Motorola Corporation

Martin A Kalfus

Samuel Anderson

John Baird

Eugene L Foutz

Robert A Gooch

Pablo Rodriguez

Joe L Martinez, Jr

An electronic assembly (20) having an insulated metal heat sink (10) and a method of manufacturing the electronic assembly (20). The electronic assembly (20) has a heat dissipater (11), a dielectric material (12), and a conductive layer (13). A semiconductor chip (21) is attached to the insulated metal heat sink (10). Heat generated by the semiconductor chip (21) is conducted to the conduction surface (14) of the heat dissipater (11). In one embodiment a convection surface (16) of the heat dissipater (11) is present and the heat is transferred from the convection surface (16) of the heat dissipater (11) to a fluid by convection. The fluid is directed by a manifold (64).

Electronic assembly for removing heat from a semiconductor device

An encapsulated microelectronic device (100) including a base (101) and a semiconductor device (305) having a top and a bottom. The bottom is attached to the base (101). The semiconductor device (105) has a thickness in the range from one-fourth to three-fourths of a millimeter and has a bottom metallization consisting of aluminum (407)/chromium (405)/nickel (403)/gold (401). The semiconductor device (305) has a contact (115) attached to the top. The encapsulated microelectronic device (100) has a molded top (120) surrounding the semiconductor device (305). The molded top (120) is made from low stress molding material.

Plastic encapsulated microelectronic device and method

An encapsulated microelectronic device (100 ) including a base (101) and a semiconductor device (305) having a top and a bottom. The bottom is attached to the base (101). The semiconductor device (105) has a thickness in the range from one-fourth to three-fourths of a millimeter and has a bottom metallization consisting of aluminum (407)/chromium (405)/nickel (403)/gold (401). The semiconductor device (305) has a contact (115) attached to the top. The encapsulated microelectronic device (100) has a molded top (120) surrounding the semiconductor device (305 ). The molded top (120) is made from low stress molding material.

Plastic encapsulated microelectronic device

An improved contact is obtained to power devices having a raised dielectric region adjacent the die contact region by providing a contact dimple on the otherwise flat metal lead used for die contact. The dimple is arranged above the die contact and soldered thereto. The radius of curvature and depth of the dimple is adjusted so that the contact lead is far enough away from the edge of the surrounding raised dielectric at the edge of the die contact to provide a laterally concave outward air-solder interface in that location. This prevents solder creep onto the dielectric surface and avoids die edge shorting. Several dimple shapes are described.

Formed top contact for non-flat semiconductor devices

An improved contact is obtained to power devices having a raised dielectric region adjacent the die contact region by providing a contact dimple on the otherwise flat metal lead used for die contact. The dimple is arranged above the die contact and soldered thereto. The radius of curvature and depth of the dimple is adjusted so that the contact lead is far enough away from the edge of the surrounding raised dielectric at the edge of the die contact to provide a laterally concave outwardly air-solder interface in that location. This prevents solder creep onto the dielectric surface and avoids die edge shorting. Several dimple shapes are described.

An improved means and method for forming leads to a power device is provided by use of a one-piece leadframe on which the die is mounted and a separate connecting clip between the leadframe and the bonding pad on the semiconductor die. The leadframe has an alignment dimple or groove for receiving a mating alignment feature on one end of the connecting clip. The other end of the connecting clip is located over the bonding pad on the die. Solder is placed between die and the leadframe and between the connecting clip and the bonding pad and between the mating alignment surfaces on the clip and leadframe. When the solder is liquid during assembly the die and clip float thereon and automatically align by surface tension so that the die is centrally located on the die flag, the connection point on the clip is centered on the bonding pad and the mating alignment surfaces on the clip and leadframe are engaged. The self-aligning process is dominated by the mating alignment regions on the connecting clip and leadframe which have a larger area and solder wetted periphery than the other regions being soldered.

Self-centering electrode for power devices

An improved means and method for forming leads to a power device is provided by use of a one-piece leadframe on which the die is mounted and a separate connecting clip between the leadframe and the bonding pad on the semiconductor die. The leadframe has an alignment dimple or groove for receiving a mating alignment feature on one end of the connecting clip. The other end of the connecting clip is located over the bonding pad on the die. Solder is placed between die and the leadframe and between the connecting clip and the bonding pad and between the mating alignment surfaces on the clip and leadframe. When the solder is liquid during assembly the die and clip float thereon and automatically align by surface tension so that the die is centrally located on the die flag, the connection point on the clup is centered on the bonding pad and the mating alignment surfaces on the clip and leadframe are engaged. The self-aligning process is dominated by the mating alignment regions on the connecting clip and leadframe which have a larger area and solder wetted periphery than the other regions being soldered.

A method is described for coupling the leadframe of a thermogenetic semiconductor device to a heatsink. This method consists of screening a first layer of thermally conductive epoxy on the heatsink. The first layer is cured and a second layer is screened on the first layer. The leadframe is then deposited on the second layer and the second layer is cured. The device then goes to encapsulation and final processing.

Method of producing a thermogenetic semiconductor device

A means and method is provided for forming power devices using multiple semiconductor die. Typically, several semiconductor die or die assemblies with contact disks are mounted on a base plate in a spaced apart relationship. A compliant connector member which supports a massive power terminal, bridges between the die to which it is bonded via crushable contact dimples, to form an assembly. The assembly deforms during insertion into the mold to accommodate thickness variations and seat the outward faces of the terminal and base plate against the matching mold faces. When the plastic molding compound is injected into the mold there is a net outward force which seals the outward terminal, base and corresponding mold faces together to prevent encroachment of the plastic therebetween.

Growing community of inventors

Scottsdale, AZ, United States of America

Martin A Kalfus