Apple's Patent Background

During the manufacture of electronic devices such as cellular telephones, digital music players, and handheld computing devices, transparent components are often held within housings or the like.

By way of example, many electronic devices have displays that include glass or plastic windows which are held by a metal housing. Typically, a metal frame or housing is formed, and a glass component or a plastic component is inserted into the formed frame or housing.

In order to properly secure a metal frame and a glass component together, the tolerances associated with the fit between the metal frame and the glass component must be strictly maintained. That is, the tolerance matches between the metal frame and the glass component are maintained such that the glass component may be inserted into the metal frame and held in place.

An overall assembly that includes a metal frame and a glass component inserted therein may be held together by a press fit, using adhesive materials, and/or using mechanical structures such as screws. If the tolerance matches between the metal frame and the glass component are not strictly maintained, the integrity of the overall assembly may be compromised.

For relatively small assemblies (like wearable computers), maintaining critical tolerances between metal frames and glass components so that there's no misalignments are difficult to achieve.

Apple notes that "Forming a metal bezel around a transparent member insert using die casting and metal injection molding techniques is known and described in U.S. Patent Application Publication No. 2009/0017263, the disclosure of which is incorporated by reference herein in its entirety."

Use of liquid metal or metal alloys requires extremely high temperatures, and in the case of an amorphous alloy, also requires specified cooling rates to maintain the amorphicity of the alloy. These conditions require specific transparent members that can withstand the temperature of the melted metal, and the cooling rate, and could create stresses within the transparent member that might cause deformations or cracks, if certain amorphous metals requiring rapid cooling were utilized.

Apple notes that "Forming an amorphous alloy frame for electronic hardware and flat panel displays is disclosed in U.S. Patent No. 6,771,490, the disclosure of which is incorporated by reference herein in its entirety."

Therefore, what is needed is a method and an apparatus that allows for the tolerances associated with a metal-based frame and a glass component, or a metal-based frame and a plastic component, to be substantially relaxed.

Apple's Solution

Apple's patent relates to techniques that enable an assembly that includes a transparent member that is integrally formed with an amorphous metal alloy member. The embodiments may be implemented in numerous ways, including, but not limited to, as a method, system, device, or apparatus. Exemplary embodiments are further discussed in the patent application.

According to one embodiment, a method includes preparing a housing made from at least a portion of a bulk-solidifying amorphous alloy, heating the housing to above its glass transition temperature but below its crystallization temperature, expanding the heated housing, positioning a transparent member within the expanded housing, contracting the housing around the transparent member, and cooling the housing and transparent member to form an integrally formed transparent member and amorphous metal alloy housing.

According to another embodiment, there is provided a method of forming an integrally formed transparent member and amorphous metal alloy housing that includes providing a band of bulk-solidifying amorphous alloy, and heating the band to a temperature above its glass transition temperature but below its crystallization temperature. The method also includes placing a transparent member in a mold apparatus, and then wrapping the heated band of bulk-solidifying amorphous alloy around the transparent member. The method further includes applying pressure to the heated band of bulk-solidifying amorphous alloy and transparent member to mold the band around the transparent member to form a bulk-solidifying amorphous alloy housing integral with a transparent member, and cooling the housing and transparent member to form an integrally formed transparent member and amorphous metal alloy housing.

According to another embodiment, a method includes preparing a housing made from at least a portion of a bulk-solidifying amorphous alloy, heating the housing to above its glass transition temperature but below its crystallization temperature, expanding the heated housing, providing a transparent member; providing an intermediate member positioned either around the transparent member or within the expanded heated housing, positioning a transparent member within the expanded housing such that the intermediate member is positioned between the transparent member and the housing, contracting the housing around the transparent member and intermediate member, and cooling the housing, transparent member, and intermediate member to form an integrally formed transparent member and amorphous metal alloy housing.

According to another embodiment, there is provided a method of forming an integrally formed transparent member and amorphous metal alloy housing that includes providing a band of bulk-solidifying amorphous alloy, and heating the band to a temperature above its glass transition temperature but below its crystallization temperature. The method also includes placing a transparent member in a mold apparatus, positioning an intermediate member either adjacent the heated amorphous alloy band, or around the transparent member, and then wrapping the heated band of bulk-solidifying amorphous alloy around the transparent member such that the intermediate member is positioned between the transparent member and the housing. The method further includes applying pressure to the heated band of bulk-solidifying amorphous alloy and transparent member to mold the band around the transparent member to form a bulk-solidifying amorphous alloy housing integral with a transparent member, and cooling the housing and transparent member to form an integrally formed transparent member and amorphous metal alloy housing.

Apple's iPhone is clearly noted in patent FIG. 3 below. The Housing, which is noted as patent point #12, is sometimes referred to as a case or band and can be fabricated from a bulk-solidifying amorphous alloy.

Further noted is that one or more portions of the housing may be processed to form a part of the antennas iPhone.

Bezel, noted as patent point #14 may serve to hold a display or other device with a planar surface in place on the iPhone and/or may serve to form an esthetically pleasing trim around the edge of device.

Possible Future iPhone Twists

In the example of Figure 3, the display screen is shown as being mounted on the front face of the iPhone, but the display screen may, if desired, be mounted on the rear face of the iPhone or on a side or on a flip-up portion of an iPhone that is attached to a main body portion by a hinge (for example), or using any other suitable mounting arrangement.

The overall housing is integral in that a transparent member and bulk-solidifying amorphous alloy, form a single, unified piece. A single, unified piece that includes a transparent member and a bulk-solidifying amorphous alloy typically are formed such that there are effectively no voids, gaps, or spaces between the transparent member and the metal. The transparent member and the bulk-solidifying amorphous alloy are substantially directly bonded together.

Forming the iPhone's Bezel

A variety of different methods may be used to form the bezel around the display. In one embodiment, shown in patent Figures 4 and 5, the housing can be formed to include a bezel or a bezel can be added later. The housing and optionally the bezel can then be heated to a temperature above the glass transition temperature, but below the crystallization temperature of the bulk-solidifying amorphous alloy, and elongated in the directions of x and y in patent Figure 4.

Elongation can be by application of an external force, or can be accomplished by insertion into an expandable mold that expands the iPhone's housing in the x and y directions in the directions of arrows x and y. Use of a mold provides advantage that heat can be continuously supplied to the housing `to maintain it in its thermoplastic state by supplying heat to the mold apparatus.

The iPhone's display which may be a glass, plastic, or any suitable transparent member, can then be positioned within the elongated housing such that a space 150 exists between the outer surface 160 of the display and inners surface 120 of the iPhone's housing. In patent Figure 4 noted above we see the display traversing only a portion of the longitudinal axis (y) of the housing.

Upon proper placement of the display, the external force that caused elongation of the housing may be removed and due to the superior elongation characteristics of the bulk-solidifying amorphous alloy used to fabricate housing 12, housing 12 will snap back into place in the directions of arrows x and y in Figure 5 to fully integrate with transparent member 16.

In addition, an external force also may be applied in the direction of arrows x and y to force the housing into position. Once in position, the space 150 no longer exists and the exterior surface 160 of the display is welded together and becomes one with the internal surface 120 of the housing thereby forming an air-tight, fluid-tight seal.

Once sealed, the housing can be cooled to room temperature. Owing to the characteristics of the bulk-solidifying amorphous alloy, and only heating the housing to below its crystallization temperature, cooling need not be as rapid as that required when a bulk-solidifying amorphous alloy goes from the melt state to cooled state.

This provides a unique advantage insofar as the display need not be subjected to such severe heating temperatures as would be encountered with a molten metal or alloy, nor is the display subjected to rapid cooling if an amorphous metal alloy were used. Accordingly, there is significantly less stress on display thereby avoiding stress cracks, fissures, fractures, and the like that might otherwise occur.

Once cooled, a single part containing the housing and a display is created. The single part may be, in one embodiment, an integral glass and metal alloy assembly or, more generally, an integral assembly.

The formation of the bezel around the display (Fig. 3) substantially eliminates tolerance issues associated with the bezel and the transparent member. Because the bulk-solidifying amorphous alloy used in the bezel is provided in a thermoplastic phase around the display, there is effectively no tolerance that has to be maintained with respect to the bezel. The thermoplastic phase alloy is formed around the edge of the display, and when solidified, effectively grabs and adheres to the display.

Liquid Metal Used in an iPad Smart Cover with a Large Window on the Face

Apple describes another example where the alloy member may be a portion of a housing of an electronic device and the display may be a window of an electronic device. The window may be a protective shield that covers a display or touchscreen.

Another embodiment for forming the integral housing and transparent member is shown in Figures 6 and 7. In this embodiment, a bulk-solidifying amorphous alloy can be provided in the form of a sheet or rod or band and then heated and formed around the transparent member. A mold apparatus 600 can be used, although not necessary, to form the bulk­ solidifying housing around the transparent member 16.

As shown in Figure 6 below, mold assembly 600 may include a surface onto which transparent member 16 can placed. Surrounding that surface can be a groove or trench 610 into which the bulk-solidifying amorphous alloy material may be positioned to form a band around transparent member 16.

In accordance with this embodiment, the bulk-solidifying amorphous alloy band 12 is heated to a temperature above its glass transition temperature and below its crystallization temperature so that it can be themoplastically deformed. Because the band 12 is not heated past its crystallization temperature, the alloy remains substantially in its amorphous state, and despite being amorphous, can be easily formed into a variety of shapes and sizes.

As shown in Figure 7, the heated bulk-solidifying amorphous alloy band 12 can be positioned in groove or trench 610 and bent around transparent member 16 as shown by the direction of arrow A. Once completely surrounding transparent member 16, any excess band 12 can be cut and joined to the remainder of the band by further heating or using other conventional joining techniques to form a seamless bulk-solidifying amorphous alloy housing.

Apple teases us with Liquidmetal Gold

Patent Credits

The three Apple patents that were published in Europe include 2013/162504, 2013/162521 and 2013/162501. With these patents, Patently Apple has now opened an Archive Category for Liquidmetal to log current and future patents on this subject matter.

Patently Apple presents a detailed summary of patent applications with associated graphics for journalistic news purposes as each such patent application is revealed by the U.S. Patent & Trade Office. Readers are cautioned that the full text of any patent application should be read in its entirety for full and accurate details. Revelations found in patent applications shouldn't be interpreted as rumor or fast-tracked according to rumor timetables. About Comments: Patently Apple reserves the right to post, dismiss or edit comments.

Status Update: I Hope to back part time next week sometime. Cheers.