JP2011018699A - Electronic circuit unit and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic circuit unit on which exfoliation of solder resist or resin burrs of a substrate material does not pose problems, even if a copper foil land is provided in the vicinity of a corner edge of a circuit board, and to provide a method of manufacturing the circuit unit.SOLUTION: The copper foil land 5 is provided at a corner of the circuit board 2 of the electronic circuit unit, and an approximately L-shaped corner space region 2b extends between a right-angled substrate outer rim 2d that defines the corner and an outwardly swelling outer peripheral rim of the copper foil land 5. The solder resist 6 is provided, only in a relatively wide region in the proximity of the corner edge 2a of the corner space region 2b, and a narrow region separate from the corner edge 2a is made into a substrate exposed region 2c where there is no solder resist. The circuit board 2 is divided into individual pieces, by cutting an assembly board 10 along cut lines 11 and 12. A leg of a shield cover which covers a high-frequency circuit portion on the circuit board 2 is inserted into a fitting hole 5a of the copper foil land 5 and is then soldered.

Description

  The present invention relates to an electronic circuit unit in which electronic components and the like are mounted on a circuit board that is cut into individual pieces by cutting an assembly board, and a method for manufacturing the same, and in particular, a copper foil land is provided at a corner of the circuit board. The present invention relates to a small electronic circuit unit provided and a manufacturing method thereof.

  A small electronic circuit unit having a high-density circuit configuration is formed by collectively providing a plurality of circuit portions corresponding to a plurality of electronic circuit units on the collective substrate, and then cutting the collective substrate into pieces. Productivity is much higher than manufacturing one by one. Therefore, conventionally, when manufacturing this type of electronic circuit unit, wiring patterns, solder resists, etc. are collectively formed in a plurality of rectangular areas partitioned by vertical and horizontal cutting lines (dicing lines) on the collective substrate. In addition, after mounting electronic parts and the like in a lump, a general method is to cut a collective substrate along a cutting line with a dicing saw or the like to obtain a large number of electronic circuit units (for example, Patent Document 1). reference). The circuit board of the electronic circuit unit thus manufactured is a portion corresponding to the rectangular region of the collective board.

  In addition, in this type of electronic circuit unit, when a shield cover that covers a high-frequency circuit is attached to the circuit board, as shown in FIG. 4, copper foil lands 22 are provided at the corners of the circuit board 21. In many cases, the copper foil land 22 is surrounded by the solder resist 23. In FIG. 4, the aggregate substrate 30 before cutting is indicated by a chain line, and the corner edge 21 a of the circuit substrate 21 is formed at the intersection of the vertical and horizontal cutting lines 31, 32 of the aggregate substrate 30. When a substantially L-shaped region sandwiched between a substrate outer edge extending perpendicularly from the corner edge 21a and an outer peripheral edge bulging outward of the copper foil land 22 is referred to as a corner space region 21b of the circuit board 21, this corner Since the space region 21b is not narrow in the immediate vicinity of the corner edge 21a, even if the corner edge 21a is chipped or cracked, it is unlikely that the electrical characteristics of the electronic circuit unit will be adversely affected. In FIG. 4, the outer shape of the copper foil land 22 at the corner of the circuit board 21 is formed in a leaf shape. However, the outer shape of the copper foil land 22 may be circular.

JP 11-186439 A

  By the way, in recent years, the size and density of electronic circuit units have been promoted, and therefore, the corner space region 21b of the circuit board 21 in FIG. 4 tends to be designed to be narrower than before. Therefore, it is easy to generate a region where the distance between the outer edge of the substrate and the copper foil land 22 is considerably narrowed at both ends of the substantially L-shaped corner space region 21b of the circuit board 21, and in such an electronic circuit unit If a slight misalignment occurs in the cutting process along the cutting lines 31 and 32 of the collective substrate 30, there is a problem that the risk of the solder resist 23 peeling off at both ends of the corner space region 21b increases. That is, the solder resist 23 that surrounds the copper foil land 22 on the circuit board 21 tends to have insufficient adhesion strength in a region where the contact area with the substrate surface is narrow. Therefore, the cutting line 31 (or 32) and the copper foil In places where the distance from the land 22 is narrow, the solder resist 23 is easily peeled off when the actual cutting position by a dicing saw or the like is slightly shifted to the copper foil land 22 side.

  In the case of an electronic circuit unit in which the corner space region 21b of the circuit board 21 is designed to be extremely narrow from the beginning, the solder resist 23 is easily peeled off even if misalignment in the cutting process is prevented.

  Therefore, the present inventors have made the corner space region 21b into the solder resist 23 as shown in FIG. 5 in order to prevent peeling of the solder resist 23 in the cutting process even if the corner space region 21b of the circuit board 21 is narrow. I tried to be a substrate exposure area that does not exist. However, if this is done, resin burrs of the substrate material can be easily formed in the vicinity of the intersection of the cutting lines 31 and 32 in the cutting process of the collective substrate 30, and bowl-shaped resin burrs are formed in the vicinity of the corner edges 21 a of the individual circuit boards 21. It has been found that another problem arises that the appearance of a commercialized electronic circuit unit tends to be damaged.

  The present invention has been made in view of such a situation of the prior art. The first object of the present invention is to remove the solder resist and to remove the resin burrs of the board material even if a copper foil land is provided near the corner edge of the circuit board. It is to provide an electronic circuit unit that does not cause a problem. A second object of the present invention is to provide a method of manufacturing an electronic circuit unit that can manufacture such an electronic circuit unit from a collective substrate without increasing the number of steps.

  In order to achieve the first object described above, the present invention comprises a rectangular circuit board separated by cutting a collective board along vertical and horizontal cutting lines, and corners of the circuit board are provided. In an electronic circuit unit in which a substantially L-shaped corner space region extends between a rectangular substrate outer edge to be partitioned and an outer peripheral edge bulging outward of a copper foil land provided at the corner, In the corner space region, the region excluding the narrow end portions is covered with a solder resist, and the both end portions are formed as substrate exposed regions where no solder resist exists.

  As described above, the solder resist is provided only in a relatively wide area near the corner edge in the corner space area of the circuit board of the electronic circuit unit, and the narrow area far from the corner edge is exposed to the board without the solder resist. If it is an area, when the collective substrate is cut along the cutting line, the solder resist having a sufficient contact area with the substrate surface in the corner space area is difficult to peel off, and near the corner edge. There is no possibility of generating resin burrs in the substrate material. Even if resin burrs are formed in the substrate exposed areas at both ends of the corner space area in the cutting process, the resin exposed burrs are not conspicuous because the substrate exposed areas are away from the corner edges. It is unlikely that the appearance of the will be impaired.

  In the above configuration, a circular mounting hole is formed in the approximate center of the copper foil land adjacent to the corner space region of the circuit board, and two perpendicular lines extending from the center of the mounting hole toward the outer edge of the board are set. When the position where these perpendicular lines cross the corner space area is substantially matched with the boundary between the solder resist and the substrate exposed area, the exposed area of the substrate is prevented from being peeled off in the corner space area. Since it can be separated from the edge as much as possible, the resin burr becomes less noticeable. Further, since the leg pieces of the shield cover that covers the high-frequency circuit on the circuit board can be inserted into the mounting holes in the copper foil land and attached, it is suitable for designing a small and high-density high-frequency circuit unit.

  In order to achieve the second object described above, the present invention provides a plurality of circuit portions corresponding to a plurality of electronic circuit units collectively on a collective substrate, and then places the collective substrate along vertical and horizontal cutting lines. In the method of manufacturing an electronic circuit unit in which a plurality of rectangular circuit boards having copper foil lands at the corners are obtained by cutting into individual pieces, a rectangular area corresponding to the circuit board on the collective board After the copper foil lands are provided at the corners, a solder resist is provided in the rectangular region so as to substantially surround the copper foil lands. Of the substantially L-shaped region extending between the outer peripheral edge bulging outward, the region excluding the narrow end portions is covered with the solder resist, and both end portions are covered with the solder resist. Not exposed board area None of the.

  Thus, in the step of providing the solder resist so as to substantially surround the copper foil land at the corner of the rectangular area on the collective substrate corresponding to the circuit board of the electronic circuit unit, the substantially L-shaped area at the corner of the rectangular area Among them, if a solder resist is provided only in a relatively wide area very close to the intersection of the vertical and horizontal cutting lines, and a narrow area away from the intersection is a substrate exposed area where the solder resist does not exist, the collective substrate When cutting along the cutting line, the solder resist that has a sufficient contact area with the substrate surface in the substantially L-shaped region is difficult to peel off, and the intersection of the cutting line that becomes the corner edge of the circuit board There is no possibility of the occurrence of resin burrs of the substrate material in the vicinity. In addition, since only a part of the substantially L-shaped region becomes a substrate exposed region where no solder resist exists, an increase in the number of steps can be avoided. Even if resin burrs are formed in the substrate exposed areas at both ends of the substantially L-shaped area in the cutting process, the resin exposed burrs are not noticeable because the substrate exposed areas are separated from the corner edges of the circuit board. It is unlikely that the appearance of the electronic circuit unit is damaged.

  Further, in the above manufacturing method, a circular mounting hole is formed in the approximate center of the copper foil land adjacent to the substantially L-shaped region, and two perpendicular lines extending from the center of the mounting hole toward the cutting line are formed. When set, if the position where the perpendicular crosses the substantially L-shaped region is substantially matched with the boundary between the solder resist and the substrate exposed region, there is a concern within the substantially L-shaped region (the corner space region of the circuit board). Since the exposed area of the substrate can be separated as much as possible from the intersection of the cutting lines (corner edge of the circuit board) while preventing the solder resist from peeling off, the resin burr becomes less noticeable. Further, since the leg pieces of the shield cover covering the high-frequency circuit on the circuit board can be inserted into the attachment holes in the copper foil land and attached, it is suitable for manufacturing a small and high-density high-frequency circuit unit.

  In the electronic circuit unit of the present invention, a solder resist is provided only in a relatively wide region in the vicinity of the corner edge in the corner space region of the circuit board, and there is no solder resist in a narrow region far from the corner edge. Because it is a substrate exposed area, when cutting the aggregate substrate along the cutting line, the solder resist that has a sufficient contact area with the substrate surface in the corner space area is difficult to peel off, and the corner edge There is no possibility of the occurrence of resin burrs of the substrate material in the vicinity. That is, in this electronic circuit unit, even if copper foil lands are provided in the vicinity of the corner edge of the circuit board, peeling of the solder resist and resin burrs of the board material do not become a problem, so that it is easy to reduce the size and increase the density.

  The method of manufacturing an electronic circuit unit according to the present invention includes a step of providing a solder resist so as to substantially surround a copper foil land at a corner of a rectangular area corresponding to the circuit board of the electronic circuit unit on a collective substrate. Of the substantially L-shaped area at the corner, a solder resist is provided only in a relatively wide area very close to the intersection of the vertical and horizontal cutting lines, and a narrow area away from the intersection is a substrate exposed area where no solder resist exists. Therefore, when the collective substrate is cut along the cutting line, the solder resist having a sufficient contact area with the substrate surface in the substantially L-shaped region is difficult to peel off, and the circuit board There is no possibility that a resin burr of the substrate material is generated near the intersection of the cutting lines serving as the corner edges. In addition, since only a part of the substantially L-shaped region becomes a substrate exposed region where no solder resist exists, an increase in the number of steps can be avoided. In other words, according to this manufacturing method, even if a copper foil land is provided in the vicinity of the corner edge of the circuit board of the electronic circuit unit, peeling of the solder resist and resin burrs of the substrate material do not become a problem. Units are easier to manufacture.

It is a top view of the electronic circuit unit which concerns on the example of embodiment of this invention. It is a principal part perspective view which shows the corner part of the electronic circuit unit of FIG. It is principal part explanatory drawing which shows the corner part shape of the circuit board in the manufacturing process of the electronic circuit unit of FIG. It is principal part explanatory drawing which shows the corner part shape of the circuit board in the manufacturing process of the electronic circuit unit which concerns on a prior art example. It is principal part explanatory drawing which shows the corner part shape of the circuit board in the manufacturing process of the electronic circuit unit which concerns on a comparative example.

  Embodiments of the present invention will be described below with reference to FIGS. An electronic circuit unit 1 shown in FIG. 1 is a high-frequency circuit unit in which a high-frequency circuit unit 3 disposed on a circuit board 2 is covered with a shield cover 4 and electromagnetically shielded. Copper foil lands 5 are provided in the four corner regions of the circuit board 2, and a solder resist 6 is provided around each copper foil land 5 except for a part thereof. In addition, a circular mounting hole 5a is formed in the approximate center of each copper foil land 5, and the leg piece 4a of the shield cover 4 is inserted into the mounting hole 5a as shown in FIG. The leg piece 4a and the copper foil land 5 are joined by solder (not shown). That is, the shield cover 4 is attached to the circuit board 2 by inserting the leg pieces 4a provided at the four corners into the corresponding attachment holes 5a and soldering.

  The shape of the corner of the circuit board 2 will be described in detail. As shown in FIG. 3, the board outer edge 2d extending at a right angle from the corner edge 2a at the corner of the circuit board 2 and the copper foil land 5 provided at the corner. A corner space region 2b that is substantially L-shaped in plan view extends between the outer peripheral edge that bulges outward. Of this corner space region 2b, a relatively wide region in the immediate vicinity of the corner edge 2a is covered with the solder resist 6, but the narrow end portions of the corner space region 2b are the substrate exposed regions where the solder resist 6 does not exist. 2c. That is, the outer peripheral edge of the copper foil land 5 is adjacent to the substrate exposed region 2c at two locations on the corner space region 2b side, and all the other is adjacent to the solder resist 6. Then, when a perpendicular is extended from the center of the mounting hole 5a of the copper foil land 5 to the two board outer edges 2d orthogonal to each other, the position where these two perpendiculars cross the corner space area 2b is defined as the corner space area. It is set so as to be the position of the boundary between the solder resist 6 and the substrate exposed region 2c (starting end of the substrate exposed region 2c) in 2b.

  A large number of the electronic circuit units 1 are taken from the collective substrate 10 indicated by a chain line in FIG. That is, when the electronic circuit unit 1 is manufactured, first, wiring patterns (not shown) or the like are respectively formed in a plurality of rectangular regions partitioned by vertical and horizontal cutting lines (dicing lines) 11 and 12 on the collective substrate 10. Copper foil lands 5 and the like are formed in a lump, and then a solder resist 6 is formed in a lump. However, when the solder resist 6 is formed, the solder resist 6 is provided only in the vicinity of the intersection of the vertical and horizontal cutting lines 11 and 12 in the substantially L-shaped region A outside the copper foil land 5 at the corner of each rectangular region. The region where the distance between the copper foil land 5 and the cutting lines 11 and 12 is narrow is the substrate exposed region 2c where the solder resist 6 does not exist. Each rectangular area of the collective substrate 10 is an area corresponding to one circuit board 2, and the intersection of the cutting lines 11 and 12 becomes a corner edge 2 a of the circuit board 2. Accordingly, the cutting lines 11 and 12 correspond to the board outer edge 2d of the circuit board 2 and the substantially L-shaped area A corresponds to the corner space area 2b of the circuit board 2 at the corners of each rectangular area of the collective board 10.

  Thereafter, an electronic component or the like (not shown) is mounted on each rectangular area of the collective substrate 10 to form the high-frequency circuit unit 3, and a shield cover 4 that covers the high-frequency circuit unit 3 is attached. As described above, the leg pieces 4a of the shield cover 4 are inserted and soldered into the mounting holes 5a of the copper foil lands 5 adjacent to the corner space region 2b.

  After that, by cutting the collective substrate 10 with a dicing saw or the like along the vertical and horizontal cutting lines 11 and 12, the collective substrate 10 is separated into a large number of circuit boards 2, and a large number of electronic circuit units 1 are obtained. Is done.

  As described above, in this embodiment, the solder resist 6 is provided only in a relatively wide area in the vicinity of the corner edge 2a in the corner space area 2b of the circuit board 2 of the electronic circuit unit 1, and the corner edge. A narrow region away from 2a is a substrate exposed region 2c where the solder resist 6 does not exist. Therefore, when the collective substrate 10 is cut along the cutting lines 11 and 12, the solder resist 6 having a sufficient contact area with the substrate surface in the corner space region 2b is difficult to peel off, and is near the corner edge 2a. There is no risk of resin burrs in the substrate material. Therefore, in this electronic circuit unit 1, even if the copper foil land 5 is provided in the vicinity of the corner edge 2a of the circuit board 2, the peeling of the solder resist 6 and the resin burrs of the board material are not a problem, and the size and density of the electronic circuit unit 1 can be reduced. It is easy to plan. In addition, since only a part of the corner space region 2b becomes the substrate exposed region 2c where the solder resist 6 does not exist, the number of processes does not increase when the electronic circuit unit 1 is manufactured.

  When the collective substrate 10 is cut along the cutting lines 11 and 12, a resin burr may be formed in the substrate exposed region 2c of the corner space region 2b. However, since the substrate exposure region 2c is away from the corner edge 2a, the resin burr is not conspicuous, and therefore, it is unlikely that the appearance of the electronic circuit unit 1 manufactured is damaged. Moreover, in the present embodiment, the position where the perpendicular extending from the center of the mounting hole 5a of the copper foil land 5 to the substrate outer edge 2d crosses the corner space region 2b is substantially matched with the position of the starting end portion of the substrate exposed region 2c. In this way, since the substrate exposed region 2c can be separated from the corner edge 2a as much as possible while preventing the peeling of the solder resist 6 which is a concern in the corner space region 2b, the resin burr becomes less noticeable.

  However, the position of the starting end portion of the substrate exposure region 2c in the corner space region 2b can be appropriately selected according to the size, shape, etc. of the corner space region 2b. For example, both end portions of the corner space region 2b are extremely When the width is narrow, it is preferable to set the starting end of the substrate exposed region 2c slightly shifted from the position of FIG. 3 toward the corner edge 2a.

  In the above embodiment, the outer shape of the copper foil land 5 is a leaf shape. However, the outer shape of the copper foil land 5 may be circular or the like. If the foil land 5 has an outer peripheral edge that bulges outward, a substantially L-shaped corner space region 2b is generated, so that the present invention can be applied.

  Even if the electronic circuit unit 1 is not a high-frequency circuit unit as in the above-described embodiment, copper foil lands 5 are provided at the corners of the circuit board 2 that is separated by cutting the collective substrate 10. The present invention is applicable as long as it is.

DESCRIPTION OF SYMBOLS 1 Electronic circuit unit 2 Circuit board 2a Corner edge 2b Corner space area 2c Board exposure area 2d Board outer edge 3 High frequency circuit part 4 Shield cover 4a Leg piece 5 Copper foil land 5a Mounting hole 6 Solder resist 10 Collective board 11, 12 Cutting line A L-shaped region

Claims (4)

A rectangular circuit board that is separated by cutting the assembly board along vertical and horizontal cutting lines, and a rectangular board outer edge that divides the corner of the circuit board, and copper provided at the corner An electronic circuit unit in which a substantially L-shaped corner space region extends between the outer peripheral edge bulging outward from the foil land,
An electronic circuit unit characterized in that a region excluding the narrow end portions of the corner space region is covered with a solder resist, and the both end portions are substrate exposed regions where no solder resist exists.   In Claim 1, The circular attachment hole is formed in the approximate center of the said copper foil land, When these two perpendicular lines extended toward the said board | substrate outer edge from the center of this attachment hole are set, An electronic circuit unit characterized in that a position crossing the corner space region is substantially matched with a boundary portion between the solder resist and the substrate exposed region. After a plurality of circuit portions corresponding to a plurality of electronic circuit units are collectively provided on the collective substrate, the collective substrate is cut into individual pieces by cutting the collective substrate along vertical and horizontal cutting lines. A method of manufacturing an electronic circuit unit that can obtain a plurality of rectangular circuit boards having lands,
In the step of providing a solder resist so as to substantially surround the copper foil land in the rectangular region after providing the copper foil land in the corner of the rectangular region corresponding to the circuit board on the collective substrate, the corner portion Of the substantially L-shaped region extending between the vertical and horizontal cutting lines defining the copper foil land and the outer peripheral edge bulging outward, the region excluding the narrow ends is the solder resist. And manufacturing the electronic circuit unit, wherein both end portions are exposed areas of the substrate without a solder resist.   In Claim 3, The circular attachment hole is formed in the approximate center of the said copper foil land adjacent to the said substantially L-shaped area | region, Two extending toward the said cutting line from the center of this attachment hole A method of manufacturing an electronic circuit unit, characterized in that, when a perpendicular line is set, a position where the perpendicular line crosses the substantially L-shaped region substantially coincides with a boundary portion between the solder resist and the substrate exposed region.

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