JP2009302554A - Prepreg with metal foil, laminate sheet, and interposer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an interposer which is bonded to a semiconductor element without using an adhesive component such as an adhesive and a method of manufacturing the same, and a semiconductor package which can be made thin and a method of manufacturing the same. <P>SOLUTION: The interposer 1 has a prepreg 11, a conductor pattern (circuit) 12 formed on one surface of the prepreg, and a coating layer (solder resist layer) 13 formed so as to cover at least a part of the conductor pattern. Further, the semiconductor package has a semiconductor element mounted on the interposer, and the method of manufacturing the interposer includes a step of forming the conductor pattern on a metal foil of the prepreg formed by bonding the metal foil to the one surface by etching and a step of forming the coating layer so as to cover at least the part of the conductor pattern. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

The present invention relates to a prepreg with a metal foil, a laminate, and an interposer .

  Usually, a prepreg constituting a printed wiring board or the like is obtained by impregnating a base material such as a glass cloth with a thermosetting resin varnish such as an epoxy resin or a phenol resin, followed by heat drying and reacting. Next, using this prepreg, a copper-clad laminate, a printed wiring board and the like are manufactured.

  When the resin that constitutes the prepreg is uncured, the surface of the prepreg becomes sticky (occurrence of tack), resulting in a problem that workability is lowered. In addition, there is a problem that the resin flow becomes large at the time of heating and pressurization and the moldability is lowered.

  Therefore, in general, the prepreg suppresses the occurrence of tackiness on the surface of the prepreg by controlling the flow during heating and pressurization by setting the thermosetting resin to be in a semi-cured state by the above-described heating reaction process. Yes.

  However, the semi-cured prepreg has problems such as lack of flexibility and easy cracking. Therefore, the circuit processing of the semi-cured prepreg could not be performed directly.

  In addition, when the prepreg is cut and processed because the adhesive strength between the semi-cured resin and the base material is not sufficient, powder composed of the resin composition and the base material is generated, and the workability is lowered. Had. Furthermore, when this powder is removed from the prepreg when handling the prepreg for lamination, it adheres to a metal foil such as a copper foil or a metal plate for lamination molding, and on the laminated board or printed wiring board that has been molded, There was a problem of causing so-called dents.

  Therefore, there has been no material that can be directly processed into a circuit in an uncured or semi-cured prepreg. Furthermore, there has been no idea that circuit processing or the like is performed on an uncured or semi-cured prepreg.

  In recent years, with the demand for higher functionality and lighter, thinner and smaller electronic devices, high-density integration and further high-density mounting of electronic components have progressed. Semiconductor packages used in these electronic devices have been In addition, the size and number of pins are increasing.

  With the miniaturization of semiconductor packages, the conventional package using a lead frame has a limit on miniaturization. Therefore, recently, it is assumed that a chip is mounted on a circuit board, and BGA (Ball Grid) is used. Array) and a new area mounting type package system such as CSP (Chip Scale Package) have been proposed. An interposer used for a new package such as BGA or CSP is composed of a laminated plate made of a completely cured resin composition or a thermoplastic polyimide.

  In an interposer composed of a laminated plate in which the resin composition is completely cured, an adhesive component for bonding the semiconductor element and the interposer is required when the semiconductor element is mounted on the interposer.

  Further, in an interposer composed of thermoplastic polyimide, it is difficult to achieve both heat resistance (interposer itself) and adhesiveness (interposer and semiconductor element). That is, in order to improve adhesiveness, it is necessary to facilitate adhesion at a low temperature, but in that case, heat resistance is lowered. On the other hand, when the heat resistance is improved, the adhesiveness is lowered.

An object of the present invention, the adhesive is capable of metallic foil prepreg between the semiconductor device without using an adhesive component such as an adhesive, to provide a laminated plate and an interposer.

Such an object is achieved by the present invention of the following (1) to ( 12 ).
(1) A prepreg with a metal foil having a prepreg formed by impregnating a resin composition into a glass fiber substrate subjected to fiber opening treatment, and a metal foil formed on one side or both sides of the prepreg ,
The resin composition includes a first thermosetting resin and a second thermosetting resin having a molecular weight lower than that of the first thermosetting resin.
(2) The prepreg with a metal foil according to (1 ), wherein the first thermosetting resin is an epoxy resin or a cyanate resin .
(3) The prepreg with a metal foil according to the above (1 ) or (2), wherein the second thermosetting resin is an epoxy resin or a cyanate resin .
( 4 ) The prepreg with metal foil according to any one of the above ( 1 ) to ( 3 ), wherein the reaction rate of the resin composition is 30% or less .
( 5 ) The prepreg with metal foil according to any one of (1) to (4), wherein the prepreg has a through hole .
(6) the through hole, metallic foil prepreg according to the above (5) and is formed by laser processing.
( 7 ) The prepreg with metal foil according to (5) or (6) , wherein the through hole is plated .
(8) The prepreg with a metal foil according to any one of (1) to (7), wherein the constituent material of the metal foil is any one of copper, a copper alloy, aluminum, and an aluminum alloy .
(9) The prepreg with a metal foil according to any one of (1) to (8), wherein the metal foil has a thickness of 3 to 70 μm .
(10) A laminated board obtained by molding the prepreg with metal foil according to any one of (1) to (9) .
(11) A laminated plate obtained by patterning the metal foil included in the laminated plate according to (10) into a predetermined shape, and a coating layer formed so as to cover at least a part of the patterned metal foil. An interposer characterized by having.
(12) The interposer according to (11), wherein the prepreg has adhesiveness utilizing the adhesive force of the uncured resin composition .

According to the present invention, it is possible to provide an adhesive capable metallic foil prepreg between the semiconductor device without using an adhesive component such as an adhesive, laminates and interposer.

Also, in the case of manufacturing a laminate and interposer by metal foil prepreg using the particular substrate, it is possible to obtain particularly laminates and interposer excellent laser via processability.

It is sectional drawing which shows typically an example of the interposer in this invention. It is sectional drawing which shows typically an example of the prepreg with metal foil in this invention. It is sectional drawing which shows typically an example of the semiconductor package obtained using the interposer of this invention.

Hereinafter, the prepreg with metal foil of the present invention , a laminate, and an interposer will be described in detail.

  The prepreg with metal foil of the present invention comprises a prepreg and one or both sides of the prepreg. And a formed metal foil.

  Moreover, the laminate of the present invention is formed by molding the prepreg with metal foil of the present invention. To do.

The interposer of the present invention covers a prepreg, a conductor pattern (circuit) formed by patterning a metal foil formed on one or both sides of the prepreg into a predetermined shape, and at least a part of the conductor pattern. It has the formed coating layer (solder resist layer).

The semiconductor package may be Seisuru created by mounting a semiconductor element on the interposer.

In the interposer of the present invention, a step of forming a conductor pattern by etching on a metal foil of a prepreg with a metal foil having a metal foil on one side or both sides , and a covering layer is formed so as to cover at least a part of the conductor pattern. It is manufactured through processes .

In addition, in the semiconductor package described above, a conductive pattern is formed on a metal foil of a prepreg with a metal foil having a metal foil on one side or both sides , and a covering layer is formed so as to cover at least a part of the conductor pattern It is manufactured through a process of mounting a semiconductor element on an interposer manufactured from the process .

Hereinafter, a prepreg with a metal foil, a laminate, and an interposer of the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.

First, the interposer of the present invention and the manufacturing method thereof will be described.
FIG. 1 is a schematic side view for explaining an interposer according to the present invention. As shown in FIG. 1, the interposer 1 includes a prepreg 11, a conductor pattern (circuit) 12 formed on one surface of the prepreg 11, and a coating layer (solder resist layer) formed so as to cover at least a part of the conductor pattern 12. 13).

  A through-hole (via hole) 111 is formed in the prepreg 11 from the resin surface (upper surface in FIG. 1) side. This through hole may be formed by any method, but it is particularly preferable to form the through hole by laser processing.

  In order to maintain or improve the connection reliability of the conductor pattern 12 exposed by the through hole 111 and the land 14 described later, it is preferable to perform plating treatment of gold or solder in the through hole 111 and the land 14 respectively.

The conductor pattern formed on one side of the prepreg can be obtained, for example, by subjecting the prepreg 11 ( prepreg with metal foil) joined with the metal foil 21 shown in FIG. 2 to processing the conductor pattern (including other processes). it can.

  A prepreg having a metal foil is formed by, for example, forming an etching resist layer on the surface of the metal foil → exposing a conductive pattern having a predetermined shape → developing the etching resist layer → etching the metal foil using the developed etching resist layer as a mask → resist A conductor pattern is formed through steps such as removal of the layer (mask).

Examples of the metal constituting the metal foil include copper or a copper-based alloy, aluminum or an aluminum-based alloy, and the like. The thickness of the metal foil is preferably 3 to 70 μm, particularly preferably 12 to 35 μm.
The metal foil may be laminated on both sides of the prepreg.

  The covering layer 13 is formed so as to cover at least a part of the conductor pattern 12, for example, as shown in FIG.

  The covering layer 13 is formed by, for example, a process of forming a covering layer over the entire surface on which the conductor pattern 12 shown in FIG. 1 is formed → exposure of a pattern having a specific shape → developing the covering layer. Thereby, at least a part of the conductor pattern is covered, and the land 14 (uncovered portion) is formed.

The interposer of this invention can be manufactured according to the above-mentioned process.
The interposer of the present invention obtained by the above-described method can be bonded to a semiconductor element without using an adhesive component such as an adhesive. This is because a semiconductor element can be mounted in a prepreg state.

  In addition, since the resin is cured by heating in a post process after mounting the semiconductor element on the interposer of the present invention, an interposer having excellent heat resistance can be provided.

  Hereinafter, the prepreg, the conductor pattern, and the coating layer constituting the interposer will be described in detail.

The prepreg is composed of a resin composition and a base material.
For example, as shown in FIG. 2 , the prepreg 11 is obtained by impregnating a sheet-like base material 23 with a resin composition 22.

  Thereby, the rigidity of the interposer can be improved. When the rigidity of the interposer is improved, workability is improved.

  As resin which comprises the said resin composition, thermosetting resins, such as a phenol resin, an epoxy resin, cyanate resin, can be mentioned, for example. In particular, it is preferable to mainly use a cyanate resin as described later.

The resin composition may include a curing catalyst, an inorganic filler, and the like.
The resin composition is not particularly limited, but preferably contains at least one liquid resin. Thereby, flexibility can be imparted to the prepreg. “Liquid” means a material that exhibits fluidity at room temperature.

The resin composition is composed of a thermosetting resin as described above, and in particular, the first thermosetting resin and the second heat having a lower molecular weight than the first thermosetting resin. it is intended to include a curable resin. Thereby, in addition to the said effect, generation | occurrence | production of the tack | tuck of the prepreg surface can be prevented.

  The reaction rate of the resin composition in the prepreg is not particularly limited, but a reaction rate of 30% or less is preferable, and a reaction rate of 0.1 to 20% is particularly preferable. Thereby, in addition to the above-mentioned effect, generation | occurrence | production of powder | flour can be prevented. Furthermore, laser via processability can also be improved.

  The reaction rate can be determined by differential scanning calorimetry (DSC). That is, by comparing the area of the exothermic peak due to the DSC reaction for both the unreacted resin composition and the resin composition in the prepreg, it can be obtained by the following formula (I). Note that the measurement can be performed in a nitrogen atmosphere at a heating rate of 10 ° C./min.

Reaction rate (%) = (1-reaction peak area of resin composition in prepreg / reaction peak area of unreacted resin composition) × 100 (I)

Those exothermic peak of the resin composition of the unreacted impregnated with varnish made of the resin composition to a substrate, after 10 minutes and air dried at 40 ° C., 40 ° C., 1 kPa under a vacuum of, in 1 hour, the solvent was removed Was measured as a sample.

  The resin composition is not particularly limited, but preferably includes a first cyanate resin and a second cyanate resin having a weight average molecular weight lower than that of the first cyanate resin. Thereby, flexibility can be provided by the prepreg. Moreover, generation | occurrence | production of the crack of a prepreg can be prevented. Therefore, the process resistance at the time of processing the conductor pattern is excellent. Excellent processing process resistance means, for example, that cracks do not occur due to the pressure between the transport roll and the restraining roll during material transport, and that cracks do not occur due to the shower pressure of the etching solution during conductor pattern etching.

  Furthermore, the prepreg which can be wound up continuously can be obtained because the prepreg has flexibility.

  The weight average molecular weight of the first cyanate resin is not particularly limited, but is preferably 2,000 or more, and particularly preferably 2,200 to 10,000. When the weight average molecular weight of the first cyanate resin exceeds the upper limit, the viscosity when the resin composition is made into a varnish increases, and the impregnation property to the base material may decrease, and is less than the lower limit. In some cases, the resin flow becomes too large and the moldability is lowered.

  In addition, when the weight average molecular weight of the first cyanate resin is within the above range, even when the resin composition in the prepreg is uncured, the occurrence of tackiness on the prepreg surface can be prevented. If generation | occurrence | production of a tack can be prevented, the workability | operativity at the time of prepreg conveyance can be improved.

  The weight average molecular weight of the second cyanate resin is not particularly limited, but is preferably 1,500 or less, particularly preferably 200 to 1,300. When the weight average molecular weight of the second cyanate resin exceeds the upper limit, the effect of suppressing the generation of powder from the prepreg may be reduced. When the weight average molecular weight is less than the lower limit, the resin flow becomes excessively large and molded. May decrease.

  In addition, the flexibility of a prepreg can be improved more as the weight average molecular weight of 2nd cyanate resin exists in the said range. Moreover, generation | occurrence | production of the powder from a prepreg can be suppressed. Furthermore, the dispersibility of the filler mentioned later in the resin composition can also be improved.

  In addition, the weight average molecular weight of cyanate resin can be measured by polystyrene conversion using, for example, gel permeation chromatography.

  The first cyanate resin is not particularly limited, but is preferably solid at normal temperature. Thereby, even if the resin composition in the prepreg is in an uncured state, the occurrence of tackiness on the prepreg surface can be prevented.

  The second cyanate resin is not particularly limited, but is preferably liquid at room temperature. Thereby, in addition to improving the flexibility of a prepreg, generation | occurrence | production of the powder from a prepreg can be suppressed.

  In addition, a liquid state means what shows fluidity | liquidity at normal temperature. For example, the viscosity of the second cyanate resin is not particularly limited, but is preferably 500 Pa · s or less, and particularly preferably 1 to 300 Pa · s. The viscosity is measured using an E-type viscometer under conditions of a temperature of 25 ° C. and shear rates of 0.5, 1.0, 2.5 and 5.0 rpm. As the viscosity, a value that can be measured at the lowest rotational speed among the above conditions is used.

  The first and second cyanate resins can be obtained, for example, by reacting a cyanogen halide compound with phenols. Specific examples include novolac type cyanate resins and bisphenol type cyanate resins. Among these, it is preferable that at least one of the first cyanate resin and the second cyanate resin contains a novolak-type cyanate resin (particularly, it is preferable that the novolak-type cyanate resin contains 15% by weight or more of the entire resin composition). . Furthermore, it is particularly preferable that both the first and second cyanate resins contain a novolac type cyanate resin. Thereby, the heat resistance (glass transition temperature, thermal decomposition temperature) of a prepreg can be improved. Further, the thermal expansion coefficient of the prepreg (particularly, the thermal expansion coefficient in the thickness direction of the prepreg) can be reduced. When the thermal expansion coefficient in the thickness direction of the prepreg is lowered, the stress strain of the multilayer printed wiring can be reduced. Furthermore, in a multilayer printed wiring board having fine interlayer connection portions, the connection reliability can be greatly improved.

  The first and second cyanate resins may have different molecular structures, but preferably have the same molecular structure. Thereby, the compatibility of cyanate resin from which molecular weight differs can be improved.

  As said 1st and 2nd novolak-type cyanate resin, what is shown, for example by Formula (I) can be used.

  When the novolak-type cyanate resin represented by the formula (I) is used as the first cyanate resin, the weight average molecular weight is not particularly limited, but is preferably 2,000 to 10,000, particularly 2,200 to 3, 500 is preferred. When the weight average molecular weight is within the above range, even if the resin constituting the prepreg is in an uncured state, the occurrence of tackiness on the prepreg surface can be effectively prevented.

  Moreover, when using the novolak-type cyanate resin shown by said Formula (I) as 2nd cyanate resin, although a weight average molecular weight is not specifically limited, 300-2,000 are preferable, Especially 500-1,500 are preferable. . When the weight average molecular weight is within the above range, the flexibility of the prepreg is further improved. Moreover, generation | occurrence | production of the powder from a prepreg can be suppressed. Furthermore, the dispersibility of the filler mentioned later in the resin composition can also be improved.

  Although content of said 1st cyanate resin is not specifically limited, 5-23 weight% of the whole resin composition is preferable, and 6-18 weight% is especially preferable. When the content of the first cyanate resin is within the above range, the occurrence of tackiness on the prepreg surface can be prevented even when the resin constituting the prepreg is uncured.

  Further, the content of the second cyanate resin is not particularly limited, but is preferably 2 to 15% by weight, particularly preferably 4 to 10% by weight, based on the entire resin composition. When the content of the second cyanate resin is within the above range, the prepreg can be further improved in flexibility, and generation of powder from the prepreg can be suppressed.

  Although the said resin composition is not specifically limited, It is preferable that the resin of hygroscopicity is lower than 1st and 2nd cyanate resin. Thereby, the moisture resistance (especially solder heat resistance after moisture absorption) of a prepreg can be improved.

  As the resin having low hygroscopicity, for example, a resin having a low content of oxygen atoms (particularly a hydroxyl type) (particularly a resin having an oxygen atom content of 5% by weight or less) is preferable. Further, it is preferable that the degree of crystallinity and the degree of packing are large and the constituent molecules are composed only of C, H, Cl, and F (however, it is better to avoid the halogen content due to recent environmental protection problems). For example, a resin in which at least one selected from a naphthalene skeleton, a biphenyl skeleton, and a cyclopentadiene skeleton is introduced into the resin skeleton can be given. Specific examples include a naphthol novolac type epoxy resin.

  In consideration of reactivity with cyanate resin, an epoxy resin (particularly an aralkyl epoxy resin) is preferable as the resin having low hygroscopicity. Thereby, moisture resistance can be improved especially. Of the aralkyl type epoxy resins, biphenyl type epoxy resins are particularly preferable. Thereby, in addition to the effect which improves moisture resistance, favorable heat resistance can be acquired.

  The content of the low hygroscopic resin is not particularly limited, but is preferably 20% by weight or less, particularly preferably 10 to 18% by weight, based on the entire resin composition. Thereby, it is excellent in the balance of the heat resistance which is the characteristic of cyanate resin, low expansibility, and moisture resistance. Further, non-halogen flame retardant can be achieved.

  The resin composition is not particularly limited, but preferably contains a curing catalyst. Thereby, the crosslinking density of cyanate resin is controllable.

  The said curing catalyst can use a well-known thing as a curing catalyst of cyanate resin. For example, organic metal salts such as zinc naphthenate, cobalt naphthenate, tin octylate, cobalt octylate, tertiary amines such as triethylamine, tributylamine, diazabicyclo [2,2,2] octane, 2-phenyl-4- Imidazoles such as methylimidazole, 2-ethyl-4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, phenol, bisphenol A, nonylphenol, etc. A phenol compound, a phenol resin, an organic acid, etc. are mentioned. These can be used alone or as a mixture thereof. Of these, phenol resins (particularly phenol novolac resins) are preferred.

  The content of the curing catalyst is not particularly limited, but is preferably 0.01 to 5.0% by weight, and particularly preferably 0.05 to 3.0% by weight. When the content of the curing agent is within the above range, good moisture resistance and heat resistance can be obtained.

  Further, the content of the curing catalyst in the case of using the curing catalyst containing the low hygroscopic resin and acting also as the curing agent is not particularly limited, but is 50 to 100 of the resin functional group equivalent of the low hygroscopic property. % Functional group equivalent is preferable, and 15 weight% or less of the whole resin composition is preferable. When the content of the curing agent is within the above range, good moisture resistance and heat resistance can be obtained.

  Further, the curing catalyst that also acts as a curing agent for the resin having low hygroscopicity is not particularly limited, but a liquid catalyst at room temperature can be used.

Although the said resin composition is not specifically limited, It is preferable that a filler is included. Thereby, the resin flow at the time of shape | molding a prepreg in an uncured state is controllable. If the resin flow can be controlled, the moldability when the prepreg with a metal foil of the present invention is molded into a laminate or the like can be improved.

  The filler is not particularly limited, but a powder is preferable, and a powder inorganic filler is particularly preferable. Thereby, the fluidity | liquidity of a resin composition can be controlled more. Further, the prepreg can be further reduced in thermal expansion.

  Examples of the filler include silicates such as talc, clay, mica and glass, oxides such as alumina and silica, carbonates such as calcium carbonate and magnesium carbonate, hydroxides such as aluminum hydroxide and magnesium hydroxide. Etc. Among these, oxides such as silica are preferable. Thereby, the prepreg can be further reduced in thermal expansion (particularly, the thermal expansion coefficient in the thickness direction of the prepreg can be reduced).

  Among the silicas, fused silica is preferable. Further, the shape of silica is crushed or spherical, but spherical is preferable in order to lower the melt viscosity of the resin composition, such as ensuring impregnation into a glass substrate. Thereby, the filling efficiency can be improved and the prepreg can be further reduced in thermal expansion.

  The average particle diameter of the filler is not particularly limited, but is preferably 2.0 μm or less, and particularly preferably 0.2 to 1.0 μm. When the average particle size of the filler is within the above range, in addition to imparting thixotropy, the fluidity of the resin can be controlled better.

Although content of the said filler is not specifically limited, 40 to 80 weight% of the whole resin composition is preferable, and 50 to 70 weight% is especially preferable. When the content of the filler is within the above range, thixotropy can be imparted to the resin composition. When thixotropy to the resin composition is applied, at the time of press-forming the prepreg from this resin composition, it is possible to control the resin flow.

As a base material which comprises the said prepreg, glass fiber base materials, such as a glass woven fabric, a glass nonwoven fabric, and glass paper, are used. Besides glass fiber base materials, woven fabrics and nonwoven fabrics made of organic fibers such as paper (pulp), aramid, polyester, fluororesin, woven fabrics, nonwoven fabrics, mats made of metal fibers, carbon fibers, mineral fibers, etc. may be contained, nonwoven composed of organic fibers among these, preferred. Thereby, the laser via processability can be improved.

Further, among the glass fiber base materials, those that have been opened are used . Thereby, the laser via processability can be improved.

  The term “opening process” refers to an arrangement in which the adjacent yarns of warp and weft are arranged substantially without any gap.

  Examples of the method for producing a prepreg using the resin composition and the substrate include a method of impregnating the resin composition into the substrate, a method of applying the resin composition to the substrate, and the like. Among these, a method of impregnating the base material with the resin composition is preferable.

  Examples of the method of impregnating the base material with the resin composition include a method of immersing the base material in a resin varnish, a method of applying with various coaters, and a method of spraying with a spray. Among these, the method of immersing the base material in the resin varnish is preferable. Thereby, the impregnation property of the resin composition with respect to a base material can be improved. In addition, when a base material is immersed in a resin varnish, a normal impregnation coating equipment can be used.

  The solvent used in the resin varnish desirably has good solubility in the resin composition, but a poor solvent may be used as long as it does not adversely affect the resin varnish. Examples of the solvent exhibiting good solubility include methyl ethyl ketone and cyclohexanone.

  The solid content of the resin varnish is not particularly limited, but the solid content of the resin composition is preferably 40 to 80% by weight, and particularly preferably 50 to 65% by weight. Thereby, the impregnation property to the base material of a resin varnish can further be improved.

  The prepreg constituting the interposer of the present invention has sufficient processing process resistance in the above-described conductor pattern processing and subsequent processes. Therefore, inconveniences such as cracking of the prepreg and generation of powder do not occur during the assembly work of such an interposer and semiconductor package.

Next, the semiconductor package will be described.
Semi conductor package 3, for example, the interposer 1 as shown in FIG. 3, is made by mounting a semiconductor element (IC chip) 31.

  The semiconductor element 31 has bumps 32 on the lower surface (lower side in FIG. 1). The semiconductor element 31 is mounted on the resin surface of the prepreg 11 of the interposer 1. At this time, the semiconductor element 31 and the conductor pattern 12 are joined by the bump 32 in the through hole 111. Although not shown, the bumps 32 may be formed in advance in the through holes 111 of the interposer 1. In this way, the semiconductor package 3 can be obtained.

  Then, solder balls 33 are formed on the lands 14 of the semiconductor package 3. The semiconductor package 3 is joined to a printed board (not shown) by the solder balls 33.

  The semiconductor package obtained by the above-described method can be reduced in thickness because cracks hardly occur even if it is thinned. Further, since the thickness can be reduced, the wiring distance can be shortened, so that high speed operation is possible.

Any semiconductor element can be used. For example, a semiconductor memory device, a central processing device, a micro processing device, and the like can be given.
Although not shown, the semiconductor element may be molded with resin.

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

First, the Example and comparative example about an interposer are demonstrated.
Manufacture of interposer (Example 1)
<Preparation of prepreg>
[1] Preparation of resin varnish First novolak-type cyanate resin (Lonza Japan Co., Ltd., Primaset PT-60 weight average molecular weight 2,300) 10 parts by weight (hereinafter abbreviated as part), second novolac-type cyanate Resin (Lonza Japan Co., Ltd., Primaset PT-30 Weight average molecular weight 1,300 Viscosity 500-1000 Pa · s) 10 parts, Biphenyldimethylene type epoxy resin (Nippon Kayaku Co., Ltd., NC-3000SH) 12 parts, 8 parts of biphenyl dimethylene type phenol resin (Maywa Kasei Co., Ltd., MEH-7851-3H), 60 parts of spherical fused silica SFP-10X (Electric Chemical Co., Ltd.) having an average particle size of 0.3 μm were added to methyl ethyl ketone. It melt | dissolved at normal temperature and stirred for 10 minutes with the high-speed stirrer, and obtained the resin varnish.

[2] Impregnation and drying of varnish The above-described resin varnish was impregnated into a fiberglass base material (thickness 50 μm, manufactured by Nitto Boseki Co., Ltd., WEA-05E), and then heated in a 120 ° C. heating furnace for 2 minutes. A prepreg was obtained by drying. Copper foil (Furukawa Circuit Foil, GTS, thickness 18 μm) was laminated on the prepreg to obtain a prepreg with a metal foil having a total thickness of 70 μm. The reaction rate of the resin composition in the obtained prepreg was 5%.

<Production of interposer>
[1] Production of Conductive Pattern After the prepreg with metal foil described above formed a dry film resist (38A212 manufactured by Nichigo-Morton), a conductive pattern having a predetermined shape was exposed. Next, the resist layer was developed with a 1.5 wt% sodium carbonate aqueous solution. Next, the metal foil was etched using the dry film resist as a mask, and the resist was removed with a 3 wt% sodium hydroxide aqueous solution to prepare a predetermined conductor pattern.

[2] Formation of Coating Layer Next, a coating layer was formed with a dry film solder resist (CFP-1122 manufactured by Sumitomo Bakelite Co., Ltd.) so as to cover the conductor pattern of the prepreg described above. Next, a pattern having a predetermined shape was exposed, and the coating layer was developed with a 1.5 wt% sodium hydroxide aqueous solution.

[3] Formation of Through Hole Next, a via hole was formed on the resin surface of the prepreg with a CO ₂ laser to produce an interposer.

(Example 2)
The same procedure as in Example 1 was performed except that 13 parts of the first cyanate resin, 13 parts of the second cyanate resin, 8 parts of the low hygroscopic resin, and 6 parts of the curing catalyst were used in the prepreg.

(Example 3)
The same procedure as in Example 1 was performed except that the drying temperature was set to 160 ° C. during the preparation of the prepreg and the reaction rate of the resin composition in the prepreg was set to about 20%.

(Example 4)
The same procedure as in Example 1 was conducted except that the drying temperature was set to 170 ° C. during the preparation of the prepreg and the reaction rate of the resin composition in the prepreg was changed to about 30%.

(Example 5)
28 parts of bisphenol A type epoxy resin (EP-1007 manufactured by Japan Epoxy Resin Co., Ltd., epoxy equivalent 2000) instead of the first cyanate resin in the prepreg, bisphenol F type epoxy resin (Nipponization) instead of the second cyanate resin Except for adding 11 parts of 2-phenyl-4-methylimidazole without using biphenyl dimethylene type epoxy resin and biphenyl dimethylene type phenol resin and 11 parts of RE-404S manufactured by Yakuhin Co., Ltd. Same as Example 1.

(Example 6)
32 parts of bisphenol A type epoxy resin (EP-1001, Epoxy equivalent 475 manufactured by Japan Epoxy Resin Co., Ltd.) instead of the first cyanate resin, phenol resin (HF manufactured by Sumitomo Bakelite Co., Ltd.) instead of the second cyanate resin -3) The procedure was the same as Example 1 except that 7 parts were used and 1 part of 2-phenyl-4-methylimidazole was added without using the biphenyldimethylene type epoxy resin and the biphenyldimethylene type phenol resin.

(Comparative Example 1)
The laminate described below, in which the epoxy resin constituting the prepreg was almost completely cured, was used as an interposer.

  A through-hole (through hole) is provided with a mechanical drill or the like at a predetermined position of a double-sided copper-clad laminate (ELC-4781 manufactured by Sumitomo Bakelite Co., Ltd.) made of a 100 μm thick insulating layer and a 18 μm thick copper foil, Copper circuit layers on both sides were connected by plating through holes with copper.

(Comparative Example 2)
Instead of the prepreg constituting the interposer, the polyimide film described below was used. Otherwise, the same procedure as in Example 1 was performed.

  A 15 wt% NMP solution of polyamic acid having a linear expansion coefficient of 10 ppm after imidization is applied on a 75 μm thick polyester film with a die coater, dried at 100 ° C. for 10 minutes, and a polyamic acid film having a thickness of 80 μm. Got. The above polyamic acid film was layered on 18 μm rolled copper foil (manufactured by Nippon Mining), and thermocompression bonded at 140 ° C. using a roll laminator. The obtained polyamic acid film with copper foil was continuously heated in a nitrogen dryer at 150 ° C., 200 ° C., 250 ° C., 300 ° C., 350 ° C. for 15 minutes each and further at 400 ° C. for 2 hours to imidize. Went. The thickness of the polyimide layer after imidization was 40 μm. On this polyimide layer, NMP solution of adhesive resin mixed with silicone modified polyimide and epoxy resin was cast coated with a bar coater and dried at 80 ° C, 150 ° C and 220 ° C for 3 minutes, respectively, and 10µm adhesive A layer was formed. A polyimide adhesive film with a metal foil having a total thickness of 70 μm was obtained.

Table 1 shows the results obtained by the above-described examples and comparative examples.
Each evaluation was performed by the following method.

Chip adhesion Chip adhesion is achieved by mounting a flip chip type semiconductor element on the interposer obtained by the above-described method under a pressure of 3 kg / cm ² for 10 seconds, and the chip peeling strength after curing is 0.8 kN. The mounting temperature that is at least / m was measured. The table shows their mounting temperature and moldability. A mark of moldability indicates that the moldability is good. ○ indicates that slight voids are observed, but there is no practical problem. Δ indicates the occurrence of slight voids, which may cause practical problems. X indicates that a large number of voids are observed and is problematic in practical use.

  In Comparative Example 1, the semiconductor element was mounted on the surface of the double-sided interposer on which the bump connection pads were disposed, and then the underfill material was filled in the gap between the semiconductor element and the interposer to seal the functional surface.

Manufacturing cost The manufacturing cost was compared with the manufacturing cost of Comparative Example 1 being a conventional method as 100.

As shown in Table 1, the interposers of Examples 1 to 6 were excellent in chip adhesiveness.
In addition, the interposers of Examples 1-2 and 6 were excellent in chip adhesion, and chip adhesion at a particularly low temperature was possible.
Moreover, the interposer of Examples 1-6 was excellent in the moldability at the time of chip | tip adhesion | attachment.

Next, examples and comparative examples of the semiconductor package will be described.
Manufacturing of semiconductor package (Examples 11 to 16)
The interposers shown in the table were used. The semiconductor element was mounted on the interposer as follows. The flip chip type semiconductor element having solder bumps was sucked and transferred by the mounting tool, and the semiconductor element and the preheated interposer were aligned. 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. Thereafter, after-curing at 180 ° C. for 60 minutes, a semiconductor package was obtained.

(Comparative Example 11)
After mounting the flip chip type semiconductor element having solder bumps on the surface of the double-sided interposer obtained in Comparative Example 1 where the bump connection pads are arranged, the gap between the semiconductor element and the interposer is filled with an underfill material, and 180 ° C. After curing for 60 minutes, a semiconductor package was obtained.

(Comparative Example 12)
Except having used the interposer obtained by the comparative example 2, it carried out similarly to Examples 11-16.

  The results obtained by the above method are shown in Table 2. Each evaluation was performed by the following method.

Temperature cycle test In the temperature cycle test, the initial continuity of the semiconductor package obtained above was confirmed, and then a test was performed with 30 minutes at -40 ° C and 30 minutes at 125 ° C as one cycle. Table 2 summarizes the results of the number of defective disconnections after 1000 cycles of the temperature cycle test of the 10 semiconductor packages that were input.

Moisture absorption insulation Moisture absorption insulation measures the initial insulation resistance of the semiconductor package obtained above, and then applies a DC voltage of 5.5 V in an atmosphere of 85 ° C / 85% RH, and insulation after 1000 hours has elapsed. Resistance was measured. The applied voltage at the time of measurement was 100 V for 1 minute, and the initial insulation resistance and the insulation resistance after treatment are shown together in Table 2. The insulation resistance was measured with a comb-type electrode of line / space = 50 μm / 50 μm.

Moisture absorption reflow Moisture absorption reflow is performed by treating the interposer obtained above in an atmosphere of 85 ° C / 85% RH for 168 hours, and then passing through a reflow device set to a peak temperature of 260 ° C three times and observing the subsequent state. did. Table 2 shows the number of defects among the 10 processed.

Semiconductor Package Thickness The thickness of the semiconductor package was measured with a micrometer.

  As is apparent from the table, the thickness of the semiconductor packages of Examples 11 to 16 can be reduced.

  Moreover, the semiconductor packages of Examples 11 to 16 were excellent in heat resistance after moisture absorption, and had good quality and performance.

1 Interposer 11 Prepreg 111 Through-hole 12 Conductor Pattern (Circuit)
13 Coating layer (solder resist layer)
14 Land 21 Metal foil 22 Resin composition 23 Sheet-like base material 3 Semiconductor package 31 Semiconductor element (IC chip)
32 Bump 33 Solder ball

Claims (17)

  An interposer comprising: a prepreg; a conductor pattern formed on one surface of the prepreg; and a coating layer formed to cover at least a part of the conductor pattern.   The interposer according to claim 1, wherein the prepreg has a through hole.   The interposer according to claim 2, wherein the through hole is plated.   The interposer according to any one of claims 1 to 3, wherein the prepreg is formed by impregnating a base material with a resin composition.   The interposer according to claim 4, wherein the base material is a nonwoven fabric composed of organic fibers.   The interposer according to claim 4, wherein the base material is a glass fiber base material that has been subjected to fiber opening treatment.   The interposer according to any one of claims 4 to 6, wherein a reaction rate of the resin composition is 30% or less.   The interposer according to any one of claims 4 to 7, wherein the resin composition contains at least one liquid resin.   The interposer according to claim 8, wherein the resin composition includes a resin having a higher molecular weight than the liquid resin.   10. A semiconductor package comprising a semiconductor element mounted on the interposer according to claim 1.   10. The semiconductor package according to claim 1, wherein the interposer and the semiconductor element are joined by bumps. Forming a conductive pattern by etching on a metal foil of a prepreg formed by bonding a metal foil to one side;
And a step of forming a coating layer so as to cover at least a part of the conductor pattern. Forming a conductive pattern by etching on a metal foil of a prepreg formed by bonding a metal foil to one side;
Forming a coating layer so as to cover at least a part of the conductor pattern;
And a step of forming a through hole in the prepreg.   The method for manufacturing an interposer according to claim 13, wherein the through hole is formed by laser processing.   The method for producing an interposer according to any one of claims 12 to 14, wherein a reaction rate of the resin composition constituting the prepreg is 30% or less. Forming a conductive pattern by etching on a metal foil of a prepreg formed by bonding a metal foil to one side;
In the interposer produced from the step of forming a coating layer so as to cover at least a part of the conductor pattern,
A method of manufacturing a semiconductor package, comprising a step of mounting a semiconductor element.   The method of manufacturing a semiconductor package according to claim 16, wherein the interposer and the semiconductor element are bonded using an adhesive force of an uncured resin composition constituting a prepreg.

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