JP2007173446A - Substrate with built-in parts - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that connection reliability is reduced substantially derived from the deformation of parts, the generation of a crack or parts destruction causing a subsequent electric shortage, a short-circuit or the like, due to the pressure of a prepreg directly added to the whole upper surface of parts by the heating pressurization at the time of lamination in such a lamination structure that the parts are mounted to the circuit conductor of the upper surface of a core board, the whole upper surfaces of the parts elements are directly covered with the prepreg of insulating resin, and a lid member is laminated in piles in the upper part of this prepreg. <P>SOLUTION: A substrate with built-in parts comprises a core substrate, mounting parts mounted in this core substrate, a prepreg laid on the core substrate which has glass fibers with a storage hole of mounting parts impregnated by synthetic resin, and a conductive metal or a resin base material which blockades the storage hole formed on this prepreg. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a component-embedded substrate that incorporates mounting components such as semiconductors, LEDs, and capacitors.

  In recent years, there has been an increasing demand for higher performance and smaller electronic devices, and the density of electric circuits has been increasing at an accelerating pace. Therefore, many component-embedded substrates with built-in components have been manufactured in which mounted components such as semiconductors and capacitors are built into the substrate in order to increase the efficiency of component mounting.

The electronic component built-in substrate shown in Patent Document 1 has a capacitor built in a multilayer printed wiring board in which an insulating layer and a conductor layer are alternately formed, and a capacitor lower portion is partially formed on the insulating layer forming the multilayer printed wiring board. In this electronic component-embedded substrate, an electrode is provided, a dielectric layer is provided so as to cover the capacitor lower electrode, and a capacitor upper electrode having a larger area than the capacitor lower electrode is provided on the dielectric layer. That is, a capacitor is built in a multilayer printed wiring board by screen-printing a high dielectric resin paste mainly composed of a thermosetting resin to provide a dielectric layer.
However, it has been difficult to provide a dielectric layer by screen printing of a high dielectric resin paste, and to stabilize the capacitor capacity tolerance with high accuracy and high quality.

Further, as seen in Patent Document 2, an electronic component is mounted on the upper conductor layer of the lower wiring board, a middle wiring board provided with a storage hole for storing the electronic component, and an upper wiring board for sealing the storage hole; An electronic component built-in type multilayer wiring board is disclosed.
However, since the storage hole area for storing these electronic components is provided with an airtight space, moisture is absorbed and moisture is collected, and there is a problem in connection reliability when soldering the printed wiring board with moisture or gas. It was.
JP 2005-116604 A JP 2002-84070 A

  However, there is a limit to providing a dielectric layer by screen printing to stabilize the capacitor capacity tolerance with high precision and high quality. Therefore, a capacitor element with high precision and high quality with reduced capacitor capacity tolerance ( Mounting component) is mounted on the circuit conductor on the upper surface of the core substrate, and a prepreg which is an insulating resin having a storage hole for storing the capacitor element (mounting component), and a conductive material for closing the storage hole provided on the prepreg. A component-embedded substrate comprising a conductive metal or a resin base material.

As shown in FIG. 4, the capacitor element 15 is mounted on the circuit conductor 11 on the upper surface of the core substrate 10 and the prepreg 16 that is an insulating resin is directly covered on the entire upper surface of the capacitor element 15 as shown in FIG. Since the upper lid member 18, which is a copper foil or a resin base material, is stacked on top of each other, the pressure of the prepreg 16 is directly applied to the entire upper surface of the capacitor element 15 by heating and pressurization during the stacking. In addition, the capacitor element 15 is deformed or destroyed.

  In other words, deformation of the capacitor element (mounted component) leads to crack generation, component destruction, and subsequent electrical short-circuiting and short-circuiting, which greatly reduces connection reliability. This is a big problem in increasing the efficiency and density.

  An object of the present invention is to provide a component-embedded substrate capable of high efficiency and high density without impairing connection reliability.

  According to a first aspect of the present invention, a core substrate, a mounting component to be mounted on the upper surface of the core substrate, and a glass fiber placed on the core substrate and having a storage hole for the mounting component are impregnated with a synthetic resin. A component-embedded substrate comprising a prepreg and a conductive metal or resin base material that closes a storage hole provided on the prepreg.

  A second aspect of the present invention is that, in the first aspect, the mounting component is mounted on the core substrate, and the prepreg having a mounting hole for the mounting component and the conductive metal or resin base material on the prepreg are heated under pressure. After that, the component built-in board is filled with the prepreg inside the storage hole provided in the prepreg.

  A third aspect of the present invention is the component-embedded substrate according to the first or second aspect, wherein the shape of the mounting component storage hole is circular, oval, square, or irregular.

According to the present invention, there is no pressure such that the prepreg directly presses the mounted component by heating and pressurizing when the mounted component is built in the wiring board, and the deformation of the component can be minimized, and the connection Reliability is not reduced.
Further, since the prepreg is sealed by the prepreg resin that flows out into the mounting component housing hole by heat and pressure, the mounted component is sealed, so that it does not absorb moisture or form a void that accumulates moisture. Since such a storage hole area does not form an airtight space, a highly reliable component-embedded substrate can be provided.

The mounted component used in the present invention is not particularly limited, but specifically, a semiconductor IC chip, a capacitor, an inductance, a resistor, an LED component, or the like can be used.
The connection between the mounted component and the core substrate is not particularly limited, but specifically, solder, solder paste, silver-copper mixed paste, or the like can be used.

The prepreg used in the present invention is not particularly limited as long as it has a hole penetrating the prepreg (mounting hole for mounting component), and the size of the hole can store the mounting component. It only needs to be large.
The shape of the hole is not particularly limited, and can be appropriately selected from circular, oval, elliptical, quadrangular, triangular, star-shaped, etc., but the shortest distance between the mounting component and the peripheral edge of the hole is equal. It is preferable to have a shape similar to that of the mounting component in plan view, or a circular shape, an oval shape, or an elliptical shape. In this way, when the mounting component is sealed, the prepreg resin reaches the mounting component evenly, and it is difficult to form a gap or the like.
One or a plurality of holes may be provided for one prepreg, and it is not always necessary to provide holes for all the mounted components. Further, a plurality of mounting parts may be arranged in one hole.

  The prepreg used in the present invention may be glass fiber or synthetic fiber impregnated with a synthetic resin. As the resin, a thermosetting resin or a composite sheet in which an inorganic filler is dispersed in a thermosetting resin is used. be able to.

  The thickness of the prepreg is not particularly limited, and the number of sheets to be used is not limited, but the distance from the upper surface of the core substrate to the lower surface of the conductive metal foil or the lower surface of the substrate is 10% higher than the height of the mounted component before heating and pressing. Need to be ~ 30% higher.

The metal foil used for this invention should just have electroconductivity, Specifically, copper foil, aluminum foil, nickel foil, etc. can be used. In particular, the copper foil has good electrical characteristics and is preferably used.
The thickness of the metal foil is not particularly limited, but is mainly about 12 μm to 35 μm in thickness.

Based on FIG. 1, the manufacturing method of the first half of the component built-in substrate of the present invention will be described.
First, a capacitor element 15 which is a mounting component is mounted on the circuit conductor 11 on the upper surface of the core substrate 10 with the solder paste 13.
In a separate process, the storage hole 20 penetrating through the prepreg 16 is aligned with the component mounting location so that the capacitor element 15 mounted inside the through-hole storage hole 20 provided in the prepreg 16 in which the glass fiber is impregnated with synthetic resin is accommodated And mechanical punching.
A prepreg 16 in which a synthetic fiber is impregnated with a glass fiber having a storage hole 20 around the capacitor element 15 as a mounting component is placed on the upper surface of the core substrate 10.

Based on FIG. 2, a method for manufacturing the latter half of the component-embedded substrate of the present invention will be described.
The prepreg 16 in which the glass fiber having the accommodation hole 20 around the capacitor element 15 described above is impregnated with a synthetic resin is a prepreg 16 that is 10% to 30% thicker than the thickness of the capacitor element 15 and is mounted on the upper surface of the core substrate 10. The capacitor element 15 thus formed is surrounded and laminated.

After an upper lid member 18 made of copper foil or a resin base material is laminated on the upper portion of the prepreg 16 and the upper portion of the housing hole 20 in which the capacitor element 15 is housed and built, it is heated and heated to integrate the whole. A component-embedded substrate is formed by laminating and pressure bonding under pressure (temperature: 180 ° C., pressure: 2.5 MPa).

As shown in FIG. 3, the resin portion 17 of the prepreg 16 softened by the thermosetting process of the prepreg 16 flows into the hollow portion of the housing hole 20 in which the capacitor element 15 is housed and incorporated, and around the capacitor element 15. Seal (fill).
Therefore, no gap remains in the storage hole 20 of the capacitor element 15 (mounting component), and the upper portion of the capacitor element 15 is covered with the softened resin portion 17 of the prepreg 16, and the lid member 18 is stacked thereon. .
That is, the capacitor element 15 is not crushed by the glass fiber of the prepreg 16.

It is sectional drawing explaining the manufacturing method of the first half of the component built-in board | substrate by this invention. It is sectional drawing explaining the manufacturing method of the second half of the component built-in board | substrate by this invention. It is sectional drawing explaining the component built-in board | substrate by this invention. It is sectional drawing explaining the component built-in board by the conventional invention.

Explanation of symbols

10 ... core substrate, 11 ... circuit conductor, 15 ... capacitor element, 16 ... prepreg,
17 ... Resin content of prepreg, 18 ... Lid member, 20 ... Storage hole.

Claims (3)

  A core substrate, a mounting component mounted on the upper surface of the core substrate, a prepreg placed on the core substrate and impregnated with a synthetic resin in a glass fiber having a housing hole for the mounting component, and provided on the prepreg A component-embedded board comprising a conductive metal or resin base material that closes the storage hole.   In Claim 1, after mounting a mounting component on the core substrate and pressurizing and heating the prepreg having the mounting component storage hole and the conductive metal or resin base material on the prepreg, the mounting component was provided on the prepreg. A component-embedded board, wherein the inside of the storage hole is filled with prepreg.   3. The component-embedded substrate according to claim 1, wherein the shape of the mounting component storage hole is circular, oval, square, or irregular.

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