Plated chrome solder dam for high power mmics
OwnerCheng P. Wen, Rawley D. Larsoninventors
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Abstract
A microwave device includes a circuit element and a chromium layer disposed over the circuit element. The circuit element may have an electrolytically plated gold surface. The microwave device further includes a bump disposed over the circuit element. The bump may include silver, while the chromium layer may include a portion extending from the bump to form a solder dam. A native oxide forms on the portion of the chromium layer to inhibit solder contamination and/or silver migration. The native oxide may also act as an adhesion agent for a subsequently deposited dielectric passivation layer.
Claims21
A microwave device, comprising:
- a circuit element;
- a layer comprising chromium disposed over the circuit element;
- and
- a bump disposed over the circuit element.
A method of forming a flip-chip bump on a circuit element of microwave device, comprising the steps of:
- (a) depositing a layer comprising chromium over the circuit element;
- (b) providing a bump photoresist profile;
- and
- (c) depositing a metal layer over the circuit element to form the flip-chip bump according to the bump photoresist profile.
Dependencies are inferred from the claim text.