JP2007036015A - Circuit device and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a circuit device for optimizing the shape of a groove for preventing a jointing material, such as solder, from flowing out, and to provide a manufacturing method of the circuit device. <P>SOLUTION: Conductive patterns 11A-11I are provided in the circuit device 10, and circuit elements, such as a transistor 12D, are stuck to the conductive patterns via the jointing material 19. Then, the groove 14 is provided on the main surface of the conductive patterns so that a region where the jointing material 19 is formed is surrounded incompletely. While the back of the conductive patterns 11A-11I is being exposed, the conductive patterns and the circuit element are covered with a sealing resin 16. <P>COPYRIGHT: (C)2007,JPO&amp;INPIT

Description

  The present invention relates to a circuit device in which a circuit element is fixed to a conductive pattern through a bonding material inside the device, and a method for manufacturing the circuit device.

  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. In order to satisfy these conditions, a circuit device called a CSP (Chip Scale Package) having a size equivalent to a built-in semiconductor element has been developed.

  FIG. 9 shows a CSP 66 that employs a substrate 65 as a support substrate and is slightly larger than the chip size. Here, the transistor chip T is mounted on the substrate 65 via a bonding material 75 such as solder.

  A first electrode 67, a second electrode 68, and a die pad 69 are formed on the surface of the substrate 65, and a first back electrode 70A and a second back electrode 70B are formed on the back surface. The first electrode 67 and the first back electrode 70A are connected via the through hole TH. Further, the second electrode 68 and the second back electrode 70B are electrically connected through the through hole TH.

  The transistor chip T is fixed to the die pad 69, and the emitter electrode of the transistor and the first electrode 67 are connected through the thin metal wire 72. Further, the base electrode of the transistor and the second electrode 68 are connected through a thin metal wire 72. A resin layer 73 is provided on the substrate 65 so as to cover the transistor chip T.

  However, in the CSP 66 described above, there is a problem that the melted liquid bonding material 75 flows out from the die pad 69 in the process of mounting the transistor chip T via the bonding material 75. When the bonding material 75 flows out from the die pad 69 to the periphery, there is a possibility that the first electrode 67 or the second electrode 68 and the die pad 69 are short-circuited by the flowing bonding material 75. Furthermore, the amount of the bonding material 75 that contributes to the bonding of the transistor T is reduced, and the connection reliability of the transistor T may be lowered.

  In order to solve these problems, the present applicant has developed a circuit device 100 shown in FIG. 10 (see Patent Document 1 below). FIG. 10A is a plan view of the circuit device 100, and FIG. 10B is a cross-sectional view thereof.

  In the circuit device 100, the semiconductor element 103 is fixed to the upper surface of the die pad 101 via a bonding material 109. A groove 104 that completely surrounds the semiconductor element 103 is provided on the upper surface of the die pad 101. In addition, a large number of bonding pads 102 are provided so as to surround the die pad 101. The semiconductor element 103 and the bonding pad 102 are connected by a thin metal wire 105. Further, an insulating resin 106 is formed so as to cover the semiconductor element 103, the die pad 101, and the bonding pad 102. Further, the back surface of the circuit device 100 is covered with a resist 108. Further, external electrodes 107 made of solder or the like are formed at desired locations on the back surfaces of the die pad 101 and the bonding pad 102.

  The die pad 101 and the bonding pad 102 are separated by a separation groove 106.

In the circuit device 100, the groove 104 is provided in the periphery of the upper surface of the die pad 101, thereby preventing the liquefied bonding material 109 from flowing out to the outside in the process of mounting the semiconductor element 103. That is, when the bonding material 109 flows into the groove 104, the liquid bonding material 109 is prevented from flowing out from the upper surface of the die pad 101. Further, the groove 104 described above has been formed by wet etching.
JP 2004-071898 A

  However, since the groove 104 is formed so as to completely surround the region where the bonding material 109 is formed in the circuit device 100 described above, there is a problem that a large amount of the bonding material 109 flows into the groove 104. When a large amount of the bonding material 109 flows into the groove 104, the amount of the bonding material 109 that contributes to the connection of the semiconductor element 103 is reduced, which causes a problem that the connection reliability of the semiconductor element 103 is lowered.

  Furthermore, there is a problem that the groove 104 formed by wet etching is locally deeply formed. Referring to FIG. 10A, this problem has occurred particularly at the corners of the grooves 104 that are formed in a square shape in plan view. This is because, in the wet etching process for forming the groove 104, the etchant used for etching joins at the corner of the groove 104 arranged in a rectangular shape.

  When the groove 104 is locally deeply formed, the depth of the groove 104 becomes approximately the same as that of the separation groove 106, and there is a problem that the die pad 101 is separated at the position where the groove 104 is formed.

  The present invention has been made in view of such problems, and a main object of the present invention is to provide a circuit device in which the shape of a groove for preventing the outflow of a bonding material is optimized, and a method for manufacturing the circuit device. is there.

  The circuit device of the present invention includes a conductive pattern and a circuit element fixed to the conductive pattern via a bonding material, and a groove that imperfectly surrounds the region to which the bonding material is applied is formed on the conductive pattern. It is provided on the main surface.

  The circuit device manufacturing method of the present invention encloses the conductive pattern in a region to which the bonding material is applied, in the circuit device manufacturing method including the step of fixing the circuit element to the conductive pattern via the bonding material. As described above, grooves are formed discontinuously on the main surface of the conductive pattern.

  Furthermore, the method of manufacturing a circuit device according to the present invention includes a step of forming a conductive pattern in a convex shape by providing a separation groove on a main surface of a conductive foil, and a circuit element via a bonding material applied to the conductive pattern. A step of fixing, a step of forming a sealing resin so that the separation groove is filled and the conductive pattern and the circuit element are covered, and the sealing resin filled in the separation groove is exposed. Removing the conductive foil from the back surface and separating the conductive pattern, and in the step of providing the separation groove, a groove shallower than the separation groove so as to surround a region where the bonding material is applied, It forms discontinuously on the main surface of the conductive foil.

  In the circuit device of the present invention, a groove is provided on the main surface of the conductive pattern so as to incompletely surround the region where the bonding material is applied. Therefore, compared to the background art in which the groove 104 is provided so as to completely surround the bonding material 109, the amount of the bonding material flowing into the groove can be reduced. Accordingly, the amount of the bonding material that contributes to the connection of the circuit elements can be increased, so that the connection reliability of the circuit elements can be ensured.

  Furthermore, in the method for manufacturing a circuit device according to the present invention, the groove is formed so as to completely surround the region to which the bonding material is applied, so that the etchant concentration is suppressed in the wet etching process, and the etching is substantially omitted. It can be performed uniformly. Therefore, the depth of the groove formed by wet etching can be made substantially uniform.

  Furthermore, in the present invention, by making the groove depth uniform, the groove depth can be made sufficiently shallow with respect to the separation groove. From this, it is possible to prevent the conductive pattern from being separated at the location where the groove is formed.

<First Embodiment>
In the present embodiment, the configuration of the circuit device 10 of the present invention will be described with reference to FIG. 1A is a plan view of the circuit device 10, and FIG. 1B is a cross-sectional view taken along the line BB ′ of FIG. 1A. FIG. 1C is a cross-sectional view taken along the line CC ′ of FIG.

  Referring to FIGS. 1A and 1B, in circuit device 10, conductive patterns 11A to 11I are provided, and circuit elements such as transistor 12D are interposed through bonding material 19 in these conductive patterns. It is fixed. And the groove | channel 14 is provided in the main surface of the conductive pattern so that the area | region in which the bonding | jointing material 19 is formed may be surrounded incompletely. Further, these conductive patterns and circuit elements are covered with the sealing resin 16 with the back surfaces of the conductive patterns 11 </ b> A to 11 </ b> I being exposed. Each of these components will be described below.

  The conductive patterns 11 </ b> A to 11 </ b> I are made of a metal such as copper (Cu) and are embedded in the sealing resin 16 with the back surface exposed. The conductive patterns 11A, 11B, 11C, and 11D are located at the four corners of the circuit device 10 and have a die pad shape. Conductive patterns 11E, 11F, 11G, and 11I are formed between the conductive patterns 11A to 11D. The respective conductive patterns 11A to 11I are spaced apart at substantially equal intervals by the separation groove 13, and the side surfaces are curved. On the upper surface of the conductive pattern 11, a plating film 20 made of silver (Ag), gold (Au), or the like is formed in a region where circuit elements such as the transistor 12D are mounted. Further, the upper surface of the conductive pattern 11 to which the fine metal wire 15 is connected is also covered with the plating film 20.

  Each of the conductive patterns 11 </ b> A to 11 </ b> I is separated by the separation groove 13. The width W1 of the separation groove 13 is, for example, about 125 μm to 150 μm. The depth of the separation groove 13 is about 60 μm.

  A circuit element such as a transistor 12 </ b> D is mounted on the conductive pattern 11 via a bonding material 19. As a circuit element mounted on the conductive pattern 11, both an active element and a passive element can be employed. Specifically, transistors, diodes, ICs, system LSIs, capacitors, resistors, and the like can be used as circuit elements.

  As the bonding material 19 used for fixing the circuit elements, a conductive material such as lead eutectic solder, lead-free solder, or conductive paste is employed. Furthermore, an insulating adhesive made of an epoxy resin or the like can be used as the bonding material 19.

  On the upper surfaces of the conductive patterns 11B, 11C, and 11D, a diode 12B, a diode 12C, and a transistor 12D are mounted via a bonding material 19, respectively. Discontinuous grooves 14 are provided on the upper surfaces of these conductive patterns in order to prevent the bonding material 19 from flowing out.

  Providing the groove 14 prevents the liquid or semi-solid bonding material 19 from flowing out from the upper surface of the conductive pattern in the process of mounting circuit elements such as the transistor 12D using the bonding material 19. can do. Specifically, even if the liquefied bonding material 19 tries to spread around, the bonding material 19 flows into the grooves 14, thereby preventing the bonding material 19 from spreading. Therefore, the bonding material 19 does not leak from the upper surface of the conductive pattern. The detailed configuration of the groove 14 will be described below.

  The sealing resin 16 seals the whole by exposing the back surfaces of the conductive patterns 11A to 11I. Further, the sealing resin 16 is filled in the grooves 14 formed on the surface of the conductive pattern. Here, the sealing resin 16 seals circuit elements such as the chip element 12A, the fine metal wires 15, and the conductive patterns 11A to 11I. As the material of the sealing resin 16, a thermosetting resin formed by transfer molding or a thermoplastic resin formed by injection molding can be used.

  The resist 18 is formed so as to cover the lower surface of the sealing resin 16 and the lower surface of the conductive pattern 11. Further, the conductive pattern in the region where the external electrode 17 made of solder or the like is formed is exposed from the resist 18.

  In this embodiment, the grooves 14 are provided on the surface of the conductive pattern 11 to prevent the bonding material 19 used for mounting circuit elements from flowing out. This will be described in detail by taking the conductive pattern 11D shown in FIGS. 1A and 1B as an example.

  The transistor 12D is fixed to the upper surface of the conductive pattern 11D through the bonding material 19. A discontinuous groove 14 is formed on the surface of the conductive pattern 11D so as to surround a region where the transistor 12D is mounted. Further, the transistor 12D is connected to the conductive patterns 11F and 11C via the fine metal wire 15.

  Four grooves 14A, 14B, 14C, and 14D extending linearly are formed on the upper surface of the conductive pattern 11D. The grooves 14 </ b> A, 14 </ b> B, 14 </ b> C, 14 </ b> D are arranged so as to form a quadrangle as a whole, and are discontinuous at the corner 21. That is, the grooves 14A, 14B, 14C, and 14D are independent and are not in a continuous state.

  The size of the groove 14 is smaller than the separation groove 13 provided between the conductive patterns. That is, the width W2 of the groove 14 is, for example, about 30 μm and is narrower than the separation groove 13. Further, the depth of the groove 14 is about 20 μm, which is shallower than the separation groove 13.

  In addition, discontinuous grooves 14 are formed on the upper surfaces of the conductive patterns 11B and 11C so as to surround the diodes 12B and 12C, similarly to the conductive pattern 11D.

  Thus, by forming the grooves 14 discontinuously, the total length of the grooves 14 can be shortened as compared with the background art in which the grooves are continuously provided so as to surround the circuit elements. Therefore, the amount of the bonding material 19 flowing into the groove 14 is reduced, and the amount of the bonding material 19 positioned between the transistor 12D and the conductive pattern 11D is increased. As a result, since the bonding material 19 below the transistor 12D can be thickened, the connection reliability of the transistor 12D can be improved.

  Further, the grooves 14 are arranged in a quadrangular (polygonal) shape as a whole, and the corners 21 are discontinuous, thereby making the depth of the grooves 14 formed by wet etching substantially uniform. Can do. Therefore, since the groove 14 is not locally formed deeply, the depth of the groove 14 in all portions can be formed sufficiently shallow with respect to the separation groove 13. From this, it is possible to prevent separation at an unnecessary portion of the conductive pattern 11D due to the groove 14 reaching the bottom of the conductive pattern 11D. The matter in which the depth of the groove 14 becomes substantially uniform will be described later with reference to FIG. Here, the overall shape of the groove 14 may be a polygon other than a quadrangle.

  Next, referring to FIG. 1C, a description will be given of the groove 14 formed at a location where the chip element 12A is mounted.

  Here, one electrode of the chip element 12 </ b> A is fixed to the conductive pattern 11 </ b> A via the bonding material 19. Further, the other electrode of the chip element 12 </ b> A is fixed to the conductive pattern 11 </ b> F via the bonding material 19. On the upper surfaces of the conductive patterns 11A and 11F, a groove 14 is formed so as to surround a region to which the bonding material 19 used for fixing the chip element 12A is applied. Again, as described above, the grooves 14 are formed discontinuously.

  By forming the grooves 14 discontinuously, the amount of the bonding material 19 flowing into the grooves 14 can be reduced. Therefore, it is possible to secure a sufficient amount of the bonding material 19 for forming fillets at both ends of the chip element 12A, and to improve the connection reliability.

  Further, referring to FIG. 1A, in the conductive pattern 11F, by providing the groove 14, the bonding material 19 used for fixing the chip element 12A flows into the bonded portion of the thin metal wire 15. Is prevented.

  In the present embodiment, the circuit device 10 having a shape in which the conductive pattern 11 is embedded in the sealing resin 16 has been described as an example. However, the present embodiment can also be applied to other types of circuit devices. is there. For example, the present embodiment can be applied to a circuit device using the substrate 65 as shown in FIG. In this case, the grooves 14 are discontinuously formed on the upper surface of the die pad 69 so as to surround the bonding material 75 applied to the die pad 69. Further, the present embodiment can be applied to a circuit device having a multilayer conductive pattern of two or more layers.

<Second Embodiment>
Next, a method for manufacturing the circuit device 10 will be described with reference to FIGS.

First Step: See FIGS. 2 to 4 In this step, the separation grooves 13 and the grooves 14 are formed on the surface of the conductive foil 40 by wet etching. By providing the separation groove 13, the convex conductive pattern 11 is formed on the surface of the conductive foil 40. The groove 14 is formed in order to prevent the bonding material used for fixing the circuit element in the subsequent process from flowing out.

  With reference to FIG. 2, first, the upper surface of the conductive foil 40 is covered with an etching resist 41. 2A is a cross-sectional view of the conductive foil 40, FIG. 2B is a plan view showing the entire conductive foil 40, and FIG. 2C is a plan view in which a part of the conductive foil 40 is enlarged. .

  Referring to FIG. 2A, the material of the conductive foil 40 is selected in consideration of the adhesiveness of the brazing material, and the like. The conductive foil mainly made of Cu, the conductive foil mainly made of Al, or Fe- A conductive foil made of an alloy such as Ni is employed. The thickness of the conductive foil 40 is such that the separation groove 13 and the groove 14 can be formed in a later step, and is, for example, about 100 μm to 300 μm.

  The upper surface of the conductive foil 40 is covered with a resist 41 that is an etching mask. Here, the resist 41 is patterned so that a portion of the conductive foil 40 that becomes a conductive pattern in a later step is selectively covered. Specifically, openings 48 and 49 are provided in the resist 41, and the upper surface of the conductive foil 40 is exposed from these openings. The opening 49 is provided to form the separation groove 13 indicated by a dotted line, and its width W3 is about 100 μm to 150 μm. The opening 48 is provided in order to form the relatively shallow groove 14, and its width W4 is about 15 μm to 20 μm.

  As described above, by sufficiently narrowing the width of the opening 48 with respect to the opening 49, the depth of the groove 14 formed from the opening 48 is made larger than that of the separation groove 13 formed from the opening 49. Can be shallow. Therefore, it is possible to prevent the conductive pattern from being separated from the portion where the groove 14 is provided in the step after separating each conductive pattern (not shown) at the portion where the separation groove 13 is provided. . This matter will be described in detail with reference to FIG.

  Referring to the plan view of FIG. 2B, 4 to 5 blocks 42 in which a large number of circuit device portions 45 are formed are arranged on the strip-shaped conductive foil 40 so as to be spaced apart. One block 42 includes a plurality of circuit device sections 45 arranged in a matrix. Here, the circuit device unit 45 refers to a part constituting one circuit device.

  Moreover, the slit 43 is provided between each block 42, and the stress of the electrically conductive foil 40 which generate | occur | produces by heat processing at a molding process etc. is absorbed. Index holes 44 are provided at regular intervals at the upper and lower circumferential ends of the conductive foil 40, and are used for positioning in each step. The slit 43 and the index hole 44 are provided through the conductive foil 40 in the thickness direction, and can be formed simultaneously with the separation groove 13 and the like by etching in this step.

  With reference to FIG. 2C, resists 41A to 41I formed in one circuit device unit 45 will be described. In the circuit device section 45, resists 41A to 41I having the same shape as the conductive patterns 11A to 11I shown in FIG. 1 are formed. An opening 49 is provided between the resists 41A to 14I.

  Further, a narrow opening 48 is formed in the resist 41D and the like corresponding to the groove 14 shown in FIG. In order to form the groove 14 having a discontinuous shape, the opening 48 is also formed discontinuously. Specifically, referring to the resist 41D, the linear openings 48A, 48B, 48C, 48D are arranged so as to form a quadrangular shape as a whole, and are discontinuous at the corners. In the other resists 41A, 41B, 41C, and 41F, the opening 48 having the same shape is formed.

  Next, referring to FIG. 3, the conductive foil 40 is wet-etched using a resist 41. 3A is a cross-sectional view of the conductive foil 40 in this step, FIG. 3B is a plan view of the conductive foil 40, and FIG. 3C is an enlarged view of one circuit device portion 45. It is a top view.

  Referring to FIG. 3A, in this step, wet etching is performed by showering the etchant on conductive foil 40 using nozzle 50. Here, showering is performed from above the conductive foil 40 using the nozzle 50, but showering may be performed from below the conductive foil 40. Alternatively, wet etching may be performed by immersing the conductive foil 40 in an etchant.

  With reference to FIGS. 3B and 3C, the etchant showered from the nozzle 50 flows on the surface of the conductive foil 40. In FIG. 3B, the etchant flow F is indicated by arrows. As the etchant flows on the surface of the conductive path 40, the etching of the conductive foil 40 exposed from the resist 41 proceeds.

  The flow of the etchant will be described in detail with reference to the enlarged view of FIG. 3C. On the upper surface of the conductive foil 40, the etchant flows preferentially along the opening of the resist 41. Here, the flow of the etchant flowing along the openings 49 provided between the resists 41 is indicated by an arrow F1. As the etching progresses, a separation groove 13 (not shown) is gradually formed below the opening 49. The separation groove 13 formed gradually deeper also functions as a path for the etchant to flow.

  Similarly to the above, the etchant flows along the openings 48A to 48D formed in the resist 41D. Here, the flow of the etchant that flows to the right along the opening 48A is indicated by an arrow F2. Further, the flow of the etchant flowing upward along the opening 48B is indicated by an arrow F3. In this embodiment, in the corner portion 21, the opening 48A and the opening 48B are not continuous but are discontinuous. Therefore, the flow of etchant F2 and F3 do not merge. Further, the etchant flows at a uniform speed along each of the openings 48A to 48D extending linearly. As a result, etching bias due to local concentration of the etchant does not occur, and the etching progresses substantially uniformly from the openings 48A to 48D.

  Further, the slit 43 and the index hole 44 shown in FIG. 3B can also be formed by etching in this step.

  FIG. 4 shows a conductive foil 40 in which the separation groove 13 and the groove 14 are formed by the etching described above. 4A is a cross-sectional view of the conductive foil 40, and FIG. 4B is an enlarged plan view of one block 42.

  Referring to FIG. 4A, by the etching process, a separation groove 13 for projecting the conductive pattern 11 in a convex shape is formed below the opening 49. A groove 14 that is sufficiently shallower than the separation groove 13 is formed below the opening 48. Specifically, the depth D1 of the separation groove 13 is, for example, about 60 μm, and the depth of the groove 14 is about 20 μm.

  4B, in one block 42, four circuit device sections 45 are arranged in a matrix of 2 rows and 2 columns, and the same conductive pattern 11 is provided for each circuit device section 45. ing. A frame-like pattern 46 is provided around the block 42, and an alignment mark 47 for dicing is provided on the inner side slightly apart from the frame-like pattern 46.

  Further, after the etching process is completed, the resist 41 is peeled off. Further, a plating film 20 made of silver (Ag) or the like is formed on the surface of the conductive pattern 11 in a region where a circuit element is mounted in a later step and a region where a thin metal wire is connected.

Second Step: See FIGS. 5 and 6 In this step, circuit elements such as a transistor 12D are mounted on the conductive pattern 11 and are electrically connected.

  First, referring to FIG. 5, a circuit element such as a transistor 12 </ b> D is fixed to the surface of the conductive pattern 11 using a bonding material 19 such as solder. FIG. 5A is a cross-sectional view showing this step, and FIG. 5B is a plan view.

  As the bonding material 19 used for mounting the transistor 12D and the like, solder, a conductive paste, or an insulating adhesive can be used. As the solder, lead eutectic solder or lead-free solder is used. When solder is employed as the bonding material 19, first, a solder cream (not shown) is applied to the surface of the conductive pattern 11, and then a circuit element such as a transistor 12 </ b> D is placed on the solder cream. Thereafter, the solder cream is heated and melted by a reflow process. Through these steps, the circuit element is mounted on the conductive pattern 11 using the bonding material 19 made of solder.

  In this embodiment, since the groove 14 is provided so as to surround the region where the bonding material 19 is provided, the liquid or semi-solid bonding material 19 flows out from the upper surface of the conductive pattern 11 into the separation groove 13. Can be prevented.

  Specifically, referring to FIG. 5A, in this step, the bonding material 19 is in a liquid or semi-solid state. Therefore, when the transistor 12D is placed on the bonding material 19, the bonding material 19 tends to spread around due to the weight of the transistor 12D. Therefore, in this embodiment, the groove 14 is provided so as to surround the region where the bonding material 19 is applied (the region where the transistor 12D is placed). Therefore, the bonding material 19 that tries to spread to the periphery is prevented from spreading by flowing into the groove 14, and does not flow out from the upper surface of the conductive pattern 11 to the separation groove 13.

  If the bonding material 19 flows out into the separation groove 13, even if the conductive foil 40 is etched from the back surface and the respective conductive patterns 11 are separated in a later step, the bonding material 19 that has flowed into the separation groove 13 The conductive patterns 11 are short-circuited. In particular, when solder is used as the bonding material 19, the heat-melted solder is in a liquid state, so that there is a high risk of flowing out. In this embodiment, since the groove 14 is provided to prevent the bonding material 19 from flowing out, the conductive patterns 11 can be reliably separated at the location where the separation groove 13 is provided in a later step. .

  In the conductive patterns 11A and 11F to which the chip element 12A is fixed, a groove 14 is formed so as to surround the bonding material 19 attached to the electrode of the chip element 12A. Further, in the conductive pattern 11F, the bonding material 19 used for fixing the chip element 12A can be prevented from reaching the plating film 20 by the action of the groove 14 of this embodiment. In addition, when solder is used as the bonding material 19, it is possible to prevent the flux contained in the solder cream from reaching the plating film 20 by the grooves 14.

  Furthermore, in this embodiment, as described above, the grooves 14A to 14D formed on the upper surface of the conductive pattern 11D are formed discontinuously. Therefore, as compared with the background art in which the groove 104 (see FIG. 10) is formed completely continuously, the amount of the bonding material 19 flowing into the groove 14 even when the bonding material 19 flows into all the grooves 14A to 14D. Can be reduced. Therefore, the connection reliability of the transistor 12D can be improved by increasing the amount of the bonding material 19 positioned between the transistor 12D and the conductive pattern 11D.

  Next, referring to FIG. 6, the circuit element such as the transistor 12 </ b> D and the conductive pattern 11 are electrically connected using the thin metal wire 15. FIG. 6A is a cross-sectional view showing this step, and FIG. 6B is a plan view.

  Specifically, referring to FIG. 6B, the electrode formed on the upper surface of diode 12B is connected to conductive pattern 11E through thin metal wire 15. The diode 12C is connected to the conductive pattern 11I through the metal thin wire 15. Further, the source electrode of the transistor 12D is connected to the conductive pattern 11F through the fine metal wire 15, and the gate electrode is connected to the conductive pattern 11C.

Third Step: See FIGS. 7 and 8 In this step, the sealing resin 16 is formed so as to cover the circuit elements and the like, and the conductive foils 40 are removed from the back surface to separate the conductive patterns 11. Further, the block 42 is diced to obtain individual circuit devices 10.

  Referring to FIG. 7A, first, a sealing resin 16 is formed so as to cover circuit elements such as the transistor 12D and fill the separation groove 13 and the groove.

  In this step, as shown in FIG. 7A, the sealing resin 16 completely covers the transistor 12D and the plurality of conductive patterns 11. Further, the sealing resin 16 is also filled in the separation groove 13 and the groove 14. Since the side surfaces of the separation groove 13 and the groove 14 have a curved shape formed by etching, they are firmly bonded to the sealing resin 16. This step can be realized by transfer molding, injection molding, or potting. 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.

  Furthermore, when performing transfer molding in this step, as shown in FIG. 7B, the molding is performed in common with one sealing resin 16 for each block 42.

  Next, referring to FIG. 7C, the conductive foil 40 described above is removed from the back surface by etching to separate each conductive pattern 11.

  Specifically, the entire back surface of the conductive foil 40 is wet etched until the sealing resin 16 embedded in the separation groove 13 is exposed downward. In this step, the conductive foil 40 is etched until the thickness D3 of the conductive pattern 11 becomes thinner than the depth D1 of the separation groove 13. Therefore, the sealing resin 16 filled in the separation groove 13 is exposed to the outside from the back surface of the conductive pattern 11. By doing in this way, each conductive pattern 11 can be reliably separated even if the depth of the separation groove 13 is non-uniform. For example, when the depth D1 of the separation groove is about 60 μm, the conductive foil 40 is over-etched so that the thickness D3 of the conductive pattern 11 is as thin as about 40 μm.

  Further, since the groove 14 is sufficiently shallower than the separation groove 13 and formed to a uniform depth, the etching in this step does not reach the groove 14. For example, since the depth of the groove 14 is 20 μm or less, even if a deviation of about ± 10 μm occurs in the depth of the groove 14, the etching in this step that leaves the thickness of the conductive pattern 11 does not reach the groove 14. . Therefore, in this embodiment, there is no problem that the conductive pattern 11 is separated at the location where the groove 14 is formed.

  Furthermore, the bonding material 19 used for bonding the transistor 12D is prevented from flowing out from the upper surface of the conductive pattern 11 by the action of the groove 14 described above. That is, the conductive bonding material 19 does not flow into the separation groove 13. Therefore, each conductive pattern 11 is reliably separated by the etching in this step at the location where the separation groove 13 is provided.

  After the above steps are completed, the back surface treatment of the conductive pattern 11 is performed to obtain, for example, the final structure shown in FIG. That is, the sealing resin 16 and the back surface of the conductive pattern 11 exposed therefrom are covered with the resist 18 (see FIG. 1). Further, the back surface of the conductive pattern 11 is partially exposed from the resist 18 to form an external electrode 17 (see FIG. 1) made of a conductive material such as solder.

  Referring to FIG. 8, next, the circuit device portions 45 are individually separated by dicing the sealing resin 16 of each block 42.

  In this step, the block 42 is vacuum-adsorbed to a mounting table of a dicing device (not shown), and the sealing resin 16 is diced along dicing lines (one-dot chain lines) between the circuit device portions 45 with a dicing blade 49. The circuit device is separated.

  Through the above steps, the circuit device 10 having the structure shown in FIG. 1 is manufactured.

It is a figure which shows the circuit apparatus of this invention, (A) is a top view, (B) is sectional drawing, (C) is sectional drawing. It is a figure which shows the manufacturing method of the circuit apparatus of this invention, (A) is sectional drawing, (B) is a top view, (C) is a top view. It is a figure which shows the manufacturing method of the circuit apparatus of this invention, (A) is sectional drawing, (B) is a top view, (C) is a top view. It is a figure which shows the manufacturing method of the circuit apparatus of this invention, (A) is sectional drawing, (B) is a top view. It is a figure which shows the manufacturing method of the circuit apparatus of this invention, (A) is sectional drawing, (B) is a top view. It is a figure which shows the manufacturing method of the circuit apparatus of this invention, (A) is sectional drawing, (B) is a top view. It is a figure which shows the manufacturing method of the circuit apparatus of this invention, (A) is sectional drawing, (B) is a top view, (C) is sectional drawing. It is a top view which shows the manufacturing method of the circuit apparatus of this invention. It is sectional drawing which shows the conventional circuit apparatus. It is a figure which shows the conventional circuit device, (A) is a top view, (B) is sectional drawing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Circuit apparatus 11 Conductive pattern 11A-11F Conductive pattern 12 Circuit element 12A Chip element 12B, 12C Diode 12D Transistor 13 Separation groove 14 Groove 15 Metal fine wire 16 Sealing resin 17 External electrode 18 Resist 19 Bonding material 20 Plated film 21 Corner 40 Conductive foil 41 Resist 42 Block 43 Slit 44 Index hole 45 Circuit device part 46 Pattern 47 Alignment mark 48, 49 Opening part 50 Nozzle

Claims (14)

A conductive pattern;
Comprising a circuit element fixed to the conductive pattern via a bonding material,
A circuit device, wherein a groove that incompletely surrounds a region to which the bonding material is applied is provided on a main surface of the conductive pattern.   The circuit device according to claim 1, wherein the grooves arranged to form a polygon on the main surface of the conductive pattern are discontinuous at corners. By the plurality of grooves formed in a straight line,
The circuit device according to claim 1, wherein the circuit device surrounds a region to which the bonding material is applied.   The circuit device according to claim 1, wherein the groove is formed by wet etching a main surface of the conductive pattern. The circuit element is a semiconductor element;
The back surface of the semiconductor element is fixed to the main surface of the conductive pattern through the bonding material,
2. The circuit device according to claim 1, wherein the grooves arranged in a rectangular shape so as to surround the semiconductor element are discontinuous at corners.   The circuit device according to claim 1, further comprising: a sealing resin that seals the conductive pattern and the circuit element in a state where a back surface of the conductive pattern is exposed.   The circuit device according to claim 1, wherein the bonding material is solder, a conductive paste, or an insulating adhesive. The circuit element is a chip element;
The circuit device according to claim 1, wherein the groove is formed so as to surround a region where a bonding material connected to the electrode of the chip element is formed. In a method of manufacturing a circuit device comprising a step of fixing a circuit element to a conductive pattern through a bonding material,
A method of manufacturing a circuit device, wherein grooves are formed discontinuously on a main surface of the conductive pattern so as to surround the conductive pattern in a region to which the bonding material is applied. A step of forming a conductive pattern in a convex shape by providing a separation groove on the main surface of the conductive foil; a step of fixing a circuit element through a bonding material applied to the conductive pattern; and filling the separation groove; Forming a sealing resin so as to cover the conductive pattern and the circuit element; and removing the conductive foil from the back surface until the sealing resin filled in the separation groove is exposed. Separating, and
In the step of providing the separation groove, a groove shallower than the separation groove is formed discontinuously on the main surface of the conductive foil so as to surround a region where the bonding material is applied. Production method.   11. The method for manufacturing a circuit device according to claim 9, wherein the grooves arranged so as to form a polygon on the main surface of the conductive pattern are discontinuous at corners.   The method of manufacturing a circuit device according to claim 10, wherein the separation groove and the groove are formed by wet etching performed simultaneously. The groove and the separation groove are simultaneously formed by wet etching using an etching mask provided with a first opening and a second opening,
11. The method of manufacturing a circuit device according to claim 10, wherein the width of the first opening in which the groove is formed is narrower than the width of the second separation groove in which the separation groove is formed.   14. The method of manufacturing a circuit device according to claim 13, wherein the first opening is formed in a straight line.

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