JP2010283312A - Manufacturing method of semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a semiconductor device, which suppresses metal precipitation on a back surface of a thin wafer and the warpage and damage of the wafer when plating the wafer and has a good plating efficiency for the wafer. <P>SOLUTION: The method for manufacturing a semiconductor device includes a step 1 of making a wafer thin, a step 2 of mounting the back surface of the thin wafer into a ring frame by a dicing tape, and a step 3 of plating a surface of the wafer mounted in the ring frame. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a semiconductor device.

  In recent years, with the introduction of SIP (System In Package) for mobile products, IC (Integrated Circuit) cards, RFID (Radio Frequency IDentification) tags, etc., semiconductor devices with a chip thickness of 100 μm or less are put into practical use as products. It has become. Along with such a demand for thinning the final product, the importance of a technique for processing a thin wafer used therefor is also increasing.

  In general, semiconductor devices are manufactured by using a dicing tape and a ring frame in order to perform a plating process for forming electrodes on a wafer as a device substrate, a process for thinning the wafer, and dicing stably. A step of preparing and mounting the wafer in a ring frame with a dicing tape (frame mounting step), a step of dividing the wafer stabilized by the dicing tape and the ring frame into individual chips by dicing, and the like are provided.

As a method for manufacturing such a semiconductor device, the following is known.
1. Manufacturing method 1
The conventional manufacturing method 1 performs each process mentioned above in order of the following (1)-(7).
(1) Plating process for forming electrode metal on the wafer surface (2) Wafer surface protective tape application process (3) Wafer back gliding process (thinning process by grinding the back of the wafer)
(4) Frame mounting process (5) Wafer surface protection tape peeling process (6) Dicing process (7) Chip separation process

2. Manufacturing method 2
The conventional manufacturing method 2 performs each process mentioned above in order of the following (1)-(7).
(1) Plating process for forming electrode metal on the wafer surface (2) Half-cut dicing process (3) Wafer surface protective tape application process (4) Wafer back gliding process (5) Frame mounting process (6) ) Wafer surface protection tape peeling process (7) Chip separation process

3. Manufacturing method 3
The conventional manufacturing method 3 performs each process mentioned above in order of the following (1)-(7).
(1) Half-cut dicing process (2) Plating process for forming electrode metal on the wafer surface (3) Wafer surface protective tape attaching process (4) Wafer back gliding process (5) Frame mounting process (6) ) Wafer surface protection tape peeling process (7) Chip separation process

  In the above methods 1 to 3, after the plating process for forming the electrode metal on the wafer surface is performed, the back gliding process is performed to thin the wafer. However, if the plating film thickness is large, the plating stress increases and the wafer warps, which adversely affects the subsequent back gliding process. For this reason, the thickness of the plating formed on the wafer surface cannot be increased.

In order to solve such a problem, a method of performing the back gliding process before the plating process has been studied as follows.
4). Manufacturing method 4
The conventional manufacturing method 4 performs each process mentioned above in order of the following (1)-(7).
(1) Wafer surface protective tape attaching process (2) Wafer back gliding process (3) Wafer surface protective tape peeling process (4) Plating process for forming electrode metal on wafer surface (5) Frame mounting Process (6) Dicing process (7) Chip separation process

  However, in the manufacturing method 4 described above, since the back gliding process is performed before the plating process, there is a problem of adhesion of plating to the back surface of the wafer and damage to the wafer. For this reason, as disclosed in Patent Documents 1 to 3, respectively, a plating jig is used, a protective film such as a resist is formed, or a protective tape is applied to the rear surface of the plating wafer. The prevention of adhesion is intended.

JP 2002-339078 A JP 2002-339079 A JP 2002-343851 A

However, when a plating jig is used, the wafer warps due to the attachment of the jig. Further, the plating jig has poor wafer handling properties, and further requires a large space, so that it is difficult to plate many wafers at once.
Also, the formation of a protective film such as a resist has a problem that the protective film wraps around the wafer surface.
In addition, when a protective tape is applied, the wafer is warped, and the wafer is easily damaged when the tape is peeled off.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a method for manufacturing a semiconductor device that suppresses wafer warpage and damage when plating a wafer and has good wafer plating efficiency.

  As a result of intensive studies, the inventors of the present invention have provided a frame mounting process using a ring frame between the wafer thinning process and the plating process so that the wafer is warped and damaged when the wafer is plated. It was found that the plating efficiency of the wafer is improved.

  The present invention completed on the basis of the above knowledge, in one aspect, the step 1 for thinning the wafer, the step 2 for mounting the back surface of the thinned wafer in a ring frame with dicing tape, and the inside of the ring frame A method of manufacturing a semiconductor device, comprising a step 3 of performing a plating process on the surface of the wafer mounted on the substrate.

  In one embodiment of the method for manufacturing a semiconductor device according to the present invention, the plating process is an electroless plating process.

  In another embodiment of the method for producing a semiconductor device according to the present invention, the thickness of the thinned wafer is 150 μm or less.

  In still another embodiment of the method for manufacturing a semiconductor device according to the present invention, at least the surface of the ring frame is formed of a non-plating adhesion material.

  In still another embodiment of the method for manufacturing a semiconductor device according to the present invention, the non-plated adhesion material is a resin or a metal coated with a resin.

  In still another embodiment of the method for producing a semiconductor device according to the present invention, the resin is Teflon (registered trademark), PET, or polyamide.

  In yet another embodiment of the method for manufacturing a semiconductor device according to the present invention, the step of forming a protective member on the surface of the wafer, which is performed before the step 1, and the step 2 and the step 3 The method further includes the step of removing the protective member performed in between.

  According to the present invention, it is possible to provide a method for manufacturing a semiconductor device that suppresses warping and damage of a wafer when plating the wafer and has good wafer plating efficiency.

Hereinafter, typical embodiments of a semiconductor device according to the present invention will be described in detail.
(Embodiment 1)
The method for manufacturing a semiconductor device according to the first embodiment includes at least the following steps (1) to (7) in this order.
(1) Wafer surface protection tape attaching process (2) Wafer back gliding process (3) Frame mounting process (4) Wafer surface protection tape peeling process (5) Plating process for forming electrode metal on wafer surface Process (6) Dicing process (7) Chip separation process

(1) Wafer Surface Protection Tape Affixing Step First, a predetermined wafer and a wafer surface protection tape (a wafer surface protection member) are prepared. The wafer is formed in, for example, a substantially circular shape having a predetermined thickness and a diameter of about 2 to 12 inches, and is formed using a compound semiconductor such as silicon or GaAs. A plurality of semiconductor elements may already be formed on the wafer at this point.
The wafer surface protective tape is composed of a base film and a film adhesive provided on the base film. As the base film, for example, a polyethylene film, a polypropylene film, a polyvinyl chloride film, a polyethylene terephthalate film, an ethylene-vinyl acetate copolymer film, an ionomer resin film or the like is used, and the thickness is preferably about 15 to 100 μm. . As the film adhesive, acrylic resin, methacrylic resin, silicon resin, polyamide resin, polyester resin, polyurethane resin, EVA (copolymer of ethylene and vinyl acetate) resin, or the like can be used.
Next, the wafer is mounted on the film adhesive of the wafer surface protection tape from the surface side with the surface (the surface on which elements will be formed later and the surface to be plated later) facing upward. The wafer is affixed to the wafer surface protective tape. This wafer surface protective tape protects the wafer surface in a back gliding process, which will be described later, and prevents contamination of the wafer surface due to intrusion of grinding water, grinding scraps, or the like.

(2) Wafer Back Gliding Step Next, a back gliding apparatus for thinning the wafer is prepared. The back gliding apparatus may be of any configuration. For example, a vacuum suction table for fixing the wafer, a rotating grindstone for grinding the wafer, and a grinding liquid (usually water) is supplied onto the wafer during grinding. It comprises a grinding fluid supply section and the like.
Subsequently, the wafer whose surface is protected by the wafer surface protection tape by the wafer surface protection tape affixing step (1) is provided on the vacuum suction table of the back gliding apparatus with its back surface facing up. Next, in a state where the wafer is sucked and fixed by the vacuum suction table, the grinding liquid is supplied onto the wafer from the grinding liquid supply unit, and the wafer is ground to a predetermined thickness by a rotating grindstone. If necessary, after grinding with a rotating grindstone, finish grinding is subsequently performed to smoothly finish the ground surface of the wafer.
The wafer thus ground is thinned to a thickness of, for example, 50 to 400 μm, more preferably 50 to 150 μm.

(3) Frame Mounting Step Next, a step of mounting the back surface of the wafer in the ring frame with a dicing tape (frame mounting step) for fixing the wafer in a dicing step described later is performed. In the frame mounting process, first, a ring frame and a dicing tape are prepared.
At least the surface of the ring frame is formed of a non-plating adhesion material in order to suppress the adhesion of plating by a plating process described later. As the non-plating adhesion material, a resin, a hard-plating metal material, or a metal material coated with a resin can be used. The resin is preferably, for example, Teflon (registered trademark), PET, or polyamide. As the hard plating metal material, for example, aluminum, titanium, chromium, stainless steel, or the like can be used. The ring frame is more preferably made of resin from the viewpoint of lightness and suppression of wafer cracking due to stress (warpage) relaxation. The ring frame is formed in an open circular or polygonal frame shape, for example. The inner diameter of the opening of the ring frame is formed somewhat larger than the wafer diameter.
The dicing tape is provided in order to prevent individual semiconductor chips separated during dicing from being separated, and is required to have sufficient adhesive force or adhesive force to stably hold the semiconductor chip. The dicing tape is composed of, for example, a base film, a film adhesive provided on the base film, and a release material attached on the film adhesive. The substrate film may be any film as long as the plating solution or the plating pretreatment solution does not soak and the plating does not precipitate on the surface. For example, a polyester film, a polyethylene film, a polypropylene film, A vinyl chloride film, a polyethylene terephthalate film, an ethylene-vinyl acetate copolymer film, an ionomer resin film, a polyimide film, or the like is used, and the thickness is preferably about 15 to 100 μm. As the film adhesive, acrylic resin, silicon resin, polyamide resin, polyester resin, polyurethane resin, EVA resin, and the like can be used. As the release material, for example, a polyester film or a release paper can be used. The thickness of the dicing tape is, for example, 50 to 150 μm.

  On the other hand, a wafer mounting apparatus is prepared. Any type of wafer mount apparatus may be used. The wafer mount device, for example, a stage on which a wafer and a ring frame are placed, a dicing tape supply unit that sequentially feeds dicing tape to the stage and affixes the wafer and ring frame, and cuts the fed dicing tape into a predetermined length. It consists of a tape cut part and so on.

Subsequently, the ring frame is placed on the stage of the wafer mount apparatus. Next, the thinned wafer is washed with pure water and dried, and then placed on the stage of the wafer mount apparatus with the back side facing up and in the ring frame. Next, the dicing tape with the release material peeled off is sent out from the dicing tape supply unit of the wafer mount device, and is placed on the wafer and ring frame on the stage and pressed and bonded. At this time, the dicing tape is cut at a predetermined length by the tape cut portion. At this time, care should be taken not to generate a gap between the wafer and the dicing tape or sagging of the dicing tape.
Note that the dicing tape may be attached by other than pressure bonding, for example, by using a predetermined adhesive on the dicing tape, by heat bonding, UV light curing bonding, or the like.

(4) Wafer Surface Protection Tape Peeling Step Next, the wafer is provided on a predetermined stage with the surface of the wafer to which the dicing tape is attached facing upward. Subsequently, a peeling tape is attached to the wafer surface protective tape on the wafer surface, and the wafer surface protective tape is peeled off from the wafer together with the peeling tape. At this time, it is preferable that no adhesive remains.

(5) Plating process for forming electrode metal on the wafer surface Subsequently, the wafer surface fixed together with the ring frame with a dicing tape is plated. The plating treatment is not particularly limited, but it is necessary to be able to form a metal film on a nonconductive base such as a wafer. As such, an electroless plating treatment is more preferable.

  When performing the electroless plating process, first, a process of cleaning is necessary as a process of the surface to be plated of the wafer. The cleaning process may be a dry process or a wet process. In the case of dry processing, ashing processing, UV processing, reactive ion etching processing, and the like are preferable. In the case of wet processing, either the dipping method or the spin coating method may be used, but it is more preferable that the dipping method is used because batch processing is possible. Examples of the wet treatment include ultrasonic cleaning in water, immersion in an alkali or acidic degreasing solution, immersion in a surfactant aqueous solution, and immersion in a soft etching solution. Examples of the wet treatment include treatment with a commercially available acid degreasing solution, alkaline degreasing solution, and soft etching solution, and the use of these is preferable in that the treatment becomes simple. These treatments may be used alone or in combination, and it is desirable to select an optimum treatment method depending on the degree of contamination of the wafer and the type of passivation.

  After the above-described cleaning, subsequently, a metal compound having a catalytic activity when depositing metal on the wafer surface from the electroless plating solution is treated. Examples of such a metal compound include a palladium compound and a zinc compound. With respect to the palladium compound, examples include palladium chlorides, hydroxides, oxides, sulfates, ammonium salts and the like that exhibit a catalytic effect. The palladium compound is used as an aqueous solution or an organic solvent solution. As the organic solvent, for example, methyl alcohol, ethyl alcohol, isopropanol, acetone, methyl ethyl ketone, toluene, ethylene glycol, polyethylene glycol, dimethylformamide, dimethyl sulfoxide, dioxane and the like, and mixtures thereof can be used. The palladium compound is more preferably used as an aqueous solution in view of a series of treatments. Moreover, a zinc compound is common as a zincate treatment, and a commercially available chemical can be used.

After the above-described metal compound treatment, the wafer is immersed in an electroless plating solution to perform an electroless plating treatment. Electroless plating may be by substitution or by reduction. The electroless plating solution contains a metal ion source for forming a desired plating in the form of, for example, a sulfate or a chloride. In addition, electroless plating solutions include reducing agents such as formaldehyde, hydrazine, sodium hypophosphite, sodium borohydride, ascorbic acid, glyoxylic acid, sodium acetate, EDTA, tartaric acid, malic acid, citric acid, glycine, etc. Complexing agents, precipitation control agents and the like are included.
The electroless plating solution can be a commonly used pH adjusting agent such as sodium hydroxide or potassium hydroxide, but it is necessary to avoid alkali metals such as sodium and potassium in semiconductor applications. Is preferably tetramethylammonium hydroxide.
By the above-described steps, the electroless plating process can be performed on the wafer surface, and for example, a Ni / Au, Ni / Pd, Ni / Pd / Au coating or the like can be formed on the wafer surface.

  In the above-described process, a dicing tape is attached to the back surface of the wafer. For this reason, adhesion to the wafer back surface of plating is suppressed. Further, since the wafer is fixed together with the ring frame by the dicing tape, the warping of the wafer is satisfactorily suppressed during the plating process, and the damage of the wafer is suppressed. In addition, since it is not necessary to fix the wafer using a plating jig to prevent plating from adhering to the back surface of the wafer, it does not require as much space and manufacturing efficiency is improved. Similarly, it is not necessary to form a protective film such as a resist to prevent plating from adhering to the back surface of the wafer, and therefore the protective film does not wrap around the wafer surface. Furthermore, similarly, since it is not necessary to apply a protective tape to prevent plating from adhering to the back surface of the wafer, the wafer does not warp and the wafer is not damaged when the tape is peeled off.

  In addition, in the said process, although the electroless-plating process was performed as a plating process, it is not restricted to this. As other plating treatments, dry plating may be used. For example, vacuum evaporation in which a plating metal is heated and evaporated using an electron beam or resistance heating in vacuum to form a plating film, or physical vapor deposition in which a plating film is formed by accelerated collision of ionized plating metal by sputtering or the like ( PVD) and chemical vapor deposition (CVD) for forming a plating film by thermal decomposition or hydrogen reduction reaction between a volatile metal compound and a reducing gas may be used.

(6) Dicing process Next, a dicing apparatus is prepared. The dicing apparatus includes a dicing table having a suction unit, a dicing saw, and the like. The dicing saw is composed of, for example, an extremely thin circular blade with diamond fine particles attached thereto. Note that the wafer may be cut using a laser instead of the dicing saw.
Subsequently, the wafer attached to the dicing tape together with the ring frame and plated on the surface as described above is placed on the dicing table of the dicing apparatus with the surface facing upward, and the vacuum suction of the suction portion To fix.
Next, the wafer in the ring frame is cut vertically and horizontally from the surface side by a dicing saw to obtain individual chips. Since the individual chips after being cut are fixed by a dicing tape, they are kept in an aligned state.

(7) Chip Separation Step Next, if necessary, a wafer test apparatus is prepared, and the wafer that is attached to the dicing tape together with the ring frame and diced as described above is placed on the table of the apparatus. . Subsequently, the individual chips determined as non-defective products by the wafer test apparatus are separated from the dicing tape and picked up, thereby separating each chip from the wafer. At this time, it is preferable that the adhesive does not adhere to the chip.

  Subsequently, each chip separated as described above is mounted at a predetermined position on the circuit board, and a desired semiconductor device is manufactured by connecting each chip to the metal wiring of the circuit board.

(Embodiment 2)
Next, a method for manufacturing a semiconductor device according to Embodiment 2 of the present invention will be described. The method for manufacturing a semiconductor device according to the second embodiment includes at least the following steps (1) to (7) in this order.
(1) Half-cut dicing process (2) Wafer surface protective tape attaching process (3) Wafer back gliding process (4) Frame mounting process (5) Wafer surface protective tape peeling process (6) Metal for electrodes on wafer surface (7) Chip separation process

(1) Half-cut dicing process First, the same wafer and dicing apparatus as those in the first embodiment are prepared. Next, the wafer is placed on the dicing table of the dicing apparatus with the surface facing up and fixed by vacuum suction of the suction portion. Subsequently, the wafer surface is cut vertically and horizontally by a dicing saw. The cut is formed, for example, to a depth that is about half the thickness of the wafer.

(2) Wafer Surface Protection Tape Affixing Step Next, a wafer surface protection tape having the same configuration as that of the first embodiment is affixed to the surface of the wafer in which cuts are formed in the vertical and horizontal directions in the same manner as in the first embodiment.

(3) Wafer Back Gliding Step Next, a back gliding apparatus similar to that of the first embodiment is prepared. Next, the wafer on which the wafer surface protection tape is attached is provided on the vacuum suction table of the back gliding apparatus with its back surface facing up. Next, the wafer is ground by the same method as in the first embodiment, and is thinned to a thickness of, for example, 50 to 200 μm, more preferably 50 to 150 μm.

(4) Frame Mounting Step Next, the same ring frame, dicing tape, and wafer mount apparatus as those of the first embodiment are prepared, and the wafer provided in the ring frame and the ring frame is prepared from the back side of the wafer by the same method. Apply dicing tape.

(5) Wafer Surface Protection Tape Peeling Step Next, the wafer is provided on a predetermined stage with the surface of the wafer to which the dicing tape is attached facing upward. Subsequently, a peeling tape is attached to the wafer surface protective tape on the wafer surface, and the wafer surface protective tape is peeled off from the wafer together with the peeling tape.

(6) Plating Process for Forming Electrode Metal on Wafer Surface Next, the wafer surface protective tape is peeled off, and the surface of the wafer to which the dicing tape is attached together with the ring frame is combined with the first embodiment. A plating film is formed using an electroless plating process having the same configuration.
Also in the second embodiment, since the back surface of the wafer is fixed together with the ring frame by the dicing tape, the adhesion of the plating to the back surface of the wafer and the warpage of the wafer are well suppressed, and the damage to the wafer is suppressed. In addition, since it is not necessary to fix the wafer using a plating jig to prevent plating from adhering to the back surface of the wafer, it does not require as much space and manufacturing efficiency is improved. Similarly, it is not necessary to form a protective film such as a resist to prevent plating from adhering to the back surface of the wafer, and therefore the protective film does not wrap around the wafer surface. Furthermore, similarly, since it is not necessary to apply a protective tape to prevent plating from adhering to the back surface of the wafer, the wafer does not warp and the wafer is not damaged when the tape is peeled off.

(7) Chip separation step Next, a predetermined pressing device is prepared. Subsequently, the plating film is formed on the surface as described above, and the wafer attached to the dicing tape together with the ring frame is pressed by a pressing device. Since the wafer is preliminarily formed with a cut and cut in a half-cut dicing process, the wafer is separated into individual chips from the cut by this pressing.
Next, if necessary, a wafer test apparatus is prepared, and individual chips determined as non-defective products by the wafer test apparatus are peeled off from the dicing tape and picked up to separate each chip from the wafer.

  Subsequently, each chip separated as described above is mounted at a predetermined position on the circuit board, and a desired semiconductor device is manufactured by connecting each chip to the metal wiring of the circuit board.

(Embodiment 3)
Next, a method for manufacturing a semiconductor device according to Embodiment 3 of the present invention will be described. The method for manufacturing a semiconductor device according to the third embodiment includes at least the following steps (1) to (7) in this order.
(1) Wafer surface protection tape attaching process (2) Wafer back gliding process (3) Frame mounting process (4) Wafer surface protection tape peeling process (5) Dicing process (6) Forming electrode metal on wafer surface (7) Chip separation process

(1) Wafer Surface Protection Tape Affixing Step First, a wafer and a wafer surface protection tape having the same configuration as in the first embodiment are prepared, and the wafer surface protection tape is affixed to the surface of the wafer in the same manner as in the first embodiment.

(2) Wafer Back Gliding Step Next, a back gliding apparatus similar to that of the first embodiment is prepared. Next, the wafer on which the wafer surface protection tape is attached is provided on the vacuum suction table of the back gliding apparatus with its back surface facing up. Next, the wafer is ground by the same method as in the first embodiment, and is thinned to a thickness of, for example, 50 to 200 μm, more preferably 50 to 150 μm.

(3) Frame mounting step Subsequently, the same ring frame, dicing tape, and wafer mounting apparatus as those of the first embodiment are prepared, and the wafer provided in the ring frame and the ring frame is prepared by the same method as that of the first embodiment. Affix the dicing tape from the back side.

(4) Wafer Surface Protection Tape Peeling Step Next, the wafer is provided on a predetermined stage with the surface of the wafer to which the dicing tape is attached facing upward. Subsequently, a peeling tape is attached to the wafer surface protective tape on the wafer surface, and the wafer surface protective tape is peeled off from the wafer together with the peeling tape.

(5) Dicing Step Subsequently, a dicing apparatus similar to that of the first embodiment is prepared, and the wafer attached to the dicing tape together with the ring frame is placed on the dicing table of the dicing apparatus with the surface facing up. Fix by vacuum suction of the suction part.
Next, the wafer in the ring frame is cut vertically and horizontally from the surface side by a dicing saw to obtain individual chips. Since the individual chips after being cut are fixed by a dicing tape, they are kept in an aligned state.

(6) Plating process for forming electrode metal on the wafer surface Next, the wafer surface protective tape is peeled off, and a dicing tape is applied together with the ring frame, and further cut into individual chips by dicing. A plating film is formed on the surface of the wafer using electroless plating treatment having the same configuration as in the first embodiment.
Also in the third embodiment, since the back surface of the wafer cut into individual chips is fixed together with the ring frame by the dicing tape, the adhesion of the plating to the back surface of the wafer and the warpage of the wafer are well suppressed. Damage is suppressed. In addition, since it is not necessary to fix the wafer using a plating jig to prevent plating from adhering to the back surface of the wafer, it does not require as much space and manufacturing efficiency is improved. Similarly, it is not necessary to form a protective film such as a resist to prevent plating from adhering to the back surface of the wafer, and therefore the protective film does not wrap around the wafer surface. Furthermore, similarly, since it is not necessary to apply a protective tape to prevent plating from adhering to the back surface of the wafer, the wafer does not warp and the wafer is not damaged when the tape is peeled off.

(7) Chip Separation Step Next, if necessary, a wafer test apparatus is prepared, and the wafer that is attached to the dicing tape together with the ring frame and diced as described above is placed on the table of the apparatus. . Subsequently, the individual chips determined as non-defective products by the wafer test apparatus are separated from the dicing tape and picked up, thereby separating each chip from the wafer. At this time, it is preferable that the adhesive does not adhere to the chip.

  Subsequently, each chip separated as described above is mounted at a predetermined position on the circuit board, and a desired semiconductor device is manufactured by connecting each chip to the metal wiring of the circuit board.

(Other embodiments)
Further, the embodiment of the present invention is not limited to the above-described Embodiments 1, 2, and 3, but a frame mounting process using a ring frame is provided between the wafer thinning process and the plating process. Any form can be used.

  EXAMPLES Examples of the present invention will be described below, but these are provided for better understanding of the present invention and are not intended to limit the present invention.

Example 1
Backgrinding tape was applied to the surface of an 8-inch wafer, and the backside of each wafer was backgrounded to a thickness of 50, 100, 150, and 200 μm. Next, prepare resin ring frames that are slightly larger in diameter than each wafer, provide the wafer in the ring frame on the stage of the wafer mount device, and attach the dicing tape to the back side of the ring frame and wafer. It was.

  Next, the back grinding tape on the wafer surface attached to the dicing tape together with the ring frame was peeled off. At this time, there was no adhesive remaining on the back grinding tape. Thereafter, electroless plating treatment was performed, and wafers with thicknesses of 50, 100, 150 and 200 μm were formed with plating coating thicknesses of 1, 5 and 10 μm, respectively. Further, as an electroless plating treatment step, each step of alkali degreasing → soft etching → zincate treatment → electroless Ni plating (various film thicknesses) → electroless Au plating (film thickness 0.05 μm) was performed.

  As a result of the above plating treatment, all of the plating films formed on each wafer had a uniform thickness. Moreover, each test result shown in the following Table 1 was obtained.

In the wafer according to Example 1, wafer distortion (wafer warpage) was slightly observed, but all could be electrolessly plated without any problem.
Furthermore, when these wafers that have been plated and attached to the dicing tape together with the ring frame are diced, they can be cut without any problem and separated into individual chips without any adhesive residue. I was able to.

(Example 2)
An 8-inch wafer is placed on a dicing table of a dicing apparatus with the surface facing upward, fixed by vacuum suction of the suction portion, and the wafer is vertically and horizontally placed on the wafer surface along a scribe line by a dicing saw. Half-cut dicing was performed by making a cut that was approximately half the thickness. Next, a back grinding tape was applied to the front surface of the wafer, and the back surface of each wafer was back grounded to a thickness of 50, 100, 150, and 200 μm. Furthermore, a resin ring frame having a diameter slightly larger than each wafer was prepared, a wafer was provided in the ring frame on the stage of the wafer mount device, and a dicing tape was attached to the ring frame and the wafer on the back side. .

  Next, the back grinding tape on the wafer surface attached to the dicing tape together with the ring frame was peeled off. At this time, there was no adhesive remaining on the back grinding tape. Then, the electroless plating process of the structure similar to Example 1 was performed.

  As a result of the above plating treatment, all of the plating films formed on each wafer had a uniform thickness. Moreover, each test result shown in the following Table 2 was obtained.

All of the wafers according to Example 2 could be subjected to electroless plating without problems.
Furthermore, when these wafers that have been plated and attached to the dicing tape together with the ring frame are pressed with a pressing device, any of them can be separated into individual chips without any problem, and there is no adhesive remaining. I was able to pick up.

(Example 3)
Backgrinding tape was applied to the surface of an 8-inch wafer, and the backside of each wafer was backgrounded to a thickness of 50, 100, 150, and 200 μm. Next, prepare resin ring frames that are slightly larger in diameter than each wafer, provide the wafer in the ring frame on the stage of the wafer mount device, and attach the dicing tape to the back side of the ring frame and wafer. It was.

  Next, the back grinding tape on the wafer surface attached to the dicing tape together with the ring frame was peeled off. At this time, there was no adhesive remaining on the back grinding tape. Next, the wafer was cut into individual chips by dicing. Then, the electroless plating process of the structure similar to Example 1 was performed.

  As a result of the above plating treatment, all of the plating films formed on each wafer had a uniform thickness. Moreover, each test result shown in the following Table 3 was obtained.

All the wafers according to Example 3 could be subjected to electroless plating without any problem.
Furthermore, the individual chips that were plated and adhered to the dicing tape together with the ring frame could be picked up without any adhesive remaining.

(Comparative example)
A wafer similar to that used in Example 1 was prepared. Next, the backside of each wafer was back grounded to a thickness of 50, 100, 150 and 200 μm. Next, a wafer was provided on the stage of the wafer mount apparatus without using a ring frame, and a dicing tape was attached from the back side.

  Next, the surface of the wafer attached to the dicing tape was subjected to the same electroless plating treatment as in Example 1, and the thickness of the plating film was 1 for each of the wafers having thicknesses of 50, 100, 150 and 200 μm. Those of 5 and 10 μm were formed.

  All of the plating films formed on the wafers according to the comparative examples were warped, making it difficult to process a plurality of wafers at a time in the subsequent steps. In addition, a wafer having a plating film thickness of 5 and 10 μm is difficult to handle in subsequent processes. Particularly, a wafer having a thickness of 150 μm or less and a plating film having a thickness of 10 μm was damaged (cracked) after the plating was formed.

Claims (7)

Process 1 for thinning the wafer,
Mounting the back surface of the thinned wafer in a ring frame with dicing tape, and
Step 3 of plating the surface of the wafer mounted in the ring frame
A method for manufacturing a semiconductor device comprising:   The method for manufacturing a semiconductor device according to claim 1, wherein the plating process is an electroless plating process.   The method of manufacturing a semiconductor device according to claim 1, wherein a thickness of the thinned wafer is 150 μm or less.   The method of manufacturing a semiconductor device according to claim 1, wherein at least a surface of the ring frame is formed of a non-plating adhesion material.   The method of manufacturing a semiconductor device according to claim 4, wherein the non-plating adhesion material is a resin or a metal coated with a resin.   The method for manufacturing a semiconductor device according to claim 5, wherein the resin is Teflon, PET, or polyamide. A step of forming a protective member on the surface of the wafer, which is performed before the step 1, and
The method for manufacturing a semiconductor device according to claim 1, further comprising a step of removing the protective member performed between the step 2 and the step 3.