Abstract:
A semiconductor device has a flipchip or PoP semiconductor die mounted to a die attach area interior to a substrate. The substrate has a contact pad area around the die attach area and flow control area between the die attach area and contact pad area. A first channel is formed in a surface of the substrate within the flow control area. The first channel extends around a periphery of the die attach area. A first dam material is formed adjacent to the first channel within the flow control area. An underfill material is deposited between the die and substrate. The first channel and first dam material control outward flow of the underfill material to prevent excess underfill material from covering the contact pad area. A second channel can be formed adjacent to the first dam material. A second dam material can be formed adjacent to the first channel.
Abstract:
A semiconductor device has a flipchip or PoP semiconductor die mounted to a die attach area interior to a substrate. The substrate has a contact pad area around the die attach area and flow control area between the die attach area and contact pad area. A first channel is formed in a surface of the substrate within the flow control area. The first channel extends around a periphery of the die attach area. A first dam material is formed adjacent to the first channel within the flow control area. An underfill material is deposited between the die and substrate. The first channel and first dam material control outward flow of the underfill material to prevent excess underfill material from covering the contact pad area. A second channel can be formed adjacent to the first dam material. A second dam material can be formed adjacent to the first channel.
Abstract:
An interconnect structure for a semiconductor device is made by forming a contact pad on a substrate, forming an under bump metallization layer over the contact pad, forming a photoresist layer over the substrate, removing a portion of the photoresist layer to form an opening which exposes the UBM, depositing a first conductive material into the opening of the photoresist, removing the photoresist layer, depositing a second conductive material over the first conductive material, and coating the second conductive material with an organic solderability preservative. The interconnect structure is formed without solder reflow. The first conductive layer is nickel and the second conductive layer is copper. The organic solderability preservative is made with benzotriazole, rosin, rosin esters, benzimidazole compounds, or imidazole compounds. The interconnect structure decreases the pitch between the core pillars in the interconnect array and increases the density of I/O contacts on the semiconductor device.