JP6434181B2 - Hollow type electronic device sealing sheet and method for manufacturing hollow type electronic device package - Google Patents

Description

  The present invention relates to a hollow electronic device sealing sheet and a method for manufacturing a hollow electronic device package.

  Conventionally, when a hollow electronic device package having a hollow structure between an electronic device and a substrate is resin-sealed to produce a hollow electronic device package, a sheet-shaped sealing resin is often used. Yes (see, for example, Patent Document 1).

JP 2006-19714 A

  In the hollow electronic device package, the hollow electronic device may be affected by various ionic impurities derived from the sheet-like sealing resin used for sealing. In particular, in a hollow electronic device package, when ionic impurities ooze out from a sheet-shaped sealing resin, they easily accumulate in the hollow space, and as a result, characteristics as a hollow electronic device (for example, a pressure sensor, a vibration sensor, etc.) Sensor characteristics when used as a filter, filter characteristics when used as a SAW filter, etc.) may not be sufficiently exhibited. Therefore, a sealing resin with a low content of ionic impurities is desired.

  The present invention has been made in view of the above-described problems, and its purpose is to provide a hollow electronic device sealing sheet with a small amount of ionic impurities leaching, and a hollow type with a small amount of ionic impurities. An object is to provide a method for manufacturing an electronic device 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, this invention is a sheet | seat for hollow type electronic device sealing, Comprising: At least 1 of following (a)-following (d) is satisfy | filled.
(A) A sheet for sealing a hollow electronic device having a weight of 5 g is immersed in 50 ml of ion-exchanged water, and the chloride ion concentration in the ion-exchanged water after being left at 121 ° C. and 2 atm for 20 hours is: Less than 30 ppm on a mass basis,
(B) A sheet for sealing a hollow electronic device having a weight of 5 g is immersed in 50 ml of ion-exchanged water, and the sodium ion concentration in the ion-exchanged water after being left at 121 ° C. and 2 atm for 20 hours is mass. Less than 10 ppm on the basis,
(C) A sheet for sealing a hollow electronic device having a weight of 5 g is immersed in 50 ml of ion-exchanged water, and the phosphate ion concentration in the ion-exchanged water after being left at 121 ° C. under 2 atm for 20 hours is Less than 30 ppm on a mass basis,
(D) A sheet for sealing a hollow electronic device having a weight of 5 g is immersed in 50 ml of ion-exchanged water, and the sulfuric acid ion concentration in the ion-exchanged water after being left at 121 ° C. and 2 atm for 20 hours is expressed as mass. The standard is less than 5 ppm.

The hollow electronic device sealing sheet according to the present invention satisfies at least one of the above (a) to (d). Therefore, the amount of ionic impurities (at least one of chloride ions, sodium ions, phosphate ions (PO ₄ ³⁻ ), and sulfate ions (SO ₄ ²⁻ )) is reduced. As a result, in the hollow electronic device package manufactured using the hollow electronic device sealing sheet, deterioration of characteristics is suppressed, and product reliability can be improved.

In the said structure, it is preferable that the water vapor transmission rate after thermosetting when it is set to 250 micrometers in thickness is 500 g / m < ² > * 24 hours or less on the conditions of temperature 85 degreeC, humidity 85%, and 168 hours.

Even if the amount of the ionic impurities leached out when immersed in ion-exchanged water is small, the present inventors have a large amount of moisture that permeates the hollow electronic device sealing sheet and reaches the hollow portion. It has been found that there is a possibility that the ionic impurities may be accumulated on the electronic device due to the ionic impurities dissolved in moisture and flowing into the electronic device. Therefore, the moisture permeability after thermosetting when the thickness of the sheet for encapsulating a hollow electronic device is 250 μm is 500 g / m ² · 24 hours or less under the conditions of a temperature of 85 ° C., a humidity of 85%, and 168 hours. If so, it is difficult for moisture to enter the hollow portion from the outside. As a result, it is possible to suppress ionic impurities from reaching the electronic device by being dissolved in moisture from the outside.
In this way, in addition to reducing the amount of ionic impurities that exude from the sheet for encapsulating a hollow electronic device, the sheet for encapsulating the hollow electronic device can be obtained by reducing the moisture permeability. The product reliability of the hollow electronic device package manufactured by using can be further improved. The evaluation conditions of the moisture permeability were set to a temperature of 85 ° C., a humidity of 85%, and a duration of 168 hours in order to meet the Level 1 condition which is the most severe moisture absorption condition in the solder resistance test (MSL test) of the semiconductor package. is there.
When the thickness is not 250 μm, it is converted to the moisture permeability when the thickness is 250 μm under the conditions of a temperature of 85 ° C., a humidity of 85%, and 168 hours, converted by the following formula 1.
(Formula 1) A- (250-D) × 0.101
(A: moisture permeability, D: sample thickness (μm))

  In the said structure, it is preferable to contain 70-90 volume% of inorganic fillers with respect to the whole sheet | seat for hollow type electronic device sealing. If the content of the inorganic filler is 70% by volume or more with respect to the entire hollow electronic device sealing sheet, the moisture permeability can be easily reduced. On the other hand, when the content of the inorganic filler is 90% by volume or less with respect to the entire hollow electronic device sealing sheet, flexibility, fluidity, and adhesiveness are further improved.

  In the said structure, it is preferable to contain an ion-trapping agent. When the ion scavenger is contained, it is possible to further suppress ionic impurities from reaching the electronic device.

  In the above configuration, the ion scavenger is preferably a hydrotalcite compound. The hydrotalcite-based compound has ion scavenging properties without containing heavy metals such as antimony.

Moreover, the manufacturing method of the hollow type electronic device package which concerns on this invention WHEREIN: The said hollow type electronic device sealing resin sheet is hollow so that one or several hollow type electronic devices mounted on the board | substrate may be covered. Laminating step of laminating on the electronic device, and
It includes a sealing body forming step of curing the hollow electronic device sealing resin sheet to form a sealing body.
The hollow electronic device package manufactured using the above-described resin sheet for sealing a hollow electronic device has a small amount of ionic impurities that ooze out. Therefore, the hollow type electronic device package manufactured using the resin sheet for sealing a hollow type electronic device can suppress the deterioration of the characteristics, and can improve the product reliability.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the sheet | seat for hollow type electronic device sealing with little ionic impurity bleed-out amount and the hollow type electronic device package with little ionic impurity bleed-out amount can be provided.

It is sectional drawing which shows typically the sheet | seat for hollow type electronic device sealing which concerns on one Embodiment of this invention. It is a figure which shows typically 1 process of the manufacturing method of the hollow type electronic device 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 type electronic device 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 type electronic device package which concerns on one Embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings. However, the present invention is not limited only to these embodiments.

  [Hollow type electronic device sealing sheet]

  FIG. 1 is a cross-sectional view schematically showing a hollow electronic device sealing sheet according to an embodiment of the present invention. The hollow electronic device sealing sheet 11 (hereinafter also referred to as “sealing 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 applied to the support 11a in order to easily peel off the sealing sheet 11.

The sealing sheet 11 satisfies at least one of the following (a) to (d).
(A) A sheet for sealing a hollow electronic device having a weight of 5 g is immersed in 50 ml of ion-exchanged water, and the chloride ion concentration in the ion-exchanged water after being left at 121 ° C. and 2 atm for 20 hours is: Less than 30 ppm on a mass basis,
(B) A sheet for sealing a hollow electronic device having a weight of 5 g is immersed in 50 ml of ion-exchanged water, and the sodium ion concentration in the ion-exchanged water after being left at 121 ° C. and 2 atm for 20 hours is mass. Less than 10 ppm on the basis,
(C) A sheet for sealing a hollow electronic device having a weight of 5 g is immersed in 50 ml of ion-exchanged water, and the phosphate ion concentration in the ion-exchanged water after being left at 121 ° C. under 2 atm for 20 hours is Less than 30 ppm on a mass basis,
(D) A sheet for sealing a hollow electronic device having a weight of 5 g is immersed in 50 ml of ion-exchanged water, and the sulfuric acid ion concentration in the ion-exchanged water after being left at 121 ° C. and 2 atm for 20 hours is expressed as mass. The standard is less than 5 ppm.

  Since the sealing sheet 11 satisfies at least one of the above (a) to (d), an ionic impurity (at least one of chloride ions, sodium ions, phosphate ions, and sulfate ions). The amount of ooze out is reduced. As a result, in the hollow electronic device package manufactured using the hollow electronic device sealing sheet 11, deterioration of characteristics is suppressed, and product reliability can be improved. As a method for satisfying at least one of the above (a) to (d), for example, when the sealing sheet 11 is manufactured, a material with a small content of ionic impurities is selected, or the ion And a method of containing an ion scavenger capable of trapping the ionic impurities.

The chloride ion concentration is preferably less than 20 ppm. Moreover, although the said chloride ion concentration is so preferable that it is small, it is 1 ppm or more, for example.
The sodium ion concentration is preferably less than 7 ppm. Moreover, although the said sodium ion concentration is so preferable that it is small, it is 0.1 ppm or more, for example.
The phosphate ion concentration is preferably less than 20 ppm. Moreover, although the said phosphate ion concentration is so preferable that it is small, it is 1 ppm or more, for example.
The sulfate ion concentration is preferably less than 3 ppm. Moreover, although the said sulfate ion concentration is so preferable that it is small, it is 0.1 ppm or more, for example.

The sealing sheet 11 preferably has a moisture permeability of 500 g / m ² · 24 hours or less under the conditions of a temperature of 85 ° C., a humidity of 85% and 168 hours when the thickness is 250 μm. 400 g / m ² · 24 hours or less is preferable, and 300 g / m ² · 24 hours or less is more preferable. Moreover, although the said water vapor transmission rate is so preferable that it is small, it is 1 g / m < ² > * 24 hours or more, for example. The moisture permeability after thermosetting when the thickness of the sealing sheet 11 is 250 μm is 500 g / m ² · 24 hours or less under the conditions of a temperature of 85 ° C., a humidity of 85% and 168 hours, from the outside. It is difficult for moisture to enter the hollow part. As a result, it is possible to suppress ionic impurities from reaching the electronic device by being dissolved in moisture from the outside.
In this way, in addition to reducing the amount of ionic impurities that exude from the sheet for encapsulating a hollow electronic device, the sheet for encapsulating the hollow electronic device can be obtained by reducing the moisture permeability. The product reliability of the hollow electronic device package manufactured by using can be further improved.

  Next, the composition of the sealing sheet 11 will be described.

  It is preferable that the sealing sheet 11 includes 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, those having an epoxy equivalent of 150 to 250 and a softening point or melting point of 50 to 130 ° C. are preferably solid, and particularly reliable. From the viewpoint, triphenylmethane type epoxy resin, cresol novolac type epoxy resin, and biphenyl type epoxy resin 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, a phenol novolac from the viewpoint of high curing reactivity. Resin can be used suitably. 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 total content of the epoxy resin and the phenol resin in the sealing sheet 11 is preferably 2.0% by weight or more, and more preferably 3.0% by weight or more. Adhesive force with respect to an electronic device, a board | substrate, etc. is acquired favorably as it is 2.0 weight% or more. The total content of the epoxy resin and the phenol resin in the sealing sheet 11 is preferably 20% by weight or less, and more preferably 10% by weight or less. Hygroscopicity can be reduced as it is 20 weight% or less.

  It is preferable that the sealing sheet 11 includes a thermoplastic resin. Thereby, the handleability at the time of non-hardening and the low stress property of hardened | cured material are acquired.

  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. Of these, a styrene-isobutylene-styrene block copolymer is preferred from the viewpoint of low stress and low water absorption.

  1.0 weight% or more is preferable and, as for content of the thermoplastic resin in the sheet | seat 11 for sealing, 1.5 weight% or more is more preferable. A softness | flexibility and flexibility are acquired as it is 1.0 weight% or more. The content of the thermoplastic resin in the sealing sheet 11 is preferably 3.5% by weight or less, and more preferably 3% by weight or less. Adhesiveness with an electronic device or a board | substrate is favorable in it being 3.5 weight% or less.

  It is preferable that the sealing sheet 11 includes an inorganic filler.

  The inorganic filler is not particularly limited, and various conventionally known fillers can be used. For example, quartz glass, talc, silica (such as fused silica and crystalline silica), alumina, aluminum nitride, silicon nitride And boron nitride powder. These may be used alone or in combination of two or more. Among these, silica and alumina are preferable, and silica is more preferable because the linear expansion coefficient can be satisfactorily reduced.

As silica, silica powder is preferable, and fused silica powder is more preferable. Examples of the fused silica powder include spherical fused silica powder and crushed fused silica powder. From the viewpoint of fluidity, spherical fused silica powder is preferable. Especially, the thing of the range whose average particle diameter is 10-30 micrometers is preferable, and the thing of the range which is 15-25 micrometers is more preferable.
The average particle diameter can be derived, for example, by using a sample arbitrarily extracted from the population and measuring it using a laser diffraction / scattering particle size distribution measuring apparatus.

  The content of the inorganic filler in the sealing sheet 11 is preferably 70 to 90% by volume, more preferably 74 to 85% by volume with respect to the entire sealing sheet 11. If the content of the inorganic filler is 70% by volume or more with respect to the entire sealing sheet 11, moisture permeability can be easily reduced. On the other hand, when the content of the inorganic filler is 90% by volume or less with respect to the entire sealing sheet 11, flexibility, fluidity, and adhesiveness are improved.

The content of the inorganic filler can be explained by using “wt%” as a unit. Typically, the content of silica will be described in units of “% by weight”.
Since silica usually has a specific gravity of 2.2 g / cm ³ , the preferred range of the silica content (% by weight) is as follows.
That is, the content of silica in the sealing sheet 11 is preferably 81% by weight or more, and more preferably 84% by weight or more. The content of silica in the sealing sheet 11 is preferably 94% by weight or less, and more preferably 91% by weight or less.

Since alumina usually has a specific gravity of 3.9 g / cm ³ , the preferred range of the alumina content (% by weight) is as follows.
That is, the content of alumina in the sealing sheet 11 is preferably 88% by weight or more, and more preferably 90% by weight or more. The content of alumina in the sealing sheet 11 is preferably 97% by weight or less, and more preferably 95% by weight or less.

  It is preferable that the sealing sheet 11 includes an ion scavenger. When the ion scavenger is contained, it is possible to further suppress ionic impurities from reaching the electronic device.

  Examples of the ion scavenger include hydrotalcite compounds, bismuth hydroxide, antimony pentoxide and the like. These may be used alone or in combination of two or more. Of these, hydrotalcite compounds are preferably used from the viewpoint of having ion scavenging properties without containing heavy metals.

  The average particle size of the ion scavenger is preferably in the range of 0.1 to 50 μm from the viewpoint of fluidity. The average particle diameter can be derived, for example, by using a sample arbitrarily extracted from the population and measuring it using a laser diffraction / scattering particle size distribution measuring apparatus.

  The content of the ion scavenger is preferably set in the range of 0.01 to 2% by weight, particularly preferably 0.01 to 1% by weight, based on the entire sealing sheet 11. By setting the content ratio of the ion scavenger to 0.01% by weight or more with respect to the entire sealing sheet 11, sufficient ion trapping properties can be obtained. Moreover, the contamination of the package at the time of shaping | molding can be suppressed by making the content rate of an ion supplement agent into 2 weight% or less with respect to the whole sheet | seat 11 for sealing.

  It is preferable that the sealing sheet 11 includes a curing 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, 2-phenyl-4,5-dihydroxymethylimidazole is preferred because the curing reaction does not proceed rapidly even when the temperature rises during kneading, and the sealing sheet 11 can be satisfactorily produced.

  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.

  It is preferable that the sealing sheet 11 includes a flame retardant component. 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.

  From the viewpoint of exhibiting a flame retardant effect even in a small amount, the phosphorus element content contained in the phosphazene flame retardant is preferably 12% by weight or more.

  The content of the flame retardant component in the sealing sheet 11 is preferably 10% by weight or more, and more preferably 15% by weight or more in the total organic components (excluding the inorganic filler). A flame retardance is favorably acquired as it is 10 weight% or more. The content of the thermoplastic resin in the sealing sheet 11 is preferably 30% by weight or less, and more preferably 25% by weight or less. When the content is 30% by weight or less, there is a tendency that there is little decrease in physical properties of the cured product (specifically, physical properties such as glass transition temperature and high-temperature resin strength).

  It is preferable that the sealing sheet 11 includes 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 sealing sheet 11 is preferably 0.1 to 3% by weight. When the content is 0.1% by weight or more, sufficient strength of the cured product can be obtained and the water absorption rate can be lowered. If it is 3% by weight or less, the outgas amount can be lowered.

  It is preferable that the sealing sheet 11 contains a pigment. The pigment is not particularly limited, and examples thereof include carbon black.

  The content of the pigment in the sealing 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 when marking is performed by laser marking or the like. When the content is 2% by weight or less, a cured product strength is sufficiently obtained.

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

  The encapsulating sheet 11 may have a single layer structure or a multilayer structure in which two or more encapsulating sheets are laminated, but there is no risk of delamination and the sheet thickness is highly uniform. A single layer structure is preferable because it is easy to reduce moisture permeability.

  Although the thickness of the sheet | seat 11 for sealing is not specifically limited, From a viewpoint used as a sheet | seat for sealing, it is 50 micrometers-2000 micrometers, for example.

  The manufacturing method of the sealing sheet 11 is not particularly limited. For example, a method of preparing a kneaded product of a resin composition for forming the sealing sheet 11 and plastic processing the obtained kneaded product into a sheet shape, or a resin composition for forming the sealing sheet 11 The method of apply | coating to a separator etc. what melt | dissolved or disperse | distributed in a solvent (varnish), and drying after that is mentioned. When the method of plastically processing the kneaded material into a sheet shape is adopted, the sealing sheet 11 can be produced without using a solvent, so that the hollow electronic device (for example, the SAW filter 13) is affected by the volatilized solvent. This can be suppressed.

  Specifically, a kneaded material is prepared by melt-kneading each component described later with a known kneader such as a mixing roll, a pressure kneader, or an extruder, and the obtained kneaded material is plastically processed into a sheet shape. As the kneading conditions, the temperature is preferably equal to or higher than the softening point of each component described above. For example, when considering the thermosetting property of 30 to 150 ° C. and epoxy resin, preferably 40 to 140 ° C., more preferably 60 to 120. ° C. The time is, for example, 1 to 30 minutes, preferably 5 to 15 minutes.

The kneading is preferably performed under reduced pressure conditions (under reduced pressure atmosphere). Thereby, while being able to deaerate, the penetration | invasion of the gas to a kneaded material can be prevented. The pressure under reduced pressure is preferably 0.1 kg / cm ² or less, more preferably 0.05 kg / cm ² or less. Although the minimum of the pressure under pressure reduction is not specifically limited, For example, it is 1 * 10 < ^-4 > kg / cm < ² > or more.

  The kneaded material after melt-kneading is preferably subjected to plastic working in a high temperature state without cooling. The plastic working method is not particularly limited, and examples thereof include a flat plate pressing method, a T-die extrusion method, a screw die extrusion method, a roll rolling method, a roll kneading method, an inflation extrusion method, a coextrusion method, and a calendar molding method. The plastic processing temperature is preferably higher than the softening point of each component described above, and is 40 to 150 ° C., preferably 50 to 140 ° C., more preferably 70 to 120 ° C., considering the thermosetting property and moldability of the epoxy resin. is there.

  The sealing sheet 11 is used for sealing electronic devices (for example, SAW (Surface Acoustic Wave) filters; MEMS (Micro Electro Mechanical Systems) such as pressure sensors and vibration sensors) that require hollow sealing. , And can be particularly suitably used for sealing a SAW filter.

  It does not specifically limit as a sealing method, It can seal by a conventionally well-known method. For example, a method of laminating (mounting) an uncured sealing sheet 11 on the substrate so as to cover the hollow electronic device on the substrate, and then curing the sealing sheet 11 to seal it. . It does not specifically limit as a board | substrate, For example, a printed wiring board, a ceramic substrate, a silicon substrate, a metal substrate etc. are mentioned.

[Method of manufacturing hollow electronic device package]
FIG. 2A to FIG. 2C are diagrams schematically showing one step of the method for manufacturing the hollow electronic device package according to the embodiment of the present invention. In the present embodiment, a SAW filter 13 as a hollow electronic device mounted on the printed wiring board 12 is hollow-sealed with a sealing sheet 11 to produce a hollow electronic device package.

(SAW filter mounting substrate preparation process)
In the SAW filter mounting board preparing step, a printed wiring board 12 on which a plurality of SAW filters 13 are mounted is prepared (see FIG. 2A). The SAW filter 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 filter 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 filter 13 and the printed wiring board 12 are electrically connected via protruding electrodes 13a such as bumps. Further, a hollow portion 14 is maintained between the SAW filter 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 between the SAW filter 13 and the printed wiring board 12 can be set as appropriate, and is generally about 15 to 50 μm.

(Sealing process)
In the sealing step, the sealing sheet 11 is laminated on the printed wiring board 12 so as to cover the SAW filter 13, and the SAW filter 13 is resin-sealed with the sealing sheet 11 (see FIG. 2B). The sealing sheet 11 functions as a sealing resin for protecting the SAW filter 13 and its accompanying elements from the external environment.

  The method for laminating the sealing sheet 11 on the printed wiring board 12 is not particularly limited, and can be performed by a known method such as hot press or laminator. As hot press conditions, the temperature is, for example, 40 to 100 ° C., preferably 50 to 90 ° 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. Thereby, an electronic device package in which the electronic device is embedded in the thermosetting sealing sheet 16 can be obtained. Moreover, when the adhesiveness to the SAW filter 13 and the printed wiring board 12 of the sealing sheet 11 and improvement in followability are taken into consideration, it is preferable to press under reduced pressure conditions (for example, 0.1 to 5 kPa).

(Sealing body forming process)
In the sealing body forming step, the sealing sheet 11 is thermally cured to form the sealing body 15 (see FIG. 2B).

  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. 2C). Thereby, the electronic device package 18 in the SAW filter 13 unit can be obtained.

(Board mounting process)
If necessary, a substrate mounting step can be performed in which rewiring and bumps are formed on the electronic device package 18 and mounted on a separate substrate (not shown). For mounting the electronic device package 18 on the substrate, a known apparatus 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.

（式中、ｍは３〜４の整数を表す。）
硬化促進剤：四国化成工業社製の２ＰＨＺ−ＰＷ（２−フェニル−４，５−ジヒドロキシメチルイミダゾール） 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: MEH-7851-SS manufactured by Meiwa Kasei Co., Ltd. (phenol resin having a biphenylaralkyl skeleton, hydroxyl group equivalent 203 g / eq., Softening point 67 ° C.)
Thermoplastic resin: SIBSTER 072T (styrene-isobutylene-styrene block copolymer) manufactured by Kaneka Corporation
Ion scavenger: DHT-4A manufactured by Kyowa Chemical Industry Co., Ltd.
Inorganic filler: FB-9454FC manufactured by Denki Kagaku Kogyo Co., Ltd. (fused spherical silica, average particle size 20 μm)
Silane coupling agent: KBM-403 (3-glycidoxypropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd.
Carbon black: # 20 manufactured by Mitsubishi Chemical
Flame retardant: FP-100 manufactured by Fushimi Pharmaceutical (phosphazene flame retardant: compound represented by formula (4))

(In the formula, m represents an integer of 3 to 4.)
Curing accelerator: 2PHZ-PW (2-phenyl-4,5-dihydroxymethylimidazole) manufactured by Shikoku Kasei Kogyo Co., Ltd.

Examples 1-2
Each component was blended according to the blending ratio shown in Table 1, and melt-kneaded in a roll kneader at 60 to 120 ° C. for 10 minutes under reduced pressure conditions (0.01 kg / cm ² ) to prepare a kneaded product. Subsequently, the obtained kneaded material was formed into a sheet shape by a flat plate pressing method, and a sealing sheet having a thickness shown in Table 1 was produced.

Example 3
According to the formulation shown in Table 1, each component was blended with a solvent (by weight, methyl ethyl ketone (MEK): toluene = 1: 1) to obtain a coating solution having a non-solvent component concentration of 90%.
The obtained coating solution is applied on a release treatment surface of a 50 μm thick polyester film A (MRF-50, manufactured by Mitsubishi Chemical Polyester Co., Ltd.) with a comma coater so that the thickness after drying becomes 50 μm. And dried. Subsequently, the peel-treated surface of a 38 μm thick polyester film B (MRF-38, manufactured by Mitsubishi Chemical Polyester) was laminated on the varnish after drying to prepare a thin film sealing sheet.
Then, while peeling the polyester film A and the polyester film B suitably, the sheet | seat for sealing of thickness 250micrometer was produced by laminating | stacking 5 sheets of thin film sealing sheets with a roll laminator.

Comparative Example 1
Each component was blended according to the blending ratio shown in Table 1, and the same amount of methyl ethyl ketone as the total amount of each component was added thereto to prepare a varnish. The obtained varnish was coated on a release-treated surface of a 50 μm thick polyester film A (MRF-50, manufactured by Mitsubishi Chemical Polyester Co., Ltd.) with a comma coater so that the thickness after drying was 50 μm. Dried. Subsequently, the peel-treated surface of a 38 μm thick polyester film B (MRF-38, manufactured by Mitsubishi Chemical Polyester) was laminated on the varnish after drying to prepare a thin film sealing sheet.
Then, while peeling the polyester film A and the polyester film B suitably, the sheet | seat for sealing of thickness 250micrometer was produced by laminating | stacking 5 sheets of thin film sealing sheets with a roll laminator.

  The following evaluation was performed using the obtained sealing sheet. The results are shown in Table 1.

[Measurement of ionic impurity extraction concentration]
The sealing sheets of Examples and Comparative Examples were each cut to a weight of 5 g, placed in a cylindrical sealed Teflon (registered trademark) container having a diameter of 58 mm and a height of 37 mm, and 50 ml of ion-exchanged water was added. . Then, it was left to stand at 121 ° C. and 2 atm for 20 hours. After the film was taken out, chloride ion concentration, sodium ion concentration, phosphate ion concentration, and sulfate ion concentration in ion-exchanged water were measured using DX320 and DX500 manufactured by DIONEX. The results are shown in Table 1.

[Measurement of moisture permeability]
The sealing sheets prepared in Examples and Comparative Examples were thermoset. The thermosetting conditions were 150 ° C. and 60 minutes heating. Thereafter, the moisture permeability of the sealing sheets (after thermosetting) prepared in Examples and Comparative Examples was measured in accordance with JIS Z 0208 (cup method).
The measurement conditions were as follows. The results are shown in Table 1.
(Measurement condition)
Temperature 85 ° C., humidity 85%, 168 hours, sealing sheet thickness: 250 μm

11 Hollow electronic device sealing sheet (sealing sheet)
11a Support body 13 SAW filter 15 Sealing body 18 Hollow electronic device package

Claims (5)

Including thermoplastics,
Satisfy at least one of the following (a) to (d),
The hollow electronic device seal is characterized in that the moisture permeability after thermosetting when the thickness is 250 μm is 500 g / m ² · 24 hours or less under the conditions of a temperature of 85 ° C., a humidity of 85%, and 168 hours. Stop sheet.
(A) A sheet for sealing a hollow electronic device having a weight of 5 g is immersed in 50 ml of ion-exchanged water, and the chloride ion concentration in the ion-exchanged water after being left at 121 ° C. and 2 atm for 20 hours is: Less than 30 ppm on a mass basis,
(B) A sheet for sealing a hollow electronic device having a weight of 5 g is immersed in 50 ml of ion-exchanged water, and the sodium ion concentration in the ion-exchanged water after being left at 121 ° C. and 2 atm for 20 hours is mass. Less than 10 ppm on the basis,
(C) A sheet for sealing a hollow electronic device having a weight of 5 g is immersed in 50 ml of ion-exchanged water, and the phosphate ion concentration in the ion-exchanged water after being left at 121 ° C. under 2 atm for 20 hours is Less than 30 ppm on a mass basis,
(D) A sheet for sealing a hollow electronic device having a weight of 5 g is immersed in 50 ml of ion-exchanged water, and the sulfuric acid ion concentration in the ion-exchanged water after being left at 121 ° C. and 2 atm for 20 hours is expressed as mass. The standard is less than 5 ppm.   2. The hollow electronic device sealing sheet according to claim 1, comprising 70 to 90% by volume of an inorganic filler with respect to the entire hollow electronic device sealing sheet.   The sheet for sealing a hollow electronic device according to claim 1, further comprising an ion scavenger.   The sheet for sealing a hollow electronic device according to claim 3, wherein the ion scavenger is a hydrotalcite compound. Lamination | stacking which laminate | stacks the resin sheet for hollow type electronic device sealing of any one of Claims 1-4 on the said hollow type electronic device so that the 1 or several hollow type electronic device mounted on the board | substrate may be covered Process and
The manufacturing method of the hollow type electronic device package characterized by including the sealing body formation process which hardens the said resin sheet for sealing a hollow type electronic device and forms a sealing body.

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