WO2015195764A1

WO2015195764A1 - Tensioning insert useful with wafer supports

Info

Publication number: WO2015195764A1
Application number: PCT/US2015/036176
Authority: WO
Inventors: Clifton C. Haggard; James R. Thomas; Christopher DOWLING
Original assignee: E.Pak International, Inc.
Priority date: 2014-06-19
Filing date: 2015-06-17
Publication date: 2015-12-23
Also published as: TW201616593A

Abstract

An illustrative example embodiment of a wafer packaging assembly includes a frame member having a central opening, a film associated with the frame member, and a tensioning insert. The film extends across the central opening and is adapted to at least temporarily hold a wafer in a selected position on the film. The tensioning insert includes a first portion having a first surface along an outer periphery of the tensioning insert and a second portion having a second, film-contacting surface. The second portion protrudes from the first portion.

Description

TENSIONING INSERT USEFUL WITH WAFER SUPPORTS

BACKGROUND

[oooi] When packaging delicate items, such as silicon wafers, it is necessary to ensure that those items are appropriately secured within a container. For example, silicon wafers can be damaged if the packaging is not adequate to protect the wafers and hold them securely within the container.

[0002] Wafer manufacturing processes may include forming circuits or electronic devices on a wafer at one facility and then shipping them to another facility where the wafer will be cut into individual dies corresponding to the circuits or devices. One known way of shipping wafers in this condition includes securing an adhesive or UV activated film to a frame, which may be referred to as a flex frame, a film frame or a dicing frame. The wafer is secured in place inside the area outlined by the frame by the adhesive on the film.

[0003] Known flex frame containers are designed to contain a single frame and wafer. Some such containers include a projection on one side of the interior of the container. The projection places the adhesive film under tension, which assists in keeping the wafer secure within the container.

[000 ] Recent trends in wafer processing and shipping include a desire to include a plurality of frames and corresponding wafers within a single container in a stacked arrangement or within a plurality of slots in a cassette. Including multiple frames and wafers in a single container may provide some economies of scale but it introduces additional opportunity for one or more of the wafers to be damaged. SUMMARY

[0005] An illustrative example method of packaging at least one wafer includes situating at least one wafer on a film that is supported by a frame member and situating a tensioning insert adjacent the film. The tensioning insert has an outer portion received adjacent the frame member and an inner portion received against the film. The inner portion places at least some of the film under tension for reducing movement of the at least one wafer relative to the frame member.

[0006] An illustrative example embodiment of a wafer packaging assembly includes a frame member having a central opening, a film associated with the frame member, and a tensioning insert. The film extends across the central opening and is adapted to at least temporarily hold a wafer in a selected position on the film. The tensioning insert includes a first portion having a first surface along an outer periphery of the tensioning insert and a second portion having a second, film- contacting surface. The second portion protrudes from the first portion.

[0007] The various features and advantages of at least one disclosed embodiment will become apparent to those skilled in the art from the following detailed description. The drawings that accompany the detailed description can be briefly described as follows.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 is a perspective illustration of an example embodiment of a tensioning insert.

[0009] Figure 2 is a cross-sectional illustration along the lines 2-2 in Figure 1.

[oooio] Figure 3 is a perspective illustration of the tensioning insert of Figure 1 adjacent a frame member.

[oooii] Figure 4 is a cross-sectional illustration along the lines 4-4 in Figure 3 including a wafer that is not shown in Figure 3.

[00012] Figure 5 illustrates an example container configured to receive a plurality of wafer packaging assemblies, such as the assembly shown in Figure 4.

[00013] Figure 6 is a partial cross-sectional illustration of a portion of the container of Figure 5 containing a plurality of wafer packaging assemblies, such as the assembly shown in Figure 4.

[0001 ] Figure 7 is a partial cross-sectional illustration of a stack of wafer packaging assemblies received within a portion of another embodiment of a container.

DETAILED DESCRIPTION

[00015] An example embodiment of a tensioning insert 20 is shown in Figures 1 and 2. The tensioning insert 20 includes a first portion 22 with a first surface 24. A second portion 26 of the tensioning insert 20 includes a second, film-contacting surface. The first surface 24 and the second surface 28 are generally parallel to each other and situated in different planes because the second portion 26 projects from the first portion 22. The first surface 24 in this example is in a first plane Pi and the second surface 28 is in a second plane P₂. According to Figure 2, the second surface 28 is raised compared to the first surface 24.

[00016] The tensioning insert 20 is made from a vacuum molded plastic material that is suitable for being in close proximity or contact with silicon wafers or circuitry on such wafers. There are several known materials used in the wafer packaging industry from which the tensioning insert 20 may be made.

[00017] Figure 3 shows the tensioning insert 20 situated adjacent a frame member 30 (e.g., next to and below the frame member according to the drawing). The frame member may be a known flex frame, film frame or dicing frame. At least some of the first portion 22 is situated beneath the underside of the frame member 30 while the second portion 26 is situated within a central opening of the frame member. In this example, the second portion 26 has an outer periphery or border that is generally circular and the frame member central opening has a generally circular periphery or border established by an inner edge 32 of the frame member 30. The frame member 30 and the insert 20 have outer peripheries that correspond to each other, which facilitate placing the insert 20 and the frame member 30 into a container designed to receive the frame member 30.

[00018] Figure 4 illustrates an assembly 33 including the tensioning insert 20, the frame member 30, a film or tape 34 and a wafer 40. The film 34 may be a known adhesive or UV activated film. Figure 4 corresponds to a cross-sectional view of the components shown in Figure 3 with the addition of the film or tape 34 and the wafer 40. The film 34 in Figure 4 comprises a known material having an adhesive side received against one side of the frame member 30 (e.g., the underside of the frame member according to the drawing). The portion of the film extending across the central opening of the frame member provides a surface for placing a wafer 40. The film 34 adhesively holds the wafer 40 in a known manner.

[00019] The tensioning insert is configured in a manner that the second portion 26 is situated to place the film or tape 34 at least partially under tension so that the wafer 40 is held more securely against movement relative to the frame 30. Without tension on the film 34, it may be possible for the wafer to vibrate or "drum" and under some conditions such movement may result in undesired contact between the wafer and a nearby surface or item. It is also possible that such vibration may result in flexing of the wafer which may cause or contribute to the wafer cracking or otherwise being compromised. The tension provided by the insert 20 reduces any such movement of the wafer.

[00020] As can be appreciated from Figure 4, the second surface 28 is received against the film 34 within the central opening of the frame member 30 in a location that corresponds to the position of the wafer 40. The second portion 26 projects from the first portion 22 a sufficient distance to place the film 34 under tension without straining the film in a way that would compromise the ability of the film to support the wafer 40 within the frame 30 during subsequent wafer processing. The amount of projection of the second portion corresponds to the distance between the first plane PI and the second plane P2 shown in Figure 2. The spacing between the planes is selected so that the amount the second portion 26 projects from the first portion 22 and the thickness of the frame member 30 facilitates situating a plurality of assemblies 33 adjacent each other within a container. In the illustrated example, amount that the second portion 26 projects from the first portion 22 corresponds to a thickness of the frame member 30. In such embodiments the second surface 28 is aligned with the surface of the frame member that faces in the same direction as the second surface 28 (e.g., the upward facing surface on the frame 30 in Figure 4) when the insert 20 is situated adjacent the frame member 30 as illustrated. In examples where the distance between the first and second planes is greater than the thickness of the frame 30, the second surface 28 will be situated beyond the corresponding facing surface of the frame 30 (e.g., the second surface 28 will be higher than shown in Figure 4).

[00021] In the illustrated example, the frame 30 and the second portion 26 are designed to accommodate a round wafer and the second portion 26 is dimensioned to correspond generally to the size of the wafer to provide support adjacent one side of the wafer. In this example, the second, film-contacting surface 28 is flat and continuous across the entire second portion 26. In this example the first surface 24 is also flat and continuous across the entire first portion 22. Other embodiments have other surface configurations for either or both of the surfaces 24 and 28.

[00022] Figure 5 shows an example container 42 for a plurality of wafers 40 included in respective assemblies 33. The container 42 includes a base or bottom portion 44 and a lid or top portion 46. The container is held closed by a locking mechanism 48. The container 42 can be referred to as a vertical wafer shipper because the wafer assemblies 33 are in a generally vertical plane while being loaded into or removed from the container 42.

[00023] Figure 6 is a view taken along the lines 6-6 in Figure 5 and shows a plurality of assemblies 33 situated within a cassette style interior of the example container 42. Each frame 30 is received in a slot or channel 50 of the container bottom 44. A tensioning insert 20 is situated adjacent each frame 30 and received in the same slot 50 as the frame 30 associated with the insert.

[0002 ] As can be appreciated from Figure 6, the distance between the first plane within which the first surface 24 is situated and the second plane within which the second surface 28 is situated is set to provide clearance between the wafer 40 on one film 34 and the insert 20 associated with an adjacent wafer 40. In other words, the distance between the reference planes of the first and second portions is set to avoid contact between adjacent wafers 40 when a plurality of wafer assemblies 33 are situated in the container 42.

[00025] Figure 7 schematically illustrates a portion of another type of container

60 that accommodates frame and wafer assemblies 33 in a stack without slots on the inside of the container. The container 60 may be referred to as a horizontal wafer container because the assemblies 33 are in a generally horizontal plane when they are loaded into or removed from the container 60. With the frames 30, the inserts 20 are effective at keeping the film 34 under tension and maintaining clearance between adjacent wafers 40 in such containers. The inserts 20, which are a separate component distinct from the container, allow for stacks of frame-supported wafer assemblies 33 to be placed securely in more types of containers and in larger quantities than was previously possible.

[00026] The preceding description is exemplary rather than limiting in nature.

Variations and modifications to the disclosed examples may become apparent to those skilled in the art that do not necessarily depart from the essence of this invention. The scope of legal protection given to this invention can only be determined by studying the following claims.

Claims

CLAIMS We claim:

1. A method of packaging at least one wafer, comprising the steps of:

situating at least one wafer on a film that is supported by a frame member; situating a tensioning insert adjacent the film, the tensioning insert having an outer portion received adjacent the frame member and an inner portion received against the film, the inner portion placing at least some of the film under tension for reducing movement of the at least one wafer relative to the frame member.

2. The method of claim 1, wherein the tensioning insert includes a first portion having a first surface along an outer periphery of the tensioning insert and a second portion having a second, film-contacting surface, the second portion protruding from the first portion.

3. The method of claim 2, wherein the first surface is in a first plane and the second surface is in a second, different plane.

4. The method of claim 2, wherein the second portion protrudes from the first portion a distance that corresponds to a thickness of the frame member.

5. The method of claim 2, wherein

the first surface is flat, continuous and extends along the entire first portion; and

the second surface is flat, continuous and extends along the entire second portion.

6. The method of claim 1, wherein the wafer is generally circular and the second portion has a circular perimeter.

7. The method of claim 1, comprising placing the wafer, the frame member, the film, and the tensioning insert in a container.

8. The method of claim 7, comprising placing a plurality of wafers, associated frame members, associated films, and associated tensioning inserts into the container.

9. A wafer packaging assembly, comprising:

a frame member having a central opening;

a film associated with the frame member, the film extending across the central opening, the film being adapted to at least temporarily hold a wafer in a selected position on the film; and

a tensioning insert including a first portion having a first surface along an outer periphery of the tensioning insert and a second portion having a second, film- contacting surface, the second portion protruding from the first portion, the second portion placing at least some of the film under tension when the tensioning insert is positioned adjacent the frame member.

10. The assembly of claim 9, comprising a wafer supported on the film.

11. The assembly of claim 10, wherein the wafer is generally circular and the second portion has a circular perimeter.

12. The assembly of claim 9, wherein the second portion protrudes from the first portion a distance that corresponds to a thickness of the frame member.

13. The assembly of claim 9, wherein

14. The assembly of claim 9, wherein the first surface is in a first plane and the second surface is in a second, different plane.

15. The assembly of claim 9, wherein the frame member and the tensioning insert have correspondingly shaped outer peripheries.