KR100543875B1 - Composite substrate carrier - Google Patents

Abstract

The wafer carrier is formed of at least two different melt processible plastic materials and the two plastic materials are strategically placed for best performance and have thermophysical bonds created during the addition molding process. The present invention includes carriers made of said different melt processible plastics materials and includes a method of making such carriers. In a first embodiment, the H-bar wafer carrier has a first structural portion molded of polycarbonate at the first mold hollow, and then has a portion of polycarbonate molding disposed at the second mold hollow. The polyether ether ketone is injection molded to form a wafer contact portion on the H-bar carrier. Process temperature and mold temperature are controlled to provide optimum coupling between the floating materials. Thus, an integral wafer carrier of composite material is formed. A further embodiment utilizes components such as shelves or sidewall inserts molded from two floating plastics for holding the wafers, which are assembled inside a disk fence such as a transport module.

Wafer carrier

Description

Composite Substrate Carrier {COMPOSITE SUBSTRATE CARRIER}

1 is an H-bar wafer carrier according to the present invention.

FIG. 2 shows an overmolded portion of the carrier of FIG. 1.

3 is a perspective view of a work-in-process (WIP) box of the prior art.

4 is a perspective view of a WIP box and an H-bar carrier according to the present invention.

5 is a side view of a WIP box according to the present invention.

6 is a perspective view of a disk shipper of the prior art.

7 is a fuselage body of a disc siffer according to the present invention.

8 is a view of a transportation module of the prior art.

9 is an exploded view of a transport module according to the invention similar to that shown in FIG. 8.

10 is a perspective view of a composite wafer carrier.

FIG. 11 is an exploded view of the wafer carrier of FIG. 10.

12 is a perspective view of a process enhancing carrier according to the present invention.

13 is a model diagram illustrating the method of the present invention.

The present invention relates to a mechanism for receiving, transporting, storing, and processing a memory disk, a silicon wafer, or the like. More particularly, the present invention relates to a composite wafer or disk carrier.

 Carriers are used to transport and store patches of silicon wafers or magnetic disks prior to, during, and after processing of disks or wafers. The wafer is processed into an integrated circuit and the disk is processed using a magnetic memory device for a computer. As used herein, wafers refer to silicon wafers, magnetic substrates, and the like.

The processing of a wafer disk into an integrated circuit chip involves several processes, in which the disk is repeatedly processed and stored. Since the disk is quite fine and quite expensive, it is important that the disk is properly protected during its series of processing. One purpose of the wafer carrier is to provide such protection. In addition, since the processing of wafer disks is generally automated, it is important to position the disk correctly relative to the processing apparatus when the wafer is removed or inserted by the robot. The second purpose of the wafer carrier is to securely hold the wafer disk when carrying the wafer disk.

The carrier is configured to align the wafer or disk in the axial direction in the slot to support the wafer or disk at or near its edge. The wafer or disk is typically removed radially upwards or laterally from the carrier. The carrier has a cover, bottom cover, or enclosure as an auxiliary member surrounding the wafer or disk.

There are many material properties that are useful and advantageous for wafer carriers, but this varies depending on the type of carrier and the characteristics of the carrier to be targeted.

When processing semiconductor wafers or magnetic disks, the presence of particles or the generation of particles creates significant contamination problems. In the semiconductor industry, pollution is recognized as the single largest cause of yield loss. As the size of integrated circuits becomes smaller, the reduction of contaminants is very important because the dimensions of the particles that contaminate the integrated circuit also become smaller. Particulate contaminants are generated by carriers by wafers or discs, carrier covers or enclosures, storage shelves, other carriers, or processing equipment, and by rubbing or scraping. Thus, the most desirable property of the carrier is to prevent the generation of particles upon wear, rub, or scratching of the plastic molding material. U. S. Patent No. 5,780, 127 describes the proper properties of plastics of such materials for wafer carriers. The patent is incorporated by reference.

The carrier material needs to be suppressed with the release of volatiles, i.e., the release gas, as well. This is because volatility forms films, which are contaminants that damage wafers or disks.

The carrier material also needs to maintain dimensional stability, ie rigidity, when loading the carrier.

Dimensional stability is necessary to prevent damage to the wafer or disks and to minimize the movement of the wafer or disk around the carrier. Since the tolerances of the slots holding the wafer and the disk are extremely small, if the carrier deforms, it can directly damage very vulnerable wafers or cause particle generation upon wear or tear when the wafers or disks are moved in or out of the carrier. You can increase it. Dimensional stability is also of great importance. Carrier materials also need to maintain dimensional stability at high temperatures that occur during storage or cleaning.
Conventional carriers used in the semiconductor industry generate electrostatic charges to charge them. When a charged plastic part comes into contact with an electronic device or a processing device, a discharge occurs in this part and a destructive shape known as electrostatic discharge (ESD) occurs. In addition, the electrostatically charged carrier attracts and attaches particles, particularly suspended particles. In addition, when a static buildup occurs on the carrier, the semiconductor processing device is automatically stopped. Electrostatic integration on the carriers may cause the semiconductor processing equipment to stop automatically. It is most desirable to have the electrostatic dissipation characteristics of the carrier to exclude ESD and avoid attracting particles.

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Trace metals are a common component or residue in many wafer materials. Metal contaminants should be considered in the choice of material for the carrier or in the assembly of the carrier. Anion contamination in the carrier material creates problems of contamination and corrosion.

The materials used for the carriers also need to be chemically compatible with any drug that they may be governed by. The use of chemicals is not assumed in wafer carriers for transport or storage only, but the carriers need to be resistant to solvents generally used, such as cleaning liquids and isopropyl alcohol. Treatment carriers are exposed to highly pure acids or strong chemicals.

It is quite desirable that the wafer in the closed container is visible and is required by the end user. Transparent plastics suitable for such containers, such as polycarbonates, are preferred in terms of low cost, but such plastics do not have desirable electrostatic dissipation properties and thus do not have desirable wear resistance.

Other important properties of the carrier material are cost and ease of forming the material.

Carriers are injection molded plastics such as polycarbonate (PC), acrylonitrile butadiene styrene (ABS), polypropylene (PP), polyethylene (PE), perfluoroalkoxy (PFA), and polyetheretherketone (PEEK). Typically formed.

Fillers in which injection molded plastics have been added to provide electrostatic dissipation properties include carbon powder or carbon fiber, metal fibers, metallized graphite, and organic (amine base) additives.

One common wafer carrier used for transport or storage is called the H-bar carrier, which includes a front end with an H-bar interface, a rear end with a plate, and a lower axis curve portion, i. It consists of a side having a portion and is molded into a single molding member having an open top and an open bottom. The H-bar carrier is normally discarded after several reuses. In use, the carrier is generally washed with hot water or other chemicals and then dried by warm air. In cleaning, drying, transporting and processing a wafer, it is a very important characteristic that the carrier can maintain its shape when exposed to high temperatures.

Another common carrier is a box having a structure configured to hold an H bar carrier. This box is commonly known as a work in process (WIP).

Another conventional carrier is a standardized mechanical interface (SMIF) box, which has a box that seals and encloses the H bar carrier mechanically interfaced with the processing device. In general, SMIF boxes have an open door at the bottom and are accessible by an H-bar carrier with a wafer. Boxes are also known which have doors that are open to the front for access to the H-bar carrier. Another conventional carrier consists of a box enclosure with an inner shelf supporting the wafer, which is not present in the H carrier of the other body, and is a transport module having an open door in front.

It is necessary to recognize that the ideal material for one member of the carrier is limited to the ideal material even though it is necessary for the material of another part of the same carrier. PEEK, for example, is a material that has ideal wear resistance for wafer contact portions, but is difficult to mold and is considerably more expensive than other plastics. Therefore, PEEK is not preferable as the material of the structural part, and other plastics such as polycarbonate are suitable.

The only case where different materials are used for different parts of the disk carrier is when this other part, the component is molded separately and then assembled into the carrier. In the formation of such assembled carriers, there is a drawback in that they form particles in contact with the surface of other components and form contaminant attachment parts that are difficult to clean. In addition, particles are also generated in the granulation step. In addition, the formation of other component parts and the assembly thereof require expensive efforts for the carrier, which is expensive.

The wafer carrier of the present invention is molded from two or more different meltable plastic materials. The two plastic materials are arranged for optimal performance and thermophysical bonding is performed by an overmolded processor. The present invention includes carriers made of such different melt processable plastics materials and includes methods of making such carriers. In a first embodiment the H-bar wafer carrier has a first structural portion molded of polycarbonate in a first mold cavity, and then of a polycarbonate molding disposed in a second mold hollow. And a polyetheretherketone is injection molded to form a wafer contact portion on the H-bar carrier. The processing temperature and mold temperature are controlled to provide the optimum coupling between the different materials. Thus, an integral wafer carrier of composite material is formed. A further embodiment utilizes components such as shelves or sidewall inserts molded from two different plastics for holding the wafer, the components being assembled inside the disk enclosure such as the transport module.

An advantage and feature of the present invention is that a carrier is formed which provides the best performance characteristics of the least material and labor cost.

A further advantage and advantage of the particular preferred embodiments of the present invention is that there is no assembly of the components and at the same time maintains the advantage of using a combination of materials.

A further advantage and object of particular preferred embodiments of the present invention is that virtually an integral carrier or component is created by two plastic parts molded together.

Another advantage and feature of the present invention is that the seam between two different materials is closed to eliminate potential traps of contaminants or other chemicals.

Another advantage and feature of the present invention is that the process can exclude post-molding adjustment of the wafer carrier, which may otherwise be necessary, such as annealing.

Referring to FIG. 1, an H-bar wafer carrier is depicted and generally indicated at 20. This H-bar carrier, like the conventional H-bar carrier, has a whole 22, rear 23, side walls 24, 26, slots 28 for receiving wafers, an open top 30, and H bars. It has a device interface formed as (32). Each slot is defined by a pair of wafer engagement teeth 34.

The conventional H-bar wafer carrier has, in addition to the H-bar, i.e., the device interface, a bottom device interface 38 constituting four feet having contact portions at the corners 40.
In addition, the pick-up handle 42 for the robot and the flange 44 of the robot also function as a device interface. Such a hybrid H-bar carrier generally has a first base portion 44 and a second overmolded portion configured as a wafer engaging portion 46. In this embodiment, the wafer carrier 20 is an integrated single component 20.

In FIG. 2 an overmolded portion 50 is shown, in which the integral base portion 44 is omitted. The overmolded portion 50 has a wafer engaging portion 46 and an accessory part 52. The accessory part 52 is a part corresponding to the flow path through which the overmolded material in the molten state flows at the time of the molding press. This part, as shown, represents the configuration of the mold hollow for the overmolding.

In a preferred embodiment, the support or base portion 44 is a polycarbonate or polycarbonate filled with a carbon fiber filler, which is a plastic formed with good numerical stability, easy formation and low cost. The overmolded portion 50 is then molded from other melt processable crystalline plastics, such as PEEK or PEEK filled with carbon fiber filler. These materials differ in their morphological struction and processing temperature. These materials are examples, and as long as they are obtained by exhibiting the same function, it is also possible to use a combination of morphologically different materials. In the combination of polycarbonate, which is an amorphous material, and PEEK, which is a crystalline material, a thermophysical bond is formed when the amorphous material comes into contact with a crystalline material in a molten state. It is believed that the bond is formed by increasing the energy of the surface of the polymer glass at the interface. Therefore, when the high-temperature amorphous melt comes into contact with the polymer glass or the polycarbonate, the surface energy of the polymer glass is thereby increased and crystallized at the interface as the high-temperature melt is cooled. In theory, this crystallization process contributes to the bonding of the two materials. Since polymer glass is significantly lower in specific heat, heat dissipates into polymer glass at a very slow rate, which delays cooling of the hot melt of PEEK and increases crystallization at the interface. When this process is performed by injection molding, the molded product has a higher crystallization level at the interface between the polymer glass and the interface between the polymer crystal and the molding mold. This is because there is a difference in specific heat between metal and polymer glass.

In a preferred embodiment, the polycarbonate, ie, the polymer glass, is first molded and then the molded article is placed in an injection mold to form a PEEK thereon. In this process, the molding temperature is ideally maintained below the glass transition point (149 ° C.) of the polycarbonate so as not to deform the portion of the base of the polycarbonate. The overmolded portion 50 as the wafer contact will be strategically arranged so that the wafer will not come into contact with the polycarbonate.

Amorphous materials other than the above are polyetherimide (PEI). In this case, the chemical bonding element is also involved.

Various types of coupling components relate to joining the overmolded part with the base part. It is believed that thermophysical bonding occurs when the molten overmolded material contacts the unmelted base portion. Thermophysical bonding occurs when molecules in two parts are less than three times the radius of the molecule.

3, 4, and 5, a work in process box is disclosed and generally indicated at 60. Such a walk-in process box typically holds an H-bar wafer carrier 62 as shown in FIG. 1 and engages and rests thereon in top cover 64, base portion 66, and base portion 66. H-bar wafer carrier 62 has a main component. In this case, "carrier" means an enclosure box or an enclosure box with an H-bar carrier. Some components may be formed as overmolded processes, taking advantage of the unique features and processes and advantages of the present invention. For example, as shown in FIG. 5, the cover section 64 is made of polycarbonate. The hinge 68 is overmolded with PEEK and attached to the upper carver section 64. Further, as can be seen with reference to FIG. 4, first, the polycarbonate window 70 is formed in a desired structure and size so that the polycarbonate is inserted into the mold with respect to the window 70 when the upper cover section 64 is formed. . As a result, the polycarbonate is overmolded with respect to the window 70 with respect to the shaping of the upper portion section 64, thereby forming a window cover upper cover section 64. The overmolding makes it possible to achieve considerably high quality joining without the use of adhesives or mechanical fasteners.
As can be seen with reference to FIGS. 6 and 7, the magnetic disk cipher carrier consists of a base portion 76 and an upper cover portion 78. The base portion 76 also has a support portion 82, and after the base body 79 as the support portion is molded, the disc engaging portion 84 is injection molded thereon. The support portion 82 is formed of polycarbonate or equivalent material and the support engagement portion is formed of PEEK or equivalent material. The disk contacts can also be formed from PEEK or similar material.

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8 and 9, there is shown a transport module 200 for use for a semiconductor wafer, for example 300 mm large. In this particular configuration, the wafer support portion 90 comprises a base portion 91 with an interface 92, a vertical column 94 with a wafer support shelf 96 as a low particle generation engagement component, and an upper portion. Has 98 Wafer engagement shelf 96 has an overmolded portion 99. This overmolded portion 99 is in contact with the wafer contained in the transport module. It also has an overmolded portion in contact with the device interface device 92 as a low particle generation engagement component. The transport module 200 includes an enclosure portion 201 and a door 202 closing the enclosure 201.

12 shows a wafer carrier formed as a carrier having improved wafer processability. This carrier is shown at 110. The carrier 110 has base support portions 112 and 114 and arms 116 extending therebetween. Each arm has a plurality of teeth 118 that form a slot 120. This slot 120 is for holding a wafer in the wafer processing step. In this particular embodiment, the arm 116 and the outer portion of the teeth are overmolded with a framework 122 of the base support, provided the features of the present invention.

10 and 11 illustrate a composite wafer carrier formed from components 122 in an assembled state. The component consists of sidewall portion 124 and carrier framework 126. Sidewall inserts 124 are engaged in the framework 26 and assembled to form a fixed wafer carrier. In addition, at the rear end 134 of the carrier, a robot flange, that is, a device interface 132 is provided. In this case, each of the sidewall portions 124 is provided with an overmolded wafer carrier portion 139, and the generation of particles due to scratching of the wafer is minimized. The overmolding can be carried out under stricter control than the shaping of the base to position the wafer with a small tolerance.
Figure 13 shows a diagram illustrating a method for practicing the present invention. First, a base part, that is, a support part, is formed using a mold. The support portion is another carrier portion, such as a carrier framework or base portion 130 of the side wall shown in the figure. The molded base portion is then fitted to another mold. Alternatively, the formed member is removed and inserted into the same mold. In this state, the mold is closed and other overmolded material such as PEEK is injected into the molding cavity. This molded hollow is hung on a particular part that is overmolded. Thereafter, the finished molded article consisting of the base portion and the overmolded portion is removed. If the base portion is a component member, this component member is assembled in the carrier 136.

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In particular applications, the base portion, which is the first injection molded portion, is suitable for reducing the volume compared to the second portion, ie the overmolded portion. In addition, the first member may be deposited on, for example, a wafer contact portion and a predetermined portion in the molding die to solidify the material so that the second support portion is overmolded on the first material without replacing the mold. It is also possible.

In another particular application, the two materials may be joined in a molten state without solidifying the second material. This injection molding has a small positioning accuracy of the boundary between the first part and the second part, but the process of solidifying the second part without requiring the second molding mould, the first from the molding mould. The step of removing the part, the step of removing the first part from the second molding die, and the step of installing the first part into the second molding die are not required.

The present invention has the effect of forming a carrier of best performance with minimal material and labor costs.

The present invention is effective in producing an integral carrier or component without the assembly of the components and at the same time using a combination of materials.

The present invention has the effect of eliminating the potential synthesis of contaminants or other chemicals by closing the seam between two dissimilar materials.

The present invention has the effect that the process can exclude post-molding adjustment of the wafer carrier, which may otherwise be necessary, such as annealing.

Claims (23)

A wafer carrier with multiple slots for keeping wafers in line, a) a base portion formed of a first thermoplastic material; b) having a wafer engaging portion having a plurality of wafer contact portions overmolded on said base portion, An overmolded wafer carrier in which the wafer engagement portion is formed of a second thermoplastic material, the wafer contact portion is a plurality of slots, and the wafer engagement portion is coupled to the base portion. The method of claim 1, The wafer carrier is an overmolded wafer carrier configured as an H-bar wafer carrier. The method of claim 1, An overmolded wafer carrier further comprising a container portion for enclosing the wafer. The method of claim 1, An overmolded wafer carrier wherein the base portion is comprised of polycarbonate and the wafer contact portion is comprised of polyetheretherketone. A wafer carrier having a plurality of slots for holding the wafers side by side, the carrier having an overmolded low particle generation engagement component, the engagement component in contact with an external device that is fitted and detached relative to the wafer carrier. Having a surface, wherein the engagement component has a first base portion molded from a first moldable plastic and a second overmolded portion attached to the first base portion, the second overmolded portion being An overmolded wafer carrier formed of a second different moldable plastic having lower particle generation properties than the first portion. The method of claim 5, The engagement component is an over-molded wafer carrier that is the portion of the device interface for engaging with external equipment. The method of claim 5, A wafer carrier with a door comprises a plurality of said engagement components, said engagement components configured as a wafer support shelf. The method of claim 7, wherein An overmolded wafer carrier further comprising a door for closing the enclosure portion. As a wafer carrier manufacturing method, a) injection molding the base portion of the first plastic into the first molded mold portion; b) disposing the molded base portion in a second molded mold portion; c) overmolding the contact over the base portion using a second plastic. The method of claim 9, Melting the polycarbonate resin as the first plastic further comprising the step of melting. The method of claim 10, Melting the resin consisting of one of a set of polyetheretherketone or polyetheramine as a second plastic. The method of claim 11, A method of producing a wafer carrier further comprising the addition of carbon fiber to one of a set of polyetheretherketones or polyetheramines. The method of claim 10, The polycarbonate has a glass transition temperature and maintains the temperature of the second mold below the transition temperature of the polycarbonate. A component comprising a first portion molded of a first thermoplastic material and a second portion injection molded of a second thermoplastic material on the first portion, the first and second portions being Wafer carriers bonded by thermophysical bonding. As a method of manufacturing a wafer carrier portion, a) injecting a first thermoplastic material into the hollow of the mold at a predetermined position to form a first portion; b) injecting a second thermoplastic material in contact with the first material to form a second portion adhered to the first portion to form an integrated type wafer carrier portion; . The method of claim 15, Solidifying the first portion prior to injection of the second thermoplastic material The method of claim 16,   Removing the first portion and disposing the first portion in the hollow portion of the second mold prior to injection of the second material. The method of claim 17, And selecting polycarbonate as the first thermoplastic material to form the polycarbonate window with the first portion. An enclosure having a plurality of slots for holding a plurality of wafers, the enclosure comprising a window that is thermophysically bonded, and wherein the thermophysical adhesion comprises an enclosure formed by overmolding Wafer carrier. The method of claim 19, A wafer carrier comprising an H bar carrier, wherein a plurality of slots are defined by the H bar carrier. The method of claim 19, The enclosure is a wafer carrier consisting of a base portion and a cover. In the method of manufacturing a wafer carrier with an enclosure and a window, Disposing a transparent window in the mold; Overmolding a second material over the window to form a wafer enclosure. A method of manufacturing a wafer carrier configured to view wafers in an enclosure, the method comprising: providing a polycarbonate window in a mold; Overmolding a second material at the polycarbonate window portion to form a wafer enclosure component.

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