JP3600132B2 - Circuit device manufacturing method - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for manufacturing a circuit device, and more particularly to a method for manufacturing a thin circuit device that does not require a support substrate.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a circuit device set in an electronic device is used for a mobile phone, a portable computer, and the like, and therefore, a reduction in size, thickness, and weight is required.
[0003]
For example, taking a semiconductor device as an example of a circuit device, a general semiconductor device is a packaged semiconductor device sealed with 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, in this package type semiconductor device 1, the lead terminals 4 are protruded from the resin layer 3, so that the overall size is large, and the size, thickness, and weight are not satisfied.
[0006]
For this reason, 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, or chip size A CSP with a size slightly larger than that has been developed.
[0007]
FIG. 13 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 front 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 each other, and the second electrode 8 and the second back electrode 11 are electrically connected to each other through the through hole TH. The bare transistor chip T is fixed to the die pad 9, the emitter electrode of the transistor is connected to the first electrode 7 via a thin metal wire 12, and the base electrode of the transistor and the second electrode 8 are connected to the thin 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]
Although the CSP 6 employs the glass epoxy substrate 5, unlike the wafer scale CSP, the extending structure from the chip T to the back surface 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 is mounted on a printed circuit board PS as shown in FIG. The printed circuit board PS is provided with electrodes and wiring constituting an electric circuit, and the CSP 6, the package type semiconductor device 1, the chip resistor CR or the chip capacitor CC and the like are electrically connected and fixed.
[0011]
The circuit formed by the printed circuit board is mounted in various sets.
[0012]
Next, a method of manufacturing the CSP will be described with reference to FIGS.
[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 thereof via an insulating adhesive. (See FIG. 14A above)
Subsequently, Cu foils 20 and 21 corresponding to the first electrode 7, the second electrode 8, the die pad 9, the first back surface electrode 10 and the second back surface electrode 11 are coated with an etching-resistant resist 22, The foils 20 and 21 are patterned. The patterning may be performed separately on the front and back sides. (See FIG. 14B 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 by the through hole TH. (See FIG. 14C above)
Although not shown in the drawings, the first electrode 7 and the second electrode 8 serving as bonding posts are plated with Au, and the die pads 9 serving as die bonding posts are plated with Au, and the transistor chip T is die-bonded. I do.
[0014]
Finally, the emitter electrode of the transistor chip T and the first electrode 7, and the base electrode of the transistor chip T and the second electrode 8 are connected via a thin metal wire 12 and covered with a resin layer 13. (See FIG. 14D above)
By the above manufacturing method, a CSP type electric element using the support substrate 5 is completed. This manufacturing method is the same even when a flexible sheet is used as the support substrate.
[0015]
On the other hand, a manufacturing method employing a ceramic substrate is shown in the flow of FIG. After a ceramic substrate as a support substrate is prepared, through holes are formed, and thereafter, front and rear electrodes are printed and sintered using a 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. 14, but the ceramic substrate is very fragile. There is a problem that can not be molded. Therefore, after potting and hardening the sealing resin, polishing for flattening the sealing resin is performed, and finally, individual separation is performed using a dicing apparatus.
[0016]
[Problems to be solved by the invention]
In FIG. 13, the transistor chip T, the connection means 7 to 12 and the resin layer 13 are necessary components for electrical connection to the outside and protection of the transistor. It has been difficult to provide a circuit element that realizes reduction in thickness, thickness, and weight.
[0017]
Further, the glass epoxy substrate 5 serving as a support substrate is not necessary as described above. However, due to the manufacturing method, the glass epoxy substrate 5 was employed as a support substrate for bonding the electrodes, and the glass epoxy substrate 5 could not be eliminated.
[0018]
Therefore, the use of the glass epoxy substrate 5 increases the cost, and further, the glass epoxy substrate 5 is thick, so that the circuit element becomes thick, and there is a limit in reducing the size, thickness, and weight.
[0019]
Further, in the case of a glass epoxy substrate or a ceramic substrate, a through-hole forming step for connecting electrodes on both sides is indispensable, and the manufacturing process becomes long, which is not suitable for mass production.
[0020]
[Means for Solving the Problems]
The present invention has been made in view of the above-mentioned many problems, prepares a conductive foil, and has a shallower than the thickness of the conductive foil on the conductive foil in a region excluding a conductive pattern that forms at least a large number of circuit element mounting portions. Forming a separation groove to form a conductive pattern for each block, and fixing a circuit element to each mounting portion of the desired conductive pattern, and collectively covering the circuit element of each mounting portion; A step of performing common molding with an insulating resin so as to fill the separation groove, a step of removing the conductive foil in a thickness portion where the separation groove is not provided, and a step of exposing the back surface of the insulating resin of each block. Covering the conductive pattern with a resist layer except for a portion where a predetermined back electrode is to be formed, adhering a creamy brazing material, heating and melting to form a back electrode, and the insulating property of the block. Tree The characterized by comprising the step of separating by dicing for each mounting portion.
[0021]
In the present invention, the conductive foil forming the conductive pattern is the starting material, and the conductive foil has a supporting function until the insulating resin is molded, and the insulating resin has the supporting function after the molding. The substrate can be eliminated, and the conventional problem can be solved.
[0022]
Further, in the present invention, since the back surface electrode can be formed for each block using screen printing or the like, a large number of circuit devices can be mass-produced, and the conventional problems can be solved.
[0023]
BEST MODE FOR CARRYING OUT THE INVENTION
First, a method for manufacturing a circuit device according to the present invention will be described with reference to FIG.
[0024]
The present invention provides a conductive foil, and forms a separation groove shallower than the thickness of the conductive foil in the conductive foil in an area excluding at least a conductive pattern forming a large number of circuit element mounting portions, and forms a conductive pattern for each block. Forming, and fixing the circuit elements to the respective mounting portions of the desired conductive pattern, and covering the circuit elements of the respective mounting portions collectively, and insulating the same so as to fill the separation grooves. A step of performing common molding with resin, a step of removing the conductive foil in a thickness portion where the separation groove is not provided, and a predetermined back surface electrode on the conductive pattern exposed on the back surface of the insulating resin of each block. Covering with a resist layer leaving an opening to be formed, applying a creamy brazing material, heating and melting to form a back electrode, and mounting portions of the block in a state of being attached to the adhesive sheet. And performing measurement of a property of the circuit element, and a step of separating by dicing the insulating resin of the block in a state in which the affixed to the adhesive sheet for each mounting portion.
[0025]
Although the flow shown in FIG. 1 does not coincide with the above-described steps, the formation of the conductive pattern is performed by three flows of Cu foil, Ag plating, and half etching. The bonding of the circuit element to each mounting portion and the connection of the electrode of the circuit element and the conductive pattern are performed by two flows of die bonding and wire bonding. In the transfer mold flow, a common mold using an insulating resin is performed. In the flow for removing the back surface Cu foil, the conductive foil in the thickness portion having no separation groove is etched. In the back surface processing flow, the back surface electrode of the conductive pattern exposed on the back surface is formed. In the flow of the adhesive sheet, a plurality of blocks are attached to the adhesive sheet. In the measurement flow, non-defective products and characteristic ranks of circuit elements incorporated in each mounting section are determined. In the dicing flow, individual circuit elements are separated from the insulating resin by dicing.
[0026]
Hereinafter, each step of the present invention will be described with reference to FIGS.
[0027]
In the first step of the present invention, as shown in FIGS. 2 to 4, a conductive foil 60 is prepared, and a conductive foil 60 is applied to at least the conductive foil 60 in a region excluding the conductive pattern 51 where a large number of mounting portions for the circuit elements 52 are formed. The purpose is to form a separation pattern 61 shallower than the thickness of the foil 60 to form the conductive pattern 51 for each block.
[0028]
In this step, first, as shown in FIG. 2A, a sheet-shaped conductive foil 60 is prepared. The material of 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 containing Cu, a conductive foil mainly containing Al, or Fe -A conductive foil made of an alloy such as Ni is employed.
[0029]
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 oz) was employed. However, it is basically good to be 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.
[0030]
In addition, the sheet-shaped conductive foil 60 is prepared by being wound in a roll shape with a predetermined width, for example, 45 mm, and may be conveyed to each step described later, or may be a strip shape cut to a predetermined size. The conductive foil 60 may be prepared and transported to each step described later.
[0031]
Specifically, as shown in FIG. 2B, four or five blocks 62 on which a large number of mounting portions are formed are arranged on the strip-shaped conductive foil 60 at a distance. Slits 63 are provided between the blocks 62 to absorb the stress of the conductive foil 60 generated by a heat treatment in a molding process or the like. Index holes 64 are provided at regular intervals at the upper and lower peripheral edges of the conductive foil 60, and are used for positioning in each step.
[0032]
Subsequently, a conductive pattern 51 for each block is formed.
[0033]
First, as shown in FIG. 3, a photoresist (etching 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 be the conductive pattern 51. Then, as shown in FIG. 4A, the conductive foil 60 is selectively etched via the photoresist PR.
[0034]
The depth of the separation groove 61 formed by etching is, for example, 50 μm, and the side surface thereof is roughened, so that the adhesiveness to the insulating resin 50 is improved.
[0035]
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.
[0036]
In the case of dry etching, anisotropic and 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. In addition, anisotropic and non-anisotropic etching can be performed depending on sputtering conditions.
[0037]
In the case of a laser, the separation groove 61 can be formed by directly irradiating a laser beam. In this case, the side surface of the separation groove 61 is formed straight.
[0038]
In FIG. 3, a conductive film (not shown) 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, Ni, Au, Pt, and Pd. Moreover, these corrosion-resistant conductive films have a feature that they can be used as they are as die pads and bonding pads.
[0039]
For example, the Ag film 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 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. 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.
[0040]
FIG. 4B shows a specific conductive pattern 51. This figure corresponds to an enlarged one of the blocks 62 shown in FIG. 2B. One of the portions painted black is one mounting portion 65, which constitutes the conductive pattern 51, and one block 62 has a large number of mounting portions 65 arranged in a matrix of 5 rows and 10 columns. The same conductive pattern 51 is provided every 65. A frame-shaped pattern 66 is provided around each block, and a positioning mark 67 at the time of dicing is provided inside the pattern 66 slightly apart therefrom. The frame-shaped pattern 66 is used for fitting with a mold and has a function of reinforcing the insulating resin 50 after the back surface etching of the conductive foil 60.
[0041]
In the second step of the present invention, as shown in FIG. 5, the circuit elements 52 are fixed to the respective mounting portions 65 of the desired conductive patterns 51, and the electrodes of the circuit elements 52 of the respective mounting portions 65 and the desired conductive patterns 51 are formed. Is to form a connecting means for electrically connecting.
[0042]
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 CSP or BGA can be mounted.
[0043]
Here, a bare transistor chip 52A is die-bonded to the conductive pattern 51A, and an emitter electrode and the conductive pattern 51B, and a base electrode and the conductive pattern 51B are fixed by ball bonding by thermocompression bonding or wet bonding by ultrasonic waves or the like. Connected via 55A. Reference numeral 52B denotes a chip capacitor or a passive element, which is fixed with a brazing material such as solder or a conductive paste 55B.
[0044]
In this step, since a large number of conductive patterns 51 are integrated in each block 62, there is an advantage that the fixing of the circuit element 52 and the wire bonding can be performed very efficiently.
[0045]
In the third step of the present invention, as shown in FIG. 6, the circuit elements 52 of each mounting portion 63 are collectively covered, and are commonly molded with the insulating resin 50 so as to fill the separation grooves 61. .
[0046]
In this step, as shown in FIG. 6A, the insulating resin 50 completely covers the circuit elements 52A, 52B and the plurality of conductive patterns 51A, 51B, 51C. 50 is fitted to the curved structure on the side surface of the conductive patterns 51A, 51B, 51C filled therein, and is firmly coupled. The conductive pattern 51 is supported by the insulating resin 50.
[0047]
Also, this step 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 a polyimide resin and polyphenylene sulfide can be realized by injection molding.
[0048]
Further, when performing transfer molding or injection molding in this process, as shown in FIG. 6B, each block 62 is provided with the mounting portion 63 in one common mold, and one block of common insulating resin 50 is used for each block. Mold. For this reason, compared with the conventional method of individually molding each mounting portion such as transfer molding, the amount of resin can be significantly reduced, and a common mold can be used.
[0049]
The thickness of the insulating resin 50 coated on the surface of the conductive foil 60 is adjusted so as to cover about 100 μm from the top of the fine metal wire 55A of the circuit element 52. This thickness can be increased or reduced in consideration of strength.
[0050]
The feature of this step is that the conductive foil 60 serving as the conductive pattern 51 becomes a support substrate until the insulating resin 50 is covered. Conventionally, as shown in FIG. 12, 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.
[0051]
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 patterns 51. Therefore, it can be handled as a sheet-shaped conductive foil 60 integrally, and when the insulating resin 50 is molded, it has a feature that the work of transporting to the mold and mounting on the mold becomes very easy.
[0052]
In the fourth step of the present invention, as shown in FIG. 6, the thickness of the conductive foil 60 where the separation groove 61 is not provided is removed.
[0053]
In this step, the back surface of the conductive foil 60 is chemically and / or physically removed and separated as the conductive pattern 51. This step is performed by polishing, grinding, etching, laser metal evaporation, or the like.
[0054]
In the experiment, the entire surface was shaved by about 30 μm with a polishing device or a grinding device, and the insulating resin 50 was exposed from the separation groove 61. This exposed surface is indicated by a dotted line in FIG. As a result, the conductive patterns 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.
[0055]
As a result, a structure in which the back surface of the conductive pattern 51 is exposed to the insulating resin 50 is obtained. That is, the surface of the insulating resin 50 filled in the separation groove 61 and the surface of the conductive pattern 51 have a structure that substantially matches.
[0056]
In the fifth step of the present invention, as shown in FIG. 7, a resist layer 90 is formed on the conductive pattern 51 exposed on the back surface of the insulating resin 50 of each block 62, leaving an opening 92 for forming a predetermined back electrode 56. To form a back electrode 56 by applying a creamy brazing material 91 and melting it by heating.
[0057]
In this step, first, as shown in FIG. 7A, a resist layer 90 is screen-printed, roll-coated or electrostatically applied on the conductive pattern 51 exposed on the back surface of the insulating resin 50 of each block 62 to obtain a desired conductive pattern. An opening 92 having substantially the same size is provided in 51. The resist layer 90 protects the conductive pattern 51 from oxidation and contamination and determines the size of the back electrode 56 to be formed.
[0058]
Next, a creamy brazing material 91 is similarly attached to the resist layer 90 including the opening 92 by screen printing to the same size. As the creamy brazing material 91, a solder cream in which solder particles are mixed with an organic solvent is used. Since the creamy brazing material 91 is attached more than the opening 92, the accuracy of the screen printing is not required, and the soldering material 91 is attached to the opening 92 of all the mounting portions 65 for each block 62 with good workability. The size, especially the height, of the back electrode 56 is determined by the size of the creamy brazing material 91. Since the opening 92 is immediately covered with the creamy brazing material 91, the conductive pattern 51 is protected from oxidation.
[0059]
Further, in this step, as shown in FIG. 7B, the cream-like brazing material 91 is heated and melted through the heating furnace in which each block 62 is supplied with a nitrogen gas to form the back electrode 56. Since the back surface electrode 56 has a creamy brazing material 91 of the same size as the opening 92 of the same size previously attached thereto, the entire size is uniform. When the back electrode 56 for obtaining a current capacity is formed, a plurality of back electrodes of the same size are preferably provided on the desired conductive pattern 51 at a distance.
[0060]
Therefore, after dicing, the final structure shown in FIG. 8 is obtained. That is, a conductive material such as solder is applied to the exposed conductive pattern 51 to form the back electrodes 56A, 56B and 56C, and the circuit device is completed. Since the circuit device 53 of the present invention does not have a step unlike the conventional back electrodes 10 and 11 shown in FIG. 13, it has a feature that it can be horizontally moved as it is by the surface tension of solder or the like during mounting and can be self-aligned.
[0061]
In the sixth step of the present invention, as shown in FIG. 9, a plurality of blocks 62 are attached to an adhesive sheet 80 by bringing an insulating resin into contact therewith.
[0062]
After the back surface etching of the conductive foil 60, each block 62 is separated from the conductive foil 60. Since the block 62 is connected to the remaining portion of the conductive foil 60 by the insulating resin 50, it can be achieved by mechanically peeling off the remaining portion of the conductive foil 60 without using a cutting die.
[0063]
In this step, the periphery of the pressure-sensitive adhesive sheet 80 is attached to a stainless steel ring-shaped metal frame 81, and four blocks 62 are provided at the center portion of the pressure-sensitive adhesive sheet 80 with an interval such that a blade does not hit during dicing. The insulating resin 50 is abutted and affixed. As the adhesive sheet 80, a UV sheet (manufactured by Lintec Corporation) is used. Since each block 62 is made of the insulating resin 50 and has mechanical strength, an inexpensive dicing sheet can be used.
[0064]
In the seventh step of the present invention, as shown in FIG. 10, the characteristic of the circuit element 52 of each mounting portion 65 of each block 62 which is collectively molded with the insulating resin 50 while being attached to the adhesive sheet 80 is used. Measurement.
[0065]
As shown in FIG. 10, the back surface electrodes 56 of the conductive patterns 51 are exposed on the back surface of each block 62, and the mounting portions 65 are arranged in a matrix exactly the same as when the conductive patterns 51 were formed. A probe 68 is applied to the back surface electrode 56 exposed from the insulating resin 50 of the conductive pattern 51, and the characteristic parameters and the like of the circuit elements 52 of each mounting portion 65 are individually measured to determine good or bad, and a defective product is determined. Performs marking with magnetic ink or the like.
[0066]
In FIG. 10, in order to show the relationship between the back electrode 56 and the conductive pattern 51, a portion painted in black indicates the conductive pattern 51, and a white circle indicates the back electrode 56, but in actuality, The portion other than the opening 92 of the pattern 51 is covered with a resist layer 90.
[0067]
In this step, since the circuit devices 53 of the respective mounting portions 65 are integrally supported by the insulating resin 50 for each block 62, they are not individually separated. Therefore, the plurality of blocks 62 stuck on the adhesive sheet 80 are vacuum-adsorbed to the mounting table of the tester, and the pitch feed is performed for each block 62 in the vertical and horizontal directions by the size of the mounting portion 65 as indicated by arrows. By doing so, the measurement of the circuit devices 53 of the respective mounting portions 65 of the block 62 can be performed very quickly in large quantities. That is, it is not necessary to determine the front and back sides of the circuit device and to recognize the positions of the electrodes, which are required in the related art. Further, since a plurality of blocks 62 are processed at the same time, the measurement time can be greatly reduced.
[0068]
In the eighth step of the present invention, as shown in FIG. 11, the insulating resin 50 of the block 62 is separated for each mounting portion 65 by dicing while being attached to the adhesive sheet 80.
[0069]
In this step, the plurality of blocks 62 stuck on the adhesive sheet 80 are sucked in vacuum on a mounting table of a dicing device, and the dicing blade 69 is used to insulate the separation grooves 61 along the dicing lines 70 between the mounting portions 65. The conductive resin 50 is diced and separated into individual circuit devices 53.
[0070]
In this step, the dicing blade 69 completely cuts the insulating resin 50, performs dicing at a cutting depth reaching the surface of the pressure-sensitive adhesive sheet, and completely separates each mounting portion 65. At the time of dicing, the positioning mark 67 inside the frame-shaped pattern 66 around each block previously provided in the first step is recognized, and dicing is performed based on this. As is well known, in dicing, after dicing all dicing lines 70 in the vertical direction, the mounting table is rotated by 90 degrees and dicing is performed according to the dicing lines 70 in the horizontal direction.
[0071]
Further, in this process, since only the insulating resin 50 filled in the separation groove 61 is present in the dicing line 70, the dicing blade 69 has a small amount of wear and does not generate metal burrs. .
[0072]
Further, even after this step and after dicing, the adhesive sheet 80 does not disintegrate into individual circuit devices due to the function of the pressure-sensitive adhesive sheet 80, so that the subsequent taping step can be performed efficiently. In other words, the circuit device integrally supported by the adhesive sheet 80 can identify only non-defective products and can be detached from the adhesive sheet 80 and accommodated in the accommodating hole of the carrier tape. For this reason, there is a feature that even a minute circuit device is not separated into pieces even before taping.
[0073]
【The invention's effect】
In the present invention, the conductive foil itself, which is the material of the conductive pattern, functions as a support substrate, and the whole is supported by the conductive foil until the separation groove is formed, the circuit element is mounted, and the insulating resin is attached. When the foil is separated as each conductive pattern, the insulating resin functions as a supporting substrate. 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, there is no need for a supporting substrate, the conductive pattern is embedded in the insulating resin, and the thickness of the insulating resin and the conductive foil can be adjusted, so that a very thin circuit device can be formed. There is also.
[0074]
Further, in the present invention, there is an advantage that the back electrode can be formed for each block by screen printing of a resist layer and a creamy brazing material, and a back electrode having a uniform size can be formed.
[0075]
Further, by adhering a plurality of blocks to the pressure-sensitive adhesive sheet 80, a minute circuit device can be processed without falling apart, and a manufacturing method with extremely high mass production effect can be realized.
[0076]
Further, as is apparent from FIG. 15, the step of forming a through-hole, the step of printing a conductor (in the case of a ceramic substrate), and the like can be omitted, so that the manufacturing process can be significantly shortened compared to the related art, and the entire process can be internally manufactured. Having. In addition, no frame mold is required at all, and this is a manufacturing method with a very short delivery time.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a manufacturing flow 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 method for manufacturing 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 mounting structure of a conventional circuit device.
FIG. 13 is a diagram illustrating a conventional circuit device.
FIG. 14 is a diagram illustrating a method for manufacturing a conventional circuit device.
FIG. 15 is a diagram illustrating a conventional method for manufacturing a circuit device.
[Explanation of symbols]
Reference Signs List 50 insulating resin 51 conductive pattern 52 circuit element 53 circuit device 61 separation groove 62 block 80 adhesive sheet 90 resist layer 91 creamy brazing material

Claims (17)

A sheet-shaped conductive foil is prepared, and a connecting portion is provided around the block so that a plurality of blocks can be arranged apart from each other. Except for a conductive pattern forming at least a large number of circuit element mounting portions in each block. Forming a separation groove shallower than the thickness of the conductive foil in the conductive foil in a region to form a conductive pattern for each block,
Fixing a circuit element to each mounting portion of the conductive pattern of each block ;
A step of collectively covering the circuit elements of the respective mounting portions of the respective blocks, and performing a common molding with an insulating resin so as to be filled in the separation grooves;
Etching the conductive foil to expose and electrically separate the conductive pattern of each block from the back surface, and to take out the insulating resin of each block in a state where the insulating resin is connected at a connection portion of the conductive foil; ,
A creamy brazing material is adhered on the conductive pattern exposed on the back surface of the insulating resin of each block while the insulating resin of each block remains connected at the connecting portion of the conductive foil. Process and
A portion of the common molded block where the insulating resin is connected to the remaining portion of the conductive foil is peeled off from the remaining portion of the conductive foil without cutting the remaining portion of the conductive foil. Separating,
Separating the insulating resin of the block into individual circuit devices by dicing . A sheet-shaped conductive foil is prepared, and a connecting portion is provided around the block so that a plurality of blocks can be arranged apart from each other. Except for a conductive pattern forming at least a large number of circuit element mounting portions in each block. Forming a separation groove shallower than the thickness of the conductive foil in the conductive foil in a region to form a conductive pattern for each block,
Fixing a circuit element to each mounting portion of the conductive pattern of each block ;
Forming connection means for electrically connecting the electrodes of the circuit elements of the respective mounting portions and the desired conductive pattern;
A step of collectively covering the circuit elements of the respective mounting portions of the respective blocks, and performing a common molding with an insulating resin so as to be filled in the separation grooves;
Etching the conductive foil to expose and electrically separate the conductive pattern of each block from the back surface, and to take out the insulating resin of each block in a state where the insulating resin is connected at a connection portion of the conductive foil; ,
A creamy brazing material is adhered on the conductive pattern exposed on the back surface of the insulating resin of each block while the insulating resin of each block remains connected at the connecting portion of the conductive foil. Process and
A portion of the common molded block where the insulating resin is connected to the remaining portion of the conductive foil is peeled off from the remaining portion of the conductive foil without cutting the remaining portion of the conductive foil. Separating,
Method of manufacturing a circuit device characterized by comprising the step of separating the individual circuit device by the insulating resin dicing, dicing of the block. The method according to claim 1, wherein the conductive foil is made of one of copper, aluminum, and iron-nickel. 3. The method according to claim 1, wherein the surface of the conductive foil is at least partially covered with a conductive film. The method according to claim 4, wherein the conductive film is formed by plating with nickel, gold, or silver. 3. The method according to claim 1, wherein the isolation groove selectively formed in the conductive foil is formed by chemical or physical etching. 3. The method according to claim 1, wherein one or both of a semiconductor bare chip and a chip circuit component are fixed to the circuit element. 3. The method according to claim 2, wherein the connection unit is formed by wire bonding. 3. The method according to claim 1, wherein the insulating resin is commonly molded for each block by transfer molding. 3. The circuit device according to claim 1, wherein a plurality of blocks in which a plurality of conductive patterns for forming at least a plurality of circuit element mounting portions are arranged in a matrix on the conductive foil. Method. 11. The method according to claim 10, wherein the insulating resin is formed by simultaneously transfer molding all the blocks of the conductive foil. 3. The method according to claim 1, wherein an opening of a resist layer for forming a predetermined back electrode is formed on the conductive pattern. The method according to claim 12 , wherein the resist layer is applied by screen printing, a roll coater, or electrostatic coating. The method according to claim 1, wherein the creamy brazing material is attached by screen printing. 15. The method according to claim 14 , wherein a solder cream is used as the creamy brazing material. 13. The method according to claim 12 , wherein the cream-shaped brazing material is attached to the resist layer so as to be larger and the same size as the opening of the resist layer, and to make the size of the back electrode uniform. A connecting portion is provided around the block so that a plurality of blocks can be spaced apart from each other, and the conductive foil is formed on the conductive foil in a region excluding a conductive pattern in which at least a large number of circuit element mounting portions are formed in each block. A step of preparing a sheet-like conductive foil in which a conductive pattern for each block is formed by forming a separation groove shallower than the thickness of
  Fixing a circuit element to each mounting portion of the conductive pattern of each block;
  A step of collectively covering the circuit elements of the respective mounting portions of the respective blocks, and performing a common molding with an insulating resin so as to be filled in the separation grooves;
  Etching the conductive foil to expose and electrically separate the conductive pattern of each block from the back surface, and take out the insulating resin of each block in a state where the insulating resin is connected at a connection portion of the conductive foil; ,
  A creamy brazing material is adhered on the conductive pattern exposed on the back surface of the insulating resin of each block while the insulating resin of each block is connected at the connecting portion of the conductive foil. Process and
  A portion of the common molded block where the insulating resin is connected to the remaining portion of the conductive foil is peeled off from the remaining portion of the conductive foil without cutting the remaining portion of the conductive foil. Separating,
  Separating the insulating resin of the block into individual circuit devices by dicing.

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