Laser diode, thermally assisted magnetic head, head gimbal assembly, hard disk drive and method of manufacturing a head gimbal assembly

A thermally assisted magnetic head, comprising:

• a slider in which an electromagnetic element is formed, and
• a light-source unit, which is joined to the slider;
• wherein the light-source unit comprises a sub-mount, and a laser diode, which is joined to the sub-mount;
• wherein the laser diode comprises an electrode pad layer, being connected to an electrode;
• and an outer surface in which the electrode pad layer is formed;
• wherein the electrode pad layer comprises a solder-bonding pad part, which is formed inside of a peripheral end part of the outer surface;
• and a solder-contact preventing part, which is formed between the solder-bonding pad part and the peripheral end part;
• wherein the solder-contact preventing part is formed with small wettability material having solder wettability which is smaller than solder wettability of the solder-bonding pad part;
• wherein the solder-bonding pad part and the solder-contact preventing part are formed so that a pad height, being a height from the outer surface to a surface of the solder-bonding pad part, is larger than a preventing height, being a height from the outer surface to a surface of the solder-contact preventing part.

A head gimbal assembly, comprising:

• a thermally assisted magnetic head, and a suspension;
• wherein the thermally assisted magnetic head comprises a structure which a light-source unit, having a laser diode, is joined to a slider in which an electromagnetic element is formed;
• wherein the suspension comprises an opening part which penetrates from a slider arrangement surface, which the slider is arranged, to a light-source unit surface, which the light-source unit is arranged, and a flexure which forms the slider arrangement surface;
• wherein the head gimbal assembly comprises an assembly structure which the light-source unit is inserted into the opening part from the slider arrangement surface of the suspension and the light-source unit is protruded from the light-source unit surface and the slider is adhered to the slider arrangement surface of the suspension, and a solder connector being formed so that the laser diode is connected to the flexure;
• wherein the laser diode comprises an electrode pad layer, being connected to an electrode;
• and an outer surface in which the electrode pad layer is formed;
• wherein the electrode pad layer comprises a solder-bonding pad part, which is formed inside of a peripheral end part of the outer surface;
• and a solder-contact preventing part, which is formed between the solder-bonding pad part and the peripheral end part;
• wherein the solder-contact preventing part is formed with small wettability material having solder wettability which is smaller than solder wettability of the solder-bonding pad part;
• wherein the solder-bonding pad part and the solder-contact preventing part are formed so that a pad height, being a height from the outer surface to a surface of the solder-bonding pad part, is larger than a preventing height, being a height from the outer surface to a surface of the solder-contact preventing part;
• wherein the solder connector touches with the solder-bonding pad part without touching with the solder-contact preventing part, thereby the solder connector is connected with the laser diode.

A hard disk drive comprising:

• a head gimbal assembly;
• and
• a magnetic recording medium;
• wherein the head gimbal assembly comprises a thermally assisted magnetic head and a suspension;
• wherein the thermally assisted magnetic head comprises a structure which a light-source unit, having a laser diode, is joined to a slider in which an electromagnetic element is formed;
• wherein the suspension comprises an opening part which penetrates from a slider arrangement surface, which the slider is arranged, to a light-source unit surface, which the light-source unit is arranged, and a flexure which forms the slider arrangement surface;
• wherein the head gimbal assembly comprises an assembly structure which the light-source unit is inserted into the opening part from the slider arrangement surface of the suspension and the light-source unit is protruded from the light-source unit surface and the slider is adhered to the slider arrangement surface of the suspension, and a solder connector being formed so that the laser diode is connected to the flexure;
• wherein the laser diode comprises an electrode pad layer, being connected to an electrode;
• and an outer surface in which the electrode pad layer is formed;
• wherein the electrode pad layer comprises a solder-bonding pad part, which is formed inside of a peripheral end part of the outer surface;
• and a solder-contact preventing part, which is formed between the solder-bonding pad part and the peripheral end part;
• wherein the solder-contact preventing part is formed with small wettability material having solder wettability which is smaller than solder wettability of the solder-bonding pad part;
• wherein the solder-bonding pad part and the solder-contact preventing part are formed so that a pad height, being a height from the outer surface to a surface of the solder-bonding pad part, is larger than a preventing height, being a height from the outer surface to a surface of the solder-contact preventing part;
• wherein the solder connector touches with the solder-bonding pad part without touching with the solder-contact preventing part, thereby the solder connector is connected with the laser diode.

A method of manufacturing a head gimbal assembly having a thermally assisted magnetic head and a suspension comprising:

• a head connecting step which the thermally assisted magnetic head is connected to the suspension;
• wherein the thermally assisted magnetic head comprises a structure which a light-source unit, having a laser diode, is joined to a slider in which an electromagnetic element is formed;
• wherein the suspension comprises an opening part which penetrates from a slider arrangement surface, which the slider is arranged, to a light-source unit surface, which the light-source unit is arranged, and a flexure which forms the slider arrangement surface;
• wherein the laser diode comprises an electrode pad layer, being connected to an electrode;
• and an outer surface in which the electrode pad layer is formed;
• wherein the electrode pad layer comprises a solder-bonding pad part, which is formed inside of a peripheral end part of the outer surface;
• and a solder-contact preventing part, which is formed between the solder-bonding pad part and the peripheral end part;
• wherein the solder-contact preventing part is formed with small wettability material having solder wettability which is smaller than solder wettability of the solder-bonding pad part;
• wherein the solder-bonding pad part and the solder-contact preventing part are formed so that a pad height, being a height from the outer surface to a surface of the solder-bonding pad part, is larger than a preventing height, being a height from the outer surface to a surface of the solder-contact preventing part;
• wherein the head connecting step comprises a solder ball arrangement step which a solder ball is arranged so that the laser diode is connected to the flexure, in an assembly structure which the light-source unit is inserted into the opening part from the slider arrangement surface of the suspension and the light-source unit is protruded from the light-source unit surface and the slider is adhered to the slider arrangement surface of the suspension;
• wherein the solder ball arrangement step is performed so that the solder ball touches with the solder-bonding pad part without touching with the solder-contact preventing part, thereby the solder ball is connected with the laser diode.