JP2015128114A - Multi-piece wiring board and manufacturing method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multi-piece wiring board which is unlikely to cause chips and cracks in wiring board at the time of dicing; and provide a multi-piece wiring board which can form a wiring board having another shape other than a rounded rectangle and a rectangle after being divided by dicing.SOLUTION: A wiring board comprises: an etchable support substrate 1 in which a frame part 4 having an opening 4a to partition a tabular bottom plate 3 into a number of product formation regions X arranged in a matrix is installed on the bottom plate 3 in a protruding manner; an insulation layer 5 which is formed on the bottom plate 3 in each product formation region X and formed to expose a top face of the frame part 4; and a wiring board 2 which is formed on the insulation layer 5 and includes a wiring conductor 6.

Description

  The present invention relates to a multi-piece wiring board formed by arranging a large number of small-sized wiring boards vertically and horizontally and a method for manufacturing the same.

  Conventionally, as a multi-cavity wiring board for CSP (chip size package), a large number of small wiring boards formed by laminating an insulating layer and a metal layer are integrally formed vertically and horizontally on a support substrate made of metal. A multi-cavity wiring board is known.

  In such a multi-cavity wiring board, a semiconductor element is mounted on each small wiring board formed integrally on a support substrate, and a sealing resin layer is provided so as to cover the semiconductor element on substantially the entire upper surface. After forming and then etching away the support substrate, the semiconductor element mounted on the wiring substrate is sealed with a sealing resin by cutting and dividing along the boundary of each small wiring substrate by dicing A large number of small semiconductor devices are manufactured simultaneously.

  However, in the conventional multi-cavity wiring board described above, since the resin layer forming the wiring board is thin and the mechanical strength is low, if the dicing is performed after the support substrate is removed by etching, the wiring is caused by the stress applied during the dicing. The substrate is easily cracked or chipped. In addition, since the multi-piece wiring board and the sealing resin thereon are diced to be divided into small semiconductor devices, the shape of the divided wiring board is limited to a rectangular shape with corners. Therefore, when a wiring board having a square shape with rounded corners or a shape other than a square is required according to the design of the casing of an electronic device in which a semiconductor device having a semiconductor element mounted on the wiring board is accommodated, this requirement is met. It is difficult to respond.

JP 2004-111641 A

  SUMMARY OF THE INVENTION An object of the present invention is to provide a multi-piece wiring board that is less likely to be cracked or chipped when dicing. Furthermore, an object of the present invention is to provide a multi-piece wiring board capable of forming a wiring board having a quadrangular shape with rounded corners or a shape other than a quadrangular shape after being divided by dicing.

  The multi-cavity wiring board according to the present invention includes an etching support substrate formed by projecting a frame portion having openings on a flat bottom plate to divide the bottom plate into a large number of product formation regions arranged vertically and horizontally. An insulating layer formed on the bottom plate in each of the product forming regions and including an insulating layer formed so as to expose the upper surface of the frame portion and a wiring conductor formed on the insulating layer. It is characterized by comprising.

  In the method for manufacturing a multi-piece wiring board according to the present invention, an insulating layer is formed on an etchable plate-like bottom plate having a large number of product formation regions on both sides in the vertical and horizontal directions. 1, a second step of forming a wiring conductor on the insulating layer on each of the product forming regions, and removing the insulating layer around each of the product forming regions, A third step of exposing the top surface of the bottom plate so as to surround the frame, and depositing an etchable plating conductor layer on the exposed top surface of the bottom plate to partition the product formation regions on the bottom plate. And a fourth step of projecting a frame portion having an opening.

  According to the multi-cavity wiring board of the present invention, the insulating layer formed on the bottom plate of each product formation region partitioned by the frame portion of the support substrate so as to expose the upper surface of the frame portion and the insulating layer formed thereon. Since wiring boards including wiring conductors are formed, when a semiconductor element is mounted on each wiring board, a sealing resin layer covering the semiconductor element is formed on substantially the entire upper surface, and then the support substrate is removed by etching. The boundary of each wiring board is formed by a step from which the frame portion is removed, and the wiring board itself does not exist. Therefore, when cutting and dividing along the boundary of each wiring board by dicing, it is only necessary to cut the sealing resin layer, and the wiring board is not cracked or chipped.

  Furthermore, according to the multi-cavity wiring board of the present invention, the shape of the inner periphery of the opening portion of the frame portion is, for example, a square shape with rounded corners or a shape other than a square shape, By forming a wiring board having an outer shape corresponding to the shape of the circumference, a semiconductor element is mounted on each wiring board, and a sealing resin layer covering the semiconductor element is formed on substantially the entire upper surface, and then the support substrate is etched. After removing, by cutting only the sealing resin layer by dicing along the boundary of each wiring board, the sealing resin has a square shape with rounded corners, but the wiring board itself has a square shape or a square shape with rounded corners. Other shapes can be used.

  Further, according to the method for manufacturing a multi-cavity wiring board of the present invention, an insulating layer that extends over a large number of product formation regions is formed on an etchable flat plate-like bottom plate having a large number of product formation regions. Forming a wiring conductor on the insulating layer on each product forming region, then removing the insulating layer around each product forming region, exposing the top surface of the bottom plate so as to surround each product forming region in a frame shape, Next, a plating conductor layer that can be etched is deposited on the exposed upper surface of the bottom plate, and a frame portion having an opening for partitioning each product forming region is projected on the bottom plate, thereby cracking the wiring board when dicing. It is possible to provide a multi-piece wiring board in which chipping and chipping are unlikely to occur. Furthermore, when the insulating layer around the product formation area is removed, if the insulating layer is removed so that the shape of the wiring board formed on the bottom plate is not a quadrangular shape or a square shape with rounded corners, it is divided by dicing. After that, it is possible to provide a multi-piece wiring board capable of forming a wiring board having a rounded corner or a shape other than the square.

1A and 1B are a schematic cross-sectional view showing an example of an embodiment of a multi-cavity wiring board according to the present invention and an exploded perspective view seen from the upper surface side. 2A and 2B are a schematic cross-sectional view showing a state in which a semiconductor element is mounted on the multi-piece wiring board shown in FIGS. 1A and 1B and a perspective view seen from the upper surface side. 3A and 3B are schematic cross-sectional views showing a state in which a sealing resin layer is formed on a multi-piece wiring board on which the semiconductor elements shown in FIGS. 2A and 2B are mounted. It is the perspective view seen from the upper surface side. 4A and 4B are a schematic cross-sectional view and a top view showing a state in which solder bumps are formed on the multi-piece wiring board on which the sealing resin layer shown in FIGS. 3A and 3B is formed. It is the perspective view seen from the side. 5A and 5B are a schematic cross-sectional view showing a state where the support substrate in the multi-piece wiring substrate shown in FIGS. 4A and 4B is removed by etching and a perspective view seen from the lower surface side. is there. 6 (a) and 6 (b) are schematic cross-sectional views showing a state in which the multi-piece wiring board from which the supporting board shown in FIGS. 5 (a) and 5 (b) has been removed is divided by dicing, and viewed from the lower surface side. FIG. FIGS. 7A and 7B are a schematic cross-sectional view and a top view showing a state in which the multi-piece wiring board with the supporting substrate shown in FIGS. 4A and 4B is divided together with the sealing resin layer by dicing. It is the perspective view seen from the side. FIGS. 8A and 8B are a schematic cross-sectional view and a perspective view seen from the upper surface side for explaining the method for manufacturing a multi-piece wiring board of the present invention. 9A and 9B are a schematic cross-sectional view and a perspective view seen from the upper surface side for explaining the method for manufacturing a multi-piece wiring board of the present invention. 10A and 10B are a schematic cross-sectional view and a perspective view seen from the upper surface side for explaining the method for manufacturing a multi-piece wiring board according to the present invention. 11A and 11B are a schematic cross-sectional view and a perspective view seen from the upper surface side for explaining the method for manufacturing a multi-piece wiring board of the present invention. 12A and 12B are a schematic cross-sectional view and a perspective view seen from the upper surface side for explaining the method for manufacturing a multi-piece wiring board of the present invention. FIGS. 13A and 13B are a schematic cross-sectional view and a perspective view seen from the upper surface side for explaining the method for manufacturing a multi-cavity wiring board of the present invention.

  Next, an example of an embodiment of the multi-piece wiring board of the present invention will be described with reference to the accompanying drawings. As shown in FIGS. 1A and 1B, the multi-piece wiring substrate 10 of this example includes a support substrate 1 and a wiring substrate 2 formed on the support substrate 1.

  The support substrate 1 includes a flat bottom plate 3 and a frame portion 4 projecting from the bottom plate 3. The bottom plate 3 has a plurality of product formation regions X on its upper surface, and a frame portion 4 is provided so as to have an opening 4a that partitions the product formation region X. In this example, the inner periphery of the opening 4a has a quadrangular shape with rounded corners. The bottom plate 3 is made of, for example, a copper foil having a thickness of about 100 to 200 μm. The frame part 4 consists of an electrolytic copper plating layer with a thickness of about 20 to 40 μm, for example. In this example, the case where four product forming regions X are provided is shown for the sake of brevity, but a larger number of product forming regions X are actually arranged.

  The wiring substrate 2 is formed on the product forming region X of the support substrate 1 so as to be in close contact with the bottom plate 3 and the inner peripheral surface of the frame portion 4, and the upper surface of the frame portion 4 is exposed. The wiring board 2 includes an insulating layer 5 formed on the bottom plate 3 in the product formation region X, a wiring conductor 6 formed thereon, and a solder resist layer 7 formed thereon.

  The insulating layer 5 is made of an electrically insulating material in which an inorganic insulating filler such as silica is dispersed in a thermosetting resin such as an epoxy resin or a polyimide resin. The thickness of the insulating layer 5 is, for example, about 10 to 30 μm. The wiring conductor 6 is made of, for example, a copper plating layer. The thickness of the wiring conductor 6 is, for example, about 5 to 15 μm.

  The wiring conductor 6 has a semiconductor element connection pad 8 and an external connection pad 9 in a part thereof. These semiconductor element connection pads 8 and external connection pads 9 are exposed to the outside through openings provided in the solder resist layer 7.

  The solder resist layer 7 is made of a photosensitive thermosetting resin such as an acrylic-modified epoxy resin. The thickness of the solder resist layer 7 is about 5 to 15 μm on the wiring conductor 6.

  Here, a manufacturing method of a semiconductor device in which a semiconductor element is mounted on each wiring board 2 and resin-sealed using the multi-cavity wiring board 10 of this example will be described.

  First, as shown in FIGS. 2A and 2B, the semiconductor element S is mounted on each wiring board 2 of the multi-piece wiring board 10. The semiconductor element S is mounted by flip-chip connecting the electrode terminals T of the semiconductor element S to the semiconductor element connection pads 8 of the wiring board 2 via solder.

  Next, as shown in FIGS. 3A and 3B, an opening Ma that covers the semiconductor element S and exposes the external connection pad 9 on the upper surface of the multi-piece wiring substrate 10 on which the semiconductor element S is mounted is formed. An encapsulating resin layer M is formed by a transfer molding method.

  Next, as shown in FIGS. 4A and 4B, solder bumps B are formed on the external connection pads 9 exposed in the openings Ma. The solder bump B is formed by applying a flux in the opening Ma, placing a solder ball thereon, and performing a reflow process.

  Next, as shown in FIGS. 5A and 5B, the support substrate 1 is removed by etching. Since the support substrate 1 is made of copper, it can be easily etched with an etchant containing, for example, ferric chloride or cupric chloride. At this time, the boundary of each wiring board 2 is formed by a step of the trace from which the frame portion 4 is removed. In the step portion, the insulating layer 5, the wiring conductor 6, and the solder resist layer 7 constituting the wiring substrate 2 are not present, and only the sealing resin layer M is present.

  Next, as shown in FIGS. 6A and 6B, the semiconductor element S mounted on the wiring board 2 is resin-sealed by the sealing resin layer M by dicing along the boundary of each wiring board 2. The formed semiconductor device is formed. At this time, since only the sealing resin layer M located at the boundary of the wiring board 2 has to be cut, the wiring board 2 is not cracked or chipped due to dicing stress.

  Further, according to the multi-piece wiring board 10 of the present invention, the inner periphery of the opening 4a of the support substrate 1 has a square shape with rounded corners, and the wiring board 2 is located on the product formation region X of the support substrate 1. Are formed so as to be in close contact with the inner surface of the bottom plate 3 and the opening 4a. Therefore, as described above, the semiconductor element S is mounted on each wiring board 2, and the semiconductor element S is formed on substantially the entire upper surface. In a semiconductor device obtained by forming a sealing resin layer M covering the substrate, and then etching away the support substrate 1 and then cutting only the sealing resin layer M by dicing along the boundaries of the wiring substrates 2. Although the encapsulating resin layer M has a quadrangular shape with corners, the wiring board 2 itself can have a quadrangular shape with rounded corners. Furthermore, the shape of the opening 4a of the frame portion 4 is a shape other than a quadrangle, and the wiring substrate 2 is formed so as to be in close contact with the inner peripheral surface of the opening 4a, thereby obtaining the wiring substrate 2 having a shape other than the quadrangle. Can do.

  In the above-described example, the support substrate 1 of the multi-piece wiring substrate 10 is diced after being removed by etching. However, as shown in FIGS. 7A and 7B, the support substrate 1 of the wiring substrate 10 is left attached. After dicing, the support substrate 1 may be removed by etching from the divided wiring substrate 2.

  Next, a method for manufacturing the multi-piece wiring board 10 described above will be described. First, as shown in FIGS. 8A and 8B, the bottom plate 3 is prepared. The bottom plate 3 has a plurality of product formation regions X on the upper surface thereof. As described above, the bottom plate 3 is made of a copper foil having a thickness of about 100 to 200 μm.

  Next, as shown in FIG. 9, the insulating layer 5 is formed on the entire upper surface of the bottom plate 3. As described above, the insulating layer 5 is made of an electrically insulating material in which an inorganic insulating filler such as silica is dispersed in a thermosetting resin such as an epoxy resin or a polyimide resin, and has a thickness of about 10 to 30 μm. The insulating layer 5 is formed, for example, by sticking an uncured film of an electrically insulating material to the upper surface of the bottom plate 3 by hot pressing and then thermosetting.

  Next, as shown in FIG. 10, the wiring conductor 6 is formed on the upper surface of the insulating layer 5 on each product formation region X. The wiring conductor 6 is made of a copper plating layer having a thickness of about 5 to 15 μm and is formed by a known semi-additive method.

  Next, as shown in FIG. 11, a solder resist layer having openings for exposing a part of the wiring conductor 6 as the semiconductor element connection pad 8 and the external connection pad 9 on the upper surface of the insulating layer 5 on which the wiring conductor 6 is formed. 7 is formed. The solder resist layer 7 is made of a photosensitive thermosetting resin such as an acrylic-modified epoxy resin, and the thickness on the wiring conductor 6 is about 5 to 15 μm. The solder resist layer 7 is formed by applying a photosensitive thermosetting resin paste to the upper surface of the insulating layer 5 on which the wiring conductor 6 is formed so as to completely cover the wiring conductor 6 and drying it, and then performing well-known photo processing. The semiconductor device connection pad 8 and the external connection pad 9 are exposed and developed so as to have an opening for exposing the semiconductor element connection pad 8 and the external connection pad 9, and then thermally cured.

  Next, as shown in FIG. 12, the solder resist layer 7 and the insulating layer 5 around each product formation region X are selectively removed to expose the upper surface of the bottom plate 3 around each product formation region X. For removing the solder resist layer 7 and the insulating layer 5, for example, a sand blast method or a laser scrub method is employed. Thereby, the rectangular wiring board 2 with rounded corners is formed on the bottom plate 3 with a predetermined adjacent interval.

  Next, as shown in FIG. 13, the frame portion 4 is formed around the product formation region X on the upper surface of the bottom plate 3. The frame portion 4 is made of an electrolytic copper plating layer having a thickness of about 20 to 40 μm, and is formed by depositing an electrolytic copper plating layer around the formation region X on the upper surface of the bottom plate 3. At this time, the side surface of each wiring board 2 is wrapped in the deposited copper plating layer and is in close contact with the frame portion 4.

  Thus, according to the method of manufacturing the multi-cavity wiring board 10 of the present invention, the insulating layer that extends over each product formation region X is formed on the bottom plate 3 that can be etched and has a large number of product formation regions X. Next, the wiring conductor 6 is formed on the insulating layer 5 on each product forming region X, and then the insulating layer around each product forming region X is removed so as to surround each product forming region X in a frame shape. The top surface of the bottom plate 3 is exposed, and then a plated conductor layer that can be etched is deposited on the exposed top surface of the bottom plate 3 so that a frame portion 4 having openings 4 for partitioning the product forming regions X is provided on the bottom plate 3. By doing so, it is possible to provide a multi-cavity wiring board in which the wiring board 2 is not easily cracked or chipped when dicing. Furthermore, when the solder resist layer 7 and the insulating layer 5 around each product formation region X are selectively removed to expose the upper surface of the bottom plate 3 around each product formation region X, the top of each product formation region X is exposed. When the solder resist layer 7 and the insulating layer 5 are removed so that the shape of the wiring board 2 formed on the substrate is a quadrangular shape with rounded corners or a shape other than the square shape, the wiring substrate 2 is divided by dicing and then divided into quadrangular shapes or quadrangular shapes with rounded corners. A multi-piece wiring board 10 capable of forming wiring boards 2 having other shapes can be provided.

  Note that the present invention is not limited to the above-described embodiment, and various modifications are possible as long as they do not depart from the gist of the present invention. For example, in the above-described embodiment, the wiring conductor 6 has Although formed by the semi-additive method, it may be formed by a well-known subtractive method. In this case, a copper foil can be used as the wiring conductor 6. In the above-described embodiment, the wiring board 2 is formed with one insulating layer 5 and one wiring conductor 6 each. However, the wiring board 2 may be formed with a multilayer structure in which a plurality of insulating layers 5 and wiring conductors 6 are stacked. good.

DESCRIPTION OF SYMBOLS 1 Support substrate 2 Wiring board 3 Bottom plate 4 Frame part 5 Insulating layer 6 Wiring conductor 7 Solder resist layer X Product formation area

Claims (4)

  An etchable support substrate in which a frame having an opening that divides the bottom plate into a large number of vertical and horizontal product forming regions on the flat plate is projected, and the bottom plate in each product forming region An insulating layer formed on the upper surface of the frame portion to expose the wiring board including a wiring conductor formed on the insulating layer. Wiring board.   2. The multi-cavity wiring board according to claim 1, wherein the inner periphery of the opening has a quadrangular shape with rounded corners or a shape different from the quadrangular shape.   A first step of forming an insulating layer over each of the product forming regions on an etchable plate-like bottom plate having a large number of product forming regions arranged vertically and horizontally, and on the insulating layer on each of the product forming regions; A second step of forming a wiring conductor; and a third step of removing the insulating layer around each product formation region and exposing the upper surface of the bottom plate so as to surround each product formation region in a frame shape, And a fourth step of projecting a frame portion having openings for partitioning the respective product formation regions on the bottom plate by depositing an etchable plating conductor layer on the exposed upper surface of the bottom plate. A method of manufacturing a multi-cavity wiring board,   4. The method for manufacturing a multi-piece wiring board according to claim 3, wherein an inner periphery of the opening is a quadrangular shape with rounded corners or a shape different from the quadrangular shape.

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