Magnetic shielding of MRAM package

A method of forming a magnetic random access memory (MRAM) package comprising:

• providing a package substrate having first and second major surfaces, wherein the package substrate comprises a plurality of through-hole contacts extend from the first to the second major surface of the package substrate;
• forming package contact traces on the first major surface and forming package balls on the second major surface of the package substrate, wherein the through-hole contacts couple the package contact traces and package balls on the first and second major surfaces of the package substrate;
• providing a die having active and inactive surfaces, wherein the die comprises a magnetic storage element formed in the die, a plurality of die microbumps formed on the active surface and a top magnetic shield layer formed on the inactive surface of the die;
• forming a first bottom magnetic shield in the form of magnetic shield traces under the package contact traces, wherein the magnetic shield traces are formed in between the package contact traces and the first major surface of the package substrate;
• and
• mounting the die to a die attach region defined on the first major surface of the package substrate, wherein
• the die microbumps of the die are coupled to the package contact traces formed on the first major surface of the package substrate.

A method for forming a magnetic random access memory (MRAM) package comprising:

• providing a wafer having first and second major surfaces, the first major surface is an active surface and the second opposing major surface is an inaction surface, wherein the wafer is includes
• a plurality of dies having magnetic storage elements therein,
• a magnetic shield on the inactive surface of the wafer, and
• a plurality of die microbumps disposed on the active surface of the wafer;
• processing the wafer, wherein processing the wafer comprises
• separating the wafer into a plurality of individual dies, wherein an individual die comprises active and inactive surfaces, the die microbumps are formed on the active surface of the die, and a top magnetic shield layer formed on the inactive surface of the die;
• providing a package substrate having first and second major package surfaces, wherein the package substrate comprises a plurality of through-hole contacts extend from the first to the second major surface of the package substrate;
• forming package contact traces on the first major surface and forming package balls on the second major surface of the package substrate, wherein the through-hole contacts couple the package contact traces and the package balls on the first and second major surfaces of the package substrate;
• forming a first bottom magnetic shield in the form of magnetic shield traces under the package contact traces, wherein the magnetic shield traces are formed in between the package contact traces and the first major surface of the package substrate;
• and
• mounting the die to a die attach region defined on the first major surface of the package substrate, wherein
• the die microbumps of the die are coupled to the package contact traces formed on the first major surface of the package substrate, and
• the top magnetic shield layer is disposed only on the second major surface of the die which is the opposite major surface of the first major surface with the microbumps.