JPH03252153A - Holding member for semiconductor wafer - Google Patents

Abstract

PURPOSE:To obtain members capable of preventing torsion in dicing large-sized wafers, coping with interference among chips in pickup, and attaining efficient transfer, etc., based on loading multistaging by providing a tacky layer on the support plate of a holding laboratory dish recess-shaped in cross section having a loading frame at the outer edge of a support plate made of foaming resin. CONSTITUTION:A support plate 11 in a holding laboratory dish 1 recess-shaped in cross section having a high loading frame 21 at the outer edge of the needle- penetrable support plate 11 made of foaming resin is provided with a tacky layer 6 for chucking a semiconductor wafer 7 with circuit patterns at the time of dicing it into chips. For example, the support plate 11 and the loading frame 21 are integrally foam-molded with foaming resin to form the holding laboratory dish 1 recess-shaped in cross section, and the support plate 11 is provided with the tacky layer 6. The tacky layer 6 can be multilayered with an adhesive layer 61 to mount semiconductor chips 8 obtained by dicing a semiconductor wafer 7 so that the mounting adhesive layer 61 can be peeled from the tacky layer 6 serving as the base.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a semiconductor wafer holding member that is excellent in holding a semiconductor wafer or a semiconductor chip made of a cutting element thereof, and in multi-stage loading and transportation.

Background of the Invention A semiconductor wafer on which a circuit pattern has been formed is back-polished to adjust the thickness as necessary, and then divided into small element pieces in a dicing process, and the formed semiconductor chips are placed in a mounting process where adhesive is applied. After being fixed to the chip carrier via the intervening chip carrier, it is transferred to a subsequent process such as a bonding process. During the above-mentioned cutting process, it is customary to wash with appropriate hydraulic pressure (usually about 2 kg/cd) to remove cutting debris.

In the above, with the increase in the size of semiconductor wafers,
Due to various issues such as the increased space required for clean rooms, etc., instead of the conventional system where semiconductor chips are manufactured in an integrated line, the necessary processing is performed independently for each process such as the dicing process and mounting process. A transition to a division of labor system is being considered, and in that case, a new means of transporting semiconductor wafers or semiconductor chips is required.

Prior Art and Problems Conventionally, as a holding member that can also serve as a means for transporting a semiconductor wafer on which a circuit pattern is formed or a semiconductor chip formed by dividing the semiconductor wafer into small element pieces, the group to which the present inventors belong has developed a method that has needle penetrating properties. It has been proposed that an adhesive layer for adhering and holding a semiconductor wafer is provided on a support plate made of foamed resin.
Publication No. 06).

This is because semiconductor wafers have become larger in size, and with the previous method of supporting an adhesive film with a ring frame that held the semiconductor wafer in place, the film could stretch or twist, resulting in cutting errors, or it would be difficult to pick up the formed semiconductor chips. This is intended to overcome problems such as interference between elements.

Therefore, in order to realize the division of labor system described above, when a semiconductor wafer fixed with a holding member is divided into small element pieces and then transported to the next process as is, even if it is possible to load and transport the semiconductor wafer through a bin, the semiconductor wafer must be larger in size. Due to the increase in weight caused by carbonization, etc., and the strength constraints of the support plate, which requires needle penetration, the number of items that can be loaded is small, making it impractical for large-scale transportation or long-distance transportation by aircraft or trucks. A high degree of clarity is required, as the upper holding member bends between the stacks and the bottom surface comes into contact with the semiconductor wafer, and gaps are formed between the stacked holding members, allowing contaminants to enter through these gaps. There were problems that made it unsuitable as a device for transporting semiconductor chips.

Means for Solving the Problems The present invention overcomes the above problems by providing a holding member with a concave cross section.

That is, the present invention provides a holding petri dish with a concave cross section and a supporting plate made of foamed resin having needle penetrability and having a tall loading frame on the outer periphery of the supporting plate. The present invention provides a semiconductor wafer holding member characterized by having an adhesive layer for adhering and holding the semiconductor wafer when it is divided into pieces.

By providing a loading frame on the outer periphery of the support plate to create a holding petri dish with a concave cross-section, the needle penetration of the foamed resin support plate is satisfied, while the tall loading frame provided on the outer periphery provides reinforcement. As a result, resistance to deformation such as elongation and twisting can be improved, and based on the improved rigidity or strength, it is possible to prevent twisting when cutting wafers and to prevent pickup as semiconductor wafers become heavier due to larger sizes. In addition, it is possible to prevent interference between small element pieces when loading the elements, and to achieve efficient transfer by stacking the elements in multiple stages, as well as to prevent the formation of gaps between the holding members. Furthermore, it is possible to satisfy requirements such as light weight and bow absorption properties.

Example Various embodiments of the holding member of the present invention are illustrated in the accompanying drawings.

1 is a holding petri dish with a concave cross section, and 6 is an adhesive layer. Note that 7 is a semiconductor wafer with a circuit pattern formed thereon that is adhered and held by an adhesive layer, kuzu is a semiconductor chip formed by dividing the semiconductor wafer into small element pieces, and 9 is a dividing line.

In FIG. 1, the holding petri dish 1 is formed by integrally forming a support plate 11 and a loading frame 21 by foam molding using a foamable resin. Holding petri dish 1 illustrated in Fig. 2
In this embodiment, a reinforcing frame 4, which is added as required, is adhesively added to a groove formed on the outer periphery of the bottom of the support plate 11, and a skin layer 5 is provided on the bottom surface of the support plate 11. The skin layer is provided on necessary parts such as the entire surface, top surface, and bottom surface of the holding petri dish as necessary for the purpose of preventing the generation of debris and improving vacuum suction performance by eliminating air permeability. The skin layer can be formed, for example, by adhering a film, forming a coating, or thermally melting the surface of a foamed resin layer. Note that when the holding petri dish or the support plate is made of a foam having a closed cell structure, the skin layer is often unnecessary.

Further, in the holding petri dish of the above embodiment, drainage holes 3 are formed at predetermined intervals, if necessary. The purpose of the drain hole is to drain cleaning fluid together with cutting waste when cutting a semiconductor wafer. A loading frame having a gap may be used instead of a drainage hole.

The holding petri dish 1 illustrated in FIG. 3 has a structure in which a loading frame 22 has a protrusion 23 and a groove 24 that fits therein. The purpose of these protrusions 23 and grooves 24 is to prevent misalignment and collapse of the stack when holding members are stacked in multiple stages. The holding petri dish 1 illustrated in FIGS. 4 and 5 is made by bonding support plates 12, 13 and non-foamed loading frames 25, 26, and is intended to improve rigidity or strength. The support plate and the loading frame may be made of different materials, and the loading frame may have relatively high strength by making the foaming ratio lower than that of the support plate.

As mentioned above, the holding petri dish 1 according to the present invention has a concave cross section and consists of a support plate and a loading frame provided on the outer periphery of the support plate. An appropriate structure is provided.

The support plate in the holding petri dish is made of foamed resin and has a thickness that allows a needle to pick up the formed semiconductor chip to pass through. Typical thickness is 1 to 5 centimeters. Examples of the foamed resin include foamed styrene, foamed rigid polyolefin, foamed rigid urethane, and foamed rigid rubber, but are not particularly limited. The expansion ratio may be determined as appropriate depending on the required strength, etc., and may be approximately IO times, for example. The foam structure may be an open cell structure or a closed cell structure.

The loading frame provided on the outer peripheral edge of the support plate is formed to have a higher height than the support plate so as to form a holding petri dish with a concave cross section. The length is at least when the holding member is loaded with the semiconductor wafer bonded and held on the adhesive layer.
The height is set so that the back side of the support plate does not come into contact with the semiconductor wafer. - The general length is about 1 to 2 inches taller than the support plate surface.
It has a protruding length of m.

The holding petri dish or the support plate may be provided with antistatic property to protect the circuit pattern formed on the semiconductor wafer. The antistatic properties may be imparted by any appropriate method, such as by mixing a conductive substance such as carbon. The method of mixing carbon suppresses light reflection on at least the surface of the holding member to which the semiconductor wafer is bonded, and detects the semiconductor wafer 1 or semiconductor chip with a light reflection sensor to prevent mistakes when dividing or picking up the semiconductor wafer. It has the advantage that it can also be used as a coloring treatment to prevent this.

The holding member of the present invention is attached to the support plate of the holding petri dish.
An adhesive layer is provided for adhering and holding the semiconductor wafer on which a circuit pattern is formed when it is cut into small element pieces. The adhesive layer 6 is attached to the support plate 1 as illustrated in FIG.
It may also be provided on the side opposite to the side from which the loading frame 21 in 1 protrudes. In this case, there is an advantage that the cleaning liquid and the like that are used when cutting the semiconductor wafer into small element pieces are less likely to accumulate.

There are no particular limitations on the adhesive layer used. The adhesive layer may be formed by any appropriate method, such as a coating layer formed by a screen printing method, a layer cured by UV rays, etc., a heat-sealing layer of an adhesive film, or an adhesive layer of a double-sided adhesive film. The adhesive layer has a multi-layer structure in which, as illustrated in FIG. 7, an adhesive layer 61 is preliminarily provided for mounting the semiconductor chip 8 obtained by cutting the semiconductor wafer 1 into small element pieces while adhering and holding it onto a chip carrier or the like. It may be of. The thickness of the adhesive layer may be determined as appropriate, but is generally 1 to 500 μm.

The adhesive layer 6 having a multilayer structure can be obtained, for example, by reducing or losing the adhesive force so that the mounting adhesive layer 61 can be peeled off from the adhesive layer 62 serving as the base. Application No. 1-68939, Japanese Patent Application No. 1-119062).

Specific examples include those that use heat-curing pressure-sensitive adhesives that increase the degree of crosslinking and reduce adhesive strength for the base adhesive layer, and those that use foaming or engraving by heating. A foaming method or a heat engraving method using a base adhesive layer containing foaming agents or heat-engravable microcapsules that reduces the bonding area and lowers adhesive strength through plate processing, and heat-engravable A blooming method in which a blooming agent is precipitated at the interface with the mounting adhesive layer to reduce the adhesive force, and a blooming method in which the adhesive force is reduced by lowering the temperature of the base adhesive layer or mounting adhesive layer. In this cooling method, an adhesive force reducing layer that changes when heated is interposed between the base adhesive layer and the mounting adhesive layer, and the adhesive force at the interface is reduced by the action of the adhesive force reducing layer. For example, the method may be a combination of the above methods, or a combination of the above methods. In that case, an appropriate adhesive made of thermoplastic resin or thermosetting resin may be used to form the mounting adhesive layer. Examples include thermoplastics such as ethylene/vinyl acetate copolymers, ethylene/acrylic acid ester copolymers, polyethylene, polypropylene, polyamides, polyesters, polycarbonates, cellulose, carbonaceous derivatives, polyvinyl acetals, polyvinyl ethers, polyurethanes, and phenoxy resins. Hot-melt adhesives made of resins, adhesives using thermosetting resins such as epoxy resins, polyimide resins, maleimide resins, silicone resins, and phenolic resins, acrylic resins, rubber-based polymers, fluororubber-based polymers, and fluorine resins. Examples include adhesives made of resin or the like. The mounting adhesive layer made of a thermosetting resin adhesive is formed in a B-stage state. The adhesive layer for mounting may contain fine powder of a conductive substance such as aluminum, copper, silver, gold, palladium, or carbon to impart conductivity. Further, fine powder made of a thermally conductive substance such as alumina may be included to improve thermal conductivity. The adhesive strength between the base adhesive layer and the mounting adhesive layer is 180 degrees beer value (normal temperature, tensile speed 300
■/min), when dividing semiconductor wafers, 20
The adhesive layer has a multi-layer structure so that the weight is 0g/20m or more and 150g/20cm or less when the formed semiconductor chip is peeled off, the holding power of the semiconductor wafer when it is separated, the ease of peeling the semiconductor chip when it is peeled off, etc. This is more preferable. The thickness of the base adhesive layer in a multilayer adhesive layer is preferably 1 to 100 μm, particularly 1 to 40 μm, and the thickness of the mounting adhesive layer is preferably 1 to 100 μm.

A preferred method of using the holding member of the present invention is that its adhesive layer (
After adhering and holding the semiconductor wafer (7) on which a circuit pattern has been formed on the substrate 6), it is cut into small element pieces using a suitable cutting means such as a rotary circular blade, and the formed semiconductor chips (8) are bonded to the adhesive layer (6).
) is a method in which the holding members are stacked in multiple stages while being adhesively held on the holder and transported to the next process.

The formed semiconductor chip can be removed or peeled off from the adhesive layer by a method of pushing up the semiconductor chip while penetrating the support plate with a needle. If the adhesive layer already has a mounting adhesive layer,
For example, after applying the necessary treatment to the adhesive layer to make it possible to separate the base adhesive layer from the mounting adhesive layer,
Individual semiconductor chips can be peeled off and removed using the same holding means, such as a method in which the individual semiconductor chips are pushed up with a needle or the like, picked up by a vacuum chuck, and then moved to the vacuum chuck while being held and mounted on a chip carrier. A method of mounting in series is preferred. In this case, there is an advantage that the formed semiconductor chips can be subjected to a mounting process without being scattered.

Effects of the Invention According to the holding member of the present invention, since the holding petri dish has a concave cross section and has a support plate made of foamed resin, high accuracy cutting of large semiconductor wafers and semiconductor chips based on needle penetration, prevention of twisting, etc. While satisfying the interference prevention property between semiconductor wafers or semiconductor chips, it can be stacked stably and compactly in multiple stages while adhesively held, and is also lightweight. Efficient and safe transfer to processes etc. can be realized.

In addition, the loading frame portion prevents crushing due to multi-stage stacking, and forms a shielding wall between stacks to prevent contaminants from entering. As a result, it is possible to achieve packaging that does not allow contaminants to enter the stack by using simple and light binding methods such as adhesive tape or other operations, and the efficiency of packing and unpacking is excellent. It also has the advantage of being difficult to damage.

Furthermore, when the adhesive layer has a mounting adhesive layer in advance, the process from dicing the semiconductor wafer to mounting the formed chips can be performed in a series while being adhesively held by the same holding member.

[Brief explanation of drawings]

FIG. 1 is a perspective sectional view illustrating the holding member of the present invention, and FIG.
3, 4, 5, and 6 are sectional views of other embodiments, respectively, and FIG. 7 is a perspective sectional explanatory view showing an example of the structure of the adhesive layer. 1: Holding petri dish 11.12.13: Support plate 21.22.25, 26: Loading frame 6: Adhesive layer 61: Mounting adhesive layer 62: Base adhesive layer 7: Semiconductor wafer 8: Semiconductor chip

Claims (1)

[Scope of Claims] 1. A semiconductor wafer on which a circuit pattern is formed on the support plate in a holding petri dish with a concave cross section and a tall loading frame on the outer periphery of the support plate made of foamed resin having needle penetrability. 1. A holding member for a semiconductor wafer, comprising an adhesive layer for adhering and holding the semiconductor wafer when dividing the semiconductor wafer into small element pieces. 2. The holding member according to claim 1, wherein the adhesive layer has a multilayer structure having a removable mounting adhesive layer on the adhesive layer serving as a base.