A solid state drive apparatus, comprising: a casing comprising a top plate, a bottom plate, a first sidewall, and a second sidewall; a first substrate provided within the casing; at least one first semiconductor chip mounted on the first substrate; a second substrate provided within the casing; at least one second semiconductor chip mounted on the second substrate; and a heat dissipation structure disposed between the first substrate and the second substrate, the heat dissipation structure comprising: a lower heat dissipation panel contacting the at least one first semiconductor chip; an upper heat dissipation panel contacting the at least one second semiconductor chip; and an air passage disposed between the lower heat dissipation panel and the upper heat dissipation panel and extending from the first sidewall of the casing to the second sidewall of the casing, wherein the heat dissipation structure comprises a first end portion exposed through the first sidewall of the casing and a second end portion exposed through the second sidewall of the casing, and the air passage extends from an outlet formed at the first end portion of the heat dissipation structure to an inlet formed in the second end portion of the heat dissipation structure, and wherein the outlet of the air passage and the inlet of the air passage are exposed to an outside of the casing, and the air passage is configured to guide a flow of air from the inlet of the air passage to the outlet of the air passage. a casing comprising a top plate, a bottom plate, a first sidewall, and a second sidewall; a first substrate provided within the casing; at least one first semiconductor chip mounted on the first substrate; a second substrate provided within the casing; at least one second semiconductor chip mounted on the second substrate; and a heat dissipation structure disposed between the first substrate and the second substrate, the heat dissipation structure comprising: a lower heat dissipation panel contacting the at least one first semiconductor chip; an upper heat dissipation panel contacting the at least one second semiconductor chip; and an air passage disposed between the lower heat dissipation panel and the upper heat dissipation panel and extending from the first sidewall of the casing to the second sidewall of the casing, a lower heat dissipation panel contacting the at least one first semiconductor chip; an upper heat dissipation panel contacting the at least one second semiconductor chip; and an air passage disposed between the lower heat dissipation panel and the upper heat dissipation panel and extending from the first sidewall of the casing to the second sidewall of the casing, wherein the heat dissipation structure comprises a first end portion exposed through the first sidewall of the casing and a second end portion exposed through the second sidewall of the casing, and the air passage extends from an outlet formed at the first end portion of the heat dissipation structure to an inlet formed in the second end portion of the heat dissipation structure, and wherein the outlet of the air passage and the inlet of the air passage are exposed to an outside of the casing, and the air passage is configured to guide a flow of air from the inlet of the air passage to the outlet of the air passage.