JP2007250594A - Base film, film for mounting semiconductor, semiconductor package, semiconductor device, and methods of manufacturing the semiconductor package and semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a base film having a flux function and enhancing mountability of a semiconductor element or a semiconductor package, to provide a film for mounting a semiconductor and a semiconductor package and a semiconductor device employing it, to provide a method for manufacturing a semiconductor package easily with little yield, and to provide a method for manufacturing a semiconductor device. <P>SOLUTION: The base film having a flux function and used for mounting a semiconductor element, or the like, can form a first region where the flux function is deactivated, and a second region having the flux function by irradiating the base film selectively with active radiation. In the film for mounting a semiconductor, a first region where the flux function is deactivated, and a second region having the flux function, are formed by irradiating the base film selectively with active radiation. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to a base film, a semiconductor mounting film, a semiconductor package, and a semiconductor device.
The present invention also relates to a semiconductor package manufacturing method and a semiconductor device manufacturing method.

With the demand for higher functionality of electronic devices, semiconductor packages used in these electronic devices are becoming smaller and more pins than ever before.
In recent years, as a method for mounting a semiconductor element on a printed wiring board, a new area mounting type package method such as BGA (Ball Grid Array) or CSP (Chip Scale Package) has been proposed.

For mounting a semiconductor package on a BGA or CSP type printed wiring board, solder bonding using bumps formed of solder balls is employed.
Also, solder bonding is often used for the electrical connection method between the electrode of the semiconductor element and the terminal of the semiconductor mounting substrate in the manufacturing process of the BGA or CSP.

In general, in the case of solder joint, a soldering flux is used to remove oxides attached to the metal surface of the electrode facing the solder surface or to prevent reoxidation on the metal surface during solder joint. (For example, see Patent Document 1).
However, if the flux remains after soldering, problems such as deterioration of electrical insulation and corrosion of printed wiring occur at high temperatures and high humidity.
Therefore, currently, after soldering, the remaining flux is cleaned and removed. However, there are disadvantages such as environmental problems related to the disposal of the cleaning agent and cost increase due to the addition of a cleaning process.

  Further, due to miniaturization of the semiconductor package, the bumps are miniaturized, the pitch between the bumps is narrowed, and it may be difficult to bond the predetermined bump and the pad (for example, a solder bridge).

Japanese Patent Laid-Open No. 11-266073

An object of the present invention is to provide a base film having a flux function and improving the mountability of a semiconductor element or a semiconductor package, a film for mounting a semiconductor, and a semiconductor package and a semiconductor device using the same.
Another object of the present invention is to provide a method for manufacturing a semiconductor package and a method for manufacturing a semiconductor device, which are easy to manufacture and have a low yield.

Such an object is achieved by the present invention described in the following (1) to (17).
(1) A base film used when mounting a semiconductor element or a semiconductor package and having a flux function, wherein the flux function is substantially deactivated by selectively irradiating the base film with active radiation. A base film capable of forming one region and a second region having a flux function.
(2) The base film is composed of a resin composition including a first resin having a first functional group that causes a curing reaction upon irradiation with actinic radiation and having a phenolic hydroxyl group or a carboxylic acid group. The base film according to (1) above.
(3) The base film according to (2), wherein the first functional group is a modification of the phenolic hydroxyl group or the carboxylic acid group.
(4) The base film according to (3), wherein the first functional group is modified by 20 to 60% of the phenolic hydroxyl group or the carboxylic acid group.
(5) The base film according to any one of (2) to (4), wherein the resin composition further includes a second resin of a different type from the first resin.
(6) The base film according to any one of (2) to (5), wherein the resin composition further includes a flux auxiliary agent that improves the flux function.
(7) The base film according to any one of (1) to (6), wherein the semiconductor element or the semiconductor package has solder bumps.
(8) The base film according to (7), wherein the second region is disposed at a position corresponding to a portion to which the solder bump is bonded.
(9) The base film according to any one of (1) to (8), wherein the softening temperature is 40 to 150 ° C.
(10) The base film according to any one of (1) to (9), wherein the thickness is 3 to 80 μm.
(11) A first film in which the flux function is substantially deactivated by selectively irradiating the base film according to any one of the above (1) to (10) with a flux function; A film for mounting a semiconductor, wherein a second region is formed.
(12) The above-mentioned (11), wherein the second region is a plurality of dots or small pieces, and each second region is surrounded by the first region and the second regions are independent from each other. The film for semiconductor mounting as described in).
(13) The film for mounting semiconductor according to (11) or (12), wherein the irradiation region of the active radiation is a first region, and the non-irradiation region of the active radiation is the second region.
(14) A semiconductor package, wherein the semiconductor element and the interposer are mounted via the semiconductor mounting film according to any one of (11) to (13).
(15) A semiconductor device, wherein the semiconductor package and the printed wiring board are mounted via the semiconductor mounting film according to any one of (11) to (13).
(16) A method for manufacturing a semiconductor package comprising a semiconductor element mounted on a substrate, the step of previously bonding the base film according to any one of (1) to (10) to the substrate, and the base film A method of manufacturing a semiconductor package, comprising: a step of selectively irradiating actinic radiation; and a step of bonding the semiconductor element to a region of the base film not irradiated with the actinic radiation.
(17) A method of manufacturing a semiconductor device in which a semiconductor package is mounted on a substrate, the step of previously bonding the base film according to any one of (1) to (10) to the substrate, and the base film A method for manufacturing a semiconductor device, comprising: a step of selectively irradiating actinic radiation; and a step of bonding the semiconductor package to a region of the base film not irradiated with the actinic radiation.

ADVANTAGE OF THE INVENTION According to this invention, the base film which has a flux function, and the mounting property of a semiconductor element or a semiconductor package improves, the film for semiconductor mounting, a semiconductor package and a semiconductor device using the same can be obtained.
Further, according to the present invention, it is possible to provide a semiconductor package and a method for manufacturing a semiconductor device that are easy to manufacture and have a low yield.
Moreover, when using 1st resin which has a specific functional group, a flux function can be improved especially.
Moreover, when the modification amount of the first functional group of the first resin is set within a specific range, the balance between the photoreactivity and the flux function is particularly excellent.

  Hereinafter, a base film, a film for mounting a semiconductor, a semiconductor package, a semiconductor device, a method for manufacturing a semiconductor package, and a method for manufacturing a semiconductor device according to the present invention will be described.

  The base film of the present invention is used when a semiconductor element or a semiconductor package is mounted, and has a flux function. The base film is selectively irradiated with actinic radiation so that the flux function is substantially reduced. The first region to be deactivated and the second region having a flux function can be formed.

  Moreover, the film for semiconductor mounting of the present invention is a first region in which the flux function is substantially deactivated by selectively irradiating the base film described above with active radiation, and a second film having a flux function. A region is formed.

  The semiconductor package of the present invention is characterized in that a semiconductor element and an interposer (substrate for mounting a semiconductor element) are mounted with the above-described semiconductor mounting film.

  The semiconductor device (substrate on which a semiconductor package is mounted) of the present invention is characterized in that the semiconductor package and the printed wiring board are mounted via the above-described semiconductor mounting film. .

  The method for manufacturing a semiconductor package of the present invention is a method for manufacturing a semiconductor package in which a semiconductor element is mounted on a substrate, the step of previously bonding the base film described above to the substrate, And a step of selectively irradiating radiation, and a step of bonding the semiconductor element to a region of the base film not irradiated with the active radiation.

  The method for manufacturing a semiconductor device of the present invention is a method for manufacturing a semiconductor device in which a semiconductor package is mounted on a substrate, the step of previously bonding the base film described above to the substrate, and the active to the base film. And a step of selectively irradiating radiation, and a step of bonding the semiconductor package to a region of the base film not irradiated with the active radiation.

(Base film)
First, the base film will be described. The base film has a function capable of forming a first region in which a flux function is substantially deactivated and a second region having a flux function that are structurally changed by irradiation with actinic radiation. Yes.
Such a flux function can be obtained by, for example, a method of adding a flux aid described later to the resin composition constituting the base film or a method using a resin having a flux function as the resin constituting the base film.

(First resin)
Such a base film is preferably composed of a resin composition containing a first resin having a first functional group that undergoes a curing reaction upon irradiation with actinic radiation and having a phenolic hydroxyl group or a carboxylic acid group, for example. .
Examples of the resin constituting the first resin having the first functional group include a resin having a phenolic hydroxyl group such as a novolak type phenol resin, a resol type phenol resin, and a polyvinyl phenol resin, and an epoxy resin having a carboxylic acid or a dicarboxylic acid. Examples thereof include a resin having a carboxylic acid group obtained by reacting (or an anhydride of dicarboxylic acid) or the like. Among these, a resin having a phenolic hydroxyl group is preferable. Thereby, the film function for semiconductor mounting 100 can express a flux function, without adding a flux auxiliary agent or adding a small amount of flux auxiliary agent.

  Thus, for example, when a resin having a phenolic hydroxyl group is used, it is possible to remove dirt such as solder and oxide on the metal surface and to act as a solder bonding flux. The reason is that since the phenolic hydroxyl group has a reducing action, oxides and the like attached to the solder surface and the metal surface of the facing electrode can be removed. Furthermore, the resin that acts as a flux and has a phenolic hydroxyl group can eliminate the need to remove the residual flux. The reason is that the resin having the phenolic hydroxyl group is cured in the heating process after the solder bonding, so that no volatile matter or the like is generated. If the removal of the residual flux can be made unnecessary, a cleaning step after solder joining can be made unnecessary, and electrical insulation can be maintained even in a high temperature and high humidity atmosphere, and solder joining with high joining strength and reliability becomes possible.

  Specific examples of the resin having a phenolic hydroxyl group include novolak type phenol resins such as phenol novolak resin, alkylphenol novolak resin, and polyfunctional phenol novolak resin, resol type phenol resin, and polyvinyl phenol resin. Among these, at least one phenol resin selected from a phenol novolak resin, an alkylphenol novolak resin, and a polyfunctional phenol novolak resin is preferable, and a polyfunctional phenol novolak resin is particularly preferable. Thereby, the soldering time can be shortened. Moreover, the wet spreading rate of the film for semiconductor mounting described later can be improved. When the wet spreading rate is improved, the solder connection reliability can be improved. Here, the wetting spread rate refers to a value calculated by (H−D) / H by measuring the solder ball diameter H and the height D of the wet spread solder.

  The phenol resin may be a polyfunctional phenol resin obtained by a condensation reaction of a phenol compound having two or more phenolic hydroxyl groups on one benzene ring and formaldehyde under an acidic catalyst. . Examples of the phenol compound having two or more phenolic hydroxyl groups on one benzene ring include catechol, resorcin, hydroquinone, hydroxyhydroquinone, pyrogallol and the like. Among these, catechol and / or resorcin are preferable. Thereby, the condensation reaction of the first resin can be facilitated.

The first functional group preferably undergoes a curing reaction upon irradiation with actinic radiation. Thereby, a difference can be given to the flux function in the active radiation irradiation region and the non-irradiation region.
Examples of the first functional group include an acryloyl group, a methacryloyl group, and an allyl group. Among these, an acryloyl group or a methacryloyl group is preferable. Thereby, photocuring reactivity can be improved (irradiation time can be shortened).

The first functional group is not particularly limited, but it is preferable to modify the phenolic hydroxyl group or the carboxylic acid group.
The amount of modification of the first functional group is not particularly limited, but preferably 20 to 60% by weight of the phenolic hydroxyl group or the carboxylic acid is modified, particularly 30 to 55% by weight. Is preferred. When the content is within the above range, the balance between the photoreactivity and the flux function is particularly excellent.

  Although content of the said 1st resin is not specifically limited, 20 to 70 weight% of the whole resin composition which comprises the said base film is preferable, and 40 to 60 weight% is especially preferable. If the content of the first resin is less than the lower limit, the effect of improving the flux function may be reduced, and if it exceeds the upper limit, the insulation reliability may be reduced.

  The weight average molecular weight of the first resin is not particularly limited, but is preferably 6,000 or less, particularly preferably 3,000 or less, and most preferably 300 to 1,000. If the weight average molecular weight is less than the lower limit, the effect of improving the flux function may be reduced due to volatilization of the first resin in solder reflow or the like. On the other hand, if the weight average molecular weight exceeds the upper limit, the fluidity of the resin at the time of solder bonding is lowered, and the effect of improving the solder connection reliability may be lowered.

  The softening point of the first resin is not particularly limited, but is preferably 30 to 120 ° C, particularly preferably 60 to 100 ° C. If the softening point of the first resin is less than the lower limit value, it may cause voids. If the softening point of the first resin exceeds the upper limit value, the fluidity of the resin at the time of soldering decreases, and the effect of improving the solder connection reliability. May decrease.

(Second resin)
Although the said resin composition is not specifically limited, It is preferable that the 2nd resin from which a kind differs from the said 1st resin is included. As the second resin, for example, a resin having a second functional group capable of reacting with the first resin is preferable. Thereby, insulation reliability can be improved. The reason is that it is possible to reduce the residual phenolic hydroxyl group or carboxylic acid group of the first resin after curing by irradiation with actinic radiation and further thermosetting.
Examples of such second resin include epoxy resins such as novolak type epoxy resins and bisphenol type epoxy resins, thermosetting resins such as cyanate resins such as novolak type cyanate resins and bisphenol type cyanate resins, polyimide resins, and polyetherimides. Examples thereof include thermoplastic resins such as resins and polyethersulfone resins.

The second resin is not particularly limited, but is preferably liquid at normal temperature (particularly when the first resin is solid). Thereby, it is possible to improve the embedding property of circuit irregularities such as an interposer and a mother board when a semiconductor element or a semiconductor package is mounted. Furthermore, the moldability of an interposer or the like can be improved. In addition, the flexibility of the base film can be improved, thereby improving workability.
In addition, a liquid state means what shows fluidity | liquidity at normal temperature. The melt viscosity is not particularly limited, but is preferably 500 Pa · s or less, and particularly preferably 1 to 300 Pa · s. The melt viscosity is measured using an E-type viscometer under conditions of a temperature of 25 ° C., shear rates of 0.5, 1.0, 2.5, and 5.0 rpm. As the melt viscosity, a value that can be measured at the lowest rotational speed among the above conditions is used.

  The weight average molecular weight of the second resin is not particularly limited, but is preferably 200 to 600, and particularly preferably 250 to 500. If the weight average molecular weight of the second resin is less than the lower limit, tackiness may occur on the surface of the film, and if the upper limit is exceeded, the effect of improving the unevenness embedding of the circuit may be reduced.

  Although content of the said 2nd resin is not specifically limited, 5 to 50 weight% of the whole resin composition which comprises the film for semiconductor mounting is preferable, and 10 to 40 weight% is especially preferable. If the content of the second resin is less than the lower limit value, the film-forming property may be reduced due to generation of voids, and if the upper limit value is exceeded, the fluidity of the resin at the time of solder bonding is reduced, and the solder connection The effect of improving reliability may be reduced.

(Flux aid)
Although the said resin composition is not specifically limited, It is preferable that the flux adjuvant which improves a flux function further is included. Thereby, the flux function of the film for semiconductor mounting can be further improved.
Examples of the flux aid include compounds having one phenolic hydroxyl group such as phenol, alkylphenol, naphthol, biphenol, hydroquinone, resorcinol, catechol, methylidene diphenol, ethylidene diphenol, isopropylidenediphenol, pyrogallol, hydroxyhydroquinone. And polyphenol compounds such as phloroglucinol, phenol compounds having a carboxylic acid group such as hydroxybenzoic acid, dihydroxybenzoic acid, and phenolphthalin. Among these, a polyhydric phenol compound is preferable in that it has excellent flux activity.

  Although content of the said flux adjuvant is not specifically limited, 0.5 to 10 weight% of the whole said resin composition is preferable, and 2 to 8 weight% is especially preferable. If the content of the flux auxiliary agent is less than the lower limit value, the effect of further improving the flux function may be reduced, and if it exceeds the upper limit value, moisture absorption heat resistance may be reduced.

(Polymerization initiator)
Although the said resin composition is not specifically limited, It is preferable that the polymerization initiator which starts superposition | polymerization by irradiation of actinic radiation is included. Thereby, it becomes easy to substantially deactivate the flux function by irradiation with actinic radiation.
Examples of the polymerization initiator include benzophenones such as benzophenone, benzoylbenzoic acid, 4-phenylbenzophenone, and hydroxybenzophenone, benzoin, benzoin methyl ether, benzoin dimethyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin butyl ether, benzoin isobutyl ether, and the like. Benzoin alkyl ethers, 4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone, 4-t-butyl-trichloroacetophenone, acetophenones such as diethoxyacetophenone, thioxanthone, 2-chlorothioxanthone, 2-methylthio Thioxanes such as xanthone, 2,4-dimethylthioxanthone, ethyl anthraquinone, butyl Mention may be made of alkyl anthraquinone such as Ntorakinon like. These can be used alone or as a mixture of two or more.

  Although the addition amount of the said polymerization initiator is not specifically limited, 0.1 to 10 weight% of the whole said resin composition is preferable, and 1 to 5 weight% is especially preferable. When the addition amount is within the above range, the polymerization reactivity with respect to irradiation with actinic radiation is particularly excellent.

(Curing aid)
Although the said resin composition is not specifically limited, It is preferable that the hardening adjuvant which accelerates | stimulates the hardening reaction of the said resin component is included.
Examples of the curing aid include 2-phenylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-ethyl-4-methylimidazole, 2 -Imidazole compounds such as phenyl-4-methyl-5-hydroxymethylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-undecylimidazole, bis (2-ethyl-4-methylimidazole), 2,4 -Diamino-6- [2'-methylimidazolyl- (1 ')]-ethyl-s-triazine, 2,4-diamino-6- (2'-undecylimidazolyl) -ethyl-s-triazine, 2,4 -Diamino-6- [2'-ethyl-4-methylimidazolyl- (1 ')]-ethyl-s-tria Triazine-addition type imidazole compounds such emissions, 1,8-diazabicyclo (5,4,0) diazabicycloalkene and derivatives thereof -7 undecene, tributylamine, and amine compounds such as benzyl dimethyl amine. Among these, imidazole selected from 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole and 2-phenyl-4,5-dihydroxymethylimidazole Compounds are preferred. Thereby, it is possible to maintain good curing reactivity while maintaining workability (because it does not react in the step before final curing, so that fluidity and the like can be maintained).

  Although content of the said hardening adjuvant is not specifically limited, 0.05 to 3.0 weight% of the whole said resin composition is preferable, and 0.1 to 1.0 weight% is especially preferable. When the content is within the above range, the balance between curing reactivity and storage stability is particularly excellent.

The resin composition may contain an ultraviolet ray inhibitor, a thermal polymerization inhibitor, a plasticizer, a leveling agent and the like as necessary for storage stability.
In addition, the resin composition includes a third resin having a weight average molecular weight different from that of the second resin for reasons such as controlling the film forming property of the base film and controlling the fluidity of the base film when acting as a flux. May be.
Examples of the third resin include epoxy resins such as novolac type epoxy resins and bisphenol type epoxy resins, and thermosetting resins such as cyanate resins such as novolac type cyanate resins and bisphenol type cyanate resins. The third resin may be a different type of resin from the second resin, but it is preferable to use the same type (same functional group) resin in terms of curability.

(Manufacture of base film)
The resin composition is dissolved in a ketone solvent such as methyl ethyl ketone or methyl isobutyl ketone to prepare a resin varnish. Thereafter, the base film can be obtained by applying the resin varnish to a support member or the like.

Although the softening temperature of the said base film is not specifically limited, 40-150 degreeC is preferable and 60-120 degreeC is especially preferable. When the softening temperature is within the above range, the embedding property of circuit irregularities is particularly excellent.
The softening temperature can be measured, for example, with a dynamic viscoelastic device.

  Although the thickness of the said base film is not specifically limited, 5-80 micrometers is preferable and 10-70 micrometers is especially preferable. Within the said range, it is excellent also in the reinforcement hardening between solder bumps.

(Manufacturing method of semiconductor mounting film)
This base film is selectively irradiated with actinic radiation to obtain a semiconductor mounting film.
Specifically, the active radiation is irradiated to a portion (corresponding to the first region) other than a portion (corresponding to the second region) where the flux function is desired to remain. In the portion irradiated with actinic radiation (first region), the fluidity decreases because the first resin constituting the base film undergoes a curing reaction. When the fluidity of the first region is lowered, the solder wettability in the first region is lowered, so that the flux function is substantially deactivated.
As described above, by having the region having the flux function and the inactive region, the solder generated by the interfacial tension with the solder ball at the time of solder bridge formation or solder reflow even in the joining with the solder bump of the narrow pitch Aggregation of the balls can be prevented.
Further, it is possible to perform solder bonding between the semiconductor element and the substrate without using a solder resist, and the man-hour can be reduced.
Furthermore, after soldering, it hardens with a shape that reinforces the periphery of the solder joint in a ring shape (forms a meniscus) due to the interfacial tension between the base film and the solder bump, compared to solder joining by conventional flux, Bonding strength and reliability can be greatly improved. Therefore, it can be particularly suitably used for bonding fine bumps, which has been difficult to improve reliability with conventional solder bonding.

Examples of the active radiation include ultraviolet rays and electron beams. Among these, ultraviolet rays are preferable. Thereby, a curing reaction can be easily performed.
The actinic radiation may be applied in the state of the base film alone, or the actinic radiation may be applied after the base film is bonded to a substrate, a semiconductor element or a semiconductor package in advance. Among these, it is preferable to irradiate the active radiation with the base film bonded to the substrate in advance from the viewpoint of improving the alignment accuracy between the semiconductor element or the like and a predetermined region of the semiconductor mounting film.

(Film for semiconductor mounting)
Next, the semiconductor mounting film will be described in detail based on a preferred embodiment.
As shown in FIG. 1, the semiconductor mounting film 100 has a first region 1 in which the flux function is deactivated by irradiation with active radiation, and a second region 2 in which the flux function is not irradiated with active radiation. ing.
The second area 2 has a plurality of small pieces, and each second area 2 is surrounded by the first area 1 so that the second areas 2 are independent from each other. In addition, each 2nd area | region 2 does not need to be small piece shape, and may be dot shape.
The second region 2 is disposed in the vicinity of the outer peripheral portion of the semiconductor mounting film 100. Thereby, joining with the solder bump of a semiconductor element can be made easy.

  The minimum value of the separation distance of each second region 2 is not particularly limited, is preferably 30 μm or more, and particularly preferably 40 to 100 μm. When the distance between the second regions 2 is within the above range, the reliability at the time of solder bonding of solder bumps with a narrow pitch is excellent.

Thus, by forming the semiconductor mounting film 100 selectively having the first region 1 in which the flux function is substantially deactivated and the second region 2 having the flux function, the solder bumps are arranged. The 2nd area | region 2 which has a flux function can be selectively arrange | positioned in the position performed, and the flux function of the other position (1st area | region 1) can be deactivated substantially. Thereby, for example, the bonding between the semiconductor element or the like by a solder bump and the substrate or the like can be made more accurate. In particular, even when recent solder bumps are formed at a high density, only portions that require solder bonding can be selectively bonded.
This is because the semiconductor mounting film 100 has the second region 2 having the flux function and the first region 1 in which the flux function is substantially deactivated, so that the flux function is substantially reduced. This is because the solder bumps do not spread in the first region 1 which is deactivated and the solder connection can be made only in the first region 1.

  Although the softening temperature of the film 100 for semiconductor mounting is not specifically limited, 40-150 degreeC is preferable and 50-140 degreeC is especially preferable. If the softening temperature is lower than the lower limit value, voids or wrinkles may occur. If the softening temperature exceeds the upper limit value, the fluidity of the resin at the time of soldering decreases and the solder connection reliability is improved. Effect may be reduced. The softening temperature can be measured at, for example, 5 ° C./minute using a viscoelasticity measuring device (DMA, manufactured by TA Instruments) (the inflection point of the elastic modulus is defined as the softening temperature).

Moreover, although the melt viscosity of the film 100 for semiconductor mounting is not specifically limited, 1-5000 mPa * s is preferable and especially 5-4000 mPa * s is preferable. If the melt viscosity is less than the lower limit, voids may be generated or wrinkles may occur.If the melt viscosity exceeds the upper limit, the fluidity of the resin at the time of soldering decreases, and the solder connection reliability is reduced. The improvement effect may be reduced.
The melt viscosity can be measured at 240 ° C. and a frequency of 1 Hz by using a dynamic viscoelastic device, for example, by sandwiching a film in a disc-shaped jig having a diameter of 25 mm and a thickness of 0.8 mm.

The thickness of the film for semiconductor mounting is adjusted according to the height of the semiconductor element to be mounted and the bump height of the semiconductor package.
Therefore, the thickness of the film for semiconductor mounting is not particularly limited, but is preferably 3 to 80 μm, particularly preferably 5 to 75 μm. Thereby, adhesion / sealing can be achieved even within a thickness range in which adhesion / sealing is difficult by a conventional method such as underfill.

(Semiconductor package)
Next, a method for manufacturing a semiconductor package and a semiconductor package will be described based on preferred embodiments.
As shown in FIG. 2, the base film 10 described above is bonded to the interposer (substrate) 3 using a roll 101 in a vacuum to obtain a bonded body 31 as shown in FIG. 3. As a method of joining the base film 10 to the interposer 3, for example, a method using a laminate roll can be mentioned.
Next, the active radiation (for example, ultraviolet rays) is selectively applied to the surface of the base film 10 of the joined body 31, and the first region 1 irradiated with the active radiation as shown in FIG. 1 and the unirradiated second region. 2 (the base film 10 becomes the semiconductor mounting film 100). Here, in the first region 1, the flux function of the base film 10 is substantially deactivated. On the other hand, the second region 2 leaves the flux function of the base film 10.
In addition, although the case where the base film 10 was previously joined to the interposer 3 was demonstrated here, it is not limited to this, You may join the base film 10 to the semiconductor element 4 previously.
In the above embodiment, the laminate roll is used. However, the present invention is not limited to this, and a method of joining the substrate and the base film by a vacuum press may be used.

  Next, as shown in FIG. 4, the semiconductor element 4 is mounted on the bonded body 31 so that each solder ball 41 of the semiconductor element 4 contacts the second region 2 of the semiconductor mounting film 100. For example, the semiconductor package 5 is obtained by heating and soldering at 200 to 280 ° C. for 10 to 60 seconds. As shown in FIG. 5, in the semiconductor package 5, the semiconductor element 4 is mounted on the interposer 3 via the semiconductor mounting film 100.

Furthermore, it is preferable that the semiconductor package 5 is heat-treated, for example, at 150 to 180 ° C. for 1 to 2 hours. Thereby, the semiconductor mounting film 100 can be completely cured.
In the semiconductor mounting film 100 of the present invention, the second region 2 exhibits a flux function and removes oxides on the metal surface at the stage of solder bonding. Then, after the solder bonding, the semiconductor mounting film 100 is thermoset and functions as an insulating sealing adhesive, so that a decrease in electrical insulation, corrosion of the interposer, and the like do not occur.
Moreover, the film 100 for semiconductor mounting of the present invention is filled in the gap between the semiconductor element 4 and the interposer 3 after solder bonding, and can give an action as an underfill (improvement of reliability of solder connection) (for example, a semiconductor) When the thickness of the mounting film is adjusted to the gap between the interposer and the semiconductor element when mounted).
Furthermore, since the semiconductor mounting film 100 of the present invention is in the form of a film, it is excellent in workability for manufacturing the semiconductor package 5.

(Semiconductor device)
Next, a method for manufacturing a semiconductor device and a semiconductor device will be described based on preferred embodiments.
As illustrated in FIG. 6, the base film 10 described above is bonded to the mother board 6 using a roll 101 in a vacuum to obtain a bonded body 61 as illustrated in FIG. 7.
Next, the active film (for example, ultraviolet rays) is selectively irradiated to the surface of the base film 10 of the joined body 61, and the first region 1 irradiated with the active radiation as shown in FIG. 1 and the unirradiated second region. 2 (the base film 10 becomes the semiconductor mounting film 100). Here, in the first region 1, the flux function of the base film 10 is substantially deactivated. On the other hand, the second region 2 leaves the flux function of the base film 10.
In addition, although the case where the base film 10 was previously joined to the mother board 6 was demonstrated here, it is not limited to this, You may join the base film 10 to the semiconductor package 5 previously.
In the above embodiment, the laminate roll is used. However, the present invention is not limited to this, and a method of joining the mother board and the base film by a vacuum press may be used.

  Next, as shown in FIG. 8, the semiconductor package 5 is mounted on the joined body 61 such that each solder ball 51 of the semiconductor package 5 comes into contact with the second region 2 of the semiconductor mounting film 100. Then, for example, the semiconductor device 7 is obtained by heating and soldering at 200 to 280 ° C. for 10 to 60 seconds (FIG. 9). As shown in FIG. 9, in the semiconductor device 7, the semiconductor package 5 is mounted on the mother board 6 via the semiconductor mounting film 100.

Furthermore, it is preferable that the semiconductor device 7 is heat-treated, for example, at 150 to 180 ° C. for 1 to 2 hours. Thereby, the semiconductor mounting film 100 can be completely cured.
In the semiconductor mounting film 100 of the present invention, the second region 2 exhibits a flux function at the solder bonding stage to remove oxide on the metal surface. Then, after the solder bonding, the semiconductor mounting film 100 is thermally cured and functions as an insulating sealing adhesive, so that the electrical insulation is not deteriorated and the interposer is not corroded.
Furthermore, since the semiconductor mounting film 100 of the present invention is in the form of a film, it is excellent in workability for manufacturing the semiconductor device 7.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail based on an Example and a comparative example, this invention is not limited to this.

Example 1
1. Synthesis of the first resin Phenol novolac (manufactured by Dainippon Ink and Chemicals, Phenolite TD-2090-70M) 600 g of a non-volatile content 70% methyl ethyl ketone (MEK) solution (about 4 equivalents of OH group) was put into a 2 L flask. To this, 1 g of tributylamine and 0.2 g of hydroquinone were added and heated to 110 ° C. Into this, 284 g (2 mol) of glycidyl methacrylate was added dropwise over 30 minutes, followed by stirring reaction at 110 ° C. for 5 hours, so that a methacryloyl group-containing phenol novolac (50% of the phenolic hydroxyl group was converted into methacryloyl) having a nonvolatile content of about 80%. The first resin a having a modified group was obtained.

2. Production of base film 54% by weight of first resin a, 37% by weight of liquid bisphenol F type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., RE-404S, weight average molecular weight of about 300) as second resin a, flux aid As a curing aid, 2-phenyl-4,5-dihydroxymethylimidazole (manufactured by Shikoku Kasei Co., Ltd., 2PHZ) is used as a photopolymerization initiator and benzoin dimethyl ether (Ciba A varnish was obtained by dissolving 2.2% by weight of Geigy's Irgacure 651) and 0.5% by weight of a leveling agent (Big Chemie 361N, manufactured by Big Chemie) in cyclohexanone. The obtained varnish was applied on a PET film at a maximum temperature of 150 ° C. with a comma coater to obtain a base film having a thickness of 60 μm.

3. Manufacturing of Semiconductor Package The above base film was vacuum laminated to an interposer at 5 Torr. Next, the base film is masked with a mask material so as to cover a position corresponding to a solder ball of a semiconductor element to be described later, and then exposed to a dose of 200 mJ / cm ² using a high pressure mercury lamp exposure device. A film for mounting a semiconductor having two regions and a first region in which the flux function is substantially deactivated was obtained.
Next, with a mounting tool, a flip chip type semiconductor element having a solder bump with a bump diameter of 40 μm and a bump pitch of 80 μm is adsorbed and transferred, and the semiconductor element and an interposer preheated to 80 ° C. ) Was performed (so that the solder bumps coincided with the second region). Thereafter, the semiconductor element was mounted on the interposer. Then, thermocompression bonding was performed at an optimum temperature of 3 kg / cm ² for 10 seconds. Next, it was passed through a reflow furnace at a maximum temperature of 240 ° C. and 220 ° C. for 30 seconds. Thereafter, after-curing at 180 ° C. for 60 minutes, a semiconductor package was obtained.

(Example 2)
Instead of the 1st resin a, it carried out similarly to Example 1 except having mix | blended the base film as follows using the 1st resin b described below.
1. Resin synthesis Bisphenol A type novolak (manufactured by Dainippon Ink and Chemicals, Phenolite LF-4871) 685 g of MEK solution (approximately 4 equivalents of OH group) having a nonvolatile content of about 70% was put into a 2 l flask, Hydroquinone 0.2g and glycidyl methacrylate 284g (2 mol) were added to this, and it heated at 110 degreeC. Into this, 1 g of tributylamine was added, followed by stirring reaction at 110 ° C. for 5 hours to obtain a first resin b having a non-volatile content of about 80% methacryloyl group-containing phenol novolak (methacryloyl group modification rate of 50%).

2. Formulation of base film: 55% by weight of first resin b, 36% by weight of liquid bisphenol F type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., RE-404S, weight average molecular weight of about 300) as second resin a, flux aid As a curing aid, 2-phenyl-4,5-dihydroxymethylimidazole (manufactured by Shikoku Kasei Co., Ltd., 2PHZ) is used as a photopolymerization initiator and benzoin dimethyl ether (Ciba A varnish was prepared by dissolving 2.2% by weight of Irgacure 651) manufactured by Geigy Co., Ltd. and 0.5% by weight of a leveling agent (Bic Chemie 361N manufactured by Big Chemie) in cyclohexanone.

(Example 3)
Instead of the 1st resin a, it carried out similarly to Example 1 except having mix | blended the base film as follows using the 1st resin c described below.
1. Resin synthesis Bisphenol A type novolak (manufactured by Dainippon Ink and Chemicals, Phenolite LF-4871) 685 g of MEK solution (approximately 4 equivalents of OH group) having a nonvolatile content of about 70% was put into a 2 l flask, Hydroquinone 0.2g and glycidyl methacrylate 115g (0.8 mol) were added to this, and it heated at 110 degreeC. To this, 0.5 g of tributylamine was added, followed by stirring reaction at 110 ° C. for 5 hours to obtain a first resin c having a non-volatile content of about 80% methacryloyl group-containing phenol novolak (methacryloyl group modification rate of 20%). It was.

2. Formulation of base film: 41% by weight of first resin c, 53% by weight of liquid bisphenol F type epoxy resin (Nippon Kayaku Co., Ltd., RE-404S, weight average molecular weight of about 300) as second resin a, flux aid As a photopolymerization initiator, 3% by weight of phenolphthaline, 0.3% by weight of 2-phenyl-4,5-dihydroxymethylimidazole (manufactured by Shikoku Kasei Co., Ltd., 2PHZ) as a curing aid, A varnish was prepared by dissolving 2.2% by weight of Irgacure 651) manufactured by Geigy Co., Ltd. and 0.5% by weight of a leveling agent (Bic Chemie 361N manufactured by Big Chemie) in cyclohexanone.

Example 4
Instead of the 1st resin a, it carried out similarly to Example 1 except having mix | blended the base film as follows using 1st resin d described below.
1. Resin synthesis Bisphenol A type novolak (manufactured by Dainippon Ink and Chemicals, Phenolite LF-4871) 685 g of MEK solution (approximately 4 equivalents of OH group) having a nonvolatile content of about 70% was put into a 2 l flask, Hydroquinone 0.2g and glycidyl methacrylate 350g (2.5 mol) were added to this, and it heated at 110 degreeC. Into this, 1 g of tributylamine was added, followed by stirring reaction at 110 ° C. for 5 hours to obtain a first resin d having a nonvolatile content of about 80% methacryloyl group-containing phenol novolak (methacryloyl group modification rate 60%).

2. Formulation of base film: 60% by weight of first resin d, 31% by weight of liquid bisphenol F type epoxy resin (Nippon Kayaku Co., Ltd., RE-404S, weight average molecular weight of about 300) as second resin a, flux aid As a curing aid, 2-phenyl-4,5-dihydroxymethylimidazole (manufactured by Shikoku Kasei Co., Ltd., 2PHZ) is used as a photopolymerization initiator and benzoin dimethyl ether (Ciba A varnish was prepared by dissolving 2.2% by weight of Irgacure 651) manufactured by Geigy Co., Ltd. and 0.5% by weight of a leveling agent (Bic Chemie 361N manufactured by Big Chemie) in cyclohexanone.

(Example 5)
The same procedure as in Example 1 was conducted except that the composition of the base film varnish was as follows.
30% by weight of the first resin a, 57% by weight of the liquid bisphenol F type epoxy resin (Nippon Kayaku Co., Ltd., RE-404S, weight average molecular weight of about 300) as the second resin a, and phenolphthaline as a flux aid 10% by weight, 0.3% by weight of 2-phenyl-4,5-dihydroxymethylimidazole (manufactured by Shikoku Kasei Co., Ltd., 2PHZ) as a curing aid, and benzoin dimethyl ether (manufactured by Ciba-Geigy) as a photopolymerization initiator, Irgacure 651) 2.2% by weight and 0.5% by weight of a leveling agent (Big Chemie 361N, manufactured by Big Chemie) were dissolved in cyclohexanone to obtain a varnish.

(Example 6)
The same procedure as in Example 1 was conducted except that the composition of the base film varnish was as follows.
65% by weight of the first resin a, 30% by weight of the liquid bisphenol F type epoxy resin (Nippon Kayaku Co., Ltd., RE-404S, weight average molecular weight of about 300) as the second resin a, and phenolphthaline as a flux aid 2% by weight, 0.3% by weight of 2-phenyl-4,5-dihydroxymethylimidazole (manufactured by Shikoku Kasei Co., Ltd., 2PHZ) as a curing aid, and benzoin dimethyl ether (manufactured by Ciba-Geigy) as a photopolymerization initiator, Irgacure 651) 2.2% by weight and 0.5% by weight of a leveling agent (Big Chemie 361N, manufactured by Big Chemie) were dissolved in cyclohexanone to obtain a varnish.

(Example 7)
The following was used as the second resin b, and the same as in Example 1 except that the formulation was as follows.
As the second resin b, a novolac type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., EPPN-501H, softening point 54 ° C., epoxy equivalent 167) was used.

2. Blending of base film: 55% by weight of first resin a, 36% by weight of novolak type epoxy resin (Nippon Kayaku Co., Ltd., EPPN-501H, softening point 54 ° C., epoxy equivalent 167) as second resin b, and as flux aid 6% by weight of phenolphthaline, 0.3% by weight of 2-phenyl-4,5-dihydroxymethylimidazole (manufactured by Shikoku Kasei Co., Ltd., 2PHZ) as a curing aid, and benzoin dimethyl ether (Ciba-Geigy) as a photopolymerization initiator Irgacure 651) 2.2% by weight and 0.5% by weight of a leveling agent (Bic Chemie, Big Chemie 361N) were dissolved in cyclohexanone to obtain a varnish.

(Example 8)
The same procedure as in Example 1 was conducted except that the first resin c was used instead of the first resin a, and the varnish of the base film was blended as follows without using the flux auxiliary agent.
45% by weight of the first resin c, 52% by weight of the liquid bisphenol F type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., RE-404S, weight average molecular weight of about 300) as the second resin a, and 2-phenyl as a curing aid -4,5-dihydroxymethylimidazole (manufactured by Shikoku Kasei Co., Ltd., 2PHZ), a photopolymerization initiator, benzoin dimethyl ether (manufactured by Ciba Geigy, Irgacure 651), 2.2% by weight, and a leveling agent 0.5% by weight (by Big Chemie, Big Chemie 361N) was dissolved in cyclohexanone to obtain a varnish.

Example 9
Instead of the 1st resin a, it carried out similarly to Example 1 except having mix | blended the base film as follows using the 1st resin e described below.
1. Synthesis of first resin (synthesis of carboxyl group-containing epoxy acrylate)
An epoxy resin (Epicoat 828, epoxy equivalent 190, 760 g, 4 equivalents) and 1 g of methoxyphenol and 1 g of benzyldimethylamine as polymerization inhibitors were added to a 2 liter flask and heated to 100 ° C., and 180 g of acrylic acid (2.5 g) was added. Mol) was added dropwise over 1 hour, followed by stirring reaction at 100 ° C. for 6 hours. Thereafter, 234 g (1.6 mol) of adipic acid was added and reacted with stirring for 2 hours to obtain a first resin e.

2. Blending of base film: 55% by weight of first resin e, 36% by weight of liquid bisphenol F type epoxy resin (Nippon Kayaku Co., Ltd., RE-404S, weight average molecular weight of about 300) as second resin a, flux aid As a curing aid, 2-phenyl-4,5-dihydroxymethylimidazole (manufactured by Shikoku Kasei Co., Ltd., 2PHZ) is used as a photopolymerization initiator and benzoin dimethyl ether (Ciba A varnish was prepared by dissolving 2.2% by weight of Irgacure 651) manufactured by Geigy Co., Ltd. and 0.5% by weight of a leveling agent (Bic Chemie 361N manufactured by Big Chemie) in cyclohexanone.

(Comparative Example 1)
SR (Taiyo Ink Co., Ltd., PFR-800) is laminated to the interposer, exposed and developed to form the joint, apply the flux, install the semiconductor element, solder joint, flux cleaning, and inject the underfill by capillary method A semiconductor package was obtained.

Each example and each comparative example were evaluated as follows. The evaluation items are shown together with the contents. The obtained results are shown in Table 1.
1. Position retention of bumps The base film is masked with a mask material so as to cover a position corresponding to a solder ball of a semiconductor element to be described later, and then exposed to a dose of 200 mJ / cm ² using a high-pressure mercury lamp exposure apparatus to have a flux function. A solder ball was mounted at a predetermined position with a ball mounter on the semiconductor mounting film having the second region having the first region and the first region in which the flux function was substantially deactivated, and reflow treatment was performed. At this time, the positional accuracy of the solder balls (diameter: 100 μm) was visually evaluated.
A: Solder balls could be mounted at a predetermined position (second region).
◯: Although there is some misalignment of solder balls, it was at a practical level.
(Triangle | delta): There existed some position shifts of a solder ball, and it was a practicable level.
X: Solder balls aggregated.

2. Mountability of Semiconductor Element The mountability of the semiconductor element was evaluated by the connection rate of 10,000 bumps of solder connection terminals. Each code is as follows.
A: The connection rate was 100%.
○: The connection rate was 99% or more and less than 100%.
Δ: The connection rate was 80% or more and less than 99%.
X: The connection rate was less than 80%.

3. Formability The adhesive film was vacuum-heated and pressure-molded at a temperature of 60 to 80 ° C. and a pressure of 0.5 to 1 MPa using a vacuum pressure laminator device. The inner layer circuit embedding at that time was evaluated for the presence of voids with a microscope.
○: There was no void between the circuits.
X: Some voids were generated between the circuits.

4). Insulation Reliability A printed wiring board for insulation reliability test having a comb pattern with a conductor spacing of 50 μm plated with solder was used, and a film for mounting a semiconductor was placed on the printed wiring board.
After passing the above-mentioned printed wiring board through a reflow oven set at a peak temperature of 240 ° C., the film for semiconductor mounting was cured by heat treatment at 180 ° C. for 60 minutes, and the insulation resistance was measured as a printed wiring board for testing ( Before processing).
Next, a DC voltage of 50 V was applied to the above-mentioned printed wiring board in an atmosphere of 85 ° C./85%, and the insulation resistance after 1000 hours was measured (after treatment). The applied voltage during measurement was 100 V for 1 minute. If the insulation resistance value was 10 ⁹ or more, the test was accepted.

5). Workability The number of man-hours until a semiconductor package was manufactured was evaluated using Comparative Example 1 as a reference (100).

As is clear from Table 1, Examples 1 to 9 were confirmed to be excellent in solder ball position retention. As a result, it has been shown that it is difficult to form a solder bridge or the like even in solder connection using fine solder bumps.
Examples 1 to 9 were also excellent in moldability and insulation reliability.
Moreover, Examples 1-9 were also confirmed to improve workability.

Next, examples of the semiconductor device will be described.
The above base film was previously vacuum-laminated on the motherboard at 5 Torr. Next, the base film is masked with a mask material so as to cover a position corresponding to a solder ball of a semiconductor element, which will be described later, and then exposed to a dose of 500 mJ / cm ² using a high-pressure mercury lamp exposure device. A film for mounting a semiconductor having two regions and a first region in which the flux function is substantially deactivated was obtained.
Next, solder bumps (bump diameter 350 μm, solder bump interval 350 μm) are formed on the semiconductor package obtained in Examples 1 to 9, and the semiconductor package is sucked and transferred with a mounting tool, and the semiconductor package is heated to 80 ° C. The preheated mother board (with the semiconductor mounting film installed) was aligned (so that the solder bumps coincided with the second region). Then, the semiconductor package was mounted on the motherboard. Then, thermocompression bonding was performed at an optimum temperature of 3 kg / cm ² for 10 seconds. Next, it was passed through a reflow furnace at a maximum temperature of 240 ° C. and 220 ° C. for 30 seconds. Thereafter, after-curing at 180 ° C. for 60 minutes, a semiconductor device was obtained.

  As a result of confirming the continuity of the semiconductor device obtained in each example, it was confirmed that all the semiconductor devices operated normally.

It is a top view which shows an example of the film for semiconductor mounting typically. It is sectional drawing explaining the manufacturing process of a semiconductor package. It is sectional drawing explaining the manufacturing process of a semiconductor package. It is sectional drawing explaining the manufacturing process of a semiconductor package. It is sectional drawing which shows an example of a semiconductor package. It is sectional drawing explaining the manufacturing process of a semiconductor device. It is sectional drawing explaining the manufacturing process of a semiconductor device. It is sectional drawing explaining the manufacturing process of a semiconductor device. It is sectional drawing which shows an example of a semiconductor device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st area | region 2 2nd area | region 3 Interposer 31 Junction body 4 Semiconductor element 41 Solder ball 5 Semiconductor package 51 Solder ball 6 Mother board 61 Junction body 7 Semiconductor device 10 Base film 100 Film for semiconductor mounting 101 Roll

Claims (17)

A base film having a flux function, used when mounting a semiconductor element or a semiconductor package,
The base film can be formed by selectively irradiating the base film with actinic radiation to form a first region where the flux function is substantially deactivated and a second region having the flux function. .   The base film is composed of a resin composition containing a first resin having a first functional group that undergoes a curing reaction upon irradiation with actinic radiation and having a phenolic hydroxyl group or a carboxylic acid group. 1. The base film according to 1.   The base film according to claim 2, wherein the first functional group is a modification of the phenolic hydroxyl group or the carboxylic acid group.   The base film according to claim 3, wherein the first functional group is modified by 20 to 60% of the phenolic hydroxyl group or the carboxylic acid group.   The base film according to any one of claims 2 to 4, wherein the resin composition further includes a second resin of a different type from the first resin.   The base film according to claim 2, wherein the resin composition further contains a flux auxiliary agent that improves the flux function.   The base film according to claim 1, wherein the semiconductor element or the semiconductor package has solder bumps.   The base film according to claim 7, wherein the second region is disposed at a position corresponding to a portion to which the solder bump is bonded.   The base film according to any one of claims 1 to 8, which has a softening temperature of 40 to 150 ° C.   The base film according to claim 1, which has a thickness of 3 to 80 μm.   The base film according to claim 1 is selectively irradiated with actinic radiation to form a first region in which the flux function is substantially deactivated and a second region having the flux function. A film for mounting semiconductors characterized by the above.   12. The second region according to claim 11, wherein the second region is a plurality of dots or small pieces, and each second region is surrounded by the first region and the second regions are independent from each other. Film for semiconductor mounting.   The film for semiconductor mounting according to claim 11, wherein the irradiation region of the active radiation is a first region, and the non-irradiation region of the active radiation is the second region.   14. A semiconductor package, wherein the semiconductor element and the interposer are mounted via the semiconductor mounting film according to claim 11.   A semiconductor device, wherein the semiconductor package and the printed wiring board are mounted via the film for mounting semiconductor according to claim 11. A method of manufacturing a semiconductor package comprising a semiconductor element mounted on a substrate,
A step of previously bonding the base film according to any one of claims 1 to 10 to a substrate;
Selectively irradiating the base film with actinic radiation;
Bonding the semiconductor element to a region of the base film that has not been irradiated with the actinic radiation. A method for manufacturing a semiconductor device comprising a semiconductor package mounted on a substrate,
A step of previously bonding the base film according to any one of claims 1 to 10 to a substrate;
Selectively irradiating the base film with actinic radiation;
Bonding the semiconductor package to a region of the base film that has not been irradiated with the active radiation. A method for manufacturing a semiconductor device, comprising:

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