JP2001217372A - Circuit device and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problems of a circuit device where circuit elements are mounted on a supporting board, e.g. a printed board, a ceramic board or a flexible sheet, that the size of the circuit device is increased by the thickness of the supporting board which is an essentially unnecessary extra material and a blade is worn or damaged badly because it cuts the supporting board at the time of forming one package through dicing. SOLUTION: After isolation trenches 54 are made in a conductive foil 60, circuit elements are mounted and insulating resin 50 is applied using the conductive foil 60 as a supporting board. Subsequently, it is inverted and the conductive foil is polished using the insulating resin 50 as a supporting board and isolated as a conduction path. Consequently, a circuit device where the conduction paths 51 and the circuit elements 52 are supported on the insulating resin 50 without employing any supporting board can be realized. Since no supporting board nor conduction path is located at a part corresponding to a dicing line, wear and damage of a dicing blade can be suppressed significantly.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit device and a method for manufacturing the same, and more particularly to a thin circuit device which does not require a supporting substrate and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, a circuit device set in an electronic device is employed in a cellular phone, a portable computer, and the like, and therefore, a reduction in size, thickness, and weight is required.

For example, a semiconductor device will be described as an example of a circuit device. As a general semiconductor device, there is a package type semiconductor device sealed with a conventional transfer mold. This semiconductor device is mounted on a printed circuit board PS as shown in FIG.

In this package type semiconductor device, the periphery of a semiconductor chip 2 is covered with a resin layer 3, and lead terminals 4 for external connection are led out from the side of the resin layer 3.

However, this package type semiconductor device 1 has
The lead terminals 4 were outside the resin layer 3, and the overall size was large, and the size, thickness and weight were not satisfied.

Therefore, various companies have competed to develop various structures in order to realize miniaturization, thinning and weight reduction, and recently called a CSP (chip size package), a wafer scale CSP equivalent to the chip size. Alternatively, a CSP having a size slightly larger than the chip size has been developed.

FIG. 24 shows a case where a glass epoxy substrate 5 is used as a supporting substrate, and the CS is slightly larger than the chip size.
It shows P6. Here, the glass epoxy substrate 5
It is assumed that the transistor chip T is mounted on the semiconductor device.

A first electrode 7, a second electrode 8, and a die pad 9 are formed on the surface of the glass epoxy substrate 5, and a first back electrode 10 and a second back electrode 11 are formed on the back surface.
Are formed. And, through the through hole TH,
The first electrode 7 and the first back electrode 10 are electrically connected, and the second electrode 8 and the second back electrode 11 are electrically connected. The bare transistor chip T is fixed to the die pad 9, and the emitter electrode of the transistor and the first electrode 7 are fixed.
Are connected via the thin metal wire 12, and the base electrode of the transistor and the second electrode 8 are connected via the thin metal wire 12. Further, a resin layer 13 is provided on the glass epoxy substrate 5 so as to cover the transistor chip T.

Although the CSP 6 employs the glass epoxy substrate 5, unlike the wafer scale CSP, the structure extending from the chip T to the back surface electrodes 10 and 11 for external connection is simple, and the CSP 6 can be manufactured at low cost. Have.

The CSP 6 is mounted on a printed circuit board PS as shown in FIG. In the printed circuit board PS,
The CSP is provided with electrodes and wiring constituting an electric circuit.
6. The package type semiconductor device 1, the chip resistor CR or the chip capacitor CC and the like are electrically connected and fixed.

The circuit constituted by the printed circuit board is mounted in various sets.

Next, a method of manufacturing the CSP will be described with reference to FIGS. In FIG. 26,
Reference is made to the flow diagram entitled Central Glass Epoxy / Flexible Substrate.

First, a glass epoxy substrate 5 is prepared as a substrate (supporting substrate), and C
The u foils 20 and 21 are pressed. (See FIG. 25A above.) Subsequently, the first electrode 7, the second electrode 8, the die pad 9,
The Cu foils 20 and 21 corresponding to the first back surface electrode 10 and the second back surface electrode 11 are coated with an etching resistant resist 22, and the Cu foils 20 and 21 are patterned. The patterning may be performed separately for the front and back sides (see FIG. 25B).
Subsequently, a hole for the through hole TH is formed in the glass epoxy substrate using a drill or a laser, and the hole is plated to form the through hole TH. The first electrode 7 and the first back electrode 1 are formed by the through hole TH.
0, the second electrode 8 and the second back electrode 10 are electrically connected. (Refer to FIG. 25C.) Further, although not shown in the drawings, the first electrode 7 and the second electrode 8 serving as the bonding posts are plated with Ni, and the die pad 9 serving as the die bonding post is formed with Au.
Plating is performed, and the transistor chip T is die-bonded.

Finally, the emitter electrode of the transistor chip T and the first electrode 7, and the base electrode and the second electrode 8 of the transistor chip T are connected via a thin metal wire 12 and covered with a resin layer 13. (See FIG. 25D above.) Then, if necessary, dicing is performed to separate individual electric elements. In FIG. 25, the glass epoxy substrate 5
Although only one transistor chip T is provided, a large number of transistor chips T are provided in a matrix. Therefore, they are finally separated by a dicing device.

By the above manufacturing method, a CSP type electric element using the support substrate 5 is completed. This manufacturing method
The same applies to the case where a flexible sheet is used as the support substrate.

On the other hand, a manufacturing method using a ceramic substrate is shown in a flow chart on the left side of FIG. After preparing a ceramic substrate that is a support substrate, a through hole is formed, and then
The front and back electrodes are printed and sintered using conductive paste. After that, until the resin layer of the previous manufacturing method is covered, the manufacturing method is the same as that of FIG. 25. However, the ceramic substrate is very fragile, and unlike a flexible sheet or a glass epoxy substrate, it is chipped immediately, so a mold is used. There is a problem that can not be molded. For this reason, after sealing resin is potted and cured, it is polished to flatten the sealing resin, and finally separated individually using a dicing device.

[0017]

In FIG. 24, a transistor chip T, connecting means 7 to 12 and a resin layer 13 are shown.
Is a necessary component for electrical connection to the outside and protection of the transistor, but it is difficult to provide an electric circuit element that realizes reduction in size, thickness, and weight with only these components. Was.

Further, the glass epoxy substrate 5 serving as the support substrate is essentially unnecessary as described above. However, in the manufacturing method, the glass epoxy substrate 5 is used as a supporting substrate for bonding the electrodes, and the glass epoxy substrate 5 cannot be eliminated.

Therefore, the use of the glass epoxy substrate 5 increases the cost, and further, since the glass epoxy substrate 5 is thick, the circuit element becomes thick.
There was a limit to miniaturization, thinning, and weight reduction.

Further, in the case of a glass epoxy substrate or a ceramic substrate, a step of forming a through hole for connecting electrodes on both surfaces is indispensable, and there has been a problem that the manufacturing process becomes long.

In some cases, the CSP 6 is formed in a matrix on the substrate 5 and the resin layer 13 is molded and then diced. In this case, if the substrate is a ceramic substrate, there is a problem that the dicing blade is severely worn or damaged, and the substrate is chipped or cracked.

In some cases, electrodes are extended to the dicing line. For example, in a package employing a lead frame in which all the electrodes are connected by connecting pieces such as a tie bar, and a package employing a support substrate on which a pattern corresponding to the lead frame is formed, there is inevitably an electrode material in a dicing line. When dicing is performed along this dicing line, the electrode material is clogged by the blade, deteriorating the function of the blade, and causing a problem that the blade must be replaced frequently.

[0023]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned many problems, and firstly, a plurality of conductive paths each formed in an island shape without connecting means,
A circuit device comprising: a circuit element fixed on a desired conductive path; and an insulating resin that covers the circuit element and exposes a back surface and embeds the conductive path above the back surface. The problem is solved by cutting the insulating resin located outside the road into one package.

By providing the present circuit device, the conventional problems can be solved by minimizing the components. Further, in the present circuit device, the conductive path formed in an island shape is embedded in the insulating resin without using the support substrate, so that the conductive path does not extend to the dicing line. Therefore, neither dicing of the supporting substrate nor dicing of the conductive path is required. Therefore, wear, replacement and breakage of the dicing blade can be significantly reduced.

Second, a plurality of conductive paths each formed in an island shape by a separation groove without a connection means, a desired circuit element fixed on the conductive path, and a circuit element covering the circuit element. And a circuit device having an insulating resin filled in the separation groove by burying the conductive path above the back surface by exposing the back surface, and filling the separation groove located outside the conductive path with the insulating resin. The problem is solved by cutting the insulating resin thus formed into one package.

By providing the circuit device, the back surface of the conductive path can provide connection to the outside, and the through hole can be eliminated. Further, as described above, neither dicing of the supporting substrate nor dicing of the conductive path can significantly reduce wear, replacement and breakage of the dicing blade.

Third, a step of preparing a conductive foil, forming a conductive groove by forming a separation groove shallower than the thickness of the conductive foil around a region to be a conductive path, and forming a circuit on the desired conductive path Fixing the element, covering the circuit element, and molding with an insulating resin so as to fill the separation groove, removing the conductive foil corresponding to the separation groove, and separating the conductive path. And a step of cutting the insulating resin corresponding to the separation groove from front to back.

Fourthly, a step of preparing a conductive foil and forming a conductive path by forming a separation groove shallower than the thickness of the conductive foil in the conductive foil except for a region serving as a conductive path; A step of fixing a plurality of circuit elements on the conductive path, a step of forming connection means for electrically connecting an electrode on the circuit element and a desired conductive path, and covering the plurality of circuit elements, This problem is solved by providing a step of molding with an insulating resin so as to fill the separation groove, and a step of cutting the insulating resin corresponding to the separation groove from front to back.

By providing a method of manufacturing these circuit devices, the conductive foil forming the conductive path is the starting material, and the conductive foil has a supporting function until the insulating resin is molded. Since the insulating resin has a supporting function, a supporting substrate can be made unnecessary, and the conventional problem can be solved.

Further, since the supporting substrate can be eliminated and the insulating resin can be cut after the conductive paths are buried in an island shape, a large number of circuit devices can be mass-produced, and at the same time, a cutting jig, for example, a dicing blade, Wear and breakage of the press, cutter, etc. can be prevented.

[0031]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment for Explaining a Circuit Device First, the structure of a circuit device according to the present invention will be described with reference to FIG.

FIG. 1 has a conductive path 51 embedded in an insulating resin 50, and a circuit element 52 is provided on the conductive path 51.
A circuit device 53 is shown in which the conductive path 51 is supported by the insulating resin 50.

In this structure, the circuit elements 52A and 52B, the plurality of conductive paths 51A, 51B and 51C,
A, 51B, and 51C are formed of three materials of insulating resin 50 embedded therein.
Separation grooves 54 filled with zeros are provided. The conductive path 51 is supported by the insulating resin 50.

As the insulating resin, a thermosetting resin such as an epoxy resin, or a thermoplastic resin such as a polyimide resin or polyphenylene sulfide can be used. As the insulating resin, any resin can be adopted as long as the resin can be hardened using a mold, or can be coated by dipping or coating. Further, as the conductive path 51, a conductive foil mainly composed of Cu, a conductive foil mainly composed of Al, a conductive foil composed of an alloy such as Fe-Ni, or the like can be used. Of course, other conductive materials are also possible. Particularly, a conductive material that can be etched and a conductive material that evaporates by laser are preferable.

The connection means of the circuit element 52 includes a thin metal wire 55A, a conductive ball made of brazing material, a flat conductive ball, a brazing material 55B such as solder, a conductive paste 55C such as Ag paste, a conductive film or an anisotropic conductive material. Resin. These connection means are selected depending on the type of the circuit element 52 and the mounting form of the circuit element 52. For example, in the case of a bare semiconductor element, a thin metal wire is selected for the connection between the electrode on the surface and the conductive path 51, and in the case of a CSP, a solder ball or a solder bump is selected. For the chip resistor and the chip capacitor, the solder 55B is selected. There is no problem even if a packaged circuit element, for example, a BGA or the like is mounted on the conductive path 51, and when this is adopted, solder is selected as the connection means.

The adhesion between the circuit element and the conductive path 51A is as follows.
If no electrical connection is required, an insulating adhesive is chosen,
When electrical connection is required, a conductive coating is used. Here, at least one conductive film is sufficient.

The material considered as the conductive film is A
g, Au, Pt, Pd, or the like, and is coated by deposition under low or high vacuum such as vapor deposition, sputtering, or CVD, plating, or sintering.

For example, Ag adheres to Au and also adheres to the brazing material. Therefore, if the Au film is coated on the back surface of the chip, the chip can be thermocompression-bonded by directly covering the conductive path 51A with the Ag film, Au film, or solder film, and the chip can be fixed via a brazing material such as solder. .
Here, the conductive film may be formed on the uppermost layer of the conductive film laminated in a plurality of layers. For example, a conductive path 51 of Cu
On top of A, two layers of Ni coating and Au coating are sequentially applied, three layers of Ni coating, Cu coating and solder coating are sequentially applied, two layers of Ag coating and Ni coating are provided. Those coated in order can be formed. There are many other types and laminated structures of these conductive films, but they are omitted here.

In this circuit device, since the conductive path 51 is supported by the insulating resin 50 as a sealing resin, a support substrate is not required, and the conductive path 51, the circuit element 52 and the insulating resin 5 are not required.
0. This configuration is a feature of the present invention. As described in the section of the related art, the conductive path of the conventional circuit device is supported by a support substrate or supported by a lead frame, and therefore, a configuration that may be unnecessary originally is added. However, this circuit device has a feature that it is thin and inexpensive because it is composed of the minimum necessary components and does not require a support substrate.

In addition to the above-described structure, there is provided an insulating resin 50 which covers the circuit element 52 and fills the separation groove 54 between the conductive paths 52 and integrally supports the same.

A separation groove 54 is formed between the conductive paths 51.
By filling the insulating resin 50 here, there is an advantage that mutual insulation is achieved.

The circuit element 52 is covered and the conductive path 5
There is an insulating resin 50 that is filled in the separation groove 54 between the two and that only the back surface of the conductive path 51 is exposed and supported integrally.

The fact that the back surface of the conductive path is exposed is one of the features of the present invention. The back surface of the conductive path can be used for connection to the outside, and has a feature that the through hole TH of the conventional structure as shown in FIG. 24 can be omitted.

Further, when the circuit element is directly fixed via a conductive film such as brazing material, Au, Ag or the like, the conductive path 51
Is exposed, the heat generated from the circuit element 52A can be transmitted to the mounting board via the conductive path 51A. In particular, the present invention is effective for a semiconductor chip capable of improving characteristics such as an increase in drive current due to heat radiation.

The circuit device has a structure in which the surface of the separation groove 54 and the surface of the conductive path 51 substantially coincide with each other. This structure is a feature of the present invention, and since there is no step between the back electrodes 10 and 11 shown in FIG.
3 can be moved horizontally as it is.

The present invention also provides a plurality of conductive paths 51A-51.
C is not supported by a connecting piece such as a tie bar or a tab suspension lead adopted for the lead frame, and is independently supported by the insulating resin 5.
0. Moreover, these independent conductive paths are characterized in that they are sealed without supporting the support substrate or the adhesive tape. Therefore, in the finished product, the cut portion of the connecting piece is not formed, and the entire area is formed of the conductive path formed into an island shape by etching.

The conventional lead frame is completed except for connecting pieces such as suspension leads and tie bars. That is, the lead is processed as a finished product from the front surface to the side surface and the back surface. Therefore, after mounting the semiconductor chip on the lead frame, it is sealed with an insulating resin, and the connecting piece is cut. For this reason, the only way to connect the conductive paths 7 arranged in an island shape without being connected to any other place is to bond and fix them with a support member such as a support substrate or an adhesive tape.

However, in the present invention, on the lead frame manufacturing side, the conductive path is supplied in a semi-finished product in which the conductive foil is half-etched. The elements are mounted, electrically connected, and sealed with an insulating resin. Finally, the back surface of the conductive path is processed so that the shape of the conductive path is separated over the entire area. Therefore, a completed product can be obtained without using a supporting substrate, a connecting piece such as a tab suspension lead, or an adhesive tape, and without mechanical separation of the connecting piece.

Further, since no supporting substrate is employed, and the insulating resin in which the conductive path is not extended is cut into one circuit device, wear and breakage of the cutting jig can be greatly reduced. In particular, the life of a dicing blade, a blade used for breathing and cutting can be greatly extended. Second Embodiment for Explaining Circuit Device Next, a circuit device 56 shown in FIG. 7 will be described.

In this structure, the conductive film 5 is formed on the surface of the conductive path 51.
7 are formed, and the rest is substantially the same as the structure of FIG. Therefore, the conductive film 57 will be described.

The first feature is that a conductive film 57 is provided to prevent a warp of a conductive path or a circuit device.

Generally, due to the difference in the coefficient of thermal expansion between the insulating resin and the conductive path material (hereinafter, referred to as a first material), the circuit device itself warps, and the conductive path is bent or peeled off. In addition, since the thermal conductivity of the conductive path 51 is superior to the thermal conductivity of the insulating resin, the conductive path 51 expands by increasing the temperature first. Therefore, by covering the second material having a smaller coefficient of thermal expansion than the first material, it is possible to prevent the conductive path from being warped or peeled off, and to prevent the circuit device from being warped.
In particular, when Cu is used as the first material, Au, Ni, Pt, or the like is preferable as the second material. The expansion coefficient of Cu is 16.7 × 10 −6 (10 −6), and A
u is 14 × 10 −6, Ni is 12.8 × 10 −6,
Pt is 8.9 × 10 −6.

A second feature is that the second material has an anchor effect. The eaves 58 are formed of the second material, and the eaves 5 are attached to the conductive paths 51.
Since 8 is embedded in the insulating resin 50, an anchor effect is generated, and a structure in which the conductive path 51 can be prevented from coming off is obtained.

Although the circuit device in which the transistor chip 52A and the passive element 52B are mounted has been described above, the present invention relates to a circuit device in which one semiconductor chip is sealed as shown in FIG. , As shown in FIG.
The present invention can also be implemented in a circuit device on which a face-down type element such as SP is mounted, or a circuit device in which passive elements such as chip resistors and chip capacitors are sealed as shown in FIG. Further, a thin metal wire may be connected between the two conductive paths and sealed. This can be used as a fuse. First Embodiment Explaining a Method for Manufacturing a Circuit Device Next, a method for manufacturing a circuit device 53 will be described with reference to FIGS. 2 to 6 and FIG.

First, as shown in FIG. 2, a sheet-shaped conductive foil 60 is prepared. The material of the conductive foil 60 is selected in consideration of the adhesion of the brazing material, the bonding property, and the plating property.
As the material, a conductive foil mainly containing Cu, a conductive foil mainly containing Al, a conductive foil made of an alloy such as Fe-Ni, or the like is used.

The thickness of the conductive foil is preferably about 10 μm to 300 μm in consideration of later etching.
A 0 μm (2 oz) copper foil was employed. But 300μ
Basically, it is good even if it is more than m or less than 10 μm. As will be described later, it is only necessary that the separation groove 61 shallower than the thickness of the conductive foil 60 can be formed.

The sheet-shaped conductive foil 60 is prepared by being wound into a roll with a predetermined width, and may be conveyed to each step described later, or the conductive foil cut into a predetermined size may be used. It may be prepared and transported to each step described later. Subsequently, there is a step of removing the conductive foil 60 excluding at least a region to be the conductive path 51 so as to be thinner than the thickness of the conductive foil 60. Then, there is a step of coating the insulating resin 50 on the separation groove 61 and the conductive foil 60 formed in this removing step.

First, a photoresist (etching resistant mask) PR is formed on the Cu foil 60, and the photoresist PR is patterned so as to expose the conductive foil 60 excluding a region to become the conductive path 51 (see FIG. 3). reference). Then, etching may be performed through the photoresist PR (see FIG. 4).

The depth of the separation groove 61 formed by etching is, for example, 50 μm, and the side surface thereof is rough, so that the adhesiveness with the insulating resin 50 is improved.

The side wall of the separation groove 61 is schematically shown as a straight line, but has a different structure depending on the removing method. This removal step can employ wet etching, dry etching, laser evaporation, and dicing. In the case of wet etching, ferric chloride or cupric chloride is mainly used as an etchant, and the conductive foil is dipped in the etchant or showered with the etchant. Here, since the wet etching is generally performed non-anisotropically, the side surface has a curved structure.

In the case of dry etching, anisotropy,
Non-anisotropic etching is possible. At present, it is said that it is impossible to remove Cu by reactive ion etching, but it can be removed by sputtering. Further, etching can be performed anisotropically or non-anisotropically depending on sputtering conditions.

In a laser, a separation groove can be formed by directly irradiating a laser beam. In this case, the side surface of the separation groove 61 is formed straight.

In dicing, it is impossible to form a bent complicated pattern, but it is possible to form a lattice-shaped separation groove.

In FIG. 3, a conductive film having corrosion resistance to an etching solution may be selectively coated instead of the photoresist. When the conductive film is selectively applied to a portion to be a conductive path, the conductive film serves as an etching protective film, and the separation groove can be etched without employing a resist. Materials that can be considered as the conductive film include Ag, Au, Pt, and Pd. Moreover, these corrosion-resistant conductive films are
It has the feature that it can be used as it is as a die pad or a bonding pad.

For example, an Ag film adheres to Au and also adheres to a brazing material. Therefore, if the Au film is coated on the back surface of the chip, the chip can be thermocompression-bonded to the Ag film on the conductive path 51 as it is, and the chip can be fixed via a brazing material such as solder. Further, since the Au thin wire can be bonded to the Ag conductive film, wire bonding is also possible. Therefore, there is an advantage that these conductive films can be used as die pads and bonding pads as they are.

Subsequently, as shown in FIG. 5, there is a step of electrically connecting and mounting the circuit element 52 to the conductive foil 60 in which the separation groove 61 is formed.

The circuit element 52 is a semiconductor element such as a transistor, a diode, or an IC chip, or a passive element such as a chip capacitor or a chip resistor. Although the thickness is increased, a face-down semiconductor element such as a CSP or a BGA can be mounted.

Here, the bare transistor chip 52
A is die-bonded to the conductive path 51A, and the emitter electrode and the conductive path 51B and the base electrode and the conductive path 51B are connected via a thin metal wire 55A fixed by ball bonding by thermocompression bonding or wet bonding by ultrasonic waves. . 52B is a chip capacitor or a passive element, which is a brazing material such as solder or a conductive paste 5;
It is fixed at 5B.

Further, as shown in FIG.
And a step of attaching the insulating resin 50 to the separation groove 61. This can be achieved by transfer molding, injection molding, or dipping. As the resin material, a thermosetting resin such as an epoxy resin can be realized by transfer molding, and a thermoplastic resin such as a polyimide resin and polyphenylene sulfide can be realized by injection molding.

In the present embodiment, the thickness of the insulating resin coated on the surface of the conductive foil 60 is adjusted so as to cover about 100 μm from the top of the circuit element. This thickness can be increased or reduced in consideration of strength.

The feature of this step is that the conductive foil 60 serving as the conductive path 51 becomes a support substrate until the insulating resin 50 is covered. Conventionally, as shown in FIG. 25, the conductive paths 7 to 11 are formed by using the support substrate 5 which is not originally required. However, in the present invention, the conductive foil 60 serving as the support substrate is required as an electrode material. Material. Therefore, there is a merit that the operation can be performed while omitting the constituent materials as much as possible, and the cost can be reduced.

Further, since the separation grooves 61 are formed shallower than the thickness of the conductive foil, the conductive foils 60 are not individually separated as the conductive paths 51. Therefore, the sheet-shaped conductive foil 60
When molding insulating resin,
It has the feature that the work of transporting to the mold and mounting on the mold is very easy.

Subsequently, there is a step of chemically and / or physically removing the back surface of the conductive foil 60 and separating it as the conductive path 51. Here, the removing step is performed by polishing, grinding, etching, laser metal evaporation, or the like.

In the experiment, the entire surface was shaved by about 30 μm by a polishing device or a grinding device, and the insulating resin 50 was removed from the separation groove 61.
Is exposed. This exposed surface is indicated by a dotted line in FIG. As a result, the conductive path 51 having a thickness of about 40 μm is formed.
And separated. Alternatively, the entire surface of the conductive foil 60 may be wet-etched before the insulating resin 50 is exposed, and thereafter, the entire surface may be ground by a polishing or grinding device to expose the insulating resin 50.

As a result, a structure in which the surface of the conductive path 51 is exposed to the insulating resin 50 is obtained. Then, the separation groove 61 is shaved to form the separation groove 54 of FIG. (See FIG. 6 above.) Finally, a conductive material such as solder is applied to the exposed conductive paths 51 as necessary, thereby completing a circuit device.

When a conductive film is applied to the back surface of the conductive path 51, the conductive film may be formed in advance on the back surface of the conductive foil shown in FIG. In this case, the portion corresponding to the conductive path may be selectively applied. The deposition method is, for example, plating. The conductive film is preferably made of a material having resistance to etching. When this conductive film is employed, it can be separated as the conductive path 51 only by etching without polishing.

In the present manufacturing method, only the transistor and the chip resistor are mounted on the conductive foil 60. However, these may be arranged in a matrix as one unit.
One of the circuit elements may be arranged in a matrix as one unit. In this case, as will be described later, they are individually separated by a dicing device.

According to the above manufacturing method, the insulating resin 50
A conductive circuit 51 is buried in the substrate, and a flat circuit device 56 in which the back surface of the insulating resin 50 and the back surface of the conductive path 51 match can be realized.

The feature of this manufacturing method is that the conductive path 51 can be separated by utilizing the insulating resin 50 as a supporting substrate. The insulating resin 50 is a material necessary as a material for embedding the conductive path 51, and does not require an unnecessary supporting substrate 5 unlike the conventional manufacturing method of FIG. Therefore, it has a feature that it can be manufactured with a minimum amount of material and that cost reduction can be realized.

The thickness of the insulating resin from the surface of the conductive path 51 can be adjusted when the insulating resin is attached in the previous step. Accordingly, the thickness of the circuit device 56 has a characteristic that it can be thick or thin, though it differs depending on the circuit element to be mounted. Here, 40 μm is applied to the insulating resin 50 having a thickness of 400 μm.
The circuit device has the m conductive paths 51 and the circuit elements embedded therein. (Refer to FIG. 1 above) Second Embodiment Explaining a Method of Manufacturing a Circuit Device Next, a method of manufacturing a circuit device 56 having an eave 58 will be described with reference to FIGS. 8 to 12 and FIG. Note that, except that the second material 70 serving as an eaves is adhered, the second embodiment is substantially the same as the first embodiment, and thus detailed description is omitted.

First, as shown in FIG. 8, a second material 70 having a small etching rate is formed on a conductive foil 60 made of a first material.
A conductive foil 60 coated with is prepared.

For example, when Ni is deposited on a Cu foil, Cu and Ni can be etched at a time with ferric chloride or cupric chloride, and Ni has an eaves 5 due to a difference in etching rate.
8, which is preferable. Thick solid line is Ni
And a film thickness of 1 to 10 μm.
The degree is preferred. Also, as the thickness of Ni increases, the eaves 58 increase.
Are easily formed.

The second material may be coated with a material which can be selectively etched with the first material. In this case, first, a film made of the second material is patterned so as to cover the formation region of the conductive path 51, and the first film is formed using this film as a mask.
This is because the eaves 58 can be formed by etching the coating made of the above material. As the second material, Al, A
g, Au and the like are conceivable. (Refer to FIG. 8 as described above.) Subsequently, there is a step of removing the conductive foil 60 except for at least a region to be the conductive path 51 so as to be thinner than the conductive foil 60.

A photoresist PR may be formed on Ni70, and the photoresist PR may be patterned so that Ni70 excluding the region serving as the conductive path 51 is exposed, and etching may be performed via the photoresist.

As described above, when etching is performed by using an etchant of ferric chloride or cupric chloride or the like, since the etching rate of Ni70 is smaller than the etching rate of Cu60, the eaves 58 appear as the etching proceeds.

The conductive foil 6 on which the separation groove 61 is formed
0, a step of mounting the circuit element 52 (FIG. 11), covering the conductive foil 60 and the separation groove 61 with an insulating resin 50, and chemically and / or physically removing the back surface of the conductive foil 60;
Step of separating as conductive path 51 (FIG. 12) and step of forming a conductive film on the back surface of conductive path to completion (FIG. 7)
Is the same as that of the previous manufacturing method, and the description thereof is omitted. Third Embodiment Explaining a Method for Manufacturing Circuit Elements Subsequently, one type of circuit element is arranged in a matrix,
A method of manufacturing a discrete element or an IC element by separating individually after sealing will be described with reference to FIGS. Since this manufacturing method is almost the same as the first embodiment, the same parts will be described briefly.

First, as shown in FIG.
Prepare

The sheet-shaped conductive foil 60 is prepared by being wound into a roll with a predetermined width, and may be conveyed to each step described later, or the conductive foil cut into a predetermined size may be used. It may be prepared and transported to each step described later.

Subsequently, there is a step of removing the conductive foil 60 excluding at least the region serving as the conductive path 51 so as to be thinner than the thickness of the conductive foil 60.

First, as shown in FIG.
A photoresist PR is formed, and the photoresist PR is patterned so as to expose the conductive foil 60 excluding a region serving as the conductive path 51. Then, as shown in FIG. 15, etching may be performed via the photoresist PR.

The depth of the separation groove 61 formed by etching is, for example, 50 μm, and the side surface thereof is rough, so that the adhesiveness with the insulating resin 50 is improved.

Although the side wall of the separation groove 61 is schematically shown as a straight line, it has a different structure depending on the removing method. This removal step can employ wet etching, dry etching, laser evaporation, and dicing. (Refer to the first embodiment for details.) In FIG. 14, a conductive film having corrosion resistance to an etchant may be selectively coated instead of the photoresist PR. If selectively applied to the part that will be the conductive path,
This conductive film serves as an etching protection film, and the separation groove can be etched without using a resist.

Subsequently, as shown in FIG. 16, there is a step of electrically connecting and mounting the circuit element 52A to the conductive foil 60 in which the separation groove 61 is formed.

As the circuit element 52A, a transistor,
Semiconductor devices such as diodes and IC chips, and passive devices such as chip capacitors and chip resistors. Although the thickness is increased, a face-down semiconductor element such as a CSP or a BGA can be mounted.

Here, the bare transistor chip 52
A is die-bonded to the conductive path 51A, and the emitter electrode and the conductive path 51B, and the base electrode and the conductive path 51B are connected via the thin metal wire 55A.

Further, as shown in FIG.
There is a step of attaching the insulating resin 50 to the separation groove 61 and the separation groove 61. This can be achieved by transfer molding, injection molding, or dipping.

In the present embodiment, the thickness of the insulating resin coated on the surface of the conductive foil 60 is adjusted so as to cover about 100 μm from the top of the circuit element. This thickness can be increased or reduced in consideration of strength.

The feature of this step is that, when the insulating resin 50 is coated, the conductive foil 60 which becomes the conductive path 51 becomes a supporting substrate. Conventionally, as shown in FIG. 25, the conductive paths 7 to 11 are formed by using the support substrate 5 which is not originally required. However, in the present invention, the conductive foil 60 serving as the support substrate is required as an electrode material. Material. Therefore, there is a merit that the operation can be performed while omitting the constituent materials as much as possible, and the cost can be reduced.

Since the separation grooves 61 are formed shallower than the thickness of the conductive foil, the conductive foils 60 are not individually separated as the conductive paths 51. Therefore, the sheet-shaped conductive foil 60
When molding insulating resin,
It has the feature that the work of transporting to the mold and mounting on the mold is very easy.

Subsequently, there is a step of chemically and / or physically removing the back surface of the conductive foil 60 and separating it as the conductive path 51. Here, the removing step is performed by polishing, grinding, etching, laser metal evaporation, or the like.

In the experiment, the entire surface was shaved by about 30 μm with a polishing device or a grinding device to expose the insulating resin 50. This exposed surface is indicated by a dotted line in FIG.
As a result, the conductive paths 51 having a thickness of about 40 μm are separated. Alternatively, the entire surface of the conductive foil 60 may be wet-etched before the insulating resin 50 is exposed, and thereafter, the entire surface may be ground by a polishing or grinding device to expose the insulating resin 50.

As a result, a structure is obtained in which the surface of the conductive path 51 is exposed in the insulating resin 50.

Further, as shown in FIG.
Is coated with a conductive material such as solder.

Finally, as shown in FIG. 19, there is a step of separating each circuit element to complete a circuit device.

The separation line is indicated by an arrow and can be realized by dicing, cutting, pressing, chocolate break, or the like. When a chocolate break is adopted, a protrusion may be formed on the mold so that a groove is formed in the separation line when the insulating resin is coated.

In particular, dicing is preferred because it is frequently used in a normal method for manufacturing a semiconductor device and can separate very small objects.

Further, pay attention to the cutting line indicated by the arrow. In this line, there is no support substrate and no conductive path extends. Therefore, the life of the cutting jig can be extended without wear and breakage. In particular, the dicing blade has a feature that the conductive path mainly made of Cu is not diced, so that the blade is not clogged. On the right side of FIG. 26, a flow briefly summarizing the present invention is shown. A circuit device can be realized by nine steps of preparation of Cu foil, plating of Ag or Ni or the like, half etching, die bonding, wire bonding, transfer molding, removal of backside Cu foil, backside treatment of conductive paths, and dicing. Moreover, all processes can be performed in-house without supplying a supporting substrate from a manufacturer. An embodiment describing types of circuit devices and a method for mounting them.

FIG. 20 shows a face-down type circuit element 8.
9 shows a circuit device 81 in which a “0” is mounted. The circuit element 80 corresponds to a bare semiconductor chip, a CSP or BGA with a sealed surface, or the like. FIG. 21 shows a circuit device 83 on which a passive element 82 such as a chip resistor or a chip resistor is mounted. Since they do not require a supporting substrate, they are thin and are sealed with an insulating resin, so that they have excellent environmental resistance.

FIG. 22 illustrates the real layer structure. The circuit devices 53, 81, and 83 of the present invention described above are mounted on conductive paths 85 formed on a mounting substrate 84 such as a printed substrate, a metal substrate, or a ceramic substrate.

In particular, since the conductive path 51A to which the back surface of the semiconductor chip 52 is fixed is thermally coupled to the conductive path 85 of the mounting board 84, heat can be radiated through the conductive path 85. When a metal substrate is used as the mounting substrate 84, the heat dissipation of the metal substrate is also helped, and the temperature of the semiconductor chip 52 can be further reduced. Therefore, the driving capability of the semiconductor chip can be improved.

For example, power MOS, IGBT, SIT,
Transistor for driving large current, IC for driving large current (M
OS type, BIP type, Bi-CMOS type) memory element and the like are preferable.

As the metal substrate, an Al substrate, a Cu substrate, or an Fe substrate is preferable, and an insulating resin and / or an oxide film is formed in consideration of a short circuit with the conductive path 85.

[0113]

As is evident from the above description, according to the present invention, the circuit device is constituted by the minimum required of the circuit device, the conductive path and the insulating resin, so that the circuit device has no waste of resources. Therefore, there is no extra component until completion, and a circuit device that can greatly reduce the cost can be realized. Further, by setting the coating thickness of the insulating resin and the thickness of the conductive foil to optimal values, it is possible to realize a very small, thin, and lightweight circuit device.

The conductive path is supported by a support substrate,
Alternatively, since each is not supported by a connecting piece or the like employed in a lead frame and is individually embedded in an insulating resin,
The support substrate or the conductive path does not extend to a cut portion (for example, a dicing line) for processing as a package. Therefore, at the time of cutting, the blade cuts only the insulating resin, so that the life of the blade can be extended.

Further, since only the back surface of the conductive path is exposed from the insulating resin, the back surface of the conductive path can be immediately used for connection to the outside, and the back electrode and the through hole of the conventional structure as shown in FIG. 24 are unnecessary. It has the advantage that can be.

In addition, when the circuit element is directly fixed via a conductive film such as brazing material, Au, Ag or the like, since the back surface of the conductive path is exposed, heat generated from the circuit element is directly transferred through the conductive path. Heat can be transmitted to the mounting board. In particular, this heat dissipation makes it possible to mount a power element.

Further, the present circuit device has a structure in which the surface of the separation groove and the surface of the conductive path have a flat surface substantially coincident with each other, and the circuit device itself can be horizontally moved as it is when a narrow pitch QFP is mounted. Therefore, it is extremely easy to correct the lead deviation.

Further, since the second material is formed on the front side of the conductive path, it is possible to suppress the warpage of the mounting substrate due to the difference in the coefficient of thermal expansion, particularly the warping or peeling of the elongated wiring.

By forming a coating made of the second material on the surface of the conductive path, an eave attached to the conductive path can be formed. Therefore, an anchor effect can be generated, and the conductive path can be prevented from warping or coming off.

In the method of manufacturing a circuit device according to the present invention, the conductive foil itself, which is the material of the conductive path, functions as a support substrate, and is used for forming a separation groove, mounting a circuit element, and attaching an insulating resin. When the whole is supported by the conductive foil and the conductive foil is separated as each conductive path, the insulating resin is used as a supporting substrate to function. Therefore, the circuit element, the conductive foil, and the insulating resin can be manufactured with the minimum necessary. As described in the conventional example, a support substrate is not required for originally configuring the circuit device, and the cost can be reduced. In addition, the need for a support substrate, the fact that the conductive path is embedded in the insulating resin, and the ability to adjust the thickness of the insulating resin and the conductive foil allow the formation of extremely thin circuit devices. There is also.

The conductive path on the back surface of the separation groove is removed, and by cutting the insulating resin in the separation groove, the circuit device can be formed as one package. Therefore, since the cutting jig cuts only the insulating resin, the wear, clogging and breakage of the blade can be suppressed, and the life of the jig can be greatly extended.

As is apparent from FIG. 26, the step of forming a through-hole and the step of printing a conductor (in the case of a ceramic substrate) can be omitted. It has the advantage that it can be made. In addition, no frame mold is required at all, and the manufacturing method has a very short delivery time.

Until the step of removing the conductive foil to a thickness smaller than the thickness of the conductive foil (for example, half etching), the conductive paths can be handled without being separated individually, so that the workability is improved in the subsequent step of coating the insulating resin. It also has the feature of

Further, since the same surface is formed of the conductive path and the insulating resin, the mounted circuit device can be shifted without hitting the side of the conductive path on the mounting board. In particular, it is possible to re-arrange the circuit devices mounted in a misaligned manner while being shifted in the horizontal direction. Also, if the brazing material is melted after mounting the circuit device, the misaligned mounted circuit device will try to return to the upper part of the conductive path by the surface tension of the melted brazing material, and can be rearranged by the circuit device itself. Becomes

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a circuit device of the present invention.

FIG. 2 is a diagram illustrating a method for manufacturing a circuit device according to the present invention.

FIG. 3 is a diagram illustrating a method for manufacturing a circuit device according to the present invention.

FIG. 4 is a diagram illustrating a method for manufacturing a circuit device according to the present invention.

FIG. 5 is a diagram illustrating a method for manufacturing a circuit device according to the present invention.

FIG. 6 is a diagram illustrating a method for manufacturing a circuit device according to the present invention.

FIG. 7 is a diagram illustrating a circuit device according to the present invention.

FIG. 8 is a diagram illustrating a method for manufacturing a circuit device according to the present invention.

FIG. 9 is a diagram illustrating a method for manufacturing a circuit device according to the present invention.

FIG. 10 is a diagram illustrating a method for manufacturing a circuit device according to the present invention.

FIG. 11 is a diagram illustrating a method for manufacturing a circuit device according to the present invention.

FIG. 12 is a diagram illustrating a method for manufacturing a circuit device according to the present invention.

FIG. 13 is a diagram illustrating a method for manufacturing a circuit device according to the present invention.

FIG. 14 is a diagram illustrating a method for manufacturing a circuit device according to the present invention.

FIG. 15 is a diagram illustrating a method for manufacturing a circuit device according to the present invention.

FIG. 16 is a diagram illustrating a method for manufacturing a circuit device according to the present invention.

FIG. 17 is a diagram illustrating a method for manufacturing a circuit device according to the present invention.

FIG. 18 is a diagram illustrating a method for manufacturing a circuit device according to the present invention.

FIG. 19 is a diagram illustrating a method for manufacturing a circuit device according to the present invention.

FIG. 20 is a diagram illustrating a circuit device of the present invention.

FIG. 21 is a diagram illustrating a circuit device of the present invention.

FIG. 22 is a diagram illustrating a method for mounting the circuit device of the present invention.

FIG. 23 is a diagram illustrating a mounting structure of a conventional circuit device.

FIG. 24 is a diagram illustrating a conventional circuit device.

FIG. 25 is a diagram illustrating a conventional method for manufacturing a circuit device.

FIG. 26 is a diagram illustrating a method for manufacturing a circuit device according to the related art and the present invention.

[Explanation of symbols]

 Reference Signs List 50 insulating resin 51 conductive path 52 circuit element 53 circuit device 54 separation groove 58 eaves

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) H01L 23/28 H01L 25/00 B 25/00 21/78 Q (72) Inventor Junji Sakamoto Keihanhondori, Moriguchi-shi, Osaka 2-5-5 Sanyo Electric Co., Ltd. (72) Inventor Shigeaki Mashimo 2-5-5 Sanyo Electric Co., Ltd., Sanyo Electric Co., Ltd. (72) Inventor Katsumi Okawa Keihan Moriguchi, Osaka 2-5-5 Hondori Sanyo Electric Co., Ltd. (72) Inventor Eiji Maehara 2-5-5 Keihan Hondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (72) Koji Takahashi Isesaki, Gunma 29F, Kita-cho, Kanto Sanyo Denshi Co., Ltd. F-term (reference) 4M109 AA01 BA01 CA21 DB15 DB16 5F067 AA01 AB00 AB04 CC01 DA16

Claims (22)

[Claims] 1. A plurality of conductive paths each having an island shape without a connecting means, a desired circuit element fixed on the conductive path, and a cover for covering the circuit element and exposing the back surface. A circuit device having an insulating resin embedded in the conductive path above the back surface, wherein the insulating resin positioned outside the conductive path is cut to form one package. Circuit device. 2. A plurality of conductive paths each formed in an island shape by a separation groove without interposing a connecting means,
A circuit element fixed on the desired conductive path; and an insulating resin filled in the separation groove by covering the circuit element and exposing the conductive path above the back surface by exposing the back surface. A circuit device, wherein the insulating resin filled in the separation groove positioned outside the conductive path is cut to form one package. 3. The circuit device according to claim 1, wherein a desired electrode on the circuit element and the conductive path are connected via a connection unit. 4. The conductive path according to claim 1, wherein the conductive path is formed of a conductive foil whose main material is any one of copper, aluminum, and iron-nickel. Circuit device. 5. The circuit device according to claim 1, wherein a conductive film made of a metal material different from that of the conductive path is provided on an upper surface of the conductive path. 6. The circuit device according to claim 5, wherein said conductive film is made of nickel, gold, or silver plating. 7. The circuit device according to claim 1, wherein the circuit element is configured by one or both of a semiconductor bare chip and a chip circuit component. 8. The circuit device according to claim 3, wherein said connection means is formed of a bonding thin wire or a brazing material. 9. The circuit device according to claim 2, wherein the back surface of the conductive path and the back surface of the insulating resin filled between the separation grooves are made substantially flat. 10. The circuit device according to claim 1, wherein the conductive path is used as a bonding pad or a die pad area. 11. The circuit device according to claim 1, wherein the insulating resin is cut by dicing, pressing, or chocolate break. 12. A step of preparing a conductive foil, forming a conductive path by forming a separation groove shallower than the thickness of the conductive foil around a region to be a conductive path, and forming a circuit element on a desired conductive path. Fixing, covering the circuit element and molding with an insulating resin so as to fill the separation groove, and removing the conductive foil corresponding to the separation groove to separate the conductive path. And a step of cutting the insulating resin corresponding to the separation groove from front to back. 13. A step of preparing a conductive foil and forming a conductive path by forming a separation groove shallower than the thickness of the conductive foil in the conductive foil except for a region serving as a conductive path; A step of fixing a plurality of circuit elements on a road; a step of forming connection means for electrically connecting an electrode on the circuit element to a desired conductive path; and covering the plurality of circuit elements with the separation groove. A method of manufacturing a circuit device, comprising: a step of molding with an insulating resin so as to be filled in the insulating resin; and a step of cutting the insulating resin corresponding to the separation groove from front to back. 14. A step of uniformly removing the conductive foil from the back surface to make the back surface of the conductive path and the insulating resin between the separation grooves substantially flat. A method for manufacturing the circuit device according to claim 12. 15. The conductive foil is made of copper, aluminum or iron.
15. The method according to claim 12, wherein the circuit device is made of nickel. 16. The conductive path according to claim 12, wherein a conductive film is formed on a surface of the conductive path, and the conductive film is formed of Ni, Au, or Ag. Manufacturing method of a circuit device. 17. The circuit device according to claim 12, wherein the separation groove selectively formed in the conductive foil is formed by chemical or physical etching. Manufacturing method. 18. The method according to claim 12, wherein one or both of a semiconductor bare chip and a chip circuit component are fixed to the circuit element. 19. The method according to claim 13, wherein said connecting means is made of a thin metal wire or a brazing material. 20. The semiconductor chip according to claim 20, wherein the semiconductor chip is mounted on the conductive path in a face-down manner, and the electrode on the semiconductor chip and the conductive path are connected via a brazing material or a conductive film. 19. The method for manufacturing a circuit device according to item 18. 21. The method for manufacturing a circuit device according to claim 12, wherein said insulating resin is attached by transfer molding. 22. The method of manufacturing a circuit device according to claim 12, wherein the insulating resin is separated into individual circuit devices by dicing.