and each of them performs as another seperate weapon. Some submunitions are designed to be used as mines, some are anti-tank or anti-personel, some are even anti-submarine. The CBU-97/CBU-105 Sensor Fuzed Weapon with BLU-108/B Submunition is one of my favorites, because each of its 10 submunitions carries 4 more hockey puck-shaped sub-submunitions, and each of these hockey pucks can take out a tank.
The Sensor Fuzed Weapon [SFW] is an unpowered, top attack, wide area, cluster munition, designed to achieve multiple kills per aircraft pass against enemy armor and support vehicles. After release, the TMD opens and dispenses the ten submunitions which are parachute stabilized. Each of the 10 BLU-108/B submunitions contains four armor-penetrating projectiles with infrared sensors to detect armored targets. At a preset altitude sensed by a radar altimeter, a rocket motor fires to spin the submunition and initiate an ascent. The submunition then releases its four projectiles, which are lofted over the target area. The projectile's sensor detects a vehicle's infrared signature, and an explosively formed penetrator fires at the heat source. If no target is detected after a period of time, the projectiles automatically fire after a preset time interval, causing damage to material and personnel.
Since each hockey puck can individually target an enemy tank, up to 40 tanks can be destroyed by a single CBU-97. In practice, some submunitions will end up targeting the same tank, and it's unlikely that there will be 40 tanks positioned properly in any event... but it's the thought that counts! A tank's armor is thinnest on the top, and so it only takes a modest explosive to penetrate and disable the vehicle from a high angle.
There are pictures at the link I gave you above, but at least check this one out. That's an image of one of the hockey pucks firing directly into the engine block of a tank.