JP6865340B2 - Manufacturing method of mounting structure and laminated sheet used for this - Google Patents

Description

The present invention relates to a method for manufacturing a mounting structure having a space inside, and more particularly to a method for manufacturing a mounting structure sealed by using a laminated sheet, and a laminated sheet used therein.

Some electronic components (circuit members) mounted on a circuit board may require a space between them and the circuit board. For example, a SAW chip used for noise removal in a mobile phone or the like is equipped with an electrode on the piezoelectric body and a SAW chip in order to filter a desired frequency by using a surface wave propagating on a piezoelectric substrate (piezoelectric body). A space is required between the circuit board and the circuit board.

By the way, it is desirable that many of the circuit members mounted on the circuit board are covered with a conductive layer containing a conductive material in order to reduce the influence of electromagnetic waves. In the case of the SAW chip as described above, for example, in Patent Document 1, in order to conduct the cover having the electromagnetic wave shielding property and the ground circuit, a conductive bump is arranged on the cover and the cover and the ground circuit are adhered to each other. It teaches that a through hole corresponding to the bump is formed in the adhesive sheet. In this case, the electromagnetic wave shielding performance is exhibited by exposing the bumps from the through holes and connecting the cover and the ground circuit via the bumps. According to Patent Document 1, it is possible to seal a circuit member (hollow sealing) while maintaining an internal space, and to shield an electromagnetic wave that is about to enter from the outside.

Japanese Unexamined Patent Publication No. 2012-160489

When the cover is molded in advance as in Patent Document 1, the number of manufacturing processes increases, which leads to an increase in manufacturing cost. Further, it is necessary to align the cover and the SAW chip. In addition, since it is necessary to mold the cover with a margin so as not to damage the SAW chip, it is difficult to reduce the height of the obtained mounting structure. Further, since it is necessary to align the through holes formed in the adhesive sheet with the bumps, the productivity tends to decrease.

In view of the above, one aspect of the present invention is a first circuit member, a plurality of second circuit members mounted on the first circuit member, and the second circuit member on the first circuit member. A step of preparing a mounting member in which a space is formed between the first circuit member and the second circuit member, and an insulating layer and a conductive layer are provided. A step of preparing a laminated sheet in which the insulating layer is arranged on at least one of the outermost layers, an arrangement step of arranging the laminated sheet on the mounting member so that the insulating layer faces the bump, and the above-mentioned. The sealing step includes a sealing step of pressing the laminated sheet against the first circuit member and heating the laminated sheet to seal the second circuit member while maintaining the space. The stopping step relates to a method for manufacturing a mounting structure in which the bump is penetrated through the insulating layer to electrically connect the bump and the conductive layer.

Another aspect of the present invention includes a first circuit member and a plurality of second circuit members mounted on the first circuit member, and between the first circuit member and the second circuit member. A laminated sheet used for sealing a mounting member in which a space is formed, comprising an insulating layer and a conductive layer, the insulating layer being arranged at least one of the outermost layers, and the second circuit. The present invention relates to a laminated sheet in which the loss positive contact tan δ1 of the insulating layer is larger than 1 at the temperature t when the member is sealed.

According to the present invention, the conductive layer of the laminated sheet and the ground electrode can be connected with high productivity while maintaining the internal space.

It is sectional drawing which shows typically the mounting structure which concerns on one Embodiment of this invention. It is sectional drawing which shows typically the laminated sheet which concerns on one Embodiment of this invention. It is explanatory drawing which shows typically the manufacturing method which concerns on one Embodiment of this invention by the cross section of the mounting member or the mounting structure.

An example of the mounting structure manufactured by the method according to the present embodiment is shown in FIG. FIG. 1 is a cross-sectional view schematically showing the mounting structure 10.
The mounting structure 10 includes a first circuit member 1, a plurality of second circuit members 2 mounted on the first circuit member 1 via, for example, bumps 3 (hereinafter, referred to as first bumps 3), and a second. A bump 5 (hereinafter, referred to as a second bump 5) arranged in a gap between the circuit members 2 and a sealing material 4 for sealing the second circuit member 2 are provided. The second bump 5 is conductive with the conductor 6 arranged in the first circuit member 1, and at least a part of the second bump 5 is buried in the sealing material 4. A space (internal space S) is formed between the first circuit member 1 and the second circuit member 2. The sealing material 4 is provided to seal the second circuit member 2 while maintaining the internal space S to prevent a short circuit of the second circuit member 2 and to shield the electromagnetic wave. In the present embodiment, the second circuit member 2 is mounted on the first circuit member 1 via the first bump 3, but the mounting method on the first circuit member 1 is not limited to this.

The sealing material 4 is a cured product of the laminated sheet 4P. The present invention includes this laminated sheet 4P. As shown in FIG. 2, the laminated sheet 4P includes at least one outermost insulating layer 41P and a conductive layer 42P. Therefore, the obtained sealing material 4 also includes at least a cured product layer 41 of the insulating layer 41P and a cured product layer 42 of the conductive layer 42P. FIG. 2 is a cross-sectional view schematically showing the laminated sheet 4P.

[Laminated sheet]
The laminated sheet 4P is pressed toward the first circuit member 1 in a state where the insulating layer 41P is arranged so as to face the second bump 5 in the sealing step. At this time, the laminated sheet 4P is in close contact with the surface of the second circuit member 2. Further, the laminated sheet 4P reaches the surface of the first circuit member 1 between the second circuit members 2, and the insulating layer 41P is perforated by the second bump 5. The second bump 5 penetrates the insulating layer 41P and reaches the conductive layer 42P. As a result, the second bump 5 is electrically connected to the conductive layer 42P, and the conductive layer 42P and the conductor 6 are electrically connected via the second bump 5. As a result, the electromagnetic wave shielding property of the conductive layer 42P (cured product layer 42 of the conductive layer) is exhibited. On the other hand, the insulating layer 41P prevents a short circuit of the second circuit member 2.

That is, the laminated sheet 4P is between the surface of the second circuit member 2 and the second circuit member 2 while maintaining the internal space S and the insulating layer 41P having a viscosity sufficient to be perforated by the second bump 5. It is provided with a conductive layer 42P having elasticity enough to be in close contact with the surface of the first circuit member 1 and to secure hollow sealing property (invasion of the laminated sheet 4P into the internal space S can be suppressed). By using the laminated sheet 4P having at least the above two layers, it is possible to achieve the sealing of the circuit member (hollow sealing) while maintaining the internal space S and the exertion of the electromagnetic wave shielding performance at the same timing. Can be done. Further, since the alignment with respect to the second bump 5 is unnecessary, the productivity is improved. In addition, since the sealing material 4 can be brought into close contact with the first circuit member 1 and the second circuit member 2, the height can be reduced.

(Insulation layer)
The insulating layer 41P is provided to prevent a short circuit of the second circuit member 2. Further, the insulating layer 41P has a viscosity that can be perforated by being pressed against the second bump 5.

The loss tangent tan δ1 at the temperature t when the second circuit member 2 of the insulating layer 41P is sealed is preferably larger than 1. The upper limit of the loss tangent tan δ1 is not particularly limited, but is, for example, 10, preferably 5. When the insulating layer 41P having such a loss tangent tan δ is used alone, it is difficult to seal it while maintaining the internal space S.

The temperature t when the second circuit member 2 is sealed is the temperature of the laminated sheet 4P when the surface of the second circuit member 2 is covered with the laminated sheet 4P while the internal space S is maintained. is there. The temperature of the laminated sheet 4P can be replaced with the set temperature of the heating means for the laminated sheet 4P in the sealing step. When the heating means of the laminated sheet 4P is a press machine, the temperature of the heating means is the set temperature of the press machine. When the heating means of the laminated sheet 4P is a heater that heats the first circuit member 1, the temperature of the heating means is a set temperature of the heater of the first circuit member 1. The temperature t can be changed depending on the material of the laminated sheet 4P and the like, and is, for example, between room temperature + 15 ° C. (40 ° C.) and 200 ° C. Specifically, the temperature t is, for example, 50 to 180 ° C. When the second circuit member 2 is sealed, the laminated sheet 4P may be in an uncured state, a semi-cured state, or a cured state.

The loss tangent tan δ1 is the ratio of the storage shear modulus (G1 ′) of the insulating layer 41P to the loss shear modulus (G1 ″) at the temperature t: G1 ″ / G1 ′. The storage shear modulus G1'and the loss shear modulus G1'can be measured by a viscoelastic meter measuring device conforming to JIS K 7244. Specifically, the storage shear modulus G1'and the loss shear modulus G1' Is measured on a test piece having a diameter of 8 mm × 1 mm using a viscoelastic meter measuring device (for example, ARES-LS2 manufactured by TA Instruments) under the conditions of a frequency of 1 Hz and a heating rate of 10 ° C./min. The same applies to the loss tangent tan δ of the conductive layer 42P and the coating layer 43P.

The storage shear modulus G1'at the temperature t ^{is preferably 1.0 × 10 7} Pa or less, and more preferably 1.0 × 10 ⁶ Pa or less. The lower limit of the storage shear modulus G1'is not particularly limited, but is, for example, 1.0 × 10 ³ Pa. When the storage shear elastic modulus G1'at the temperature t is in this range, the insulating layer 41P can be easily perforated by being pressed against the second bump 5 or being heated in that state.

The thickness T1 of the insulating layer 41P is not particularly limited as long as it is smaller than the height H of the second bump 5. Among them, the thickness T1 is preferably 30 μm or less, and more preferably 25 μm or less. This makes it easier for the second bump 5 to penetrate and makes it possible to reduce the height. Further, during the sealing step, the insulating layer 41P easily follows the conductive layer 42P, and it becomes difficult for the insulating layer 41P to enter the internal space S. On the other hand, from the viewpoint of ensuring the insulating property, the thickness T1 is preferably 5 μm or more. The thickness T1 of the insulating layer 41P is the distance between the main surfaces of the insulating layer 41P. The distance between the main surfaces can be obtained by averaging the distances at any 10 points. The same applies to the thickness of the conductive layer 42P and the coating layer 43P.

From the viewpoint of insulation, the volume resistivity of the insulating layer 41P ^{is preferably 1 × 10 8} Ω · cm or more, and more preferably 1 × 10 ¹⁰ Ω · cm or more.

The insulating layer 41P is composed of a thermosetting resin composition containing a thermosetting resin (hereinafter, referred to as a first thermosetting resin composition). The first thermosetting resin composition contains, for example, a thermosetting resin, a curing agent, a thermoplastic resin, and an inorganic filler.

The thermosetting resin is not particularly limited, but is limited to epoxy resin, (meth) acrylic resin, phenol resin, melamine resin, silicone resin, urea resin, urethane resin, vinyl ester resin, unsaturated polyester resin, diallyl phthalate resin, and polyimide. Examples include resin. These may be used individually by 1 type, and may be used in combination of 2 or more type. Of these, epoxy resin is preferable.

The thermosetting resin before sealing may be in an uncured state or a semi-cured state. The semi-cured state is a state in which the thermosetting resin contains a monomer and / or an oligomer, and the development of the three-dimensional crosslinked structure of the thermosetting resin is insufficient. The thermosetting resin in the semi-cured state does not dissolve in the solvent at room temperature (25 ° C.), but is in an incompletely cured state, that is, in the so-called B stage.

The epoxy resin is not particularly limited, but for example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AD type epoxy resin, hydrogenated bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenol novolac type epoxy resin, naphthalene. Type epoxy resin, alicyclic aliphatic epoxy resin, glycidyl ether of organic carboxylic acids and the like can be used. These may be used alone or in combination of two or more. The epoxy resin may be a prepolymer, or may be a copolymer of an epoxy resin such as a polyether-modified epoxy resin or a silicone-modified epoxy resin and another polymer. Of these, bisphenol AD type epoxy resin, naphthalene type epoxy resin, hydrogenated bisphenol A type epoxy resin and / or bisphenol F type epoxy resin are preferable. In particular, hydrogenated bisphenol A type epoxy resin and bisphenol F type epoxy resin are preferable in that they are excellent in heat resistance and water resistance and are inexpensive.

The epoxy resin may contain a monofunctional epoxy resin having one epoxy group in the molecule in an amount of about 0.1 to 30% by mass based on the entire epoxy resin in order to adjust the viscosity of the resin composition. As such a monofunctional epoxy resin, phenylglycidyl ether, 2-ethylhexyl glycidyl ether, ethyldiethylene glycol glycidyl ether, dicyclopentadiene glycidyl ether, 2-hydroxyethyl glycidyl ether and the like can be used. These may be used alone or in combination of two or more.

The thermosetting resin composition contains a curing agent for the thermosetting resin. The curing agent is not particularly limited, but for example, a phenol-based curing agent (phenol resin, etc.), a dicyandiamide-based curing agent (dicyandiamide, etc.), a urea-based curing agent, an organic acid hydrazide-based curing agent, a polyamine salt-based curing agent, and an amine adduct. A system curing agent, an acid anhydride type curing agent, an imidazole system curing agent and the like can be used. These may be used alone or in combination of two or more. The type of curing agent is appropriately selected depending on the thermosetting resin. Among them, it is preferable to use a phenolic curing agent from the viewpoints of low outgassing property at the time of curing, moisture resistance, heat cycle resistance and the like.

The amount of hardener depends on the type of hardener. When an epoxy resin is used, for example, it is possible to use an amount of a curing agent in which the equivalent number of functional groups of the curing agent is 0.001 to 2 equivalents, and further 0.005 to 1.5 equivalents per 1 equivalent of epoxy groups. preferable.

The dicyandiamide-based curing agent, urea-based curing agent, organic acid hydrazide-based curing agent, polyamine salt-based curing agent, and amine adduct-based curing agent are latent curing agents. The active temperature of the latent curing agent is preferably 60 ° C. or higher, more preferably 80 ° C. or higher. The active temperature is preferably 250 ° C. or lower, more preferably 180 ° C. or lower. This makes it possible to obtain a thermosetting resin composition that cures rapidly at an active temperature or higher.

The thermoplastic resin can be blended as a sheeting agent (eg, a pregelling agent). By forming the thermosetting resin composition into a sheet, the handleability in the sealing step is improved, the sagging of the thermosetting resin composition is suppressed, and the internal space S is easily maintained.

Examples of the types of thermoplastic resin include acrylic resin, phenoxy resin, polyolefin, polyurethane, blocked isocyanate, polyether, polyester, polyimide, polyvinyl alcohol, butyral resin, polyamide, vinyl chloride, cellulose, thermoplastic epoxy resin, and thermoplastic. Examples include phenol resin. Of these, acrylic resin is preferable because it has an excellent function as a sheeting agent. The amount of the thermoplastic resin is preferably 5 to 200 parts by mass, particularly preferably 10 to 100 parts by mass, per 100 parts by mass of the thermosetting resin.

The form of the thermoplastic resin when added to the thermosetting resin composition is not particularly limited. The thermoplastic resin may be, for example, particles having a weight average particle diameter of 0.01 to 200 μm, preferably 0.01 to 100 μm. The particles may have a core-shell structure. In this case, the core may be, for example, a polymer containing a unit derived from at least one monomer selected from the group consisting of n-, i- and t-butyl (meth) acrylates, or other (meth). ) It may be a polymer containing a unit derived from acrylate. The shell layer is composed of, for example, a monofunctional monomer such as methyl (meth) acrylate, n-, i- or t-butyl (meth) acrylate, (meth) acrylic acid and a polyfunctional monomer such as 1,6-hexanediol diacrylate. It may be a copolymer with. Further, a high-purity thermoplastic resin dispersed or dissolved in a solvent may be added to the thermosetting resin composition.

The thermosetting resin composition contains an inorganic filler. Examples of the inorganic filler include silica such as fused silica, talc, calcium carbonate, titanium white, red iron oxide, silicon carbide, and boron nitride (BN). Of these, fused silica is preferable because it is inexpensive. The average particle size of the inorganic filler is, for example, 0.01 to 100 μm. The amount of the inorganic filler is preferably 1 to 5000 parts by mass, more preferably 10 to 3000 parts by mass, per 100 parts by mass of the thermosetting resin.

The thermosetting resin composition may contain a third component other than the above. Examples of the third component include a curing accelerator, a polymerization initiator, a flame retardant, a pigment, a silane coupling agent, a thixotropic agent and the like.

The curing accelerator is not particularly limited, and examples thereof include a modified imidazole-based curing accelerator, a modified aliphatic polyamine-based accelerator, and a modified polyamine-based accelerator. The curing accelerator is preferably used as a reaction product (adduct) with a resin such as an epoxy resin. These may be used alone or in combination of two or more. The active temperature of the curing accelerator is preferably 60 ° C. or higher, more preferably 80 ° C. or higher, from the viewpoint of storage stability. The active temperature is preferably 250 ° C. or lower, more preferably 180 ° C. or lower. Here, the active temperature is a temperature at which the curing of the thermosetting resin is rapidly accelerated by the action of the latent curing agent and / or the curing accelerator.

The amount of the curing accelerator depends on the type of the curing accelerator. Generally, 0.1 to 20 parts by mass is preferable, and 1 to 10 parts by mass is more preferable per 100 parts by mass of the epoxy resin. When the curing accelerator is used as an adduct, the amount of the curing accelerator means the net amount of the curing accelerator excluding components other than the curing accelerator (epoxy resin, etc.).

The polymerization initiator exhibits curability by light irradiation and / or heating. As the polymerization initiator, a radical generator, an acid generator, a base generator and the like can be used. Specifically, benzophenon compounds, hydroxyketone compounds, azo compounds, organic peroxides, aromatic sulfonium salts, sulfonium salts such as aliphatic sulfonium salts can be used. The amount of the polymerization initiator is preferably 0.1 to 20 parts by mass, more preferably 1 to 10 parts by mass, per 100 parts by mass of the epoxy resin.

(Conductive layer)
The conductive layer 42P is a layer that can function as an electromagnetic wave shield and has conductivity. The conductive layer 42P reduces the influence of electromagnetic waves from the surroundings on the second circuit member 2, or reduces the influence of the second circuit member 2 on the surroundings. Further, the conductive layer 42P alone has enough elasticity to seal the second circuit member 2 while maintaining the internal space S.

In addition, the conductive layer 42P suppresses the highly viscous insulating layer 41P from entering the internal space S in the sealing step. The pressure received by the laminated sheet 4P in the sealing step is received by the highly elastic conductive layer 42P. Therefore, the pressure applied to the insulating layer 41P is reduced, and the invasion into the internal space S is less likely to occur.

The loss tangent tan δ2 of the conductive layer 42P at the temperature t is preferably 1 or less, more preferably 0.9 or less, and particularly preferably 0.7 or less. The lower limit of the loss tangent tan δ2 is not particularly limited, but is, for example, 0.1. As a result, the invasion of the conductive layer 42P itself into the internal space S and the invasion of the insulating layer 41P into the internal space S in the sealing step can be easily suppressed, while the surface of the second circuit member 2 and the second circuit member It becomes easy to flow to the extent that it can be brought into close contact with the surface of the first circuit member 1 between the two.

The storage shear elastic modulus G2'of the conductive layer 42P at the temperature t ^{is preferably 1.0 × 10 7} Pa or less, and more preferably 1.0 × 10 ⁶ Pa or less. The lower limit of the storage shear modulus G2'is not particularly limited, but is, for example, 1.0 ×× 10 ³ Pa, preferably 1.0 × 10 ⁴ Pa.

The conductive layer 42P is composed of a thermosetting resin composition containing a thermosetting resin (hereinafter, referred to as a second thermosetting resin composition) and a conductive powder. The composition of the second thermosetting resin composition is not particularly limited, but may be the same as that of the first thermosetting resin composition. As the conductive powder, a metal powder such as silver, copper or nickel or a carbon powder can be used. Of these, silver powder is preferable. The average particle size of the conductive powder is, for example, 0.01 to 100 μm. The amount of the conductive powder is preferably 1 to 5000 parts by mass, more preferably 10 to 3000 parts by mass, per 100 parts by mass of the thermosetting resin.

Viscoelasticity (ie, loss tangent tan δ) can be adjusted, for example, with the raw materials of the insulating layer 41P and / or the conductive layer 42P. For example, the loss tangent tan δ can be changed by changing the amount and type of the thermoplastic resin which is the sheeting agent. For example, when the amount of acrylic resin is increased, the storage shear modulus G'is increased and tan δ is decreased. The amount of the thermoplastic resin contained in the second thermosetting resin composition is preferably 5 to 200 parts by mass, more preferably 10 to 100 parts by mass per 100 parts by mass of the thermosetting resin.

The thickness T2 of the conductive layer 42P is preferably 1 to 400 μm, more preferably 15 to 250 μm. As a result, in the sealing step, it becomes easy to maintain the internal space S, and it becomes easy to exhibit sufficient electromagnetic wave shielding performance. Above all, from the viewpoint of maintaining the internal space S, the conductive layer 42P is preferably thicker than the insulating layer 41P.

From the viewpoint of electromagnetic wave shielding performance, the volume resistivity of the conductive layer 42P ^{is preferably 5 × 10 -3} Ω · cm or less, and preferably 1 × 10 ^-4 Ω · cm or less.

(Coating layer)
The laminated sheet 4P may include a coating layer 43P. In this case, the sealing material 4 further includes a cured product layer 43 of the coating layer 43P. The coating layer 43P is arranged on the outermost side of the other side opposite to the insulating layer 41P. The coating layer 43P is used, for example, to flatten the sealing surface of the mounting structure 10. This facilitates dicing of the mounting structure 10.

The loss tangent tan δ3 of the coating layer 43P at the temperature t is preferably larger than 1. The upper limit of the loss tangent tan δ1 is not particularly limited, but is, for example, 10, preferably 8. As a result, the coating layer 43P becomes easy to flow, good hollow sealing property is realized, and the sealing surface of the mounting structure 10 can be easily flattened. Therefore, the pick-up property of the mounting structure 10 is improved, and when the mounting structure 10 is individualized, dicing becomes easy.

The storage shear modulus G3'of the coating layer 43P at the temperature t ^{is preferably 1.0 × 10 3} Pa or more. The upper limit of the storage shear modulus G3'is not particularly limited, but is, for example, 1.0 × 10 ⁷ Pa, more preferably 1.0 × 10 ⁶ Pa. When the storage shear elastic modulus G3'at the temperature t is in this range, the coating layer 43P tends to flow easily and the sealing surface tends to become flat.

The thickness T3 of the coating layer 43P is preferably 10 to 1220 μm. This makes it easy to flatten the sealing surface of the mounting structure 10. The volume resistivity of the coating layer 43P is not particularly limited, but may be, for example, the same as that of the insulating layer 41P.

The coating layer 43P is composed of a thermosetting resin composition containing a thermosetting resin (hereinafter, referred to as a third thermosetting resin composition). The composition of the third thermosetting resin composition is not particularly limited, but may be the same as that of the second thermosetting resin composition.

The thickness T of the entire laminated sheet 4P is not particularly limited, but is preferably 30 to 1500 μm, more preferably 30 to 1000 μm, and 30 to 500 μm in that it can be easily brought into close contact with the surface of the second circuit member 2. Is particularly preferable.

The laminated sheet 4P may further include another third layer. However, the insulating layer 41P is arranged on the outermost side of one, the conductive layer 42P is arranged adjacent to the insulating layer 41P, and the coating layer 43P is arranged on the outermost side of the other, if necessary. That is, the third layer is arranged between the conductive layer 42P and the other outermost layer (for example, the coating layer 43P).

[Manufacturing method of mounting structure]
The manufacturing method according to this embodiment will be described with reference to FIG. FIG. 3 is an explanatory view schematically showing a manufacturing method according to the present embodiment by a cross section of a mounting member or a mounting structure 10.

The mounting structure 10 is on the first circuit member 1, a plurality of second circuit members 2 mounted on the first circuit member 1 via the first bump 3, for example, and the first circuit member 1. A second bump 5 arranged in a gap between the second circuit members 2 is provided, and a mounting member having an internal space S formed between the first circuit member 1 and the second circuit member 2 is prepared. 1 preparation step, a second preparation step of preparing the laminated sheet 4P, an arrangement step of arranging the laminated sheet 4P on the mounting member so that the insulating layer 41P of the laminated sheet 4P faces the second bump 5, and a laminated sheet. Manufactured by a method including a sealing step of pressing the 4P against the first circuit member 1 and heating the laminated sheet 4P to seal the second circuit member 2 while maintaining the internal space S. Will be done. In the sealing step, the second bump 5 penetrates the insulating layer 41P, and the second bump 5 and the conductive layer 42P are electrically connected to each other. Further, an individualization step of dicing the obtained mounting structure 10 for each second circuit member 2 may be performed.

(1st preparation process)
A mounting member including the first circuit member 1 and a plurality of second circuit members 2 mounted on the first circuit member 1 is prepared (FIG. 3A). The second circuit member 2 is mounted on the first circuit member 1 via, for example, the first bump 3. Therefore, an internal space S is formed between the first circuit member 1 and the second circuit member 2.

The first circuit member 1 is at least one selected from the group consisting of, for example, a semiconductor element, a semiconductor package, a glass substrate, a resin substrate, a ceramic substrate, and a silicon substrate. These first circuit members may have a conductive material layer such as ACF (anisotropic conductive film) or ACP (anisotropic conductive paste) formed on the surface thereof. The resin substrate may be a rigid resin substrate or a flexible resin substrate, and examples thereof include an epoxy resin substrate (for example, a glass epoxy substrate), a bismaleimide triazine substrate, a polyimide resin substrate, and a fluororesin substrate. The first circuit member 1 may be a component-embedded substrate having a semiconductor chip or the like inside.

The second circuit member 2 is mounted on the first circuit member 1 via the first bump 3. As a result, an internal space S is formed between the first circuit member 1 and the second circuit member 2. The second circuit member 2 is an electronic component that needs to be sealed (hollow sealed) while maintaining the internal space S. Examples of the second circuit member 2 include RFIC, SAW, a sensor chip (accelerometer, etc.), a piezoelectric vibrator chip, a crystal oscillator chip, a MEMS device, and the like.

The first bump 3 has conductivity, and the first circuit member 1 and the second circuit member 2 are electrically connected to each other via the first bump 3. The height of the first bump 3 is not particularly limited, but may be, for example, 40 to 70 μm. The material of the first bump 3 is also not particularly limited as long as it has conductivity, and examples thereof include solder balls.

That is, the mounting member has a chip-on-board (CoB) structure (chip-on-wafer (CoW), chip-on-film (CoF)) in which the second circuit member 2 is mounted on various first circuit members 1. , Including chip-on-glass (CoG)), chip-on-chip (CoC) structure, chip-on-package (CoP) structure and package-on-package (PoP) structure. The mounting member may be a multi-layer mounting member in which the first circuit member 1 and / or the second circuit member 2 is further laminated on the first circuit member 1 on which the second circuit member 2 is mounted.

The second bump 5 is a surface on which the second circuit member 2 of the first circuit member 1 is mounted, is arranged in a gap between the second circuit members 2, and is provided on the first circuit member 1. It is conducting with the conductor 6. Therefore, when the second bump 5 penetrates the insulating layer 41P of the laminated sheet 4P in the sealing step, the connection between the conductive layer 42P and the conductor 6 is achieved. That is, by using the laminated sheet 4P, in the sealing step, the sealing while maintaining the internal space S and the exertion of the electromagnetic wave shielding performance are simultaneously achieved.

The shape of the second bump 5 is not particularly limited. Among them, it is preferable that the diameter becomes smaller from the surface of the first circuit member 1 on which the second circuit member 2 is mounted toward the sealing material 4 in terms of easily penetrating the insulating layer 41P. The diameter of the second bump 5 is the diameter when the second bump 5 is viewed from the normal direction of the main surface of the first circuit member 1, and can change in the height direction of the second bump 5. The maximum diameter of the second bump 5 (usually the diameter at the contact surface with the first circuit member 1) is not particularly limited, and the second bump 5 fits between the second circuit members 2 mounted on the first circuit member 1. Moreover, the size may be such that it does not interfere with dicing.

The height H of the second bump 5 is not particularly limited as long as it is larger than the thickness T1 of the insulating layer 41P, and may be appropriately set. However, in order to ensure continuity, it is preferably smaller than the total thickness (T1 + T2) of the insulating layer 41P and the conductive layer 42P. The height H of the second bump 5 is, for example, larger than 30 μm and 100 μm or less.

When the loss tangent tan δ1 of the insulating layer 41P is larger than 1, the height H of the second bump 5 does not have to be excessively higher than the thickness T1 of the insulating layer 41P. The ratio of the height H of the second bump 5 to the thickness T1 of the insulating layer 41P: H / T1 is, for example, greater than 1 and may be 10 or less, or 5 or less. Ratio: Even if H / T1 is in this range, the second bump 5 can penetrate the insulating layer 41P. The height H of the second bump 5 is the maximum value from the surface on which the second circuit member 2 of the first circuit member 1 is mounted. When a plurality of second bumps 5 are arranged, the height H is obtained by averaging these maximum values.

The second bump 5 may be, for example, a plating bump formed by a plating technique, a bump formed by screen printing or the like, or a so-called stud bump. The stud bump is formed, for example, by heating the tip of a metal wire to form a ball, then joining the ball portion to a predetermined position of the first circuit member 1, stretching and cutting the metal wire. The stud bump formed in this way has a sharp tip, and even the insulating layer 41P as described above can be penetrated. The stud bump may be, for example, a gold stud bump.

The conductor 6 is arranged inside the first circuit member 1, and connects the second bump 5 with, for example, a ground electrode (not shown). The conductor 6 can be formed of, for example, a conductive paste or metal particles.

(Second preparation process)
A laminated sheet 4P including an insulating layer 41P, a conductive layer 42P, and a coating layer 43P is prepared (FIG. 3A).
The method for producing the laminated sheet 4P is not particularly limited. The laminated sheet 4P may be formed by separately producing each layer and then laminating (lamination method), or by sequentially coating the materials of each layer (coating method).

In the laminating method, a step of preparing a solvent paste or a solvent-free paste containing the thermosetting resin composition (hereinafter, simply referred to as a paste), a step of forming each layer from the paste (forming step), and a step of forming each layer from the paste. It is formed by a method including. By this method, the insulating layer 41P, the conductive layer 42P, and the coating layer 43P are formed, and then laminated in this order. If the paste contains a pregelling agent, gelation takes place during the forming process. Gelation is performed by thinning the paste and then heating the thin film at a temperature lower than the curing temperature of the thermosetting resin (for example, 70 to 150 ° C.) for 1 to 10 minutes.

On the other hand, in the coating method, for example, after forming the insulating layer 41P by the above method, the surface of the insulating layer 41P is coated with a paste containing the second thermosetting resin composition to form the conductive layer 42P. Similarly, the coating layer 43P is formed on the surface of the conductive layer 42P. Again, gelation can occur during the forming step. The gelation may be carried out sequentially after forming each thin film from each paste, or may be carried out after forming a laminate of thin films.

Each layer (thin film) is formed by, for example, a die, a roll coater, a doctor blade, or the like. In this case, it is preferable to adjust the viscosity of the paste so as to be 10 to 10000 mPa · s. When the solvent paste is used, the solvent may be removed by drying at 70 to 150 ° C. for 1 to 10 minutes. The gelation and removal of the solvent can be carried out at the same time.

(Placement process)
The laminated sheet 4P is arranged on the mounting member so that the insulating layer 41P faces the second circuit member 2 and the second bump 5 (FIG. 3A).
At this time, the plurality of second circuit members 2 may be covered with one laminated sheet 4P. As a result, the laminated sheets 4P can be collectively arranged so as to face the surfaces of the plurality of second circuit members 2 and the surface of the first circuit member 1 between the second circuit members 2.

(Seal process)
The laminated sheet 4P is pressed against the first circuit member 1 (FIG. 3 (b)), and the laminated sheet 4P is heated and cured (FIG. 3 (c)). As a result, the second circuit member 2 is sealed while maintaining the internal space S. Further, the insulating layer 41P is perforated by the second bump 5. The perforation of the insulating layer 41P by the second bump 5 occurs when pressed or heated for curing.

The pressing of the laminated sheet 4P against the first circuit member 1 is performed, for example, while heating the laminated sheet 4P at a temperature lower than the curing temperature of the thermosetting resin contained in the laminated sheet 4P (heat press). As a result, the laminated sheet 4P adheres to the surface of the second circuit member 2 and easily extends until it reaches the surface of the first circuit member 1 between the second circuit members 2. The reliability of the sealing of 2 can be improved. The hot press may be performed under atmospheric pressure or in a reduced pressure atmosphere (for example, 0.001 to 0.05 MPa). The heating conditions at the time of pressing are not particularly limited, and may be appropriately set according to the pressing method and the type of thermosetting resin. The heating is performed, for example, at 40 to 200 ° C. (preferably 50 to 180 ° C.) for 1 second to 300 minutes (preferably 3 seconds to 300 minutes).

Subsequently, the laminated sheet 4P is heated at the above-mentioned curing temperature to cure the thermosetting resin in the laminated sheet 4P to form the sealing material 4. As a result, the second circuit member 2 is sealed. The conditions for heating the laminated sheet 4P (curing the thermosetting resin) may be appropriately set according to the type of the thermosetting resin. The thermosetting resin is cured, for example, at 50 to 200 ° C. (preferably 120 to 180 ° C.) for 1 second to 300 minutes (preferably 60 minutes to 300 minutes).

The heat pressing and the curing of the thermosetting resin may be performed separately or at the same time. For example, under a reduced pressure atmosphere, the thermosetting resin contained in the laminated sheet 4P is hot-pressed at a temperature lower than the curing temperature, then the reduced pressure is released, and the thermosetting resin is heated at a higher temperature under atmospheric pressure to cure the thermosetting resin. You may. Alternatively, the thermosetting resin may be cured by hot pressing at a temperature lower than the curing temperature of the thermosetting resin contained in the laminated sheet 4P under atmospheric pressure and then heating at a higher temperature. Further, the thermosetting resin may be cured during the reduced pressure by hot pressing at the curing temperature in a reduced pressure atmosphere.

(Individualization process)
An individualization step of dicing the obtained mounting structure 10 for each second circuit member 2 may be performed (FIG. 3 (d)). As a result, a chip-level mounting structure (mounting chip 20) is obtained.

The method for manufacturing a mounting structure of the present invention can connect the conductive layer of the laminated sheet and the ground electrode with high productivity while maintaining the internal space, so that various mounting structures requiring an electromagnetic wave shield can be manufactured. It is useful as a method. The laminated sheet of the present invention used in this method is also suitable for manufacturing various mounting structures that require an electromagnetic wave shield.

10: Mounting structure 1: First circuit member 2: Second circuit member 3: First bump 4P: Laminated sheet 41P: Insulating layer 42P: Conductive layer 43P: Coating layer 4: Encapsulant (cured product of laminated sheet)
41: Hardened material layer of insulating layer 42: Hardened material layer of conductive layer 43: Hardened material layer of coating layer 5: Second bump 6: Conductor 20: Mounting chip

Claims (9)

It includes a first circuit member, a plurality of second circuit members mounted on the first circuit member, and bumps on the first circuit member and arranged in a gap between the second circuit members. At the same time, a step of preparing a mounting member in which a space is formed between the first circuit member and the second circuit member, and
A step of preparing a laminated sheet provided with an insulating layer and a conductive layer, wherein the insulating layer is arranged at least one of the outermost layers.
An arrangement step of arranging the laminated sheet on the mounting member so that the insulating layer faces the bump.
A sealing step of pressing the laminated sheet against the first circuit member and heating the laminated sheet to seal the second circuit member while maintaining the space is provided.
In the sealing step, the bump is passed through the insulating layer to electrically connect the bump and the conductive layer .
At the temperature t when the second circuit member is sealed, the loss tangent tan δ1 of the insulating layer is larger than 1.
A method for manufacturing a mounting structure, wherein the loss tangent tan δ2 of the conductive layer is 1 or less at the temperature t. The method for manufacturing a mounting structure according to claim 1 , wherein the thickness T1 of the insulating layer is 30 μm or less. The method for manufacturing a mounting structure according to claim 1 or 2 , wherein the volume resistivity of the conductive layer is 5 × 10 ^-3 Ω · cm or less. The laminated sheet comprises the other outermost covering layer.
At the temperature t
The method for manufacturing a mounting structure according to any one of claims 1 to 3 , wherein the loss tangent tan δ3 of the coating layer is larger than 1. A method for manufacturing an individualized mounting structure, comprising a step of dicing and individualizing the mounting structure obtained by the manufacturing method according to claim 1 for each of the second circuit members. A mounting member including a first circuit member and a plurality of second circuit members mounted on the first circuit member, and a space is formed between the first circuit member and the second circuit member. Laminated sheet used for sealing,
It has an insulating layer and a conductive layer,
The insulating layer is arranged on the outermost side of at least one of them.
At a temperature t when said second circuit member is sealed, the loss tangent tanδ1 before Symbol insulating layer, much larger than the 1,
A laminated sheet in which the loss tangent tan δ2 of the conductive layer is 1 or less at the temperature t. The laminated sheet according to claim 6 , wherein the thickness T1 of the insulating layer is 30 μm or less. The laminated sheet according to claim 6 or 7 , wherein the volume resistivity of the conductive layer is 5 × 10 ^-3 Ω · cm or less. In addition, it has an outermost covering layer on the other side.
At the temperature t
The laminated sheet according to any one of claims 6 to 8 , wherein the loss tangent tan δ3 of the coating layer is larger than 1.

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