peripheral hood footprint 64 and die attach paddle 14 should be carefully considered with the pressure balance of the system to provide for adequate fluid flow past leadframe 12 fig4 shows a cam 70 and linkage structure 72 attached to the hood 18 and vacuum system 20 to open and close the adhesive application apparatus 10 the linkage structure 72 is comprised of an l shaped member 74 linking the hood 18 to the cam 70 and an l shaped member 76 linking the vacuum system 20 to the cam 70 between the cam 70 and the hood 18 the l shaped member 74 is translatably attached to elongate support members 78 and 80 by pins 82 and 84 respectively likewise between the cam 70 and the hood 18 the l shaped member 76 is translatably attached to elongate support members 78 and 80 by pins or bushings 86 and 88 respectively at their proximal ends 92 and 94 the l shaped members 74 and 76 are attached to rollers 96 and 98 respectively in addition the l shaped members 74 and 76 are biased by springs 90 the spring 90 biases the l shaped members 74 and 76 toward each other cam 70 may be driven between two positions as shown by a pneumatic hydraulic or electric linear motor cylinder 93 through a rod and pivot linkage 95 as shown the cam 70 may also be driven by a rotary electric motor or a pneumatic or hydraulic drive system that is capable of varying speeds and or incremental rotation in either such arrangement as the cam 70 rotates depending on the position of the cam 70 relative to the rollers 96 and 98 the hood 18 and the vacuum system plenum 21 are either in a.