JP2003168731A - Substrate tray, sheet for laying substrate tray, and substrate housing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wafer carrier which is capable of housing a wafer without damaging it even if its surface is irregular. <P>SOLUTION: A substrate tray 7 is equipped with a curved part 1 which is curved protuberant downward, a flat part 4 provided at the periphery of the curved part 1, and a guide 3 provided outside the flat part 4, and a stepped part is provided between the periphery of the curved part 1 and the flat part 4. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate tray, a substrate tray laying sheet and a substrate storing method which are used for supplying, transferring, storing and storing substrates such as semiconductor wafers.

[0002]

BACKGROUND ART Since a wafer is thin, an invisible crack or chip is likely to occur even if a slight external force is applied. Further, if the wafer is deformed or stressed during handling, it adversely affects the semiconductor device formed on the wafer surface. In addition, it is necessary to avoid dust, dirt, or scratches on the surface of the wafer. This is because if the surface of the wafer is dusty or dirty, or if it has even a slight scratch, it becomes impossible to form a fine circuit structure.

Therefore, it is necessary to handle wafers such as transportation and storage extremely carefully so that stress is not generated and dust is not attached.

Conventionally, as a wafer carrier, a plane is approximately C
It has a large number of shelves in the shape of a letter.
A carrier having a structure in which a disk-shaped wafer is inserted to hold the outer peripheral portion of the wafer is used. Usually, one carrier can accommodate 25 wafers, and a large number of wafers are collectively supplied to each processing step for each carrier.

However, the conventional wafer carrier described above has a problem that it is difficult to handle each wafer individually.

That is, in the manufacture of IC chips and the like, the specifications and required performances of the final products are varied, so that the required processing contents and processing procedures often differ from wafer to wafer.
In such a case, in the wafer carrier that handles a large number of wafers collectively as described above, it is not possible to supply different wafers to different processing lines or processing apparatuses. Therefore, the work of taking out or inserting individual wafers from the wafer carrier is performed.

Of the large number of wafers accommodated in the carrier, only the necessary wafers are taken out or the processed wafers are returned to the carrier for each processing step.
It is very troublesome, and the device for taking out and returning the wafer is complicated.

Further, when the wafer is taken out from the carrier or returned, the subsequent processing is performed while the position of the shelf into which the wafer is inserted is wrong, and the wrong wafer cannot be used as a product. In one career,
The above problem does not occur if only the same wafers are stored in all the processing steps. However, if only a few wafers are stored in a carrier that stores 25 wafers, for example. , Very inefficient and uneconomical.

Therefore, recently, a method of accommodating one wafer at a time has been adopted. As one of them, a substrate tray as shown in FIG. 9 has been tried. This board tray is
It is composed of a curved portion 1 whose central portion is curved downward, and a flat portion 4 which is connected from the peripheral edge of the curved portion 1. The substrate 5 is stored in the substrate tray 7 by placing the peripheral portion of the substrate 5 on the flat portion 4. Generally, an adhesive is applied to the surface of the substrate 5 on which the device is formed. The adhesive protects the device. The substrate 5 is housed in the substrate tray 7 with the surface on which the device is formed facing downward.

In this substrate tray 7, since the center of the curved portion 1 is curved downward, the surface of the substrate 5 on which the devices are formed (the lower surface in the drawing) and the substrate tray 7 are peripheral portions. It is possible to prevent an unnecessary external force from being applied without making contact with each other. When another substrate tray is superposed on another substrate tray, the protrusion 2 of the upper substrate tray presses the peripheral upper surface of the substrate 5. Therefore, the substrate 5 is stable in the substrate tray 7 without rattling even during transportation.

By the way, in the field of semiconductors, the circuit function and the storage capacity of one chip have been improved in recent years by the remarkable improvement of the packaging technology. However, in order to further improve the packaging density, the two-dimensional (2D) has reached its limit as in the past, and three-dimensional (3D) packaging is indispensable as a countermeasure.

The number of 3D packaged packages is also rapidly increasing. For example, a QFP (Quad Flat Package) with lead terminals on the edge of the package, a BGA (Ba
ll Glid Alley) and CSP (Chip Size Package) are also stored in the substrate tray.

On the other hand, in response to the flow of such mounting technology, the wafer substrate is also increased in diameter and thinned. Furthermore, wafers with protrusions that take the above-mentioned 3D mounting into consideration have begun to appear on the market.

When the 3D-mounted boards are housed in the board tray 7 shown in FIG. 9, some of the boards are defective in the circuit of the semiconductor device formed thereon and other eyes. It turned out that some things could cause invisible damage.

[0015]

SUMMARY OF THE INVENTION The present invention solves the above problems and is convenient for handling individual substrates,
Moreover, it is an object of the present invention to provide a substrate tray that does not cause damage to the substrate.

It is an object of the present invention to provide a substrate storage method which is convenient for handling individual substrates and which does not damage the substrates.

An object of the present invention is to provide a substrate tray laying sheet capable of extremely easily taking out a substrate from a substrate tray.

[0018]

The substrate tray of the present invention comprises:
A curved portion that curves downward in a convex shape, a flat portion that is provided on the peripheral edge of the curved portion, and a guide portion that is provided outside the flat portion, and the peripheral edge of the curved portion and the flat portion. It is characterized in that it has a step between it and the part.

The substrate tray laying sheet of the present invention is a sheet for laying between the substrate tray and the substrate, and is characterized by having a portion protruding from the substrate.

The substrate accommodating method of the present invention is characterized in that the substrates are placed on the flat portion of the substrate tray, and the back surfaces of the other substrate trays are stacked on the substrate tray so that the rear surface faces the substrate side.

[0021]

The operation of the present invention will be described below together with the findings obtained in making the present invention.

The present inventor has earnestly sought to find out why invisible damage occurs when a substrate is stored in the substrate tray shown in FIG.

Recently, various kinds of semiconductor devices have appeared, and the surface of a wafer after device formation is not limited to a flat surface but may have irregularities. In the substrate tray shown in FIG. 9, the amount of depression of the curved portion 1 in the vicinity of the flat portion 4 is smaller than that in the central portion. Therefore, some stress is applied to the device of the wafer against the device formed at that portion on the substrate. Therefore, we have found that invisible damage occurs.

In the present invention, a step is provided between the peripheral edge of the curved portion and the flat portion. Therefore, even if the unevenness of the Debye formed on the surface of the substrate is large, the device does not hit the curved portion even in the peripheral portion of the substrate (in the vicinity of the flat portion of the substrate tray when stored), and eventually damages the substrate. Can be stored and transported without giving.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the invention will be described with reference to FIG.

The substrate tray 7 in the present invention has a curved portion 1 which is curved downward in a convex shape, a flat portion 4 provided on a peripheral edge 30 of the curved portion 1, and a guide provided outside the flat portion 4. And a step 20 between the peripheral edge 30 of the curved portion 1 and the flat portion 4.

The size of the step may be determined in advance by checking the height of the unevenness of the device to be manufactured and appropriately determining it. Considering the recent 3D mounting tendency, 100 μm
The above is preferable. The upper limit is preferably 0.8 mm or less from the viewpoint of the size of the solder ball or the like.

The length of the flat portion 4 is not particularly limited as long as it has a length sufficient to mount the substrate 5. However, considering the variation in the outer diameter of the substrate 5, it is preferable to set it within 4 mm.

It is preferable to provide the protrusion 2 at a position corresponding to the flat portion 4 on the back surface of the substrate tray 7. When the substrate 5 is housed in the substrate tray 7 and another substrate tray is overlaid on the substrate 5, the protrusion 2 serves to press the peripheral portion of the substrate 5 placed on the flat portion 4 from the back surface. The length of the protruding portion is set to be the same as the most bottom surface portion (center point of the substrate tray) on the back surface side of the curved portion 1. As a result, the board 5 and the projection 2 are formed on the bottom surface of the curved portion 1.
You can press with and.

Further, it is preferable to radially form the pressing edge 6 on the back surface of the curved portion 1. When the substrate 5 is housed in the substrate tray and another substrate tray is superposed on it, the pressing edge 6 contacts the back surface of the substrate 5 and suppresses the movement of the substrate 5. The height of the pressing edge 6 is as shown in FIG.
In the example shown in, the height is set slightly lower than the protrusion 2. Thus, when the trays are stacked, the pressing edge 6 is separated from the end surface of the protrusion 2 so as not to touch the back surface of the substrate 5. Basically, the purpose is to prevent scratches and the like from touching a part of the tray even on the back surface of the substrate. However, the holding edge 6 is provided in order to prevent the substrate from swinging up and down in the tray during transport, or from swinging up and down due to a large warp.
The height of the pressing edge 6 is 0.5 from the end surface of the protrusion 4.
It is preferably within mm.

The substrate tray of the present invention can be integrally molded. Further, since the substrate trays having the same shape can be stacked and used, mass production can be performed and the substrate can be provided at a low cost.

The material of the substrate tray of the present invention is not particularly limited, but for example, a polymer material (more specifically, for example, PP,
It is preferable to use a material such as ABS resin or the like), ceramic, metal, or a polymer material containing 50% or more of used waste paper. Further, it is preferable that the substrate 5 is made of a material having an elastic modulus such that the impact can be absorbed even if the substrate 5 collides with the substrate tray.

In the case of a polymer material containing 50% or more of used molding paper, when it is no longer necessary, it can be treated as general waste.

Further, a polymer material containing 50% or more of used molding paper is particularly preferable because it is less likely to damage the substrate even if it comes into contact with the substrate. Further, when using paper, it is possible to prevent an unexpected failure of the semiconductor device formed on the wafer due to the generation of static electricity,
This point is also preferable.

Metals and ceramics are preferable from the viewpoint of preventing the semiconductor device from being contaminated, since the amount of water and hydrocarbons released from the material is small. In particular, from the viewpoint of preventing contamination, it is effective when used for transportation between a specific film forming process and a specific film forming process.

Further, it is preferable to provide one or more holes and / or notches 10 on the outer side surface of the guide portion 3. If you insert holes or notches 10,
It is easy to lift the substrate trays 7 stacked in multiple stages. That is, if the claws of the robot are fitted into the holes or the notches 10, the transfer of the substrate tray 10 can be automated.

Further, it is preferable to provide a concave portion having an upward opening on any part of the upper surface of the three guide portions and to provide a convex portion 12 which can be fitted in the concave portion on the back surface of the substrate tray 7.

By fitting the concave portion and the convex portion 12 into each other, the substrate trays 7 are fixed to each other. Therefore, even if the substrate trays are stacked in multiple stages, stable transportation as a whole can be performed.

Further, it is preferable to provide the sheet escape portion 9 on any part of the upper surface of the guide portion 3. When the sheet 21 having the protruding portion 22 corresponding to the shape of the substrate is laid between the substrate 5 and the substrate tray 7, the protruding portion 22 can be stored in the sheet escape portion 9. That is, if the protruding portion 22 is longer to some extent, it is easier to hold by hand. However, if it is too long, the protruding portion 22 of the sheet 21 will also protrude from the guide portion 3. Guide part 3
If the sheet 21 sticks out, the protruding portion 22 of the sheet 21 may be pulled. If the seat escape portion 9 is provided, the protruding portion 22 of the seat 21 can be housed inside the seat escape portion 9. As a result, the protruding portion 22 of the sheet 21
Can be made longer without protruding from the guide portion 3.

In the substrate storing method, it is preferable to lay a sheet on the substrate tray so that at least a part of the wafer protrudes from the flat portion before the wafer is placed. This allows the substrate to be removed from the substrate tray very easily. That is, the substrate can be taken out from the substrate tray simply by picking up the protruding portion.

In the case where such a sheet is not laid, the wafer is adsorbed and taken out by an adsorbing means or the like which gives a light negative pressure, but the wafer may be impacted at the time of adsorption and the wafer may be cracked. Moreover, the wafer may be dropped. On the other hand, when the sheet is laid out between the substrate tray and the wafer so that the edge of the sheet protrudes from the substrate tray, there is no concern about such cracking or dropping of the wafer.

In the substrate accommodating method of the present invention, the sheet is laid on the substrate tray so as to protrude from the flat portion before being placed in the substrate tray. When the substrate is taken out from the substrate tray, the substrate can be easily taken out from the substrate tray by simply grasping and lifting the protruding portion of the sheet.

In the present invention, as the substrate, a semiconductor wafer (silicon semiconductor wafer, compound semiconductor wafer),
A liquid crystal substrate, a magnetic substrate, or another substrate is used. In particular,
It is particularly effective for accommodating a so-called 3D substrate on which film formation, wiring, etc. are formed, and extraction electrodes and the like are formed.

[0044]

1 to 7 show a substrate tray according to an embodiment of the present invention.

In FIG. 1, reference numeral 1 denotes a curved portion which is curved downward and convex.

The substrate tray 7 of this embodiment has a curved portion 1 which is curved downward in a convex shape, a flat portion 4 provided on the peripheral edge of the curved portion 1, and a guide portion provided outside the flat portion 4. 3 and has a step 4 between the peripheral edge of the curved portion 1 and the flat portion 4.

FIG. 2 is a plan view of the substrate tray according to this embodiment. 1 is a sectional view taken along line BB in FIG.

FIG. 3 is a front view of the substrate tray according to this embodiment, showing a case where the substrate trays are stacked in multiple stages. The rear view, right side view, and left side view are the same as the front view.

FIG. 4 is a sectional view taken along the line BB of FIG. 2, showing a case of stacking in multiple stages.

FIG. 5 is a bottom view of the substrate tray according to this embodiment.

FIG. 6 is a sectional view taken along the line CC of FIG. 2, showing a case of stacking in multiple stages.

FIG. 7 is a sectional view taken along line AA of FIG.

The projection 2 is provided around the curved portion 1 and extends downward, and the guide portion 3 is provided further outside of the projection 2. The tip of the projection 2 has a curved portion. It projects more than the bottommost surface of the part 1.

A step is provided on the upper surface side around the curved portion 2, and a flat portion 4 having a flat surface is provided on the step. The outside of the flat portion 4 serves as a guide portion. In this example, the inner side surface of the guide portion 3 is provided with a slight taper so that the wafer 5 can be easily stored and taken out.

In this example, the pressing edge 5 is provided on the lower surface side of the curved portion 1. A plurality of pressing edges are provided radially. The height of the pressing edge 5 is equal to that of the protruding portion 2.
It is set lower than the height of. In this example, the difference is 0.
It is set to 75 mm.

A 6-inch wafer 5 as a substrate was placed on the flat portion 4 with the device-formed surface facing downward. In this state, the wafer 5 is in contact with the substrate tray 7 only at the flat portion 4, and the lateral movement is suppressed by the side surface of the guide portion 3.

With the wafer 5 accommodated in the substrate tray 7, another substrate tray 7 was stacked. Since the protrusions 2 of the other substrate trays 7 positionally correspond to the flat portions 4 of the lower substrate tray 7, the protrusions 2 of the substrate tray 7 are arranged on the wafers stored in the lower substrate tray 7. It contacts the upper surface of the peripheral portion of the substrate 5, and the vertical movement of the substrate tray 5 is suppressed.

As the wafer 5, a device having a height of 100 μm formed on the upper surface thereof was used, but the wafer 5 was not unexpectedly damaged.

As shown in FIG. 7, the substrate tray 7b
An arbitrary number of other substrate trays 7a may be sequentially stacked on the above.

FIG. 8 shows a sheet 21 made of, for example, vinyl to be laid between the upper surface of the curved portion 1 of the substrate tray 7 and the wafer 5a. This sheet 21
Has four protruding portions 22a, 22b, 22c and 22d. Although the example shown in the drawing has four protruding portions, the protruding portions 22a, 22b, 22c and 22d of the sheet 21 are connected to the substrate tray 7.
The curved portion 1 of the substrate tray 7 is accommodated in the sheet escape portion 9 of
Was laid on the top of the. Then, the wafer 5 was placed on the sheet 21.

The protruding portions 22a, 22b of the sheet 21
When the sheet 21 was lifted while holding 22c and 22d, the wafer 5 could be taken out from the substrate tray very easily.

In this example, a circular cut 8 having a radius of 9 mm or more is provided on the side surface of the substrate tray 7 to facilitate handling of the substrate tray (for example, removal of fitted base trays). In addition, a plurality of beams are provided at appropriate positions to give strength.

Further, when a notch 10 having a width of 8 mm and a height of 3 mm which is opened upward is provided on the side surface of the guide portion 3, the robot tray can be easily inserted by using the notch. Could be lifted and transported.

[0064]

According to the present invention, even a wafer having irregularities can be stored without causing damage.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a substrate tray according to this embodiment.

FIG. 2 is a plan view of a substrate tray according to this embodiment.

FIG. 3 is a front view of the substrate tray according to the present embodiment.

FIG. 4 is a cross-sectional view taken along the line BB in FIG. 2, showing a case of stacking in multiple stages.

FIG. 5 is a bottom view of the substrate tray according to the present embodiment.

FIG. 6 is a cross-sectional view taken along the line CC of FIG. 2, showing a case where they are stacked in multiple stages.

7 is a cross-sectional view taken along the line AA of FIG.

FIG. 8 is a plan view of a substrate tray laying sheet according to an embodiment of the present invention.

FIG. 9 is a sectional view of a substrate tray according to a prior example.

[Explanation of symbols]

1 curved part 2 protrusion 3 Guide section 4 Flat part 5 Substrate (wafer) 6 Presser edge 7,7a, 7b Substrate tray 8 cuts 9 Seat escape area 10 notches 11 beam 12 Convex part for fitting 20 steps 21 sheets 22a, 22b, 22c, 22d protruding portion

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Urushijima Road High             1-28-24 Nakamachi, Machida, Tokyo 102 Taisei Building               Utem Co., Ltd. (72) Inventor Tadatoshi Suenaga             18-4 Sakuragaoka-cho, Shibuya-ku, Tokyo             Mu Be Kay Microtech (72) Inventor Isamu Takahashi             18-4 Sakuragaoka-cho, Shibuya-ku, Tokyo             Mu Be Kay Microtech (72) Inventor Shoichi Naruzawa             70 Akasaka, Kamiyazawa, Rifu-cho, Miyagi-gun, Miyagi Prefecture F-term (reference) 3E006 AA01 BA10 CA01 DA04 DB03                 3E033 AA10 BA06 BA07 BA10 BA13                       BB01 DA08 DD02 DD05 DD13                 3E096 AA01 BA15 BA16 BA17 BA20                       BB03 CA06 CA19 CB02 CC01                       DA03 DA04 DA23 DB01 DC01                       EA01X EA02X EA06X EA10X                       FA03 FA07 FA09 FA10 FA15                       FA16 FA27 FA28 FA30 FA31                       GA01 GA05                 5F031 CA02 CA05 DA13 EA02 EA10                       EA19 EA20 FA30 PA21 PA26

Claims (11)

[Claims] 1. A curved portion which is convexly curved downward,
A flat portion provided on a peripheral edge of the curved portion and a guide portion provided on an outer side of the flat portion, and having a step between the peripheral edge of the curved portion and the flat portion. Substrate tray to do. 2. The substrate tray according to claim 1, wherein the protrusion is provided at a position corresponding to the flat portion on the back surface of the substrate tray. 3. The substrate tray according to claim 1, wherein a pressing edge is radially formed on the back surface of the curved portion. 4. The substrate tray according to claim 1, wherein the substrate tray is integrally molded. 5. The substrate tray is made of any one of a polymer material, a ceramic material, a metal material, and a polymer material containing 50% or more of waste paper for molding. Substrate tray according to item. 6. The substrate tray according to claim 1, wherein one or more holes and / or notches are provided on the outer side surface of the guide portion. 7. The guide member is characterized in that it has a concave portion that opens upward at any part of the upper surface of the guide portion, and that a convex portion that can be fitted into the concave portion is provided on the back surface of the substrate tray. The substrate tray according to any one of claims 1 to 6. 8. The substrate tray according to claim 1, wherein a sheet escape portion is provided on any portion of the upper surface of the guide portion. 9. A sheet for laying a substrate tray, which is a sheet to be laid between the substrate tray and the substrate, and has a portion protruding from the substrate. 10. The substrate is placed on the flat portion of the substrate tray according to claim 1, and the back surface of another substrate tray is stacked on the flat portion of the substrate tray so that the back surface of the substrate tray faces the substrate side. Board storage method. 11. The substrate storing method according to claim 10, wherein the sheet is laid on the substrate tray so that at least a part thereof protrudes from the flat portion before the wafer is placed.