Manufacturing method for metallic housing of electronic device

1. A manufacturing method for a metallic housing of an electronic device, the method comprising:

providing a die-casting mold comprising a male die and a female die engaging with the male die, the male die defining a pouring gate therein, and the female die defining a cavity therein corresponding to the pouring gate;

positioning a metallic outer frame in the cavity of the female die as an insert, the outer frame comprising an inner surface, a plurality of latching portions protruding from the inner surface inwardly, and a plurality of latching grooves each formed between two adjacent latching portions, each latching portion comprising at least two parallel latching ribs, and a receiving groove formed between two adjacent latching ribs;

assembling the male die to the female die to cover the cavity, thereby communicating the pouring gage with the cavity;

casting pressured molten metal-alloy into the cavity via the pouring gate to form an inner structural member embedded in an inner side of the outer frame, the inner structural member comprising a plurality of engaging portions respectively embedded in the plurality of receiving grooves, and a plurality of matching portions respectively embedded in the plurality of latching grooves;

dissembling the male die from the female die to expose the cavity; and

removing the outer frame and the inner structural member from the female die, wherein the at least two latching ribs extend along an extending direction of the outer frame and transverse a corner of the metallic outer frame, and wherein the plurality of matching portions extend along a direction perpendicular to the extending direction of the metallic outer frame, and are respectively embedded in the plurality of latching grooves on two opposite sides of the receiving groove.

2. The manufacturing method of claim 1 , further comprising preheating the die-casting mold to a predetermined temperature after positioning the metallic outer frame in the cavity of the female die as the insert and before assembling the male die to the female die to cover the cavity.

3. The manufacturing method of claim 1 , further comprising applying a surface treating process to the outer frame and the inner structural member after removing the outer frame and the inner structural member from the female die.

4. The manufacturing method of claim 1 , wherein the plurality of engaging portions and the plurality of matching portions protrude from the peripheral sidewall outwardly.

5. The manufacturing method of claim 1 , wherein a cross-sectional view of the receiving groove is in a stepped shape or a rectangle.

6. The manufacturing method of claim 1 , wherein each latching rib defines a pair of inclining surfaces on opposite ends to engage the latching groove in a dovetail shape.

7. The manufacturing method of claim 1 , wherein the outer frame is made stainless steel, aluminum, or titanium, and the inner structural member is made from magnesium alloy, aluminum alloy, or zinc alloy.

8. The manufacturing method of claim 1 , wherein the inner structural member is an inner metallic frame or an inner metallic board.