JP2015106573A - Resin sheet for hollow sealing, and manufacturing method of hollow package - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin sheet for hollow sealing in which an electronic device can be appropriately buried and a material forming the resin sheet for sealing is unlikely to flow into a cavity between an adherend and the electronic device.SOLUTION: Bottom dynamic viscosity of the entire resin sheet for hollow sealing before curing at 60 to 150°C is 5000 Pa s or higher and 500,000 Pa s or lower. A test substrate in which a plurality of chips are flip-chip-connected is used as a substrate. In the case where the resin sheet for hollow sealing is disposed on the test substrate and the test substrate is then pressurized from the side of the resin sheet for hollow sealing at 70°C, with pressure of 1 kgf/cmand with a vacuum degree of 10 Torr, a ratio A/B of a speed A for the material forming the resin sheet for hollow sealing to move between the chips and a speed B for the material forming the resin sheet for hollow sealing to move into the cavity is 5 or more.

Description

  The present invention relates to a resin sheet for hollow sealing and a method for producing a hollow package.

  For the production of an electronic device package, typically, one or more electronic devices fixed to a substrate or the like via bumps or the like are sealed with a sealing resin, and the sealing body is united as an electronic device as necessary. The procedure of dicing so that it becomes a package of is adopted. As such a sealing resin, a sheet-shaped sealing resin may be used.

  In recent years, along with semiconductor packages, microelectronic devices called MEMS, such as SAW (Surface Acoustic Wave) filters, CMOS (Complementary Metal Oxide Semiconductor) sensors, and acceleration sensors, have been developed. Each package in which these electronic devices are sealed generally has a hollow structure for ensuring the propagation of surface acoustic waves, maintaining the optical system, and the mobility of the movable member of the electronic device. This hollow structure is often provided as a gap between the substrate and the element. When sealing, it is necessary to seal while maintaining the hollow structure so as to ensure the operation reliability of the movable member and the connection reliability of the element. For example, Patent Document 1 describes a technique of hollow-molding a functional element using a gel-like curable resin sheet.

JP 2006-19714 A

  As a manufacturing method of the package, there is a method of laminating a resin sheet for hollow sealing so as to cover one or a plurality of electronic devices arranged on an adherend, and then thermosetting the resin sheet for hollow sealing. Can be mentioned. In such a manufacturing method, it is desirable that the electronic device can be suitably embedded in the hollow sealing resin sheet, and that the material constituting the sealing resin sheet does not flow into the gap.

  The present invention has been made in view of the above-described problems, and the object thereof is to suitably embed an electronic device in a hollow sealing resin sheet, and in the gap between the adherend and the electronic device, An object of the present invention is to provide a hollow sealing resin sheet in which a material constituting the sealing resin sheet hardly flows and a method for manufacturing a hollow package.

  The inventors of the present application have found that the above-mentioned problems can be solved by adopting the following configuration, and have completed the present invention.

That is, the present invention provides a hollow sealing resin sheet on the electronic device so as to cover one or more electronic devices arranged on the adherend, and a hollow portion between the adherend and the electronic device. The hollow sealing resin sheet used for the manufacturing method of the hollow package including the lamination process which laminates | maintains while maintaining a process, and the sealing body formation process which hardens the said hollow sealing resin sheet and forms a sealing body Because
The minimum dynamic viscosity before curing at 60 to 150 ° C. of the entire resin sheet for hollow sealing is 5,000 Pa · s or more and 500,000 Pa · s or less,
A test substrate in which a plurality of chips are flip-chip connected to a substrate, the distance between the chips is 100 μm, and the gap (hollow gap) between the substrate and the chips is 20 μm,
After the resin sheet for hollow sealing is placed on the test substrate, the hollow sealing when pressurized from the hollow sealing resin sheet side at 70 ° C., a pressure of 1 kgf / cm ² , and a degree of vacuum of 10 Torr. The ratio A / B between the entry speed A of the material constituting the fixing resin sheet between the chips and the entry speed B of the material constituting the hollow sealing resin sheet into the gap is 5 or more. Features.

According to the said structure, since the minimum dynamic viscosity before hardening in 60-150 degreeC of the whole resin sheet for hollow sealing is 5000 Pa.s or more and 500,000 Pa.s or less, the resin sheet for hollow sealing is used. It is difficult for the entire material to flow into the hollow portion. Accordingly, it is possible to efficiently prevent the resin from entering the hollow portion. As a result, a hollow package can be manufactured with a high yield while maintaining the hollow structure.
Further, since the ratio A / B is 5 or more, in the laminating step, the electronic device can be suitably embedded in the hollow sealing resin sheet, and the gap between the adherend and the electronic device is The material constituting the sealing resin sheet can be made difficult to flow.

  In the said structure, 1 volume% or less may be sufficient as content of an inorganic filler.

  Even if the content of the inorganic filler is 1% by volume or less and is not substantially contained, the minimum dynamic viscosity before curing at 60 to 150 ° C. of the entire hollow sealing resin sheet is 50,000. Pa · s or more and 1 million Pa · s or less, and the ratio A / B is 5 or more. Therefore, in the laminating step, an electronic device can be suitably embedded in the hollow sealing resin sheet, and an adherend is provided. It is possible to make it difficult for the material constituting the sealing resin sheet to flow into the gap between the electronic device and the electronic device.

  In the said structure, it is preferable that the viscosity of the organic resin component in 120 degreeC is 100 Pa.s or more.

  When the viscosity of the organic resin component at 120 ° C. is 100 Pa · s or higher, the viscosity of the organic resin component (organic resin component excluding the inorganic filler) is high, so that only the organic resin component oozes into the hollow portion. This can be suppressed.

Further, the present invention is a method for manufacturing a hollow package,
A resin sheet for hollow sealing is laminated on the electronic device while maintaining a hollow portion between the adherend and the electronic device so as to cover one or a plurality of electronic devices arranged on the adherend. Lamination process;
A sealing body forming step of curing the hollow sealing resin sheet to form a sealing body,
The hollow sealing resin sheet is:
The minimum dynamic viscosity before curing at 60 to 150 ° C. of the entire resin sheet for hollow sealing is 5,000 Pa · s or more and 500,000 Pa · s or less,
A test substrate in which a plurality of chips are flip-chip connected to a substrate, the distance between the chips is 100 μm, and the gap between the substrate and the chip is 20 μm,
After the resin sheet for hollow sealing is placed on the test substrate, the hollow sealing when pressurized from the hollow sealing resin sheet side at 70 ° C., a pressure of 1 kgf / cm ² , and a degree of vacuum of 10 Torr. The ratio A / B between the entry speed A of the material constituting the stopper resin sheet between the chips and the entry speed B of the material constituting the hollow sealing resin sheet into the gap is 5 or more.

According to the said structure, since the resin sheet for hollow sealing has the minimum dynamic viscosity before hardening in 60-150 degreeC of the whole resin sheet for hollow sealing from 5,000 Pa.s to 500,000 Pa.s. The entire material constituting the hollow sealing resin sheet is unlikely to flow into the hollow portion. Accordingly, it is possible to efficiently prevent the resin from entering the hollow portion. As a result, a hollow package can be manufactured with a high yield while maintaining the hollow structure.
Further, since the ratio A / B is 5 or more, in the laminating step, the electronic device can be suitably embedded in the hollow sealing resin sheet, and the gap between the adherend and the electronic device is The material constituting the sealing resin sheet can be made difficult to flow.

It is sectional drawing which shows typically the resin sheet which concerns on one Embodiment of this invention. It is a front schematic diagram for demonstrating a test board | substrate. It is a figure for demonstrating how to obtain | require ratio A / B. It is a figure for demonstrating how to obtain | require ratio A / B. It is a figure for demonstrating how to obtain | require ratio A / B. It is a figure which shows typically 1 process of the manufacturing method of the hollow package which concerns on one Embodiment of this invention. It is a figure which shows typically 1 process of the manufacturing method of the hollow package which concerns on one Embodiment of this invention. It is a figure which shows typically 1 process of the manufacturing method of the hollow package which concerns on one Embodiment of this invention.

  The present invention will be described in detail below with reference to embodiments, but the present invention is not limited only to these embodiments.

  [Hollow sealing resin sheet]

  FIG. 1 is a cross-sectional view schematically showing a hollow sealing resin sheet (hereinafter also simply referred to as “resin sheet”) 11 according to an embodiment of the present invention. The resin sheet 11 is typically provided in a state of being laminated on a support 11a such as a polyethylene terephthalate (PET) film. Note that a release treatment may be performed on the support 11a in order to easily peel off the resin sheet 11.

FIG. 2A is a schematic front view for explaining the test substrate.
As shown in FIG. 2A, the test substrate 50 has a configuration in which a plurality of chips 54 are flip-chip connected to the substrate 52. The chip 54 is flip-chip connected to the substrate 52 by bumps 56. The distance between the chips 54 is 100 μm, and the gap 58 between the substrate 52 and the chip 54 is 20 μm.

The resin sheet 11 constitutes the resin sheet 11 when the resin sheet 11 is disposed on the test substrate 50 and then pressurized from the resin sheet 11 side at 70 ° C., a pressure of 1 kgf / cm ² , and a degree of vacuum of 10 Torr. The ratio A / B between the material entry speed A between the chips 54 and the resin entry speed B into the gap 58 is 5 or more, preferably 8 or more, and 10 or more. More preferred. The ratio A / B is preferably larger, but is, for example, 300 or less. Since the ratio A / B is 5 or more, the electronic device can be suitably embedded in the resin sheet 11, and the material constituting the resin sheet 11 flows into the gap between the adherend and the electronic device. Can be difficult.

Hereinafter, the method for obtaining the ratio A / B will be described in detail.
2B to 2D are diagrams for explaining how to obtain the ratio A / B.
First, as illustrated in FIG. 2B, the resin sheet 11 is disposed on the test substrate 50. Next, as shown in FIG. 2C, pressurization is performed from the resin sheet 11 side at 70 ° C., a pressure of 1 kgf / cm ² , and a degree of vacuum of 10 Torr. Then, the resin enters between the chips 54 by pressure. At this time, the speed in the traveling direction of the tip of the resin is measured. This is the approach speed A. The approach speed A is measured within a range until the material constituting the resin sheet 11 reaches the substrate 52. Thereafter, when the pressurization is continued, the resin reaches the substrate 52 as shown in FIG. 2D. Thereafter, pressurization is continued as it is, and the speed in the traveling direction of the tip of the resin is measured. Specifically, the speed of the resin tip in the direction of the gap 58 is measured. This is the approach speed B. Thereafter, the ratio A / B is calculated. More details are as described in the examples.

  The minimum dynamic viscosity before curing at 60 to 150 ° C. of the entire resin sheet 11 is 5,000 Pa · s to 500,000 Pa · s, and is 10,000 Pa · s to 300,000 Pa · s. Preferably, it is 20,000 Pa · s or more and 200,000 Pa · s or less. Since the minimum dynamic viscosity before curing at 60 to 150 ° C. of the entire resin sheet 11 is not less than 5,000 Pa · s and not more than 500,000 Pa · s, the entire material constituting the resin sheet 11 is difficult to flow into the hollow portion. be able to.

  The resin sheet 11 preferably contains an epoxy resin and a phenol resin. Thereby, favorable thermosetting is obtained.

  The epoxy resin is not particularly limited. For example, triphenylmethane type epoxy resin, cresol novolac type epoxy resin, biphenyl type epoxy resin, modified bisphenol A type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, modified bisphenol F type epoxy resin, dicyclopentadiene type Various epoxy resins such as an epoxy resin, a phenol novolac type epoxy resin, and a phenoxy resin can be used. These epoxy resins may be used alone or in combination of two or more.

  From the viewpoint of ensuring the toughness of the epoxy resin after curing and the reactivity of the epoxy resin, it is preferably a solid at an ordinary temperature with an epoxy equivalent of 150 to 250, a softening point or a melting point of 50 to 130 ° C. From the viewpoint of reliability, bisphenol F type epoxy resin, G, bisphenol A type epoxy resin, biphenyl type epoxy resin, and the like are more preferable.

  The phenol resin is not particularly limited as long as it causes a curing reaction with the epoxy resin. For example, a phenol novolac resin, a phenol aralkyl resin, a biphenyl aralkyl resin, a dicyclopentadiene type phenol resin, a cresol novolak resin, a resole resin, or the like is used. These phenolic resins may be used alone or in combination of two or more.

  From the viewpoint of reactivity with the epoxy resin, it is preferable to use a phenol resin having a hydroxyl group equivalent of 70 to 250 and a softening point of 50 to 110 ° C., and in particular, from the viewpoint of high curing reactivity and low cost. A phenol novolac resin can be preferably used. From the viewpoint of reliability, low hygroscopic materials such as phenol aralkyl resins and biphenyl aralkyl resins can also be suitably used.

  From the viewpoint of curing reactivity, the blending ratio of the epoxy resin and the phenol resin is blended so that the total number of hydroxyl groups in the phenol resin is 0.7 to 1.5 equivalents with respect to 1 equivalent of the epoxy group in the epoxy resin. Preferably, it is 0.9 to 1.2 equivalents.

  The lower limit of the total content of the epoxy resin and the phenol resin in the resin sheet 11 is preferably 10% by weight or more, and more preferably 20% by weight or more. Adhesive force with respect to an electronic device, a board | substrate, etc. is acquired favorably as it is 10 weight% or more. On the other hand, the upper limit of the total content is preferably 50% by weight or less, and more preferably 30% by weight or less. The hygroscopicity of a resin sheet can be reduced as it is 50 weight% or less.

  The resin sheet 11 preferably contains a thermoplastic resin. Thereby, the heat resistance of the resin sheet for hollow sealing obtained, flexibility, and intensity | strength can be improved.

  As thermoplastic resins, natural rubber, butyl rubber, isoprene rubber, chloroprene rubber, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-acrylic acid ester copolymer, polybutadiene resin, polycarbonate resin, thermoplasticity Polyimide resin, polyamide resin such as 6-nylon and 6,6-nylon, phenoxy resin, acrylic resin, saturated polyester resin such as PET and PBT, polyamideimide resin, fluorine resin, styrene-isobutylene-styrene block copolymer, etc. Can be mentioned. These thermoplastic resins can be used alone or in combination of two or more. Especially, an acrylic resin is preferable from a viewpoint that a flexibility is easy to obtain and a dispersibility with an epoxy resin is favorable.

  The acrylic resin is not particularly limited, and includes one or two or more esters of acrylic acid or methacrylic acid having a linear or branched alkyl group having 30 or less carbon atoms, particularly 4 to 18 carbon atoms. Examples thereof include a polymer (acrylic copolymer) as a component. Examples of the alkyl group include a methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, t-butyl group, isobutyl group, amyl group, isoamyl group, hexyl group, heptyl group, cyclohexyl group, 2- Examples include an ethylhexyl group, an octyl group, an isooctyl group, a nonyl group, an isononyl group, a decyl group, an isodecyl group, an undecyl group, a lauryl group, a tridecyl group, a tetradecyl group, a stearyl group, an octadecyl group, and a dodecyl group.

  The glass transition temperature (Tg) of the acrylic resin is preferably 50 ° C. or lower, more preferably −70 to 20 ° C., and further preferably −50 to 0 ° C. By setting it as 50 degrees C or less, the viscosity and flexibility of the resin sheet 11 can be improved. By increasing the viscosity and flexibility of the resin sheet 11, it is possible to efficiently prevent the resin from entering the hollow portion (see the hollow portion 14 in FIG. 3A).

  Among the acrylic resins, those having a weight average molecular weight of 50,000 or more are preferable, those having 100,000 to 2,000,000 are more preferable, and those having 300,000 to 1,600,000 are more preferable. Within the above numerical range, the viscosity and flexibility of the resin sheet 11 can be further increased. The weight average molecular weight is a value measured by GPC (gel permeation chromatography) and calculated in terms of polystyrene.

  In addition, the other monomer forming the polymer is not particularly limited, and examples thereof include acrylic acid, methacrylic acid, carboxyethyl acrylate, carboxypentyl acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid. Carboxyl group-containing monomers such as acid anhydride monomers such as maleic anhydride or itaconic anhydride, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4- (meth) acrylic acid 4- Hydroxybutyl, 6-hydroxyhexyl (meth) acrylate, 8-hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate or (4-hydroxymethylcyclohexyl) -Methyla Hydroxyl group-containing monomers such as relate, styrene sulfonic acid, allyl sulfonic acid, 2- (meth) acrylamide-2-methylpropane sulfonic acid, (meth) acrylamide propane sulfonic acid, sulfopropyl (meth) acrylate or (meth) Examples thereof include sulfonic acid group-containing monomers such as acryloyloxynaphthalene sulfonic acid, and phosphoric acid group-containing monomers such as 2-hydroxyethylacryloyl phosphate. Especially, it is preferable to include at least one of a carboxyl group-containing monomer, a glycidyl group (epoxy group) -containing monomer, and a hydroxyl group-containing monomer from the viewpoint of increasing the viscosity of the resin sheet 11 by reacting with the epoxy resin.

  The content of the thermoplastic resin in the resin sheet 11 is preferably 50% by weight or more, and more preferably 60% by weight or more. When the content is 50% by weight or more, the flexibility and flexibility of the resin sheet can be obtained. The content of the thermoplastic resin in the resin sheet 11 is preferably 95% by weight or less, and more preferably 85% by weight or less. When it is 10% by weight or less, the adhesiveness of the resin sheet to the electronic device or the substrate is good.

  The resin sheet 11 may be an embodiment that does not substantially contain an inorganic filler. Specifically, the resin sheet 11 may have an inorganic filler content of 1% by volume or less, or 0% by volume (that is, not containing an inorganic filler). Even if the content of the inorganic filler is 1% by volume or less and is not substantially contained, the minimum dynamic viscosity before curing at 60 to 150 ° C. of the entire hollow sealing resin sheet 11 is 5 Since the ratio A / B is 5 or more because it is 1,000 Pa · s or more and 500,000 Pa · s or less, the electronic device can be suitably embedded in the hollow sealing resin sheet 11 in the lamination step, and It is because the material which comprises the resin sheet for sealing can make it difficult to flow into the space | gap between an adherend and an electronic device. In addition, when the inorganic filler is a mixture of a plurality of types of particles, the content of the mixture satisfies the above range.

  Examples of the inorganic filler include quartz glass, talc, silica (such as fused silica and crystalline silica), alumina, aluminum nitride, silicon nitride, and boron nitride powder.

  It is preferable that the resin sheet 11 contains a hardening accelerator.

  The curing accelerator is not particularly limited as long as it cures the epoxy resin and the phenol resin, and examples thereof include organic phosphorus compounds such as triphenylphosphine and tetraphenylphosphonium tetraphenylborate; 2-phenyl-4, And imidazole compounds such as 5-dihydroxymethylimidazole and 2-phenyl-4-methyl-5-hydroxymethylimidazole. Of these, imidazole compounds are preferred because they have good reactivity and are easy to increase the Tg of the cured product.

  As for content of a hardening accelerator, 0.1-5 weight part is preferable with respect to a total of 100 weight part of an epoxy resin and a phenol resin.

  The resin sheet 11 may contain a flame retardant component as necessary to the extent that it does not adversely affect the hollow moldability. This can reduce the expansion of combustion when ignition occurs due to component short-circuiting or heat generation. As the flame retardant composition, for example, various metal hydroxides such as aluminum hydroxide, magnesium hydroxide, iron hydroxide, calcium hydroxide, tin hydroxide, complex metal hydroxides; phosphazene flame retardants, etc. should be used. Can do.

  The resin sheet 11 may contain a silane coupling agent. It does not specifically limit as a silane coupling agent, 3-Glycidoxypropyl trimethoxysilane etc. are mentioned.

  The content of the silane coupling agent in the resin sheet 11 is preferably 0.1 to 3% by weight. When it is 0.1% by weight or more, the hardness of the cured resin sheet can be increased and the water absorption rate can be reduced. On the other hand, generation | occurrence | production of outgas can be suppressed as the said content is 3 weight% or less.

  The resin sheet 11 preferably contains a pigment. The pigment is not particularly limited, and examples thereof include carbon black.

  The content of the pigment in the resin sheet 11 is preferably 0.1 to 2% by weight. When the content is 0.1% by weight or more, good marking properties can be obtained. The intensity | strength of the resin sheet after hardening can be ensured as it is 2 weight% or less.

  In addition to the above components, other additives can be appropriately blended in the resin composition as necessary.

  The resin sheet 11 preferably has a viscosity of an organic resin component (an organic resin component excluding an inorganic filler) at 120 ° C. of 100 Pa · s or more, and more preferably 1000 Pa · s or more and 200,000 Pa · s or less. More preferably, it is 10,000 Pa · s or more and 100,000 Pa · s or less. When the viscosity of the organic resin component at 120 ° C. is 100 Pa · s or higher, the viscosity of the organic resin component is high, so that only the organic resin component can be prevented from leaking into the hollow portion.

[Method for producing hollow sealing resin sheet]
The resin sheet 11 is prepared by dissolving and dispersing a resin or the like for forming the resin sheet 11 in an appropriate solvent to adjust the varnish, and applying the varnish on the support 11a to a predetermined thickness to form a coating film. After the formation, the coating film can be formed by drying under predetermined conditions. It does not specifically limit as a coating method, For example, roll coating, screen coating, gravure coating, etc. are mentioned. As drying conditions, for example, the drying temperature is 70 to 160 ° C. and the drying time is 1 to 30 minutes. Moreover, after apply | coating a varnish on a separator and forming a coating film, the coating film may be dried on the said drying conditions, and the resin sheet 11 may be formed. Thereafter, the resin sheet 11 is bonded together with the separator on the support 11a. In particular, when the resin sheet 11 contains a thermoplastic resin (acrylic resin), an epoxy resin, and a phenol resin, all of them are dissolved in a solvent, and then applied and dried. Thereby, the viscosity of the resin sheet 11 can be improved and the approach to the hollow part of a resin component can be suppressed. Examples of the solvent include methyl ethyl ketone, ethyl acetate, toluene and the like.

  Although the thickness of the resin sheet 11 is not specifically limited, For example, it is 100-2000 micrometers. An electronic device can be favorably sealed as it is in the said range.

The resin sheet 11 may have a single layer structure or a multilayer structure in which two or more resin sheets are laminated, but there is no fear of delamination, the sheet thickness is highly uniform, and the moisture absorption is reduced. A single layer structure is preferred because it is easy.
When the resin sheet 11 has a multilayer structure, the layer in contact with the electronic device has (1) the minimum dynamic viscosity before curing at 60 to 150 ° C. of the entire layer in contact with the electronic device is 5,000 Pa · s or more and 500,000. (2) The ratio A / B may be 5 or more, and the other layers may not satisfy the conditions (1) to (2). This is because if the layer in contact with the electronic device satisfies the above conditions (1) to (2), the resin can be efficiently prevented from entering the hollow portion.

  The resin sheet 11 is a SAW (Surface Acoustic Wave) filter; a pressure sensor, a MEMS (Micro Electro Mechanical Systems) such as a vibration sensor; an IC such as an LSI; a semiconductor such as a transistor; a capacitor; a resistor; a seal for an electronic device such as a CMOS sensor. Used for stopping. Especially, it can use suitably for sealing of the electronic device (specifically SAW filter, MEMS) which needs hollow sealing, and can use it especially especially especially for sealing of a SAW filter.

[Method of manufacturing hollow package]
3A to 2C are views schematically showing one step of the method for manufacturing the hollow package according to the embodiment of the present invention. It does not specifically limit as a hollow sealing method, It can seal by a conventionally well-known method. For example, a method of laminating (mounting) an uncured resin sheet 11 on a substrate while maintaining a hollow structure so as to cover an electronic device on an adherend, and then curing and sealing the resin sheet 11 Can be mentioned. The adherend is not particularly limited, and examples thereof include a printed wiring board, a ceramic substrate, a silicon substrate, and a metal substrate. In the present embodiment, the SAW chip 13 mounted on the printed wiring board 12 is hollow-sealed with the resin sheet 11 to produce a hollow package.

(SAW chip mounting substrate preparation process)
In the SAW chip mounting board preparing step, a printed wiring board 12 on which a plurality of SAW chips 13 are mounted is prepared (see FIG. 3A). The SAW chip 13 can be formed by dicing a piezoelectric crystal on which predetermined comb-shaped electrodes are formed by a known method. For mounting the SAW chip 13 on the printed wiring board 12, a known device such as a flip chip bonder or a die bonder can be used. The SAW chip 13 and the printed wiring board 12 are electrically connected via protruding electrodes 13a such as bumps. In addition, a hollow portion 14 is maintained between the SAW chip 13 and the printed wiring board 12 so as not to inhibit the propagation of surface acoustic waves on the surface of the SAW filter. The distance (width of the hollow portion) between the SAW chip 13 and the printed wiring board 12 can be set as appropriate, and is generally about 10 to 100 μm.

(Sealing process)
In the sealing step, the resin sheet 11 is laminated on the printed wiring board 12 so as to cover the SAW chip 13, and the SAW chip 13 is resin-sealed with the resin sheet 11 (see FIG. 3B). The resin sheet 11 functions as a sealing resin for protecting the SAW chip 13 and its accompanying elements from the external environment.

The method of laminating the resin sheet 11 on the printed wiring board 12 is not particularly limited, and can be performed by a known method such as hot pressing or laminator. As hot press conditions, the temperature is, for example, 40 to 150 ° C., preferably 50 to 120 ° C., the pressure is, for example, 0.1 to 10 MPa, preferably 0.5 to 8 MPa, and the time is, for example, 0.3 to 10 minutes, preferably 0.5 to 5 minutes. Moreover, when the adhesiveness to the SAW chip 13 and the printed wiring board 12 of the resin sheet 11 and improvement in followability are taken into consideration, it is preferable to press under reduced pressure conditions (for example, 0.01 to 5 kPa).
The resin sheet 11 has (1) a minimum dynamic viscosity before curing at 60 to 150 ° C. of the entire resin sheet 11 of 5,000 Pa · s to 500,000 Pa · s, and (2) the ratio A / B is Since it is 5 or more, the resin approach to the hollow part 14 is suppressed.

(Sealing body forming process)
In the sealing body forming step, the resin sheet 11 is thermally cured to form the sealing body 15 (see FIG. 3B). As the conditions for the thermosetting treatment, the heating temperature is preferably 100 ° C. or higher, more preferably 120 ° C. or higher. On the other hand, the upper limit of the heating temperature is preferably 200 ° C. or lower, more preferably 180 ° C. or lower. The heating time is preferably 10 minutes or more, more preferably 30 minutes or more. On the other hand, the upper limit of the heating time is preferably 180 minutes or less, more preferably 120 minutes or less. Moreover, you may pressurize as needed, Preferably it is 0.1 Mpa or more, More preferably, it is 0.5 Mpa or more. On the other hand, the upper limit is preferably 10 MPa or less, more preferably 5 MPa or less.

(Dicing process)
Subsequently, dicing of the sealing body 15 may be performed (see FIG. 3C). Thereby, the hollow package 18 in the SAW chip 13 unit can be obtained.

(Board mounting process)
If necessary, a substrate mounting step can be performed in which bumps are formed on the hollow package 18 and mounted on a separate substrate (not shown). For mounting the hollow package 18 on the substrate, a known device such as a flip chip bonder or a die bonder can be used.

  Hereinafter, preferred embodiments of the present invention will be described in detail by way of example. However, the materials, blending amounts, and the like described in the examples are not intended to limit the scope of the present invention only to those unless otherwise specified.

The components used in the examples will be described.
Epoxy resin: YSLV-80XY manufactured by Nippon Steel Chemical Co., Ltd. (bisphenol F type epoxy resin, epkin equivalent 200 g / eq., Softening point 80 ° C.)
Phenol resin: LVR8210DL (Novolak-type phenol resin, hydroxyl group equivalent 104 g / eq., Softening point 60 ° C.) manufactured by Gunei Chemical
Thermoplastic resin: carboxyl group-containing acrylate copolymer, weight average molecular weight: about 600,000, glass transition temperature (Tg): -35 ° C)
Carbon black: # 20 manufactured by Mitsubishi Chemical
Curing accelerator: 2PHZ-PW (2-phenyl-4,5-dihydroxymethylimidazole) manufactured by Shikoku Kasei Kogyo Co., Ltd.

[Examples and comparative examples]
According to the blending ratio shown in Table 1, each component was dissolved and dispersed in methyl ethyl ketone as a solvent to obtain a varnish having a concentration of 30% by weight. This varnish was applied on a release treatment film made of a polyethylene terephthalate film having a thickness of 38 μm after the release treatment with silicone, and then dried at 110 ° C. for 5 minutes. As a result, a sheet having a thickness of 65 μm was obtained. Four layers of this sheet were laminated to prepare a hollow sealing resin sheet having a thickness of 260 μm.

(Measurement of minimum dynamic viscosity of resin sheet for hollow sealing)
The minimum dynamic viscosity before thermosetting at 60 to 150 ° C. of the resin sheet for hollow sealing was measured. The dynamic viscosity was a value measured by a parallel plate method using a viscoelasticity measuring device ARES manufactured by TA Instruments. More specifically, the viscosity was measured in the range of 50 ° C. to 170 ° C. under the conditions of a gap of 1 μm, a rotating plate diameter of 8 mm, a frequency of 0.1 Hz, a strain of 0.1%, and a heating rate of 10 ° C./min. The lowest viscosity obtained at that time was taken as the lowest dynamic viscosity. The results are shown in Table 1.

(Measurement of viscosity of organic resin component at 120 ° C.)
A uniform mixture of the organic composition of the resin sheet for hollow sealing was prepared, and the viscosity was measured at a shear rate of 1 (1 / s) using a rheometer (HAAKE Rheo Stress 6000). The results are shown in Table 1.

(Measurement of ratio A / B)
First, a test substrate was prepared in which a plurality of silicon chips (3 mm square, thickness 200 μm) were flip-chip connected to a glass substrate (30 mm square, thickness 1 mm). The chip is flip-chip connected to the substrate by bumps (bump diameter 100 μm, height 20 μm). The distance between the chips is 100 μm, and the gap (hollow gap) between the substrate and the chip is 20 μm. Next, the resin sheet for hollow sealing of an Example and a comparative example was arrange | positioned on the test board | substrate (refer FIG. 2B). Next, pressure was applied from the hollow sealing resin sheet side at 70 ° C., a pressure of 1 kgf / cm ² , and a degree of vacuum of 10 Torr (see FIG. 2C). At this time, the speed in the traveling direction of the tip of the resin was measured. This was defined as approach speed A. More specifically, the test substrate is taken out every 2 seconds under pressure, and the ingress tip of the resin (material constituting the sealing resin sheet) is observed from the glass substrate side with an optical microscope with a height measuring function, The amount of penetration (distance from the top end of the chip to the tip of the resin entry) was measured. The average speed until the resin tip reaches the glass substrate was defined as the approach speed A. After the resin reached the glass substrate (see FIG. 2D), pressurization was continued as it was, and the speed in the traveling direction of the tip of the resin was measured. Specifically, the velocity in the gap direction at the tip of the resin was measured. More specifically, like the approach speed A, the test substrate was taken out every 2 seconds of pressurization, and the amount of approach in the gap direction at the tip of the resin was measured. After the resin reached the glass substrate, the measurement every 2 seconds under pressure was repeated 5 times, and the average speed was defined as the entry speed B. However, when the resin tip penetrated 50 μm from the chip edge to the inside, the measurement was terminated at that time, and the average speed from the time when the resin reached the glass substrate to the time when the resin entered 50 μm was defined as the entry speed B. Thereafter, the ratio A / B was calculated. The results are shown in Table 1.

(Evaluation of resin penetration into package hollow)
A SAW chip mounting substrate in which a SAW chip having the following specifications on which aluminum comb-shaped electrodes were formed was mounted on a ceramic substrate under the following bonding conditions was produced. The gap width with the SAW chip ceramic substrate was 20 μm.

<SAW chip>
Chip size: 1.2 mm square (thickness 150 μm)
Bump material: Au (height 20 μm)
Number of bumps: 6 bumps Number of chips: 100 (10 x 10)

<Bonding conditions>
Equipment: manufactured by Panasonic Electric Works Co., Ltd. Bonding conditions: 200 ° C., 3N, 1 sec, ultrasonic output 2W

  On the obtained SAW chip mounting substrate, each hollow sealing resin sheet was pasted by a vacuum press under the heating and pressing conditions shown below.

<Paste conditions>
Temperature: 60 ° C
Applied pressure: 4 MPa
Degree of vacuum: 1.6 kPa
Press time: 1 minute

  After opening to atmospheric pressure, the resin sheet for hollow sealing was thermoset at 150 ° C. for 1 hour in a hot air dryer to obtain a sealed body. Cleavage the substrate and sealing resin interface of the obtained sealing body, and the entry of the resin into the hollow part between the SAW chip and the ceramic substrate by the product name “Digital Microscope” (200 times) manufactured by KEYENCE The amount was measured. The resin penetration amount was determined by measuring the maximum reach distance of the resin that entered the hollow portion from the end of the SAW chip, and setting this as the resin penetration amount. The case where the resin penetration amount was 20 μm or less was evaluated as “◯”, and the case where it exceeded 20 μm was evaluated as “×”. The results are shown in Table 1.

DESCRIPTION OF SYMBOLS 11 Resin sheet | seat for hollow sealing 11a Support body 13 SAW chip 15 Sealing body 18 Hollow package 50 Test board

Claims (4)

A resin sheet for hollow sealing is laminated on the electronic device while maintaining a hollow portion between the adherend and the electronic device so as to cover one or a plurality of electronic devices arranged on the adherend. A hollow sealing resin sheet used in a manufacturing method of a hollow package including a laminating step and a sealing body forming step of curing the hollow sealing resin sheet to form a sealing body,
The minimum dynamic viscosity before curing at 60 to 150 ° C. of the entire resin sheet for hollow sealing is 5,000 Pa · s or more and 500,000 Pa · s or less,
A test substrate in which a plurality of chips are flip-chip connected to a substrate, the distance between the chips is 100 μm, and the gap between the substrate and the chip is 20 μm,
After the resin sheet for hollow sealing is placed on the test substrate, the hollow sealing when pressurized from the hollow sealing resin sheet side at 70 ° C., a pressure of 1 kgf / cm ² , and a degree of vacuum of 10 Torr. The ratio A / B between the entry speed A of the material constituting the fixing resin sheet between the chips and the entry speed B of the material constituting the hollow sealing resin sheet into the gap is 5 or more. A hollow sealing resin sheet.   Content of an inorganic filler is 1 volume% or less, The resin sheet for hollow sealing of Claim 1 characterized by the above-mentioned.   The resin sheet for hollow sealing according to claim 1 or 2, wherein the viscosity of the organic resin component at 120 ° C is 100 Pa · s or more. A method for manufacturing a hollow package, comprising:
A resin sheet for hollow sealing is laminated on the electronic device while maintaining a hollow portion between the adherend and the electronic device so as to cover one or a plurality of electronic devices arranged on the adherend. Lamination process;
A sealing body forming step of curing the hollow sealing resin sheet to form a sealing body,
The hollow sealing resin sheet is:
The minimum dynamic viscosity before curing at 60 to 150 ° C. of the entire resin sheet for hollow sealing is 5,000 Pa · s or more and 500,000 Pa · s or less,
A test substrate in which a plurality of chips are flip-chip connected to a substrate, the distance between the chips is 100 μm, and the gap between the substrate and the chip is 20 μm,
After the resin sheet for hollow sealing is placed on the test substrate, the hollow sealing when pressurized from the hollow sealing resin sheet side at 70 ° C., a pressure of 1 kgf / cm ² , and a degree of vacuum of 10 Torr. The ratio A / B between the entry speed A of the material constituting the fixing resin sheet between the chips and the entry speed B of the material constituting the hollow sealing resin sheet into the gap is 5 or more. A method for producing a hollow package.

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