Reinforced tray for delicate devices
A tray for storing and handling delicate components is strengthened with a reinforcement bar. Reinforcement bars are arranged in parallel to enhance resistance against cracking and warpage of the tray. Each reinforcement bar may include a support structure. A radius on all or a portion of tray members having a sharp edge may serve to strengthen the tray further. Tray members including ribs, openings, indentations, and pockets can have all or part of their sharp edges covered with a radius.
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The invention pertains to the storage and handling of delicate components, such as semiconductors, and to the transport of such components in a tray assembly. More specifically, the invention pertains to trays reinforced to enhance their resistance against warpage, cracking, and other types of distortion.
DESCRIPTION OF THE PRIOR ART
During manufacturing and subsequent use and handling, stresses can cause trays to crack, warp or otherwise become unsuitable for storing delicate components. Up to now, trays have been known to be provided with ribs adjacent to each pocket to enhance the tray's resistance to cracking.
In addition binding a multiplicity of trays with a strap can also induce warpage and cracking in a stack. Consequently a need exists for a tray that is better reinforced against cracking and warpage.
SUMMARY OF THE INVENTIONThe invention pertains to a tray that has been reinforced with a reinforcement bar and a support structure near the edge of the tray. The tray is also provided with an indentation that facilitates stacking and strapping of a stack of trays.
Another embodiment of the present invention is a tray assembly for storing components in a stack, where each tray in the tray assembly is reinforced with a ridge on one side of the tray. The ridge extends along a substantial part of the tray and extends inward relative to the pockets to form a reinforcement bar that imparts enhanced resistance to warpage. A support structure occupying a space between the reinforcement bar and the edge of the tray may also be present. Such a support structure may comprise one or more protrusions. Each protrusion may have a primary axis in a direction generally orthogonal to the tray edge.
Yet another embodiment concerns providing a rounded portion (or radius) on corner regions of a reinforcement bar. The invention has been found to result in greater structural integrity by enhancing resistance to cracking and warpage in plastic trays.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention discloses a tray for protecting delicate components from damage during transport or “drop testing”. If the trays are bend or twisted, tensile stress on the top surface will build up and may cause a crack to propagate. As a result, the tray will become distorted and its contents vulnerable to damage. The present invention mitigates the tensile stress by including various design features that maintain the structural integrity of the tray. The trays of the present invention are suitable for storing components such as semiconductors, electronic devices, work pieces, and medical instruments.
Tray 200 has a plurality of pockets 30 in an array as shown in
In a preferred embodiment, support structure 37 contacts reinforcement bar 35. However, it is not essential for the invention that support structure 37 be present or that support structure 37 extend into reinforcement bar 35. The support structure 37 may simply occupy some portion of the space 40 between reinforcement bar 35 and edge 20 and still adequately enhance the tray's resistance to warpage.
By providing trays with the reinforcement bar 35 and support structure 37, warpage of no more than 390 mils results during testing. More specifically, it was found that strapping the tray assembly of
A cross-section of reinforcement bar 35 and one of the protrusions of support structure 37 is shown in
In addition, it is not essential to the invention that 37A-37C of the support structure have a rectilinear shape. For example, one or more segments of the support structure may instead have a rod-like shape (
Tray 300 has an upper side 320 shown in
The maximum radius for any sharp edge of a tray of the present invention preferably does not exceed one half of the thickness of the member having the radius. In addition, the minimum radius of any member preferably does not go below 0.20 mm. The preferred radii for any sharp edge of the tray will fall within the range of 0.25 to 1.5 mm. The above radius ranges are merely preferred and the skilled artisan would recognize that other ranges could be suitable as well depending on the circumstances.
Preferably, the trays of the present invention have a unitary structure wherein the entire structure is formed simultaneously in a single mold. Although several embodiments have been described as having radii, it is understood that the radius on any portion of the tray may be ellipsoidal or have a shape other than a segment of a circle. In addition, a chamfer may be used instead of a radius on the openings, reinforcement bar and perimeter of tray 300.
The present invention is fabricated from traditional methods of injection molding. Suitable manufacturing materials for the present invention include conductive, thermoplastic, non-conductive, and insulated plastic. In addition, the trays of this invention can be fabricated from material that has electrostatic dissipating properties.
The specific examples provided above are intended to be illustrative of the invention only. It should be apparent to those skilled in the art that various features of the invention may be modified without departing from the spirit and scope of the invention. All ranges set forth herein are intended to be exemplary and not limiting in scope. As those of ordinary skill in the art can appreciate that such parameters as the tray dimension, radii ranges, and the dimensions of various tray members can be optimized to encompass other ranges than those that are set forth herein. It is therefore the intent that the scope of the invention is to be defined by the appended claims.
Claims
1. A tray assembly for storing components in a stack, each tray in the tray assembly having a first side and a second side, said tray assembly comprising:
- a) an array of pockets on said first side;
- b) a ridge on the periphery of said first side, wherein a portion of the ridge extends inward relative to the pockets to form a reinforcement bar having a first and a second corner region;
- c) an edge surrounding each of said sides; and
- d) a radius on at least one of the corner regions of the reinforcement bar.
2. The tray assembly of claim 1, wherein each tray further includes a radius at an area adjacent to the first side of the tray.
3. The tray assembly of claim 1, wherein each tray further includes
- a support structure occupying a space between the reinforcement bar and the edge,
- wherein said support structure protrudes from one of said sides.
4. The tray assembly of claim 1, further comprising at least one indentation on the edge of the tray, said indentation for receiving a strap.
5. The tray assembly of claim 3, wherein the stack is secured by aligning at least one strap over the indentation of each tray, and adhering the ends of the strap together.
6. The tray assembly of claim 1, wherein a warpage of no more than 30 mils results from strapping the tray assembly at 20 kg force over a temperature range of 125° C.-175° C. for a period of 24 hours.
7. A tray assembly for storing components in a stack, each tray in the tray assembly having a first side and a second side, said tray assembly comprising:
- c) an array of pockets on at least one of said sides;
- d) a ridge on the periphery of said first side, wherein a portion of the ridge extends inward relative to the pockets to form a reinforcement bar;
- c) an edge surrounding each of said sides; and
- d) a support structure occupying a space between the reinforcement bar and the edge, wherein said support structure protrudes from one of said sides.
8. The tray assembly of claim 7, further comprising at least one indentation on the edge of the tray, said indentation for receiving a strap.
9. The tray assembly of claim 8, wherein the stack is secured by aligning at least one strap over the indentation of each tray, and adhering the ends of the strap together.
10. The tray assembly of claim 7, wherein a warpage of no more than 30 mils results from strapping the tray assembly at 20 kg force over a temperature range of 125° C.-175° C. for a period of 24 hours.
11. The tray assembly of claim 7, wherein each tray is a unitary structure.
Type: Application
Filed: Apr 30, 2007
Publication Date: Nov 8, 2007
Applicant: Peak Plastic and Metal Products (Int'l) Ltd. (Tsuen Wan, NT)
Inventors: Tong Zhang (Shenzhen), John Pylant (Rio Rico, AZ)
Application Number: 11/799,231
International Classification: B65D 85/00 (20060101); B65D 1/34 (20060101); B65D 21/00 (20060101);