|Process Parameter||Range Specification|
|Needle size||Range: 25—15 gauge, where needle diameter (D) is 20 gauge (0.91 mm) typical|
Range: Above the device edge midpoint, or 0 to 1.5 mm below the top surface of the device
Recommended: 1.0 mm below the top surface of the device
|Needle edge spacing||
Range: Half to three quarters of needle outer diameter (D)
Recommended: Half of needle diameter (D/2), approximately 1.0 mm
|Dispense needle speed||Range: 0.1 to 200 mm/second (6 mm/sec typical)|
|Value pressure||Range: 10 to 60 psi (14.5 psi typical)|
The adhesive is dispensed along the perimeter of the assembled component at a width of 2.5–3.0 mm and a height of 50% to 90% the substrate height, leaving a small section at the center of each edge unbonded, as illustrated in the following figure. This is to ensure that there is an outlet for any expansion of the air during processing. AMD recommends centering the opening on each side with a width of 25–30% the length of the package substrate. The exact locations and size of the openings can be varied depending on the design and rework.
To ensure proper mechanical bonding between the package and PCB, the edge bonding feature must penetrate the edge bonding material under the package substrate by 1.8 mm. This requirement is necessary for packages with coplanarity ≤ 200 µm, and BGA pitch of 1 mm or 0.92 mm, to pass physical qualification tests such as thermal cycle, power cycle, and shock and vibration requirements. It is necessary for special applications such as telecom, industrial, and data center applications.
Component Clearance Surrounding Edge Bond
An adjacent component clearance surrounding the AMD device is necessary to have the 30° to 45° angle required for the edge bond dispenser to dispense the edge bond adhesive material. The surrounding component height and distance from the device is validated based on each unique product design layout.