JP3639514B2 - Circuit device manufacturing method - Google Patents

Abstract

PURPOSE: To solve the problem of a circuit device mounting a circuit element using a printed board, a ceramic board or a flexible board as a supporting board, where the supporting board is an essentially unnecessary and extra material, and the size of the circuit device is increased by the thickness of the supporting board. CONSTITUTION: After an isolation trench 54 is made in a conductive foil 60, a circuit device is flip-chip mounted and applied with insulating resin 50 using the conductive foil 60 as a support board. It is then turned over and the conductive, foil is polished using the insulating resin 50 as a supporting board and isolated as a conductive path. A circuit device, where the conductive path 51 and a circuit element 52 are supported by the insulating resin 50, can be implemented without having to adopt a supporting board.

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a circuit device and a manufacturing method thereof, and more particularly to a thin circuit device that does not require a support substrate and a manufacturing method thereof.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a circuit device set in an electronic device is employed in a mobile phone, a portable computer, and the like, and thus, a reduction in size, thickness, and weight are required.
[0003]
For example, a semiconductor device as an example of a circuit device will be described. As a general semiconductor device, there is a package type semiconductor device sealed by a conventional transfer mold. This semiconductor device is mounted on a printed circuit board PS as shown in FIG.
[0004]
In this package type semiconductor device, the periphery of the 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.
[0005]
However, the package type semiconductor device 1 has lead terminals 4 protruding from the resin layer 3 and has a large overall size, which does not satisfy the miniaturization, thickness reduction, and weight reduction.
[0006]
Therefore, various companies have competed to develop various structures to achieve miniaturization, thinning, and weight reduction, and recently called CSP (chip size package), wafer scale CSP equivalent to chip size, or chip size A slightly larger CSP has been developed.
[0007]
FIG. 16 shows a CSP 6 that employs a glass epoxy substrate 5 as a support substrate and is slightly larger than the chip size. Here, description will be made assuming that the transistor chip T is mounted on the glass epoxy substrate 5.
[0008]
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. The first electrode 7 and the first back electrode 10 are electrically connected to the second electrode 8 and the second back electrode 11 through the through hole TH. Further, the bare transistor chip T is fixed to the die pad 9, the emitter electrode of the transistor and the first electrode 7 are connected via the fine metal wire 12, and the base electrode of the transistor and the second electrode 8 are connected to the fine metal wire 12. Connected through. Further, a resin layer 13 is provided on the glass epoxy substrate 5 so as to cover the transistor chip T.
[0009]
The CSP 6 employs the glass epoxy substrate 5, but unlike the wafer scale CSP, the extending structure from the chip T to the backside electrodes 10 and 11 for external connection is simple, and has an advantage that it can be manufactured at low cost.
[0010]
The CSP 6 described above is mounted on a printed circuit board PS as shown in FIG. The printed circuit board PS is provided with electrodes and wirings constituting an electric circuit, and the CSP 6, the package type semiconductor device 1, the chip resistor CR, the chip capacitor CC, and the like are electrically connected and fixed.
[0011]
And the circuit comprised with this printed circuit board is attached in various sets.
[0012]
Next, a method for manufacturing the CSP will be described with reference to FIGS. In FIG. 18, reference is made to a flow diagram entitled the central glass epoxy / flexible substrate.
[0013]
First, a glass epoxy substrate 5 is prepared as a base material (support substrate), and Cu foils 20 and 21 are pressure-bonded to both surfaces via an insulating adhesive. (See FIG. 17A above)
Subsequently, the Cu foils 20, 21 corresponding to the first electrode 7, the second electrode 8, the die pad 9, the first back electrode 10, and the second back electrode 11 are covered with an etching resistant resist 22, and Cu The foils 20 and 21 are patterned. Patterning may be performed separately for the front and back sides (see FIG. 17B above).
Subsequently, a hole for the through hole TH is formed in the glass epoxy substrate by 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 10, and the second electrode 8 and the second back electrode 10 are electrically connected through the through hole TH. (See FIG. 17C above)
Further, although omitted in the drawings, the first electrode 7 and the second electrode 8 which are bonding posts are plated with Au, and the die pad 9 which is a die bonding post is plated with Au, so that the transistor chip T is die bonded. To do.
[0014]
Finally, the emitter electrode of the transistor chip T and the first electrode 7, the base electrode of the transistor chip T and the second electrode 8 are connected via the metal thin wire 12 and covered with the resin layer 13. (See FIG. 17D above)
If necessary, it is diced and separated as individual electric elements. In FIG. 17, only one transistor chip T is provided on the glass epoxy substrate 5, but actually, a large number of transistor chips T are provided in a matrix. Therefore, it is finally separated by a dicing device.
[0015]
With the above manufacturing method, a CSP type electric element employing the support substrate 5 is completed. This manufacturing method is the same even if a flexible sheet is adopted as the support substrate.
[0016]
On the other hand, a manufacturing method employing a ceramic substrate is shown in the flow on the left side of FIG. After preparing the ceramic substrate as the support substrate, through holes are formed, and then the front and back electrodes are printed and sintered using a conductive paste. After that, until the resin layer of the pre-manufacturing method is coated, the manufacturing method is the same as the manufacturing method of FIG. 17, but the ceramic substrate is very brittle, and unlike a flexible sheet or glass epoxy substrate, it will be chipped immediately. There is a problem that can not be molded. Therefore, the potting resin is potted and cured, and then polishing for flattening the sealing resin is performed, and finally, the dicing apparatus is used for individual separation.
[0017]
[Problems to be solved by the invention]
In FIG. 16, the transistor chip T, the connecting means 7 to 12 and the resin layer 13 are necessary components for electrical connection with the outside and protection of the transistor. It has been difficult to provide an electric circuit element that can be made thinner, thinner, and lighter.
[0018]
Moreover, the glass epoxy board | substrate 5 used as a support substrate is an essentially unnecessary thing as mentioned above. However, since the electrodes are bonded together in the manufacturing method, it is adopted as a support substrate, and the glass epoxy substrate 5 cannot be eliminated.
[0019]
For this reason, the use of the glass epoxy substrate 5 increases the cost. Further, since the glass epoxy substrate 5 is thick, it becomes thick as a circuit element, and there is a limit to miniaturization, thickness reduction, and weight reduction.
[0020]
Furthermore, a glass epoxy substrate or a ceramic substrate always requires a through-hole forming process for connecting electrodes on both sides, and there is a problem that the manufacturing process becomes long.
[0021]
Furthermore, since the fine metal wires 12 are connected in a loop, this is also a major obstacle to thinning.
[0025]
[Means for Solving the Problems]
The present invention is made in view of the many problems described above. First , a conductive foil is prepared, and a separation groove shallower than the thickness of the conductive foil is formed on the conductive foil except at least a region that becomes a conductive path. Forming a conductive path, fixing the surface electrode of the circuit element on the desired conductive path, connecting the back electrode of the circuit element and the desired conductive path with a metal connection plate, Production of a circuit device comprising: a step of covering the circuit element and molding with an insulating resin so as to fill the separation groove; and a step of removing the conductive foil in a thickness portion where the separation groove is not provided. By providing a method, the conductive foil forming the conductive path is a starting material, and the conductive foil has a supporting function until the insulating resin is molded, and after the molding, the insulating resin has a supporting function. This eliminates the need for a support substrate. It is possible to solve the problem.
[0026]
Second , preparing a conductive foil and forming a conductive path by forming a separation groove shallower than the thickness of the conductive foil on the conductive foil excluding at least a region to be a conductive path; Fixing the surface electrodes of the plurality of circuit elements on the road, connecting the back electrode of the circuit elements and the desired conductive path with a metal connection plate, covering the plurality of circuit elements, and forming the separation grooves A step of molding with an insulating resin so as to be filled, a step of removing the conductive foil in a thickness portion where the separation groove is not provided, and a step of cutting the insulating resin and separating it into individual circuit devices. By providing a method for manufacturing a circuit device including the above, a large number of circuit devices can be mass-produced, and the conventional problems can be solved.
[0027]
DETAILED DESCRIPTION OF THE INVENTION
First Embodiment Explaining the Circuit Device First, the structure of the circuit device of the present invention will be described with reference to FIG.
[0028]
In FIG. 1, a circuit device has a conductive path 51 embedded in an insulating resin 50, a circuit element 52 is fixed on the conductive path 51, and the conductive path 51 is supported by the insulating resin 50. 53 is shown.
[0029]
This structure is composed of three materials: circuit elements 52A, 52B, a plurality of conductive paths 51A, 51B, 51C, 51D, and an insulating resin 50 that embeds the conductive paths 51A, 51B, 51C, 51D. A separation groove 54 filled with the insulating resin 50 is provided therebetween. The conductive path 51 is supported by the insulating resin 50.
[0030]
As the insulating resin 50, a thermosetting resin such as an epoxy resin, 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 it is a resin that can be hardened using a mold, a resin that can be coated by dipping or coating.
[0031]
Further, as the conductive path 51, a conductive foil mainly made of Cu, a conductive foil mainly made of Al, a conductive foil made of an alloy such as Fe-Ni, or the like can be used. Of course, other conductive materials are possible, and a conductive material that can be etched and a conductive material that evaporates with a laser are particularly preferable.
[0032]
Further, the circuit element 52 includes a semiconductor bare chip 52A having a front surface electrode 521 and a back surface electrode 522, and a chip component 52B such as a chip resistor and a chip capacitor, but is not limited thereto. The semiconductor bare chip 52A will be described later in detail with reference to FIG.
[0033]
Further, as the connection means of the circuit element 52, a metal connection plate 55A, a conductive ball made of a brazing material, a flat conductive ball, a brazing material 55B such as solder, a conductive paste 55C such as an Ag paste, a conductive film or an anisotropic conductive material. For example. 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 semiconductor bare chip, for the connection between the surface electrode 521 provided on the surface and the conductive path 51, a brazing material 55B such as solder or a conductive paste 55C such as Ag paste is selected, and the back electrode 522 and the conductive path 51 are selected. Is connected to the metal connection plate 55A using a brazing material 55B such as solder. As the surface electrode 521, a protruding electrode formed with a gold bump or the like may be used. Further, the solder 55B is selected as the chip resistor and the chip capacitor.
[0034]
In this circuit device, since the conductive path 51 is supported by the insulating resin 50 that is a sealing resin, a support substrate is not required, and the conductive path 51, the circuit element 52, and the insulating resin 50 are included. This configuration is a feature of the present invention. As described in the section of the prior art, since the conductive path of the conventional circuit device is supported by the support substrate or supported by the lead frame, a configuration that may be unnecessary is added. However, since this circuit device is composed of the minimum necessary components and does not require a support substrate, it is characterized by being thin and inexpensive.
[0035]
In addition to the above-described configuration, the insulating resin 50 that covers the circuit element 52 and is filled in the separation groove 54 between the conductive paths 52 and is integrally supported is provided.
[0036]
The space between the conductive paths 51 becomes a separation groove 54, and the insulating resin 50 is filled therewith, so that there is an advantage that mutual insulation can be achieved.
[0037]
In addition, the insulating resin 50 that covers the circuit element 52 and is filled in the separation groove 54 between the conductive paths 51 and that supports only the back surface of the conductive path 51 is exposed.
[0038]
The point 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 the through hole TH having the conventional structure as shown in FIG. 16 can be eliminated.
[0039]
In the circuit device, the surface of the separation groove 54 and the surface of the conductive path 51 are substantially coincident with each other. This structure is a feature of the present invention and has a feature that the circuit device 53 can be moved horizontally as it is because the steps of the back electrodes 10 and 11 shown in FIG. 16 are not provided.
[0040]
Furthermore, since this circuit device is fixed to the conductive paths 51A and 51B by the flip chip method with the front surface electrode 521 facing downward, the circuit device can eliminate the bonding wire loop as in the prior art, and has an extremely thin structure. It has the feature which can realize.
[0041]
Second Embodiment Explaining Circuit Device Next, the circuit device 56 shown in FIG. 9 will be explained.
[0042]
In this structure, a conductive film 57 is formed on the surface of the conductive path 51, and the other structure is substantially the same as the structure in FIG. Therefore, the conductive film 57 will be described.
[0043]
The first feature is that a conductive film 57 is provided to prevent warping of the conductive path and the circuit device.
[0044]
Generally, the circuit device itself is warped or the conductive path is curved or peeled off due to the difference in thermal expansion coefficient between the insulating resin and the conductive path material (hereinafter referred to as the first material). Further, since the thermal conductivity of the conductive path 51 is superior to that of the insulating resin, the conductive path 51 first rises in temperature and expands. Therefore, by covering the second material having a smaller thermal expansion coefficient than that of the first material, warping and peeling of the conductive path and warping of the circuit device can be prevented. In particular, when Cu is employed 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 (minus the sixth power of 10), Au is 14 × 10 −6, Ni is 12.8 × 10 −6, and Pt is 8.9 × 10 6 -6.
[0045]
The second feature is that the anchor effect is provided by the second material. Since the eaves 58 are formed of the second material, and the eaves 58 attached to the conductive path 51 are embedded in the insulating resin 50, an anchor effect is generated, and the conductive path 51 can be prevented from coming off. .
[0046]
First Embodiment Explaining Method of Manufacturing Circuit Device Next, a method of manufacturing the circuit device 53 will be described with reference to FIGS. 2 to 8 and FIG.
[0047]
First, as shown in FIG. 2, a sheet-like conductive foil 60 is prepared. The conductive foil 60 is selected in consideration of the adhesiveness, bonding property, and plating property of the brazing material. As the material, a conductive foil mainly composed of Cu, a conductive foil mainly composed of Al, or Fe is used. A conductive foil made of an alloy such as Ni is employed.
[0048]
The thickness of the conductive foil is preferably about 10 μm to 300 μm in consideration of the later etching, and here, a copper foil of 70 μm (2 ounces) is employed. However, it is basically good if it is 300 μm or more and 10 μm or less. 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.
[0049]
In addition, the sheet-like conductive foil 60 is prepared by being wound in a roll shape with a predetermined width, and this may be conveyed to each step described later, or a conductive foil cut into a predetermined size is prepared, You may convey to each process mentioned later.
[0050]
Subsequently, there is a step of removing the conductive foil 60 excluding at least the region to be the conductive path 51 thinner than the thickness of the conductive foil 60. There is a step of covering the insulating groove 50 and the conductive foil 60 formed by this removal step with the insulating resin 50.
[0051]
First, a photoresist (etching-resistant mask) PR is formed on the Cu foil 60, and the photoresist PR is patterned so that the conductive foil 60 excluding the region to be the conductive path 51 is exposed (see FIG. 3 above). Then, etching may be performed through the photoresist PR (see FIG. 4 above).
[0052]
The depth of the separation groove 61 formed by etching is, for example, 50 μm, and its side surface is a rough surface, so that the adhesiveness with the insulating resin 50 is improved.
[0053]
The side wall of the separation groove 61 is schematically illustrated as a straight line, but has a different structure depending on the removal method. This removal process 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 the etchant, and the conductive foil is dipped in the etchant or showered with the etchant. Since wet etching is generally non-anisotropic, the side surface has a curved structure.
[0054]
In the case of dry etching, etching can be performed anisotropically or non-anisotropically. At present, it is said that Cu cannot be removed by reactive ion etching, but it can be removed by sputtering. Etching can be anisotropic or non-anisotropic depending on sputtering conditions.
[0055]
Further, in the laser, the separation groove can be formed by direct laser light irradiation. In this case, the side surface of the separation groove 61 is formed to be straight.
[0056]
In dicing, it is impossible to form a complicated bent pattern, but it is possible to form a lattice-like separation groove.
[0057]
In FIG. 3, instead of the photoresist, a conductive film resistant to the etching solution may be selectively coated. If the conductive film is selectively deposited on the conductive path, this conductive film becomes an etching protective film, and the separation groove can be etched without employing a resist. Possible materials for the conductive film are Ag, Au, Pt, Pd, and the like. In addition, these corrosion-resistant conductive films have the feature that they can be used as they are as die pads and bonding pads.
[0058]
Subsequently, as shown in FIG. 5, there is a step of electrically connecting the circuit element 52 to the conductive foil 60 in which the separation groove 61 is formed and mounting it.
[0059]
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.
[0060]
Here, the surface electrode 521 serving as the base electrode of the bare transistor chip 52A is fixed to the conductive path 51A, and the surface electrode 521 serving as the emitter electrode is fixed to the conductive path 51B by a soldering material such as solder or the conductive paste 55B in a flip chip manner. The The back electrode 522 serving as the collector electrode of the transistor chip 52A has one end of a metal connection plate 55A made of copper bent in an L shape connected by a brazing material such as solder or a conductive paste 55B, and the other end similar to the conductive path 51C. Connected to. Since the metal connection plate 55A has only the back electrode 522 on the back side of the transistor chip 52A, it can be easily mounted with rough alignment using a deformed component mounter. Further, 52B is a passive element such as a chip resistor, and is fixed by a brazing material such as solder or a conductive paste 55B.
[0061]
Further, as shown in FIG. 6, there is a step of attaching an insulating resin 50 to the conductive foil 60 and the separation groove 61. This can be realized 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 polyimide resin or polyphenylene sulfide can be realized by injection molding.
[0062]
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 decreased in consideration of strength.
[0063]
The feature of this step is that the conductive foil 60 that becomes the conductive path 51 becomes the support substrate until the insulating resin 50 is coated. Conventionally, as shown in FIG. 17, the conductive paths 7 to 11 are formed by using the support substrate 5 that is not originally required, but in the present invention, the conductive foil 60 that becomes the support substrate is necessary as an electrode material. Material. Therefore, there is a merit that the work can be performed with the constituent materials omitted as much as possible, and the cost can be reduced.
[0064]
Further, since the separation groove 61 is formed shallower than the thickness of the conductive foil, the conductive foil 60 is not individually separated as the conductive path 51. Therefore, the sheet-like conductive foil 60 can be handled as a unit, and when the insulating resin is molded, it has a feature that it is very easy to carry to the mold and mount to the mold.
[0065]
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, this removal step is performed by polishing, grinding, etching, laser metal evaporation, or the like.
[0066]
In the experiment, the entire surface is cut by about 30 μm by a polishing apparatus or a grinding apparatus, and the insulating resin 50 is exposed from the separation groove 61. 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 separated. Alternatively, wet etching may be performed on the entire surface of the conductive foil 60 until the insulating resin 50 is exposed, and then the entire surface may be shaved by a polishing or grinding apparatus to expose the insulating resin 50. Further, the conductive foil 60 may be wet etched to expose the insulating resin 50 until the insulating resin 50 is exposed.
[0067]
As a result, the surface of the conductive path 51 is exposed to the insulating resin 50. Then, the separation groove 61 is shaved to form the separation groove 54 in FIG. (See Figure 6 above)
Finally, a conductive material such as solder is applied to the exposed conductive path 51 as necessary, thereby completing the circuit device.
[0068]
When a conductive film is applied to the back surface of the conductive path 51, a conductive film may be formed in advance on the back surface of the conductive foil in FIG. In this case, a portion corresponding to the conductive path may be selectively attached. The deposition method is, for example, plating. The conductive film is preferably made of a material that is resistant to etching. Further, when this conductive film is employed, the conductive path 51 can be separated only by etching without polishing.
[0069]
In this manufacturing method, the transistor and the chip resistor are only mounted on the conductive foil 60. However, the transistor and the chip resistor may be arranged in a matrix shape as one unit, or one of the circuit elements is set as one unit. They may be arranged in a matrix. In this case, it separates with a dicing apparatus so that it may mention later.
[0070]
With the above manufacturing method, the flat circuit device 56 in which the conductive path 51 is embedded in the insulating resin 50 and the back surface of the insulating resin 50 and the back surface of the conductive path 51 coincide can be realized.
[0071]
The feature of this manufacturing method is that the insulating path 50 can be used as a support substrate to separate the conductive path 51. The insulating resin 50 is a material necessary as a material for embedding the conductive path 51, and does not require an unnecessary support substrate 5 unlike the conventional manufacturing method of FIG. Therefore, it has the characteristics that it can be manufactured with a minimum amount of material and cost can be reduced.
[0072]
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. In the present invention, since the semiconductor bare chip 52A is fixed to the conductive path 51 by the flip chip method, the bonding wire can be eliminated. Therefore, the thickness of the circuit device 56 has a feature that can be extremely reduced, although it varies depending on the thickness of the semiconductor bare chip 52A to be mounted. Here, a circuit device is obtained in which a 40 μm conductive path 51 and circuit elements are embedded in an insulating resin 50 having a thickness of 400 μm. (See Figure 1 above)
FIG. 7 shows a plan view of the substrate of the conductive foil 60 after the separation groove 61 is formed. This substrate has a size of 45 mm × 60 mm, the black part forms the conductive path 51, and the white part forms the separation groove 61. Accordingly, the portions to be the circuit devices 53 and 56 are arranged in a matrix in 5 columns and 17 rows, and are provided with alignment marks 611, index holes 612 used during manufacture, and the like in the periphery.
[0073]
FIG. 8 is a sectional view showing a specific structure of the semiconductor bare chip 52A. In the semiconductor bare chip 52A, a P-type base region 524 and an N-type emitter region 525 are provided on an N-type semiconductor substrate 523, and aluminum in contact with the P-type base region 524 and the N-type emitter region 525 is formed on the insulating film 526 of the semiconductor substrate 523. A base electrode 527 and a base emitter electrode 528 formed by sputtering are provided. A barrier metal layer 529 of Pd / Ti or Au / TiW is provided on the base electrode 527 and the base emitter electrode 528, and a base surface electrode 521 and an emitter surface electrode formed by a gold plating layer at a height of about 25 μm thereon. 521 is provided. Further, a back electrode 522 is provided on the entire back surface of the semiconductor substrate 523 by vapor deposition of Au / Cr or the like.
[0074]
Second Embodiment Explaining Method of Manufacturing Circuit Device Next, a method of manufacturing the circuit device 56 having the eaves 58 will be described with reference to FIGS. In addition, since it is substantially the same as 1st Embodiment except the 2nd material 70 used as eaves being adhere | attached, detailed description is abbreviate | omitted.
[0075]
First, as shown in FIG. 10, a conductive foil 60 in which a second material 70 having a low etching rate is coated on a conductive foil 60 made of a first material is prepared.
[0076]
For example, it is preferable to deposit Ni on a Cu foil because Cu and Ni can be etched at once with ferric chloride or cupric chloride, and Ni is formed into eaves 58 due to the difference in etching rate. . The thick solid line is the conductive film 70 made of Ni, and the film thickness is preferably about 1 to 10 μm. Further, the thicker the Ni film, the easier the eaves 58 are formed.
[0077]
The second material may be coated with a material that can be selectively etched with the first material. In this case, the eaves 58 can be formed by first patterning the coating made of the second material so as to cover the formation region of the conductive path 51 and etching the coating made of the first material using this coating as a mask. is there. As the second material, Al, Ag, Au, or the like can be considered. (See Figure 10 above)
Subsequently, there is a step of removing the conductive foil 60 excluding at least the region to be the conductive path 51 thinner than the thickness of the conductive foil 60.
[0078]
A photoresist PR is formed on the Ni 70, the photoresist PR is patterned so that the Ni 70 excluding the region to be the conductive path 51 is exposed, and etching is performed through the photoresist.
[0079]
As described above, when etching is performed using ferric chloride, cupric chloride etchant, etc., the etching rate of Ni 70 is smaller than the etching rate of Cu 60, and thus eaves 58 appears as etching progresses.
[0080]
The circuit element 52 is mounted on the conductive foil 60 in which the separation groove 61 is formed (FIG. 13), the conductive foil 60 and the separation groove 61 are covered with an insulating resin 50, and the back surface of the conductive foil 60 is chemically treated. The process of separating as the conductive path 51 (FIG. 14) and the process up to completion by forming a conductive film on the back surface of the conductive path (FIG. 9) are the same as those in the manufacturing method described above. Therefore, the description is omitted.
[0081]
【The invention's effect】
As is apparent from the above description, the present invention is a circuit device that is configured with the minimum necessary circuit devices, conductive paths, and insulating resin, and that does not waste resources. Therefore, it is possible to realize a circuit device in which there are no extra components until completion and the cost can be significantly reduced.
[0082]
In addition, since the semiconductor bare chip is fixed to the conductive path by the flip chip method, a bonding wire can be eliminated, and the height of the insulating resin coating film and the thickness of the conductive foil are optimized, and the height is 0.5 mm or less. Therefore, it is possible to realize a circuit device that can be made very thin and at the same time reduced in size and weight.
[0083]
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 advantage that the back electrode and the through hole having the conventional structure as shown in FIG. 16 can be eliminated. Have
[0084]
In addition, this circuit device has a structure in which the surface of the separation groove and the surface of the conductive path have a flat surface that is substantially coincident, and when the narrow pitch QFP is mounted, the circuit device itself is leveled by the surface tension of the solder as it is. Since it can move, correction of electrode displacement becomes very easy.
[0085]
In addition, since the second material is formed on the front side of the conductive path, it is possible to suppress warping of the mounting substrate, particularly warpage or peeling of the elongated wiring due to a difference in thermal expansion coefficient.
[0086]
Further, by forming a film made of the second material on the surface of the conductive path, an eaves attached to the conductive path can be formed. Therefore, an anchor effect can be generated, and the warpage and disconnection of the conductive path can be prevented.
[0087]
In the method of manufacturing a circuit device according to the present invention, the conductive foil itself, which is a material of the conductive path, functions as a support substrate, and the conductive foil is used until the separation groove is formed, the circuit element is mounted, or the insulating resin is applied. When supporting the whole and separating the conductive foil as each conductive path, an insulating resin is used as a support substrate to function. Therefore, the circuit element, conductive foil, and insulating resin can be manufactured with the minimum necessary. As described in the conventional example, a support substrate is not necessary in constructing a circuit device originally, and the cost can be reduced. In addition, the support substrate is unnecessary, the conductive path is embedded in the insulating resin, and the thickness of the insulating resin and the conductive foil can be adjusted, and the bonding wire is unnecessary, so that it is very thin. There is also an advantage that a circuit device can be formed.
[0088]
Further, as apparent from FIG. 18, the through hole forming process, conductor printing process (in the case of a ceramic substrate), etc. can be omitted, so that the manufacturing process can be greatly shortened compared to the prior art, and the entire process can be made in-house. Have Also, a frame mold is not required at all, and this is a manufacturing method with extremely short delivery time.
[0089]
Next, until the process of removing the conductive foil thinner than the thickness of the conductive foil (for example, half-etching), since the conductive paths can be handled without being separated individually, many circuit devices are integrated and manufactured on an extremely small substrate. It also has improved characteristics.
[0090]
Further, since the same surface is formed by the conductive path and the insulating resin, the mounted circuit device can be shifted without hitting the side surface of the conductive path on the mounting substrate. In particular, it is possible to reposition the circuit devices mounted with their positions shifted in the horizontal direction. In addition, if the brazing material is melted after the circuit device is mounted, the circuit device that has been mounted out of position tries 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. It becomes.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view illustrating a circuit device of the present invention.
FIG. 2 is a cross-sectional view illustrating a method for manufacturing a circuit device according to the present invention.
FIG. 3 is a cross-sectional view illustrating a method for manufacturing a circuit device according to the present invention.
FIG. 4 is a cross-sectional view illustrating a method for manufacturing a circuit device according to the present invention.
FIG. 5 is a cross-sectional view illustrating a method for manufacturing a circuit device according to the present invention.
FIG. 6 is a cross-sectional view illustrating a method for manufacturing a circuit device according to the present invention.
FIG. 7 is a plan view illustrating the method for manufacturing the circuit device of the present invention.
FIG. 8 is a cross-sectional view illustrating a method for manufacturing a circuit device according to the present invention.
FIG. 9 is a cross-sectional view illustrating a circuit device of the present invention.
FIG. 10 is a cross-sectional view illustrating a method for manufacturing a circuit device according to the present invention.
FIG. 11 is a cross-sectional view illustrating a method for manufacturing a circuit device according to the present invention.
FIG. 12 is a cross-sectional view illustrating a method for manufacturing a circuit device according to the present invention.
FIG. 13 is a cross-sectional view illustrating a method for manufacturing a circuit device of the present invention.
FIG. 14 is a cross-sectional view illustrating a method for manufacturing a circuit device according to the present invention.
FIG. 15 is a cross-sectional view illustrating a mounting structure of a conventional circuit device.
FIG. 16 is a cross-sectional view illustrating a conventional circuit device.
FIG. 17 is a cross-sectional view illustrating a conventional method for manufacturing a circuit device.
FIG. 18 is a diagram for explaining a conventional method of manufacturing a circuit device according to the present invention.
[Explanation of symbols]
50 Insulating resin 51 Conductive path 52 Circuit element 53 Circuit device 54 Separation groove 58 Eaves

Claims (16)

Preparing a conductive foil, forming a conductive path by forming a separation groove shallower than the thickness of the conductive foil on the conductive foil excluding at least a region to be a conductive path; and
Fixing a surface electrode of a circuit element on a desired conductive path;
Connecting the back electrode of the circuit element and the desired conductive path with a metal connection plate;
Covering the circuit element and molding with an insulating resin so as to fill the separation groove;
And a step of removing the conductive foil in a thickness portion where the separation groove is not provided. Preparing a conductive foil, and forming a corrosion-resistant conductive film in at least a region that becomes a conductive path on the surface of the conductive foil;
Forming a conductive path by forming a separation groove shallower than the thickness of the conductive foil in the conductive foil except at least a region to be a conductive path;
Fixing a surface electrode of a circuit element on a desired conductive path;
Connecting the back electrode of the circuit element and the desired conductive path with a metal connection plate;
Covering the circuit element and molding with an insulating resin so as to fill the separation groove;
And a step of removing the conductive foil in a thickness portion where the separation groove is not provided. Preparing a conductive foil, forming a conductive path by forming a separation groove shallower than the thickness of the conductive foil on the conductive foil excluding at least a region to be a conductive path; and
Fixing a surface electrode of a circuit element on a desired conductive path;
Connecting the back electrode of the circuit element and the desired conductive path with a metal connection plate;
Covering the circuit element and molding with an insulating resin so as to fill the separation groove;
Removing the conductive foil in a thickness portion not provided with the separation groove;
And a step of cutting the insulating resin and separating it into individual circuit devices. Preparing a conductive foil, forming a conductive path by forming a separation groove shallower than the thickness of the conductive foil on the conductive foil excluding at least a region to be a conductive path; and
Fixing the surface electrodes of a plurality of circuit elements on a desired conductive path;
Connecting the back electrode of the circuit element and the desired conductive path with a metal connection plate;
Coating the plurality of circuit elements and molding with an insulating resin so as to fill the separation grooves;
Removing the conductive foil in a thickness portion not provided with the separation groove;
And a step of cutting the insulating resin and separating it into individual circuit devices. Preparing a conductive foil, forming a conductive path by forming a separation groove shallower than the thickness of the conductive foil on the conductive foil excluding at least a region to be a conductive path; and
Fixing a surface electrode of a circuit element on a desired conductive path;
Connecting the back electrode of the circuit element and the desired conductive path with a metal connection plate;
Covering the circuit element and molding with an insulating resin so as to fill the separation groove;
Removing the conductive foil of a thickness portion not provided with the separation groove uniformly 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 a circuit device. Preparing a conductive foil, forming a conductive path by forming a separation groove shallower than the thickness of the conductive foil on the conductive foil excluding the castle that becomes a conductive path; and
Fixing a surface electrode of a circuit element on a desired conductive path;
Connecting the back electrode of the circuit element and the desired conductive path with a metal connection plate;
Covering the circuit element and molding with an insulating resin so as to fill the separation groove;
Removing the conductive foil of the thickness portion not provided with the separation groove uniformly from the back surface to make the insulating resin between the back surface of the conductive path and the separation groove substantially flat; and
And a step of cutting the insulating resin and separating it into individual circuit devices. The conductive foil is copper, aluminum, iron - method of manufacturing has been the circuit device according to any one of claims 1 to 6, characterized in that it is composed of either nickel. 3. The method of manufacturing a circuit device according to claim 2 , wherein the conductive film is formed by nickel, gold or silver plating. The isolation trench chemical or physical method of manufacturing has been the circuit device according to any one of claims 1 to 6, characterized in that it is formed by etching is selectively formed on the conductive foil. 9. The method of manufacturing a circuit device according to claim 8 , wherein the conductive film is used as a part of a mask when the separation groove is formed. The circuit element manufacturing method of the a circuit device according to claims 1, characterized in that it is affixed to a semiconductor bare chip to claim 6. Method for producing a metal connecting plate is a circuit device according to any one of claims 1 to 6, characterized in that it is secured by solder or conductive paste. The insulating resin production method of the a circuit device according to any one of claims 1 to 6, characterized in that it is deposited in the transfer molding. The insulating resin according to claim 3, characterized in that the separation into individual circuit devices by dicing, a manufacturing method of the a circuit device according to claim 4 or claim 6.   A step of preparing a conductive foil in which a conductive path is formed by forming a separation groove shallower than the thickness of the conductive foil on the conductive foil excluding at least a region to be a conductive path;
  Fixing a surface electrode of a circuit element on a desired conductive path;
  Connecting the back electrode of the circuit element and the desired conductive path with a metal connection plate;
  Covering the circuit element and molding with an insulating resin so as to fill the separation groove;
  And a step of removing the conductive foil in a thickness portion where the separation groove is not provided.   A step of preparing a conductive foil in which a conductive path is formed by forming a separation groove shallower than the thickness of the conductive foil on the conductive foil excluding at least a region to be a conductive path;
  Fixing the surface electrodes of a plurality of circuit elements on a desired conductive path;
  Connecting the back electrode of the circuit element and the desired conductive path with a metal connection plate;
  Coating the plurality of circuit elements and molding with an insulating resin so as to fill the separation grooves;
  Removing the conductive foil in a thickness portion not provided with the separation groove;
  And a step of cutting the insulating resin and separating it into individual circuit devices.

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