Wafer Bonding Seal Ring

Eutectic ausi bonding is the only method where only one joining partner requires a metal frame.

Wafer bonding seal ring.

The seal ring 150 as shown in fig. The bottom wafer generally was a 300µ m thick 4 si wafer having a low bow and a low total thickness variation ttv. As a solution bcb dry etching has been proposed to. With advances in wafer bonding technology this process has been widely applied to the fabrication of mems devices.

The bond seal area is defined by etching the backside of a cap wafer by 2 µm. Thara srinivasan lecture 25. Finally polymer cap encapsulation combining the merits of wafer to wafer bonding and thin film packaging has been reported. It is found that the principal cause of the partial bonding is due to non flat bcb sealing ring caused by multilayer bcb coating process.

The pair of seal rings for example is arranged in parallel. 17 21 it consists of a polymer membrane as a packaging cover and a polymer sealing ring. This paper presents the effect of bcb sealing ring flatness on bcb bonding for wafer scale bcb cap transfer packaging. One such technique is wafer level packaging wlp which forms a hermetically sealed cavity in which the device element is situated.

Sealing rings after eutectic wafer bonding. Finally both cap and interposer wafers were bonded together using a wafer to wafer bonder and an adapted ausn soldering process scheme. Here a cap wafer is manufactured with a gold ring metallization and the mems wafer provides a silicon frame area for the metallurgical reaction. Metal layer bonding pattern seal rings and bond pads photolithographically eutectic bonding uses eutectic point in metal si phase diagrams to form silicides au and si have eutectic point at 363 c.

A material a b c d e f cap dicing. These results demonstrate that bonding with the cusn thin film sealing ring at 400 c. Wafer to wafer bonding and packaging dr. Most of the metal seal bonding technologies require metal frames on both wafers as shown in figure 32 1.

The cap wafer was equipped with 200 μm deep dry etched cavities and electro plated au seal rings around them. Article osti 1107804 title wafer level packaging with compression controlled seal ring bonding author farino anthony j abstractnote a device may be provided in a sealed package by aligning a seal ring provided on a first surface of a first semiconductor wafer in opposing relationship with a seal ring that is provided on a second surface of a second semiconductor wafer and. 1 surrounds the main device area 110 and is parallel to the outer perimeter of the die. Deposited on patterned si bonding ring.

Bcb sealing ring has shown partial bonding or full bonding depending on its flatness.