JP2000294905A - Manufacture of package wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a package wiring board, having a wiring part containing a bonding pad and a solder ball pad with satisfactory yield. SOLUTION: This manufacturing method comprises the steps of producing a package wiring board, a process for generating an insulating layer 6 which is integrated/ arranged on one main face of a conductive metallic layer 5, a wiring part 1 containing a bonding pad 1a and a solder ball pad 1b which are formed on the face of the insulating layer 6, a conductive bump 4 which passes through the insulating layer 6 and which electrically connects the wiring part 1 to the conductive metallic layer 5, and a package wiring element board 7 which is connected to the wiring part 1 and has a plating terminal 1d led through to the outer peripheral direction, a process for forming a slit 8 in the outer work region of the package wiring element board 7 and cutting a connection lead 1c with the plating terminal 1d, a process for arranging resin layers 9 having peeling property on both main faces of the package wiring element board 7 and masking them, a process for processing the face of the slit 8 by insulating resin and insulating/coating the cut face of a connection lead 1c of a wiring part side exposed to the face of the slit 8, and a process for working an outer form along the slit 8 are provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a package wiring board suitable for a configuration of a mounted circuit device having electronic components mounted thereon.

[0002]

2. Description of the Related Art As is well known, a mounting circuit device in which electronic components such as IC elements are mounted and mounted on a wiring board is developed and put into practical use for the purpose of improving the performance and miniaturization of various electronic devices. Is being promoted. In addition, this type of package wiring board is provided with a heat radiating means so as to easily dissipate heat generated by the operation and exhibit a stable function in addition to high density wiring or fine wiring.

That is, a wiring portion including a bonding pad and a solder ball pad is integrally arranged on one main surface of a conductive metal layer (conductive metal foil) also functioning as a heat sink via an insulator layer. A formed package wiring board is known. Here, the bonding pad forms a wire bonding point with an electrode of the IC element, and is configured to be supplied with power via a solder ball pad connected to the bonding pad. The bonding pad and the solder ball pad are integrally formed by patterning a copper foil or the like.

Further, the package wiring board has a structure in which signal wiring pattern layers are arranged in a multilayer structure in an insulating layer as interlayer insulation, and signal wiring patterns are appropriately connected between layers.
Alternatively, a configuration in which a conductive metal layer is used as a ground layer or the like is employed.

Further, in manufacturing this type of package wiring board, for example, in order to mount and mount an IC element, as shown in an enlarged plan view of a main part in FIG. 3, bonding pads 1a and The wiring portion 1 including the solder ball 1b is provided integrally on at least the upper surface of the insulator layer 2. Here, the wiring portion 1 such as the bonding pad 1a and the solder ball pad 1b is patterned by, for example, selective etching of a copper foil, but the bonding pad 1a and the solder ball pad 1b are formed so as to easily form a highly reliable connection. The surface such as 1b is plated with gold.

That is, in the manufacturing process of the package wiring board, the wiring portion 1 including the bonding pad 1a and the solder ball pad 1b is electrically connected to the wiring portion 1 by the connection lead 1c, and is led out in the outer peripheral direction (outer shape processing region). A wiring substrate for a package having plated terminals (not shown) is manufactured. Next, while a plating power source is connected to the plating terminal, the package wiring base plate is immersed in an electrolytic gold plating solution to grow an electroplating layer such as gold on the surface of the bonding pad 1a and the solder ball pad 1b. Let it. After the growth of the electroplating layer, the plating terminals are cut off and removed by external processing to produce a product.

In the manufacturing process of the package wiring board, generally, in consideration of productivity or mass production,
We design and set the package wiring board to be multiple.

[0008]

However, in the case of the above-mentioned method of manufacturing a wiring board for a package, the following inconveniences are recognized, particularly at the stage of final outer shape processing and commercialization. That is, when the plating terminal region is cut and separated, at least a part of the cut end surface of the connection lead 1c that connects the plating terminal and the wiring portion 1 projects on the outer shape processing surface of the wiring board, or extends in the cutting direction. It is often recognized that it has been extended, bent, or misaligned.

If the cut end surface of the connection lead 1c partially protrudes, if the mounting density or wiring density of the package wiring board is high, in other words, an IC element having a high functional capacity is mounted / mounted. The number of bonding pads 1a, solder ball pads 1b, etc. is large, and the arrangement of the connection leads 1c extending to the corresponding plating terminal side becomes dense, causing the following problem. That is,
The cut ends of the connection leads 1c extending to the adjacent plating terminals are likely to come into contact with each other, or the cut end of the connection lead 1c and the cut surface of the conductive metal layer are likely to occur. This leads to problems such as inability to form. Therefore, the reliability of the package wiring board may be impaired, and the yield may be reduced.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a method for manufacturing a package wiring board having a wiring portion including a narrow (small) pitch solder ball pad with a high yield. .

[0011]

According to a first aspect of the present invention, there is provided an insulator layer integrally formed on at least one principal surface of a conductive metal layer (conductive metal foil), and formed on the surface of the insulator layer. A wiring portion including a bonding pad and a solder ball pad, a conductive bump that penetrates the insulator layer and electrically connects the wiring portion to a conductive metal layer, and is connected to the wiring portion and led out in an outer peripheral direction. A step of preparing a package wiring base plate having a plating terminal, and covering a portion other than the wiring portion of the package wiring base plate with a plating resist, immersing in a plating bath, and performing a plating process by supplying power from the plating terminal. A step of forming a slit in the outer shape processing area of the plated wiring substrate to cut a connection lead to a plating terminal; and peeling off both main surfaces of the package wiring substrate. Disposing the resin layer, masking, treating the slit region surface with an insulating resin, and insulating and covering the cut portion of the connection lead connected to the wiring portion side exposed on the slit region surface; And a step of processing the outer shape along the slit.

According to a second aspect of the present invention, in the method for manufacturing a package wiring board according to the first aspect, the insulator layer is a liquid crystal polymer.

According to a third aspect of the present invention, in the method for manufacturing a package wiring board according to the first or second aspect, the releasable resin layer is a dry film.

In the first to third aspects of the present invention, the insulating layer is made of, for example, an epoxy resin, a phenol resin, a polyimide resin, a polycarbonate resin, a hot melt adhesive, a polyvinyl butyral resin, a nitrile rubber, a phenoxy resin, a vinyl acetate resin, a polyamide resin. A sheet of a resin, a polyamideimide resin, a liquid crystal polymer, a polyetheretherketone resin, a polyetherimide resin, or a mixture of two or more thereof, or a sheet in which the resin is combined with a glass crusader, a mat, a synthetic fiber, a cloth, or the like. (Or film). And these resin-based sheets are, for example, 25 to 150 μm thick.
And preferably about 30 to 120 μm.

The insulator layer is made of, for example, Xidal (trade name, manufactured by Dartco), Vectra (trade name, Clanese).
A film composed of a thermoplastic polymer liquid crystal polymer of multi-axis orientation represented by the following company is preferred. That is, this type of liquid crystal polymer has almost no hygroscopicity and a dielectric constant of about 3.0 (1
MHz) and is stable over a wide frequency range. In addition, the liquid crystal polymer, depending on its molecular structure,
The melting points and the like are different, and even with the same molecular structure, the melting point varies depending on the crystal structure and additives. For example, Vectran A type (melting point, 285 ° C), Vectran C type (melting point, 325 ° C), BIAC film (melting point, 335 ° C)
And the like.

According to the first to third aspects of the present invention, the wiring portion and the plating terminal portion including the bonding pad and the solder ball pad are made of a copper foil, an aluminum foil having a thickness of about 10 to 35 μm,
It is formed by patterning a nickel foil, a gold foil, a silver foil or the like, but a copper foil is suitable from the viewpoint of economy and workability.

Further, the conductive bump which is press-fitted into the resin sheet or the like forming the interlayer insulator and whose leading end contacts the opposing conductive metal layer (metal foil) surface or the like to form an electrical connection portion is provided. For example, the projections are formed by forming projections of the conductive composition having a substantially constant height and shape by screen printing, followed by drying and curing. Here, the conductive bumps are, for example, conductive powders such as silver, gold, copper, and solder powder;
A conductive composition prepared by mixing the alloy powder or the composite (mixed) metal powder with a binder component such as a polycarbonate resin, a polysulfone resin, a polyester resin, a phenoxy resin, a phenol resin, and a polyimide resin. You.

In the first to third aspects of the present invention, the conductive metal layer also serving as a heat radiator has a thickness of, for example, 100 to 600 μm.
Copper foil (or thin plate), aluminum foil (or thin plate), nickel foil (or thin plate) and the like are included.

According to the first to third aspects of the present invention, the wiring portion including the bonding pad and the solder ball pad, the patterning of the plating terminal and the connection lead, the gold plating process for the bonding and the wiring portion including the pad solder ball pad, etc. This is performed by means employed in the manufacturing process of this type of package wiring board.

According to the third aspect of the present invention, the external shape processing area of the package wiring plate having plating terminals connected to the wiring portion including the bonding pad and the solder ball pad and extending in the outer peripheral direction is formed. The slit provided cuts off the electrical connection of the plating terminal electrically connected to the wiring portion. Therefore, the slit is formed between the area where the plating terminal is extended, in other words, each side where the plating terminal is extended.

Here, when the production of the wiring board for a package is performed in a multi-cavity type (or system),
It can be formed in a so-called outline processing line portion. Also,
As a peelable resin layer, dry film etc.
Films of about 50 μm are mentioned.

As the resin for insulating and covering the slit region surface where the cut portion of the conductor connected to the wiring portion is exposed, the resin forming the insulator layer is generally used. Here, the insulation / coating is performed by, for example, a spray coating / drying method, a dip coating / drying method, or the like, and the film thickness is such that the cut portions exposed on the slit region surface or between the cut portions and the conductive metal layer. Are respectively enough to maintain required electrical insulation.

According to the first to third aspects of the present invention, the cut portions of the connecting leads for plating, which are exposed on the end face during the outer shape processing, are insulated and covered with each other, so that the wiring board for a package having high reliability in terms of an electric circuit is also provided. Can be obtained with good yield. That is,
In the manufacture and manufacture of a package wiring board that has a wiring part including a solder ball pad etc. with a narrow end or a high placement density and has a connection lead with a plating terminal part corresponding to the wiring part, after plating processing of the wiring part The connection lead ends which are cut in the form of a slit and exposed on the slit surface are selectively and reliably insulated. Therefore,
The occurrence of an electrical short circuit between adjacent connection leads or between the adjacent connection leads and the conductive metal layer also serving as a heat sink is eliminated or avoided, and a highly reliable circuit function is exhibited.

[0024]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIGS. 1 (a) to 1 (c) and 2 (a) to 2 (c)
It is principal part sectional drawing which shows typically the manufacturing process of the wiring board for packages which concerns on an Example.

First, as shown in FIG. 1A, a conductive metal foil, for example, an electrolytic copper foil 3 having a thickness of 15 μm is prepared, and a polymer type foil is placed at a required position on one main surface of the electrolytic copper foil 3. Printed with a silver-based conductive paste, and a conical conductive pump 4
Is formed (formed). On the other hand, a conductive metal layer, for example, an Al thin plate 5 having a thickness of about 100 μm, and an insulating layer, for example, a liquid crystal polymer film (sheet) 6 having a thickness of 50 μm are prepared.

Next, as shown in FIG. 1B, a liquid crystal polymer film 6 is disposed on one main surface of the conductive metal layer 5.
Laminated (set), the electrolytic copper foil 3 on which the conductive bumps 4 are formed is positioned and arranged on the liquid crystal polymer film 6 to form a laminate. Then, by heating and pressing the laminate, the tip of the conductive bump 4 is pressed into the liquid crystal polymer film 6 as shown in FIG.
Further, the front end portion penetrates to the back surface side, and the facing Al thin plate 5
To produce a copper foil-clad laminate connected to.

Next, an etching resist is printed on the exposed surfaces of the electrolytic copper foil 3 and the Al thin plate 5, the copper foil 3 is selectively etched and removed, and a wiring including a bonding pad (not shown) and a solder ball pad 1b is provided. After forming the connection lead 1c and the plating terminal 1d to be connected to the portion 1, the solder ball pad 1b, the etching resist is peeled off with an alkaline aqueous solution. By this etching process, for example, a bonding pad, a solder ball pad 1b, and the like are formed, and wiring patterning in which a plating terminal 1d is extended outside the outer shape processing line is performed, so that a package wiring element plate is obtained. The conductive bumps 4 penetrating the insulator layer 6 and connected to the facing Al thin plate 5 allow the Al thin plate 5 to function as a heat sink or a ground layer.

Thereafter, the plated portion (the bonding pad and the solder ball pad 1b) of the package wiring plate is
Is exposed, and a solder resist is printed and partially masked. That is, the connection leads 1c and the like connected to the plating terminals 1d are masked, and gold electroplating is performed using, for example, a gold plating bath to expose the surfaces of the exposed bonding pads and solder ball pads 1b. Cover with gold.

Thereafter, as shown in FIG. 2A, the outer shape processing line (outer shape processing area) of the package wiring plate 7 is
A slit 8 is formed to break the connection with the plating terminal 1d. Here, the formation of the slit 8 can be performed as a part of the outer shape / cutting processing inside the plating terminal 1d in which the plating terminal 1d is extended (derived). After this slit forming process,
As shown in FIG. 2B, masking is performed by disposing releasable resin layers 9 on both main surfaces of the package wiring base plate 7.

The masking is preferably performed, for example, by applying a photocurable dry film 9 having a thickness of about 20 μm. In this case, selective opening of the area corresponding to the slit 8 can be easily performed. Alternatively, the selective opening of the region corresponding to the slit 8 may be performed by applying a releasable resin layer 9 and then performing slit forming processing.

The surface (region surface) of the slit 8 is coated with an insulating resin, for example, an epoxy resin solution.
Dry and cure, and insulate and cover 10 the cut portion of the lead (conductor) portion 1a connected to the wiring portion side exposed on the surface of the slit 8. Thereafter, while the peelable resin layer 9 is peeled and removed, the outer shape of the package wiring plate 7 is processed along the slit 8 so that the surface of the slit 8 is formed as shown in FIG. As a result, a package wiring board that is surely coated with insulation can be obtained. The peeling / removing of the peelable resin layer 9 may be performed after the outer shape processing of the package wiring plate 7.

The present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the invention. For example, in the above description, a configuration in which a wiring portion including a bonding pad and a solder ball pad is provided on the surface of the insulating layer on the conductive metal layer is exemplified. However, a configuration in which a plurality of signal wiring pattern layers are provided in the insulating layer. Can also be taken.

[0034]

According to the first to third aspects of the present invention, a wiring portion including a bonding pad and a solder ball pad having a small or high density is provided, and a connection lead to a plating terminal corresponding to the wiring portion is provided. In the configuration of the package wiring board having the above, the connection lead end exposed at the cut surface of the outer shape processing can be selectively and surely provided with good insulation yield with high yield. In other words, the configuration of the mounting circuit device exhibiting a highly reliable circuit function in which the connection leads led to the cut surface and the occurrence of an electrical short circuit between the connection lead and the conductive metal layer are eliminated or avoided is greatly increased. Contribute.

[Brief description of the drawings]

FIGS. 1A, 1B, and 1C are cross-sectional views schematically showing a main part of a manufacturing embodiment of a package according to an embodiment.

FIGS. 2 (a), (b) and (c) are cross-sectional views of essential parts schematically showing a process of processing a package wiring plate in a manufacturing embodiment according to an example.

FIG. 3 is a plan view showing a configuration of a main part of the package wiring board.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Wiring part 1a ... Bonding pad 1b ... Solder ball pad 1c ... Connection lead part 1d ... Plating terminal 2, 6 ... Insulator layer 3 ... Electrolytic copper foil 4 ... Conductive bump 5 ... ... conductive metal layer 7 ... wiring board for package 8 ... slit 9 ... peelable resin layer 10 ... insulating coating layer

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) H05K 3/00 H01L 23/12 Q (72) Inventor Hidehisa Yamazaki 3-28-7 Nakamagome, Ota-ku, Tokyo Yamaichi F-term (reference) in Denki Co., Ltd.

Claims (3)

[Claims] 1. An insulating layer integrally disposed on at least one main surface of a conductive metal layer, a wiring portion including a bonding pad and a solder ball pad formed on the insulating layer surface, and penetrating through the insulating layer. A step of fabricating a package wiring base plate having a conductive bump electrically connecting the inserted wiring portion to the conductive metal layer, and a plating terminal connected to the wiring portion and having a plating terminal led out in an outer peripheral direction; A step of coating a part other than the wiring part of the package wiring base plate with a plating resist, immersing it in a plating bath, and plating with power supplied from a plating terminal; and Forming a slit to cut a connection lead with a plating terminal; disposing a releasable resin layer on both main surfaces of the package wiring base plate; and masking; Processing the lit region surface with an insulating resin, insulating and covering the cut portion of the connection lead connected to the wiring portion side exposed on the slit region surface, and processing the outer shape along the slit, A method for manufacturing a wiring board for a package, comprising: 2. The method according to claim 1, wherein the insulator layer is a liquid crystal polymer. 3. The method according to claim 1, wherein the releasable resin layer is a dry film.