JP2005064087A - Wiring board and electronic component using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for forming an insulating body closing one end face of a through hole penetrating outer layer conductors on both sides of a wiring board and durable against high mold resin sealing pressure and high temperature for blocking intrusion of resin enduring against heat and pressure of transfer molding method. <P>SOLUTION: The wiring board has a non-through conduction hole 7 closed by a two-layer insulating closing body 15 consisting of a filmlike body 11 and an insulating coating 12 covering the upper surface of the filmlike body. The electronic component has an insulating body closing one end face of a through conduction hole penetrating the wiring board and durable against high mold resin sealing pressure and high temperature of transfer molding method. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a wiring substrate for mounting an electronic component or an electronic component element, and a chip-type electronic component having an end face electrode using the wiring substrate.

In general, in the case of a wiring board having a through-conduction hole (through-hole hole) penetrating the wiring board, a coating material (mold resin, etc.) for protecting electronic component elements and electronic components mounted and mounted on the wiring board ) Flows out to the opposite surface side of the wiring board through the through-conduction hole of the wiring board and the resin leaks and a defect occurs.
Also, flux, solder, solder paste, etc. when mounting and mounting electronic components on the motherboard may enter the electronic component, or there may be poor adhesion between the wiring board and the mounted or mounted electronic component element or electronic component. Occur.
Therefore, in order to prevent resin leakage, the through-conduction hole in which the filling material is filled in the through-conduction hole of the wiring board is filled with the insulating filling material in the entire inside of the hole, so that the conductor layer on the inner wall of the hole is covered. Soldering becomes difficult, and it cannot be used as an end face electrode for connecting to another wiring board.

In a chip-type electronic component having an end face electrode for connecting an IC flat package, a semiconductor circuit element, a light emitting element, a light receiving element and the like to another wiring board such as a mother board, a process of manufacturing the chip part conventionally After the electronic component element is mounted by wire bonding or surface mounting, the electronic component or bonding wire is resin-molded with a coating material such as a mold resin in order to protect the electronic component or the like.
In this process, the mold resin is connected to the connection land on the side opposite to the mounting surface of the electronic component, the through hole hole that requires soldering, or the outside of the wiring board through the through hole such as the through hole hole of the wiring board. As a result, the mold resin adheres to the end face electrodes and the like, resulting in poor solder connection.
Therefore, before the step of covering with a mold resin or the like, a step of masking a through hole such as a through hole of the wiring board with a heat resistant adhesive tape or a film film is required.

In particular, in order to make an electronic component composed of an electronic component element such as a semiconductor circuit element, a light emitting element, and a light receiving element into a chip-type electronic component for mounting with a surface, an electrode for connecting to a counterpart wiring board is required. In many cases, an end face electrode is set on the end face of the chip-type electronic component as the electrode.
The end face electrode is formed by cutting the through-hole hole in half near the center of the hole, that is, a so-called semiconductor device that is cut by a dicing cut to form an end face electrode, and soldering charges for chip components. I have to.
The through-hole hole for the end face electrode is formed in the through-hole hole so that the electronic component element and the bonding wire are coated with a mold resin, then diced and cut, and the wall surface of the through-hole hole is used as a soldering allowance. Resin leakage must be prevented.
Furthermore, when soldering to another wiring board such as a motherboard, the solder penetrates under the masking material, and the wiring board on which the electronic component element is mounted and the mounted electronic component element or electronic component Inadequate adhesion occurs.

A method of manufacturing a wiring board on which electronic components are mounted includes a step of drilling an insulating substrate or a double-sided copper-clad laminate, and a copper plating layer is formed on the surface of the substrate or laminate and the inner wall of the through hole. A process for forming a conductive circuit by applying an etching resist by a silk screen printing method or a photographic method after that, and then a masking process for closing one end face of a predetermined through hole with a film film, Next, a wiring board is manufactured in a process of surface plating such as Ni—Au plating or Ni—Ag plating on the exposed surface conductors and non-through-holes.
However, since Au plating and Ag plating have high cyan concentration and high plating solution temperature, there is no film resist that can particularly withstand Ag plating. Therefore, a masking process is performed in which a film film is closed after Ni-Ag plating.
Then, mounting with electronic components on the wiring board, mounting with electronic components, bonding and hardening the electronic component elements and bonding wires, and dicing cut near the center of the specified non-through hole Chip-type electronic parts for use.
Japanese Patent Laid-Open No. 11-251704

It forms an insulating blocking body that masks one end face of a through-penetrating conduction hole that penetrates outer layer conductors on both sides of a wiring board that can withstand Au plating, Ag plating, and particularly Ag plating.
Also, when mounting electronic components or electronic component elements on a wiring board and sealing the surface on which the electronic component elements are mounted with resin, wiring that withstands the sealing pressure and high temperature of the high-pressure mold resin in resin sealing An insulating blocking body is formed that closes one end face of the through-penetrating conduction hole that penetrates the outer layer conductors on both sides of the substrate.

  Surface conductors and non-penetrating conducting holes exposed after a masking step of closing one end face of a predetermined penetrating conducting hole with a film film or the like when forming a surface plating layer such as Ni-Au plating or Ni-Ag plating Ni-Au plating or Ni-Ag plating is applied to the substrate. The adhesive strength between the wiring board and the masking material, such as a film film, that blocked the end surface of one of the non-through-conduction holes of the wiring board by the plating process decreased, and the film film was peeled off or soaked and mounted with mold resin. The mold resin that seals the surface peels off the film film or the plating solution begins to leak, and the mold resin flows into the non-penetrating conductive holes, causing a resin leak and failure.

Further, the chip-type electronic component requires an end face electrode to be connected to another wiring board such as a mother board, and the surface to be used as the end face electrode is formed of a conductive layer having good solderability. It is a condition that it is exposed on the end face of the mold electronic component.
In other words, in a non-penetrating conduction hole in which one end face of a predetermined penetrating conduction hole is covered with an insulating plug such as a masking material, the insulating film-like body is sealed with a high-pressure mold resin in the transfer molding method resin sealing. In order to make the end face electrode, it is important to endure the stop pressure and the high temperature, and that the insulating blocker in contact with the end face of the hole does not sink into the hole. Therefore, the film film-like body is good because it is in contact with the hole end surface of the non-penetrating conduction hole at the flat surface.

In order to solve the above-described problem, in the first aspect of the present invention, in the wiring board on which the electronic component or the electronic component element is mounted, the outer layer conductors on both sides of the wiring board are passed through and on the through conduction hole. It is a wiring board that forms a non-through-conductive hole that is closed with an insulating closing body composed of two layers of a film film-like body that covers one hole end surface and an insulating coating that covers the upper surface of the film film-like body. .
Note that the wiring board of the present invention may be a single-sided board or a multilayer wiring board, and the non-penetrating conduction holes can be installed at a predetermined place as a part mounting or a lower part covering an electronic part and an end face electrode.

Moreover, in Claim 2 of this invention, two layers of the insulating coating material which coat | covers the film film body on the one hole end surface of the said through-conduction hole of said Claim 1, and the upper surface of this film film body. This is a wiring board on which a surface plating layer is formed after forming a non-penetrating conduction hole by closing with an insulating closing body.
An electronic component or an electronic component element is mounted on the wiring board, and the surface on which the electronic component is mounted is sealed with a mold resin and cured, and then the substantially end portion of the non-penetrating conduction hole is divided and cut. An electrode is formed.

  Further, in claim 3 of the present invention, the wiring board according to claim 1 or 2 is used, an electronic component or an electronic component element is mounted on the wiring board, and the electronic component element or the like is mounted on the surface. After sealing with mold resin, it is set as the electronic component which has an end surface electrode formed by dividing and cutting substantially the center part of the said non-penetrating conduction hole.

(1) Even in a wiring board having a non-through-conduction hole subjected to Au plating or Ag plating, an adhesive, a sealing material, or the like does not flow out into the non-through-conduction hole of the wiring board in a sealing process such as a mold resin. .

(2) Forming a non-through-conduction hole closed with a two-layer insulating blocker covering one hole end surface on the through-conduction hole that can withstand the sealing pressure and high temperature of the high-pressure mold resin in resin sealing As a result, it does not flow into the non-through-conduction hole of the wiring board and solder connection failure does not occur.

(3) Using the above-mentioned wiring board, mounting an electronic component or electronic component element on this wiring board, sealing the mounting surface with a mold resin, and then dividing and cutting the substantially central portion of the non-through-conduction hole. When soldering the end face electrode of the electronic component to another wiring board such as a motherboard, the solder soaks under the insulating closure and is mounted on the wiring board on which the electronic component element is mounted. An adhesion failure with an electronic component element or electronic component no longer occurs.

The insulating base material used as the wiring board is an insulating material such as a glass epoxy base material, a phenol base material, a synthetic resin base material, a polyimide resin base material, a BT resin (bismaleimide-triazine resin) base material, a modified BT resin base material, or a ceramic. Any of the conductive substrates may be used.
In order to implement the present invention, a method of manufacturing a wiring board on which electronic components are mounted includes a step of drilling an insulating base material or a double-sided copper-clad laminate, the surface of the base material or the laminate, and the inner wall of the through hole. The process of forming a copper plating layer on the substrate, the process of forming a conductor circuit by applying an etching resist after silk screen printing or photographic method, and a foreign metal with wire bonding or good solderability After the step of forming a surface plating layer such as Ni-Au plating or Ni-Ag plating as a plating layer, and then the masking step of closing one end surface of a predetermined through-conduction hole with a film film, after the masking step A wiring board is manufactured by a process of performing surface plating such as Ni—Au plating or Ni—Ag plating on the exposed surface conductor and non-through hole.

  After that, the process of mounting and mounting the electronic component on the wiring board, the step of resin-sealing the electronic component element and the bonding wire, and the step of dicing cutting the vicinity of the center of the predetermined non-penetrating conduction hole It is a chip-type electronic component for mounting.

Use a glass / epoxy base material as the insulating base material and a substrate material with an overall thickness of 0.2 mm made of 18 μm or 35 μm copper foil, and drill a predetermined through-hole at a desired location with a drill or laser light. To do.
Next, 10 μm to 25 μm in thickness of the conductor layer is formed by electroless plating and electrolytic plating on both surfaces of the copper-clad laminate and the inner wall of the through hole.
Next, a desired pattern-shaped etching resist is formed at a predetermined location by a silk screen printing method or a photo method, and unnecessary metal conductors are etched to dissolve and remove the copper foil.
After that, the etching resist film is peeled and removed, and a through conduction hole comprising a conductor layer inside the through hole for electrically connecting the desired upper outer layer surface conductor, lower outer layer surface conductor, and outer layer surface conductors on both sides of the insulating base. Form.

In other words, as shown in FIG. 4, the upper outer surface conductor 2, the lower outer surface conductor 4, and the outer outer surface conductors on both sides of the insulating base 1 that are desired outer surface conductors on both sides of the insulating base 1 are electrically connected. A through conduction hole 3 made of the conductor layer 5 inside the through hole to be conducted is formed.
Next, a non-through-conduction hole is formed by closing one end of a predetermined through-conduction hole with a film film-like body and a two-layer insulating covering body covering the upper surface of the film film-like body. After forming, a wiring board on which a surface plating layer is formed.

A wiring board according to Embodiment 1 of the present invention shown in FIG. 1 will be described.
First, in the normal through-conduction hole 3 in FIG. 4, the upper outer layer surface conductor 2 and the lower outer layer surface conductor 4, which are outer layer surface conductors on both sides of the insulating substrate 1, and the outer layer surface conductors on both sides of the insulating substrate 1. A through-conduction hole 3 made of the conductor layer 5 inside the through-hole is formed.
Next, a surface plating layer 6 of Ni-Ag plating, which is a heterogeneous metal plating layer having wire bonding property or good solderability, is formed inside the upper outer layer surface conductor 2, the lower outer layer surface conductor 4, and the through hole. It is formed on the conductor layer 5.
Thereafter, as shown in FIG. 1, a film film 11 in which one end face of the predetermined through-conduction hole 3 is in contact with the end face of the through-conduction hole 3, and an insulating film having good plating resistance is provided on the upper surface of the film film 11. This is a wiring board in which a non-penetrating conduction hole 7 is formed which is closed with an insulating closing body 15 having a two-layer structure of an insulating coating 12 covered with a state body.

  That is, the upper outer layer surface conductor 2 on which the chip component is mounted and the film film 11 in contact with the hole end surface so as to block the upper surface of one of the through-conduction holes 3 are formed into a photo-curable photosensitive film SR-2300G (Hitachi Chemical Industries). Co., Ltd., trade name), PFR800AUS402 (trade name, manufactured by Taiyo Ink Co., Ltd.), DM5030 (trade name, manufactured by Nichigo-Moton Co., Ltd.) are laminated using a vacuum laminator, exposed, developed, and dried. Then, post-exposure and heat-curing at 100 ° C. to 150 ° C. for 40 minutes to 90 minutes to form a thin insulating film film 11 having a thickness of 25 μm to 75 μm with good heat resistance, and plating resistance covering the upper surface of the film film 11 Non-penetrating, in which one hole end face of the through-conduction hole 3 is closed with a two-layer insulating blocking body 15 by forming a strong insulating coating 12 having a thickness of 10 μm to 40 μm. And forms a conductive hole 7.

  The insulative coating 12 is required to be a film having a strong plating resistance as a flexible coating film and a film that can withstand the sealing pressure and high temperature of a high-pressure mold resin. That is, the insulating coating 12 may be a liquid resist, a resist ink by screen printing, a UV ink, or a thermosetting ink.

Next, a wiring board according to a second embodiment of the present invention will be described.
As shown in FIG. 2, a two-layer configuration of a film film 11 that is in contact with the hole end face of the through-conduction hole 3 and an insulating coating 12 that covers the upper surface of the film film 11 with an insulating film-like body having good plating resistance. After forming the non-penetrating conduction hole 7 closed with the insulating closing body 15 made of, when bonding an electronic component element or electronic component to a wiring board or when necessary for high quality soldering, Ni-Au plating, Ni-Ag plating, Ni-Sn plating, or solder on the upper surface of the outer layer surface conductor (upper outer layer surface conductor 2, lower outer layer surface conductor 4) and the conductor layer 5 inside the non-through hole 7 A surface plating layer 6 made of a metal different from a normal metal conductor layer such as plating is formed.

A chip-type electronic component according to a third embodiment of the present invention will be described with reference to FIG.
The electronic component element 40 and the electronic component are mounted and fixed on a predetermined portion of the wiring substrate 10 with an adhesive or a solder paste on the wiring substrate formed by the above-described process, and the electronic component element 40 or the electronic component is connected to the wiring substrate 10. The lands are electrically connected by wire bonding with bonding wires 41. Next, the entire mounting surface of the electronic component element 40 is sealed with a sealing resin 35. If the mounted electronic component element 40 has the shape of a surface mounting component, it can be surface mounted by reflow soldering and electrically connected to the connection land of the wiring board 10.
In addition, the work of mounting and mounting the electronic component element 40 and the electronic component on the wiring substrate 10 that has been individually divided reduces the work efficiency, and the sealing resin flows out in the next resin sealing step. In order to facilitate, a film film that penetrates through the outer layer conductors on both sides of the wiring board and is in contact with one end surface of the through-conduction hole that is in contact with the hole end surface, and an insulating coating that covers the upper surface of the film film This is a wiring board for forming an end face electrode by dividing and cutting substantially the central portion of the non-through-conduction hole blocked by the two-layer insulating block 15. In many cases, component mounting is performed as a collective wiring board in which the individual wiring boards 10 are connected in a large number of rows and rows in a matrix form with the non-through-conduction holes 7 formed in the process of FIG.

Thereafter, as shown in FIG. 3, a dicing cut that is a method of ultra-precisely cutting a substantially central portion of the non-through hole 5 in which one end face of the end face electrode is closed with a two-layer insulating closing body 15. It cuts and forms as an end surface electrode.
Insulation composed of two layers: a film film 11 in which one end face of the hole is in contact with the end face of the through-conduction hole, and an insulating coating 12 that covers the upper surface of the film film 11 with an insulating film having good plating resistance Conductive grooves such as a semi-cylindrical shape, a U-shaped groove, and a long hole-shaped groove that are closed and closed by the conductive blocking body 15 are formed as end surface electrodes for soldering.
The method for cutting is not limited to dicing cut, but may be laser beam cutting.

  The present invention relates to an electronic component or a wiring board for mounting an electronic component element, and a chip-type electronic component having an end face electrode using the wiring board. In particular, the electronic component such as a semiconductor circuit element and a light receiving / emitting element is provided. The present invention can be used to set an end face electrode on a chip-type electronic component having a surface for attaching a device element.

Sectional drawing of the wiring board of Example 1 by this invention. Sectional drawing of the wiring board of Example 2 by this invention. Sectional drawing of the chip-type electronic component of Example 3 by this invention. Sectional drawing for demonstrating the penetration conduction hole of a wiring board.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Insulating base material, 2 ... Upper outer layer surface conductor, 3 ... Through conduction hole, 4 ... Lower outer layer surface conductor, 5 ... Conductor layer inside hole, 6 ... Surface plating layer, 7 ... Non-through conduction hole,
DESCRIPTION OF SYMBOLS 10 ... Wiring board, 11 ... Film film, 12 ... Insulating coating material, 15 ... Insulating obstruction, 30 ... Chip type | mold part, 35 ... Sealing resin, 40 ... Electronic component element, 41 ... Bonding wire

Claims (3)

In a wiring board on which an electronic component or an electronic component element is mounted, a film film-like body that penetrates the outer layer conductors on both sides of the wiring board and closes on one end surface of the through-conduction hole that is conducting, and the film film shape A wiring board, characterized in that a non-through-conduction hole is formed which is closed with an insulating block consisting of two layers of an insulating coating that covers the upper surface of the body. 2. The wiring board according to claim 1, wherein one end face of the through-conduction hole is closed with a film film-like body and a two-layer insulating closing body of an insulating coating covering the upper surface of the film film-like body. A wiring board, wherein a surface plating layer is formed after forming a non-penetrating conduction hole in step (b). The wiring board according to claim 1 or 2 is used, an electronic component or an electronic component element is mounted on the wiring board, and the surface on which the electronic component element or the like is mounted is sealed with a mold resin. An electronic component having an end face electrode formed by dividing and cutting a substantially central portion of a non-penetrating conduction hole.

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