Water-proof connection between a USB 3.0 type C connector and transmission cable

A water-proof connection device, comprising:

• a metal housing having an insertion opening, an accommodating slot extending from the insertion opening along an insertion direction, and a fixing slot that extends from the accommodating slot along the insertion direction;
• a transmission cable assembly inserted into the metal housing and including:
• a connector in USB 3.0 type C and having an external end portion and an internal end portion that is opposite to the external end portion, wherein the external end portion is arranged in the accommodating slot and corresponds in position to the insertion opening;
• a transmission cable including a plurality of wires connected to the internal end portion;
• a molding holder including a partition portion and a pillar portion that extends from the partition portion, wherein a cross section of the partition portion perpendicular to the insertion direction has a shape that is identical to that of a cross section of the fixing slot perpendicular to the insertion direction, and connection parts of the internal end portion and the wires are embedded in the pillar portion;
• and
• an insulating sleeve surrounding a part of the pillar portion and a part of the transmission cable that are arranged adjacent to each other, wherein a surrounding lateral edge of the partition portion abuts against an inner wall of the fixing slot, and the fixing slot receives at least part of the pillar portion and a part of the insulating sleeve so as to leave a colloid space;
• and
• a water-proof colloid filled in the colloid space so as to connect the metal housing and the transmission cable assembly, wherein the partition portion is configured to isolate the fixing slot from the accommodating slot, so that the accommodating slot and the insertion opening do not receive any part of the water-proof colloid.