Packages with low-profile polyimide layers

A package, comprising:

• a semiconductor die having a device side comprising circuitry and a formed therein;
• a planarized passivation layer abutting the device side;
• a horizontal metal member coupled to the device side by way of vias extending through the passivation layer, the horizontal metal member having a thickness ranging between 4 microns and 25 microns;
• a metal post coupled to and vertically aligned with the horizontal metal member without a sputtered seed layer between the metal post and the horizontal metal member, the metal post having a vertical thickness ranging between 10 microns and 80 microns;
• and
• a polyimide (PI) layer contacting the metal post, the horizontal metal member, and the passivation layer, wherein a thickest point of the PI layer forms a ring surrounding the metal post that is horizontally spaced from the metal post by a horizontal distance ranging between 0 micron and 30 microns.

A package, comprising:

• a semiconductor die having a device side comprising circuitry and a formed therein;
• a planarized passivation layer abutting the device side;
• a horizontal metal member coupled to the device side by way of vias extending through the passivation layer, the horizontal metal member having a thickness ranging between 4 microns and 25 microns, the vias having diameters ranging between 0.5 microns and 10 microns;
• a metal post coupled to and vertically aligned with the horizontal metal member without a sputtered seed layer between the metal post and the horizontal metal member, the metal post having a vertical thickness ranging between 10 microns and 80 microns;
• and
• a polyimide (PI) layer contacting the metal post, the horizontal metal member, and the passivation layer, wherein the PI layer is not positioned between the metal post and the horizontal metal member, and wherein the PI layer is subjected to a photolithography process to produce a top surface that includes a peak at a thickest point of the PI layer and a downward slope extending from the peak in a direction away from the metal post.

A method of manufacturing a package, comprising:

• providing a semiconductor die having a planarized passivation layer on the die and a horizontal metal member on the passivation layer, the horizontal metal member coupled to the die through a via extending through the passivation layer, the horizontal metal member having a thickness ranging between 4 microns and 25 microns, the vias having diameters ranging between 0.5 microns and 10 microns;
• plating a metal post directly on the horizontal metal member without applying a seed layer on the horizontal metal member;
• applying a polyimide (PI) layer to contact the horizontal metal member, the passivation layer, and the metal post;
• using a mask to expose a portion of the PI layer;
• and
• developing the PI layer, thereby causing the PI layer to decrease in thickness along a circumference of the metal post and to form a peak at which a thickness of the PI layer is greatest, the peak forming a ring surrounding the metal post and horizontally spaced from the metal post by a horizontal distance ranging between 0 micron and 30 microns.