A method of making an assembly can include juxtaposing a top surface of a first electrically conductive element at a first surface of a first substrate with a top surface of a second electrically conductive element at a major surface of a second substrate. One of: the top surface of the first conductive element can be recessed below the first surface, or the top surface of the second conductive element can be recessed below the major surface. Electrically conductive nanoparticles can be disposed between the top surfaces of the first and second conductive elements. The conductive nanoparticles can have long dimensions smaller than 100 nanometers. The method can also include elevating a temperature at least at interfaces of the juxtaposed first and second conductive elements to a joining temperature at which the conductive nanoparticles can cause metallurgical joints to form between the juxtaposed first and second conductive elements.

A method of making an assembly can include juxtaposing a top surface of a first electrically conductive element at a first surface of a first substrate with a top surface of a second electrically conductive element at a major surface of a second substrate. One of: the top surface of the first conductive element can be recessed below the first surface, or the top surface of the second conductive element can be recessed below the major surface. Electrically conductive nanoparticles can be disposed between the top surfaces of the first and second conductive elements. The conductive nanoparticles can have long dimensions smaller than 100 nanometers. The method can also include elevating a temperature at least at interfaces of the juxtaposed first and second conductive elements to a joining temperature at which the conductive nanoparticles can cause metallurgical joints to form between the juxtaposed first and second conductive elements.

A packaged semiconductor device with a particle roughened surface on a portion of the lead frame that improves adhesion between the molding compound and the lead frame. A packaged semiconductor device with a particle roughened surface on a portion of the lead frame that improves adhesion between the molding compound and the lead frame and with a reflow wall that surrounds a portion of the solder joint that couples the semiconductor device to the lead frame. A packaged semiconductor device with a reflow wall that surrounds a portion of a solder joint that couples a semiconductor device to a lead frame.

A packaged semiconductor device with a particle roughened surface on a portion of the lead frame that improves adhesion between the molding compound and the lead frame. A packaged semiconductor device with a particle roughened surface on a portion of the lead frame that improves adhesion between the molding compound and the lead frame and with a reflow wall that surrounds a portion of the solder joint that couples the semiconductor device to the lead frame. A packaged semiconductor device with a reflow wall that surrounds a portion of a solder joint that couples a semiconductor device to a lead frame.

A method of making an assembly can include juxtaposing a top surface of a first electrically conductive element at a first surface of a first substrate with a top surface of a second electrically conductive element at a major surface of a second substrate. One of: the top surface of the first conductive element can be recessed below the first surface, or the top surface of the second conductive element can be recessed below the major surface. Electrically conductive nanoparticles can be disposed between the top surfaces of the first and second conductive elements. The conductive nanoparticles can have long dimensions smaller than 100 nanometers. The method can also include elevating a temperature at least at interfaces of the juxtaposed first and second conductive elements to a joining temperature at which the conductive nanoparticles can cause metallurgical joints to form between the juxtaposed first and second conductive elements.

A method of making an assembly can include juxtaposing a top surface of a first electrically conductive element at a first surface of a first substrate with a top surface of a second electrically conductive element at a major surface of a second substrate. One of: the top surface of the first conductive element can be recessed below the first surface, or the top surface of the second conductive element can be recessed below the major surface. Electrically conductive nanoparticles can be disposed between the top surfaces of the first and second conductive elements. The conductive nanoparticles can have long dimensions smaller than 100 nanometers. The method can also include elevating a temperature at least at interfaces of the juxtaposed first and second conductive elements to a joining temperature at which the conductive nanoparticles can cause metallurgical joints to form between the juxtaposed first and second conductive elements.

A packaged semiconductor device with a particle roughened surface on a portion of the lead frame that improves adhesion between the molding compound and the lead frame. A packaged semiconductor device with a particle roughened surface on a portion of the lead frame that improves adhesion between the molding compound and the lead frame and with a reflow wall that surrounds a portion of the solder joint that couples the semiconductor device to the lead frame. A packaged semiconductor device with a reflow wall that surrounds a portion of a solder joint that couples a semiconductor device to a lead frame.

A packaged semiconductor device with a particle roughened surface on a portion of the lead frame that improves adhesion between the molding compound and the lead frame. A packaged semiconductor device with a particle roughened surface on a portion of the lead frame that improves adhesion between the molding compound and the lead frame and with a reflow wall that surrounds a portion of the solder joint that couples the semiconductor device to the lead frame. A packaged semiconductor device with a reflow wall that surrounds a portion of a solder joint that couples a semiconductor device to a lead frame.

A method of making an assembly can include juxtaposing a top surface of a first electrically conductive element at a first surface of a first substrate with a top surface of a second electrically conductive element at a major surface of a second substrate. One of: the top surface of the first conductive element can be recessed below the first surface, or the top surface of the second conductive element can be recessed below the major surface. Electrically conductive nanoparticles can be disposed between the top surfaces of the first and second conductive elements. The conductive nanoparticles can have long dimensions smaller than 100 nanometers. The method can also include elevating a temperature at least at interfaces of the juxtaposed first and second conductive elements to a joining temperature at which the conductive nanoparticles can cause metallurgical joints to form between the juxtaposed first and second conductive elements.

A substrate includes a support layer, a column-shaped first bump, and a second bump. The support layer has a main surface. The first bump is filled with a first conductive metal and also has a first upper surface and a side surface. The second bump includes a plurality of fine particles formed of a second conductive metal and also has a third portion configured to cover the first upper surface and a fourth portion configured to cover a part of the side surface. The first bump is disposed on the main surface, or the first bump is connected to an electrode disposed on the main surface. The second bump has a convex second upper surface. A height of the fourth portion in a direction perpendicular to the first upper surface is smaller than that of the first bump.