JP4341343B2 - Surface protective film and manufacturing method thereof - Google Patents

Description

  The present invention relates to a surface protective film, particularly a surface protective film for protecting a surface of a semiconductor element applied to a semiconductor device having a face-down structure in which a circuit surface is arranged toward a semiconductor wiring board, and the surface protective film. The present invention relates to a manufacturing method and a semiconductor element having a surface protected by using the surface protective film.

  Conventionally, electronic devices have been reduced in size and weight, and accordingly, high-density mounting of semiconductor devices on a substrate has been demanded, and semiconductor packages mounted on electronic devices have been reduced in size and weight. .

  There are various types of semiconductor packages as the times change, and there are packages called LOC (Lead On Chip), QFP (Quad Flat Package), etc., for example, DRAMs of 16M and later use LOC packages. .

  Normally, identification information such as a lot number and a manufacturer name is printed on the package to identify the product, so that the history of the product can be determined. In the case of a package such as LOC or QFP, identification information for identifying a product is directly laser-marked on a sealing material formed on the outer surface of the package.

  As lasers used for laser marking, there are a carbon dioxide gas laser and a YAG laser. When laser marking is performed on a sealing material, a YAG laser is mainly used.

  In recent years, semiconductor packages have been further reduced in size and weight, such as CSP (Chip Size Package) and μBGA (Ball Grid Array), which are further downsized and lighter than packages such as LOC and QFP described above. Package development is underway. In such a package, since the wiring for connecting the semiconductor element and the substrate is arranged at the center of the semiconductor element and only that part is sealed, the entire conventional semiconductor element is sealed with a sealing material. Compared to the shape, the package can be further reduced in size and weight.

  However, the above-described packages such as CSP and μBGA can be reduced in size and weight, but the semiconductor element is a face-down type, that is, the circuit surface of the semiconductor element is directed to the semiconductor wiring substrate side. Since the back surface of the semiconductor element is exposed at the upper part of the package, there is a problem that the end of the semiconductor element is chipped when the package is manufactured or the package is transported.

  Further, regarding the marking, in particular, some packages such as CSP have a shape in which the semiconductor element is not sealed with a sealing material. Therefore, the semiconductor element is directly laser-marked or directly applied to the semiconductor element. It is necessary to print identification information for discriminating products by printing.

  However, when laser marking is directly performed on the semiconductor element, a clear contrast between the semiconductor element and the marked identification information cannot be obtained, and thus there is a problem that the identification is low and the visibility is poor.

  When the identification information is marked by printing directly on the semiconductor element, the identification information can be clearly displayed on the semiconductor element, so that there is an advantage that the distinction between the semiconductor element and the identification information is high. However, since printing has a large number of processes, there is a problem that the working time for printing the identification information is greatly increased.

  As a method for solving these problems, there is a method of attaching a colored film such as black to which a colorant is added to the surface of a semiconductor element and laser marking the film. According to this method, the film can prevent chipping of the surface of the semiconductor element, and the colored film to which the colorant is added has a feature that the laser mark can be easily recognized. It is difficult to detect defects in the film itself, the surface of the semiconductor element to which the film having the defect is attached becomes defective, and as a result, the reliability of the semiconductor package may be lowered. That is, it has been clarified that a semiconductor device using a normal semiconductor element becomes defective due to the use of a film having a defect and may cause a significant increase in manufacturing cost (see, for example, Patent Document 1). ).

As a means to solve this problem, the surface protection film is inspected for foreign matter, dust, etc. in the manufacturing process of the surface protection film, and the surface with high reliability is removed by removing the surface protection film in which foreign matter is found to be mixed There is a method for producing a protective film. Generally, the surface protective film is composed of a resin layer that protects the surface of the semiconductor element and other layers such as a base material layer that supports the resin layer. Conventionally, defects in the resin layer of the surface protection film are detected and recognized by image processing, such as detecting abnormalities in the transmitted light, but they contain colorants and contain light transmittance. In the case of a low film, it is difficult to detect by a conventional method. Further, when trying to visually inspect, it is difficult to observe a minute foreign substance having a size of about 20 μm, and it is not desirable to precisely inspect it using a large-scale apparatus. Inspecting the foreign matter on the surface protective film leads to an increase in film production time and an increase in cost. Therefore, a means for easily inspecting the presence of foreign matter and the like has been demanded.
JP 2002-280329 A

  The present invention has been made in order to solve the above-described problems, and an object of the present invention is to easily obtain a surface protective film having excellent protection characteristics on the surface of a semiconductor element and visibility by laser marking and having few defects. Furthermore, it aims at providing the semiconductor element which protected the surface by the method of manufacturing the said surface protection film, and the said surface protection film.

  The inventors of the present invention have made various studies in order to solve the above-mentioned object, and in the inspection of the surface protection film, do not observe the foreign matter itself, but observe the voids in the surface protective film caused by the inclusion of the foreign matter. Thus, it has been found that it is possible to easily observe whether or not craters, voids, dust and the like are present in the resin layer or on the surface of the resin layer.

  The present invention is a surface protective film in which a base material layer, a resin layer, and a film for defect recognition are laminated in this order, and the surface of a semiconductor element is protected by laminating the film on a surface without a circuit of the semiconductor element. By using an opaque film to which a colorant is added, it is possible to provide a surface protection film having excellent laser marking visibility and having a film defect of a certain amount or less by a simple inspection method. is there. According to such a surface protective film, it is possible to reduce the occurrence of defects in the semiconductor device.

  In addition to the above-described effects, the present invention provides a fine foreign matter that has little influence on reliability degradation by laminating a film for defect recognition in an appropriate temperature and pressure range when producing a surface protective film. Is provided in a resin layer, and it is possible to provide a method that enables only foreign matters exceeding 20 μm, which have an influence on reliability reduction, to be detected as voids. According to such a method, since the site | part with low reliability of a surface protection film can be detected reliably without waste, it becomes possible to provide a highly reliable surface protection film at low cost.

  Furthermore, this invention provides the said surface protection film which can aim at simplification of the process at the time of assembling a semiconductor device, and the semiconductor element using the said surface protection film.

  According to the present invention, the following solutions are provided.

1. A surface protective film having a structure in which a base material layer, a resin layer, and a defect recognition film are laminated in this order, wherein the resin layer contains a colorant and transmits light in a wavelength region of 300 to 1100 nm. A surface protective film having a rate of 10% or less, and the number of voids having a diameter of 100 μm or more contained between the defect recognition film and the resin layer is 100 or less per 1 m ² .

  2. The said surface protection film whose thickness of the film for defect recognition is 5-300 micrometers, and whose storage elastic modulus in room temperature is 1-3000 MPa.

  3. It is a manufacturing method of the said surface protection film, Comprising: The said resin layer on the conditions of the temperature of 20 to 140 degreeC, the pressure of 0.01 to 100 MPa, or the temperature of 20 to 140 degreeC, and the linear pressure of 0.1 to 500 N / cm The manufacturing method of the surface protection film including the process of laminating | stacking the said film for defect recognition on it.

4). (1) A surface protection film in which a base material layer, a resin layer, and a film for defect recognition are formed in this order is a semiconductor in which the surface of the semiconductor layer is not in contact with the surface of the semiconductor layer after the base material layer is peeled off. Laminating to wafer,
(1-2) Step of peeling the film for defect recognition,
(1-3) laminating a dicing tape on the surface of the resin layer laminated on the semiconductor wafer;
(2) a step of dicing the semiconductor wafer into a predetermined size to obtain a semiconductor element;
(2-2) a step of reducing the adhesive force between the dicing tape and the resin layer;
(3) The process of peeling between a resin layer and a dicing tape, and obtaining the semiconductor element with a resin layer,
The said surface protection film used for the manufacturing method of the semiconductor device containing this.

5. (1) After the base material layer is peeled off, the resin layer surface and the surface without the circuit of the semiconductor wafer come into contact with the surface protective film in which the base material layer, the resin layer, and the adhesive defect recognition film are formed in this order. And laminating to the semiconductor wafer,
(2) a process of obtaining a semiconductor element by dicing a semiconductor wafer into a predetermined size using a defect recognition film;
(2-2) A step of reducing the adhesive force between the film for recognizing a defect having tackiness and the resin layer,
(3) The process of peeling between a resin layer and a film for defect recognition, and obtaining the semiconductor element with a resin layer,
The said surface protection film used for the manufacturing method of the semiconductor device containing this.

  6). The semiconductor element which protected the surface using the said surface protection film.

  ADVANTAGE OF THE INVENTION According to this invention, the surface protection film which is excellent in the protection characteristic of the surface of a semiconductor element and the visibility by laser marking, and there are few defects can be obtained easily. Moreover, according to one embodiment of the present invention, the defect recognition film can be used as a dicing tape, and the semiconductor element manufacturing process can be simplified. By using such a surface protective film, it is possible to obtain a semiconductor element that does not cause defects such as chipping on the element surface, has excellent visibility after laser marking, and has excellent reliability such as heat resistance. is there.

  One embodiment of the surface protective film of the present invention is shown in FIG. The surface protective film 1 of the present invention is a film in which the base layer 2, the resin layer 3, and the defect recognition film 4 are essential, and the base layer 2, the resin layer 3, and the defect recognition film 4 are laminated in this order. As long as the order of lamination is as described above, other arbitrary layers may be provided above and below each layer. Hereinafter, each layer which comprises the surface protection film of this invention is demonstrated.

<Base material layer>
As a base material layer used for the surface protection film of this invention, if a resin layer can be hold | maintained, a conventionally well-known thing can be used without being restrict | limited especially.

  Examples of the base material layer include plastic films such as a polytetrafluoroethylene film, a polyethylene terephthalate film, a polyethylene film, a polypropylene film, a polymethylpentene film, and a polyimide film. Further, surface treatment such as primer coating, UV treatment, corona discharge treatment, polishing treatment, etching treatment, mold release treatment and the like may be performed as necessary. As for the thickness of a base material layer, 5-250 micrometers is preferable, and it is preferable that a base material layer is transparent.

  Further, in <Use method> 1) and the like to be described later, when the resin layer is heat-cured before peeling the base material layer, it is preferable to use a heat resistant film as the base material layer.

<Resin layer>
The resin layer used in the film of the present invention contains a colorant and has a light transmittance of 10% or less in a wavelength region of 300 to 1100 nm, and the resin layer has an appropriate tack strength. It is preferable to have. The resin layer preferably contains a thermosetting component and a high molecular weight component from the viewpoint of the reliability of the semiconductor device. In addition to the above, a curing accelerator, a catalyst, an additive, a coupling agent and the like may be included.

  Examples of the thermosetting component include an epoxy resin, an isocyanate resin, a phenol resin, and a curing agent thereof, and it is preferable to use an epoxy resin in terms of high heat resistance. The epoxy resin is not particularly limited as long as it is cured and has an adhesive action. Bifunctional epoxy resins such as bisphenol A type epoxy resins, novolac type epoxy resins such as phenol novolac type epoxy resins and cresol novolak type epoxy resins, and the like can be used. Moreover, what is generally known, such as a polyfunctional epoxy resin, a glycidyl amine type epoxy resin, a heterocyclic ring-containing epoxy resin, or an alicyclic epoxy resin, can be applied.

  Examples of the high molecular weight component include polyimide resins, (meth) acrylic resins, urethane resins, polyphenylene ether resins, polyetherimide resins, phenoxy resins, and modified polyphenylene ether resins. It is not limited to.

  The resin layer of the present invention contains a colorant, and has a light transmittance of 10% or less in a wavelength region of 300 to 1100 nm. For this purpose, the resin component and the colorant preferably have a fine phase separation structure. . The light transmittance of the resin layer of the present invention is preferably 5% or less, and more preferably opaque. If the light transmittance exceeds 10%, the visibility by laser marking may be lowered, or the circuit on the semiconductor element may be damaged by the light transmitted through the semiconductor wafer. In the present invention, the light transmittance of the resin layer is measured by an ultraviolet spectrophotometer and a visible light-near infrared spectrophotometer. The measurement of the light transmittance may be performed in a state where a resin layer is laminated on a transparent base material layer, or may be performed in a state where the base material layer and the resin layer are peeled off.

  Examples of the colorant contained in the resin include carbon black, graphite, titanium carbon, manganese dioxide, phthalocyanine-based pigments and dyes. It is preferable to use a colorant other than white as the colorant, and it is more preferable to use a black colorant. The colorant may be directly dispersed and mixed in the resin, or a resin prepared in advance or dispersed in a solvent may be added to the resin. The content of the colorant contained in the resin layer is preferably 0.2 to 15% by weight, more preferably 0.5 to 5% by weight, based on the weight of the entire resin layer. When the content of the colorant is less than 0.2% by weight, the resin layer is not colored and the visibility after laser marking is worsened. Conversely, when the content of the colorant exceeds 15% by weight, the ionicity This is because problems such as an increase in impurities, a decrease in film ductility, or a decrease in adhesive strength with semiconductor elements occur.

  Further, since the laser used for laser marking is often a YAG laser, it is preferable to use carbon black that is easily volatilized by the YAG laser as a colorant.

  Furthermore, you may contain a filler for the purpose of the transmittance | permeability fall of resin, the improvement of mechanical strength, and the improvement of laser marking property. Examples of the filler include crystalline silica, amorphous silica, aluminum oxide, calcium carbonate, magnesium carbonate, aluminum nitride, and boron nitride. As the filler, it is preferable to use a white filler. Moreover, when it contains a filler, it is preferable to set it as 1-90 weight% with respect to the weight of the whole resin layer, and it is preferable to set it as 5-70 weight% especially. When the filler content is less than 1% by weight, the contrast between the laser marking and the surroundings is reduced, and when the filler content exceeds 90% by weight, the resin layer becomes brittle and the formability of the surface protection film is reduced. This is because problems such as a decrease in adhesive strength with the silicon wafer may occur.

  Moreover, the ratio of the coloring agent and filler in a resin layer can be adjusted suitably. For example, if the marking is faint, the content of the colorant may be increased. If the contrast is insufficient, the content of the filler may be increased. Further, when soot is likely to appear, laser marking can be performed by reducing the content of the colorant.

  The thickness of the resin layer is not particularly limited, but is preferably 5 to 250 μm, and more preferably 10 to 100 μm. If the thickness is less than 5 μm, the protective effect of the semiconductor element tends to be poor. If the thickness is more than 250 μm, it is not economical and the demand for miniaturization of the semiconductor device cannot be met.

<Defect recognition film>
Moreover, as a film for defect recognition, plastic films, such as a polytetrafluoroethylene film, a polyethylene terephthalate film, a polyethylene film, a polypropylene film, a polymethylpentene film, a polyimide film, etc. are mentioned, for example. Further, surface treatment such as primer coating, UV treatment, corona discharge treatment, polishing treatment, etching treatment, mold release treatment and the like may be performed as necessary. From the viewpoint of easily recognizing a defective portion, a cloudy film is preferable, and the visible light transmittance of the film is preferably 3 to 80%. The film may contain a white colorant such as a pigment and a dye, the above-mentioned white filler, and the like. In the present invention, it is preferable to use a cloudy polyethylene film.

  For example, in 2) of <Use method> mentioned later, when heat-hardening of a resin layer is performed before peeling a film for defect recognition, it is preferable to use a heat resistant film as a film for defect recognition.

  Furthermore, for example, in 5) of <Usage method>, when using the film for defect recognition as a dicing tape, it is preferable that the film for defect recognition has adhesiveness. As the film for recognizing defects having tackiness, a film obtained by imparting tackiness to the above-mentioned plastic film, or a film provided with an adhesive layer on both sides or one side of the above-mentioned plastic film can be used.

  As an adhesive layer, it has sufficient adhesiveness required when using a film for defect recognition as a dicing sheet, and it is possible to reduce adhesiveness by at least one of heating and radiation irradiation. Any known one can be used without particular limitation. As the pressure-sensitive adhesive layer, for example, a mixture of a high molecular weight component such as acrylic rubber, natural rubber, nitrile butadiene rubber and a tackifier can be used.

  A commercially available adhesive tape may be used as the defect-recognizing film having adhesiveness. In particular, it is preferable to use a dicing tape in terms of good workability such as picking up a semiconductor element. As the dicing tape, any known dicing tape can be used without particular limitation as long as it can be peeled off from the resin layer by at least one of heating and radiation irradiation.

  In this invention, a foreign material is recognized as a space | gap by laminating | stacking the film for defect recognition on the surface of a resin layer. The relationship between the size of the foreign matter and the size of the gap is also affected by the thickness, elastic modulus, etc. of the defect recognition film used. In this invention, it is preferable that the thickness of the film for defect recognition is 5-300 micrometers, It is more preferable that it is 10-100 micrometers, It is further more preferable that it is 10-50 micrometers. Further, the storage elastic modulus of the defect recognition film at room temperature is preferably 1 to 3000 MPa, and it is difficult for foreign matter to be embedded in the defect recognition film, that is, the foreign matter is easily observed as a void, or the defect recognition. More preferably, it is 5-1000 MPa, More preferably, it is 5-500 MPa, Most preferably, it is 10-200 MPa at the point which the curvature of the surface protection film when laminating the film for an operation is small. When the thickness of the film for defect recognition is less than 5 μm, or when the storage elastic modulus at room temperature is less than 1 MPa, foreign matter tends to be difficult to be observed as larger voids. In addition, the storage elastic modulus in this invention is the value measured on the conditions of 25 degreeC and 10 Hz about the sample of length 20mm and width 5mm using the dynamic viscoelasticity measuring apparatus.

<Manufacturing method>
The surface protective film of the present invention can be obtained by laminating a resin layer on a base material layer according to a conventionally known method, and further laminating a defect recognition film on the resin layer.

  The resin layer can be provided by, for example, applying and drying the resin layer composition directly on the base material layer.

  As a method of laminating a defect recognition film on a resin layer, a method of laminating a defect recognition film can be exemplified, and the lamination conditions are preferably 20 ° C. to 140 ° C. and a pressure of 0.01 to 100 MPa. . When laminating with a hot roll laminator, it is preferably 20 ° C. to 140 ° C. and a linear pressure of 0.1 to 500 N / cm. By laminating the film for defect recognition in the above temperature and pressure range, a fine foreign substance having little influence on the reliability deterioration is embedded in the resin layer, and a foreign substance exceeding 20 μm having an influence on the reliability reduction is detected as a void. It becomes possible.

<Detection of voids>
As described below, the present invention is based on the idea of observing voids caused by mixing of foreign substances, not observing foreign substances themselves in the resin layer or on the resin layer. There are two characteristics. When fillers or pigments are added to the resin layer for the purpose of improving the heat resistance of the resin layer or visibility by laser marking, minute irregularities are easily formed on the surface of the resin layer. Concavities and convexities have no difference in color tone and are difficult to distinguish optically.

  In general, the surface protective film is manufactured in a clean room. However, since the clean room is managed so that dust and the like are not mixed in the clean room, there is almost no large foreign matter or dust. However, since extremely small foreign matter inevitably exists in the clean room, this very small foreign matter may be mixed in the resin layer or on the resin layer.

  The mixing of foreign matter may cause a decrease in the reliability of the surface protection film, but it is difficult to confirm whether or not this minute foreign matter, particularly a foreign matter of 20 μm or less, has entered the surface protective film. is there.

  However, in the present invention, by observing the void after the surface protective film is laminated, the minute foreign matter 5 can be observed as a larger void 6 as shown in FIG. That is, the minute foreign matter 5 itself cannot be observed directly with the naked eye or with a simple microscope, but by providing the defect recognition film 4 on the resin layer 3, a void 6 larger than the foreign matter 5 is generated, and the naked eye or simple With a simple microscope, it is possible to confirm the presence of the foreign material 5 that causes a decrease in the reliability of the semiconductor device. The space | gap 6 can be discovered visually from the surface by which the film 2 for defect recognition of the surface protection film 1 was laminated | stacked.

  When the defect recognition film was laminated on the resin layer as described above to examine how much foreign matter was observed as a void, it was stored as a defect recognition film at a thickness of 25 μm at room temperature. When a slightly cloudy polyethylene film having an elastic modulus of 80 MPa is used, when the size of the gap is 100 μm, the actual size of the foreign matter is 10 to 20 μm, and the size of the foreign matter is 5 to 10 times larger. It was found that it can be observed as a void.

  As a protective film used for a semiconductor element, the presence of foreign matter of about 20 μm tends to reduce the reliability of the semiconductor device. Therefore, if the size of the gap exceeds 100 μm, it can be said that the reliability of the semiconductor device is likely to be lowered as a result.

  The surface protective film of the present invention is a surface protective film having a structure in which a resin layer is formed on one surface of a base material layer and a film for defect recognition is laminated on the resin layer. It is preferable that the number of voids exceeding 100 μm in diameter contained between the film and the film for use is smaller.

As the number of the voids, it is most appropriate to integrate the number of voids existing in the surface protective film 1m ² in terms of few errors, but in the case where the production is not so large, for example, about 0.1 m ² The voids present in the surface protective film having a size of 1 can be integrated and converted to the number per 1 m ² .

The number of voids is required to be 100 or less per 1 m ² in order to ensure the reliability of the semiconductor device, preferably 90 or less, more preferably 80 or less, and further 70 or less. Preferably, 60 or less is particularly preferable, 50 or less is very preferable, 40 or less is very preferable, and 30 or less is most preferable.

  The observation of the voids is preferably performed at the manufacturing stage of the surface protective film, but may be performed at any stage of the manufacturing process of the semiconductor device. When observing voids in the manufacturing stage of a semiconductor device, it goes without saying that the semiconductor device can be manufactured using a surface protective film obtained by cutting out a portion having a predetermined number of voids.

  In the present invention, the presence or absence of a foreign substance that causes a decrease in reliability can be easily determined through observation of a gap. This is extremely groundbreaking.

<How to use>
This surface protective film can be used, for example, by the following methods 1) to 5).

1) The defect recognition film of the surface protective film is peeled off, laminated and adhered to an adherend such as a semiconductor wafer, the remaining base material layer is peeled off, and the resin layer is heated and cured as necessary. Thus, the resin layer can be formed on the adherend. Or you may peel a base material layer, after taking processes, such as heat hardening of a resin layer.

2) The substrate layer of the surface protective film is peeled off, laminated and adhered to an adherend such as a semiconductor wafer, and the remaining defect recognition film is peeled off. If necessary, the resin layer is heated and cured. Thus, the resin layer can be formed on the adherend. Or you may peel the film for defect recognition, after taking processes, such as heat hardening of a resin layer.

3) Moreover, both the base material layer of this surface protection film and the film for defect recognition are peeled off, laminated and adhered to an adherend such as a semiconductor wafer, and if necessary, a process such as heat curing is taken. A resin layer can also be formed on the adherend.

  Moreover, after laminating a resin layer on an adherend such as a wafer by the above method, division processing such as dicing, printing processing such as laser marking, or the like may be performed as necessary.

  Examples including such processing include the following 4) and 5).

4) As shown in FIG. 3, (a) the defect-recognizing film 4 of the surface protective film 1 is peeled off and laminated on the surface of the semiconductor wafer A where no circuit is present, and (b) the remaining substrate. Layer 2 is peeled off. After passing through the heat curing step of the resin layer 3, (c) the dicing tape 7 is laminated so as to be in contact with the resin layer 3. Under the present circumstances, the heat curing of the resin layer 3 is normally performed between 100-220 degreeC. Lamination is usually performed between 20 ° C. and 200 ° C., but 20 ° C. to 130 ° C. is preferable in terms of less warping of the wafer. (D) Subsequently, dicing, cleaning, and drying steps are added to the semiconductor wafer A in this attached state. Furthermore, if necessary, at least one of heating and radiation irradiation is performed to reduce the adhesive force between the dicing tape 7 and the resin layer 3. The heating conditions and radiation irradiation conditions are not particularly limited as long as the adhesive force between the dicing tape 7 and the resin layer 3 is reduced and the semiconductor elements A1, A2, and A3 can be picked up without being damaged. This method can be appropriately determined by those skilled in the art. (E) Thereafter, the semiconductor elements A 1, A 2 and A 3 are picked up using the suction collet 9. The semiconductor elements A1, A2, A3 to be picked up can also be pushed up from the lower surface of the dicing tape 7 by the needle bar 10 as indicated by the phantom lines in the figure. In the above usage method, after the resin layer 3 is heat-cured, a step of printing identification information on the resin layer 3 by laser marking may be performed.

5) As shown in FIG. 4, (a) the base material layer 3 of the surface protective film 1 is peeled off and laminated on the surface of the semiconductor wafer A where no circuit is provided. Here, by using a plastic film having a pressure-sensitive adhesive layer on one side in contact with the resin layer 3 as the defect recognition film 4, (b) dicing and cleaning the semiconductor wafer A in this attached state. A drying step is added. Since the semiconductor wafer A is sufficiently adhered and held on the defect recognition film 4 by the resin layer 3, the semiconductor wafer A will not fall off during the above steps. After dicing, at least one of heating and radiation irradiation is performed as necessary to reduce the adhesive force between the defect recognition film 4 and the resin layer 3. The heating conditions and the irradiation conditions of radiation are not particularly limited as long as the adhesive force between the defect recognition film 4 and the resin layer 3 is reduced and pick-up can be performed without damaging the semiconductor elements A1, A2, and A3. Rather, it can be appropriately determined by a person skilled in the art by a conventionally known method. (C) Thereafter, the semiconductor elements A 1, A 2, A 3 are picked up using the suction collet 9. At this time, instead of the suction collet 9 or in combination with the suction collet 9, the semiconductor elements A1, A2, A3 to be picked up from the bottom surface of the defect recognition film 4 as shown by phantom lines in the figure. It can also be pushed up by the scissors 10. In the above usage method, a heat curing step of the resin layer 3 and a printing step by laser marking can be further added.

  3 and 4 show that the wafer A is diced by using the dicing cutter 8 so that a cut is provided, and the semiconductor elements A1, A2, and A3 are obtained.

The radiation applied to the surface protective film is an actinic ray having a wavelength range of 150 nm to 1000 μm, and includes ultraviolet rays, far ultraviolet rays, near ultraviolet rays, visible rays, electron beams, infrared rays, near infrared rays, and the like. For example, 0.01-10000 J / cm ² can be irradiated using a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a xenon lamp, or a metal halide lamp.

  Through the above steps, a semiconductor element protected by a surface protective film having no defects on the surface can be obtained, and a laser mark that can be easily recognized can be obtained.

  Hereinafter, more specific description will be given using examples.

(Example 1)
60 parts by weight of bisphenol A type epoxy resin (epoxy equivalent 175, using YD-8125 manufactured by Toto Kasei Co., Ltd.) as an epoxy resin, phenol novolac type epoxy resin (using YDCN-703 manufactured by Toto Kasei Co., Ltd.) 5 wt. Parts, 35 parts by weight of bisphenol A novolac resin (using LF-2882 made by Dainippon Ink) as a curing agent, 30 parts by weight of silicon filler (using Admafine SO-C2 made by Admatechs) as a white filler, coloring Epoxy group-containing acrylic copolymer in a varnish in which 35 parts by weight of a resin-based pigment containing 30% by weight of carbon black as an agent (CF black HGBK-02, a national dye) and 30 parts by weight of cyclohexanone as a solvent were mixed by a bead mill. Epoxy group-containing acrylic as a coalescence (Molecular weight 1 million, HTR-860P-3 manufactured by Teikoku Chemical Industry Co., Ltd.) 230 parts by weight, 1-cyanoethyl-2-phenylimidazole (using Curezol 2PZ-CN) 0.5 part by weight as a curing accelerator 1700 parts by weight of cyclohexanone as a solvent was added and mixed with stirring to obtain a varnish.

  The obtained varnish was applied on a base material layer with a release agent (Teijin Purex A31) and dried at 130 ° C. for 10 minutes to obtain a resin layer having a thickness of 50 μm after drying. The light transmittance of the resin layer at a wavelength of 300 to 1100 nm was 2%.

Further, a cloudy polyethylene film (thickness 25 μm, storage elastic modulus at room temperature of 80 MPa) was laminated at 25 ° C. and a linear pressure of 0.2 N / cm to obtain a surface protective film. Using only the part where the gap of 100 μm or less is 10 pieces / m ² , peeling the defect recognition film, laminating it on the back side of the silicon wafer at 80 ° C., laminating the surface protection film on the silicon wafer, The material layer was peeled off.

  After the resin layer of the surface protective film laminated on the silicon wafer was cured at 170 ° C. for 1 hour, laser marking was performed with a YAG laser having an output of 5.0 J / pulse to confirm the visibility.

  Then, as shown in FIG. 3, the dicing tape was laminated so that it might contact | adhere to the resin layer surface side of a wafer. The lamination at this time was performed at 80 ° C. Subsequently, dicing, washing, and drying steps were applied to the semiconductor wafer A in this attached state, and a semiconductor element cut into a 1 cm square was obtained. During dicing, it was confirmed that the occurrence of the edge of the semiconductor element and the occurrence of flash of the resin layer were extremely small.

Next, the dicing tape 7 is irradiated with radiation using a high-pressure mercury lamp (ultraviolet light having a wavelength range of 150 to 400 nm, 500 mJ / cm ² ), and the adhesive strength of the dicing tape is reduced from 100 N / m to 5 N / m. I let you.

  Thereafter, the semiconductor elements A1, A2, A3 to be picked up were picked up by, for example, a suction collet 9. Through the above steps, a semiconductor element having a surface protective film having no defects on the surface could be obtained.

(Example 2)
A semiconductor element was obtained in the same manner as in Example 1 except that a portion having a gap of 100 μm or less of 60 / m ² was used.

(Comparative Example 1)
A semiconductor element was obtained in the same manner as in Example 1 except that a part having a gap of 100 μm or less of 130 pieces / m ² was used.

(Comparative Example 2)
The amount of resin-based processed pigment containing carbon black (CF black HGBK-02 of Gokoku Dye) is 0.1 part by weight, epoxy group-containing acrylic rubber (molecular weight 1 million, HTR-860P manufactured by Teikoku Chemical Industry Co., Ltd.) A semiconductor element was obtained in the same manner as in Example 1 except that the resin layer was obtained by changing the blending amount of 3) to 100 parts by weight. The light transmittance of the resin layer at a wavelength of 300 to 1100 nm was 15%.

  About the semiconductor wafer or semiconductor element which used the surface protection film obtained in Example 1, 2 and Comparative Example 1, 2, the visibility of a laser marking part and heat resistance were evaluated.

(Evaluation methods)
(Laser marking visibility)
The surface of the film after laser marking is captured by a scanner, and the marking portion and the surrounding non-marking portion are converted into two gradations by image processing software (PHOTOSHOP manufactured by Adobe). By this operation, the image is divided into 256 levels of black and white according to the brightness. Next, the “threshold threshold value for the two gradations” in which the marking part is displayed in white and the non-marking part in black, and the marking part is also displayed in black and the boundary between the marking / non-marking part is eliminated. The threshold value is determined to be good when the difference is 40 or more (◯), and the visibility is almost good when the difference is 30 or more and less than 40 (Δ), and when the difference is less than 30, the visibility is evaluated as poor (x). The obtained results are shown in Table 1.

(Heat-resistant)
As a heat resistance evaluation method, a reflow crack resistance test and a humidity cycle resistance test were applied.

  The evaluation of the reflow crack resistance used a semiconductor element cut into a 1 cm square obtained as described above as a sample. Cracks in the resin layer of a sample that was passed through an IR reflow furnace whose temperature was set so that the surface of the sample was maintained at a maximum temperature of 260 ° C. for 20 seconds and then cooled by leaving it at room temperature twice. Was observed visually and with an ultrasonic microscope. In all 10 samples, no crack occurred, and one or more cracks occurred.

  The evaluation of the temperature cycle resistance was performed by leaving the sample in an atmosphere of −55 ° C. for 30 minutes and then leaving it in an atmosphere of 125 ° C. for 30 minutes as one cycle. After 1000 cycles, the resin layer was peeled off using an ultrasonic microscope. The presence or absence of breakage such as cracks was observed. The case where the destruction of the resin layer did not occur in all 10 samples was evaluated as ◯, and the case where one or more samples occurred occurred as x.

The obtained results are shown in Table 1.

  The surface protective film of the present invention is suitably used as a surface protective film for a semiconductor element applied to a semiconductor device having a face-down structure.

It is sectional drawing which shows one embodiment of the surface protection film of this invention. It is sectional drawing which shows an example of the surface protection film containing the space | gap produced by the foreign material and the foreign material. It is a flowchart which shows an example of the usage method of the surface protection film of this invention. It is a flowchart which shows an example of the usage method of the surface protection film of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Surface protective film 2 Base material layer 3 Resin layer 4 Defect recognition film 5 Foreign material 6 Gap 7 Dicing tape 8 Dicing saw 9 Suction collet 10 Needle rod A Semiconductor wafer A1, A2, A3 Semiconductor element

Claims (2)

Substrate layer has a structure formed by laminating a resin layer and a defect recognition film in this order, it was peeled off the defect recognizing film, laminating the resin layer surface in a semiconductor wafer, a surface protective film for the semiconductor element you bond And
The resin layer contains a colorant and has a light transmittance of 10% or less in a wavelength region of 300 to 1100 nm,
The defect recognition film was laminated on the resin layer under conditions of a temperature of 20 ° C. to 140 ° C. and a pressure of 0.01 to 100 MPa, or a temperature of 20 ° C. to 140 ° C. and a linear pressure of 0.1 to 500 N / cm. The thickness is 25 to 300 μm, the storage elastic modulus at room temperature is 80 to 3000 MPa, and the visible light transmittance of the defect recognition film is 3 to 80%,
The surface protective film, wherein the number of voids having a diameter of 100 μm or more contained between the defect recognition film and the resin layer is 100 or less per 1 m ² . A method for producing a semiconductor element having a surface protected using the surface protective film according to claim 1,
(1) A surface protection film in which a base material layer, a resin layer, and a defect recognition film are formed in this order is made so that the surface of the resin layer and the surface without the circuit of the semiconductor wafer come into contact after the defect recognition film is peeled off. Laminating on a semiconductor wafer,
(1-2) Step of peeling the base material layer ,
(1-3) laminating a dicing tape on the surface of the resin layer laminated on the semiconductor wafer;
(2) a step of dicing a semiconductor wafer to obtain a semiconductor element;
(2-2) a step of reducing the adhesive force between the dicing tape and the resin layer;
(3) The process of peeling between a resin layer and a dicing tape, and obtaining the semiconductor element with a resin layer,
A method of manufacturing a semiconductor element having a surface protected with

Images