JP2005085845A - Packaging structure of electronic component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the standup of an electronic component mounted on a wiring board by maintaining pulling strength by solder between two land patterns arranged on the wiring board to be uniform. <P>SOLUTION: In the packaging structure of an electronic component, a wiring pattern having the land patterns which are composed of conductive materials and to which an electronic component is bonded with solder, and a resist which covers a part of the wiring pattern, are formed on the substrate. A pattern cut portion in which the conductive material does not exist is arranged on a part of the periphery of the land pattern, and the resist does not cover upper parts of the land pattern and the pattern cut portion. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a mounting structure for an electronic component, and more particularly to a structure for preventing the rise of an electronic component to be reflow soldered.

FIG. 3 is a schematic top view showing a conventional electronic component mounting structure, and FIG. 4 is a schematic cross-sectional view taken along line 1-1 in FIG. A wiring pattern 6 made of a conductive material is formed on the wiring board 2 constituting the mounting structure, and a resist 5 is printed as a film that covers a part of the wiring pattern 6 and protects the wiring pattern 6. ing. The wiring pattern 6 has land pattern portions 6a and 6b for joining the electronic component 1 with the solder 4. One land pattern portion 6b is in the wide pattern portion 6c for grounding, for example. In this case, the land pattern portions 6 a and 6 b and the wiring pattern portion 6 d around the land pattern portion 6 b are exposed without being covered with the resist 5.

In such an electronic component mounting structure, when mounting an extremely small electronic component 1 such as a chip resistor or a chip capacitor, the solder 4 intended to be attached to one land pattern portion 6b is reduced in the amount of the solder 4. Due to the large amount or the displacement of the supply position, it may flow into the wiring pattern portion 6d around the land pattern portion 6b. If the solder 4 is attached not only to the land pattern portion 6b intended to be attached with the solder 4 but also to the wiring pattern portion 6d around the land pattern portion 6b, one solder shown in FIG. 4 can be attached. There is a difference in the tensile strength of the solder 4 between a certain land pattern portion 6a, a land pattern portion 6b to which the other solder 4 can be attached, and a wiring pattern portion 6d around the land pattern portion 6b. Then, the electronic component 1 was strongly pulled in the direction of one land pattern portion 6b, and the electronic component 1 was raised. As a result, the electrode 7 of the electronic component 1 and the land pattern portion 6a are not joined, and there is a disadvantage that the electronic joining between the electronic component 1 and the circuit of the wiring board 2 is not performed.
Japanese Utility Model Publication No. 5-69976 (FIGS. 1 to 5)

  In order to prevent such a problem, for example, as shown in FIG. 5, the wiring pattern portion 6d around the land pattern portion 6b provided in the wide area pattern portion 6c is also covered with the resist 5, and only the land pattern 6b is coated. It is conceivable to suppress the spread of the solder due to the inflow of the solder so as to be exposed.

However, since the resist 5 is ink-printed, a positional deviation between the resist 5 and the wiring pattern 6 occurs due to printing deviation or blurring, and the exposed land pattern portions 6a and 6b have different areas. For example, (1) in FIG. 6 is a schematic cross-sectional configuration diagram taken along line 2-2 in FIG. 5 and shows a case where there is no misalignment of printing of the resist 5, but in this case, a portion to which the solder 4 can adhere The areas of 6a and 6b are substantially the same. However, in the case of (2) in FIG. 6 in which the printing of the resist is shifted, the areas of the portions 6X and 6Y to which the solder 4 can be attached are different. For this reason, when the printing of the resist 5 is shifted, as in the conventional case, the tensile strength by the solder 4 at the portions 6X and 6Y to which the solder 4 of both poles can adhere is different, and the electronic component 1 is in one land. The electronic component 1 rises due to strong pulling in the direction of the pattern portion 6b.

  The present invention has been made in view of such a problem, and by mounting the tensile strength by solder between two land pattern portions provided on a wiring board so as to be substantially uniform, the mounted electronic An object of the present invention is to provide a mounting structure for an electronic component that prevents the component from rising and functions normally.

According to a first aspect of the present invention, there is provided a mounting structure for an electronic component comprising a conductive member, a wiring pattern having a land pattern portion to which the electronic component is joined by solder, and a resist covering a part of the wiring pattern on the substrate. In the electronic component mounting structure formed in
Provided with a pattern cut part where no conductive member exists in a part of the periphery of the land pattern part,
The resist is characterized by not covering the land pattern portion and the pattern cut portion.

  According to a second aspect of the present invention, in the electronic component mounting structure according to the first aspect, the land pattern portion and the pattern cut portion are provided in a wide area pattern made of a conductive material.

  According to a third aspect of the present invention, in the electronic component mounting structure according to the first or second aspect, the pattern cut portion is divided into two or more around the land pattern portion. And

  According to the present invention, the land pattern portion of the mounting structure of the electronic component is provided by providing the pattern cut portion having no conductive member in the peripheral portion of the two land pattern portions provided corresponding to the connection terminals of the electronic component. This prevents the solder attached to the solder from spreading. For this reason, the solder adhesion area between two land patterns can be kept substantially the same, and a difference in tensile strength due to solder between the two land pattern portions can be suppressed. In addition, even if a misalignment between the resist and the wiring pattern occurs due to misprinting or blurring of the resist, the pattern cut portion suppresses variation in the area of the land pattern portion due to the resist coating, thereby reducing the distance between the two land pattern portions. It is possible to suppress the difference in the tensile strength caused by soldering.

  Thus, it is possible to avoid non-bonding between the electronic component and the land pattern portion due to the rise of the electronic component, and to ensure electrical bonding between the electronic component and the circuit of the wiring board.

  In addition, by changing the arrangement configuration of the pattern cut part provided around the land pattern part according to the position of the lead part of the wiring pattern, the conventional board design can be performed without causing the position restriction of the lead part by the pattern cut part. It is possible to freely lay out the wiring pattern without changing.

  FIG. 1 is a schematic top view showing an electronic component mounting structure according to an embodiment of the present invention.

  The wiring board 2 is a board as a mounting structure. A wiring pattern 6 described later made of a conductive material is formed, a resist 5 described later covering a part of the wiring pattern 6 is printed, and the electronic component 1 is mounted. The electronic circuit is formed by mounting.

  The wiring pattern 6 is made of a conductive material and is a wiring portion for forming an electronic circuit.

  The resist 5 is a film that covers a part of the wiring pattern 6 and protects the wiring pattern 6.

  The land pattern portions 6a and 6b are parts of the wiring pattern 6, are exposed portions without being covered with the resist 5, and are portions intended to join the electronic component 1 with solder.

  The lead-in portion 6e functions as a wiring that secures electrical connection between the continuous land pattern portions 6a and 6b and the other wiring pattern 6 portions, and is covered with a resist provided around the land pattern portions 6a and 6b. It is a part that is exposed without any problems.

  The wide area pattern portion 6c is a part of the wiring pattern, and is a large area portion provided for grounding, for example. In the wide area pattern 6c, a land pattern portion 6b, a lead-in portion 6e around the land pattern portion 6b, and a pattern cut portion 3 described later are provided.

  The pattern cut portion 3 is a portion where the wiring pattern 6 does not exist, is a portion which is provided around the land pattern portions 6 a and 6 b and is exposed without being covered with the resist 5. For example, when the pattern cut portion 3 is provided around the land pattern portion 6b, the two pattern cut portions 3a and 3b are dividedly arranged in a portion not facing the land pattern portion 6a, and the two pattern cut portions 3a, A lead-in portion 6e is provided between 3b. Further, the pattern cut portion 3 provided around the land pattern portion 6a is provided substantially symmetrically with the pattern cut portion 3 provided around the land pattern portion 6b.

  In such a structure, when the solder is attached to the land pattern portion 6b to join the electronic components, even when the amount of solder is large or the solder is likely to spread to the periphery of the land pattern portion 6b due to the deviation of the supply position. The surrounding land cut portions 3 prevent the solder from spreading (because the solder adheres to the wiring pattern 6). Similarly, in the land pattern portion 6a, the spread of solder is prevented by the pattern cut portion 3, so that the solder adhesion areas in the two land pattern portions 6a and 6b can be kept substantially the same. Thus, it is possible to suppress a difference in tensile strength due to solder between the two land pattern portions 6a and 6b.

  Further, by providing the pattern cut portion 3 around the two land pattern portions 6a and 6b, even if a positional shift between the resist 5 and the wiring pattern 6 occurs due to a printing shift or bleeding of the resist 5, the pattern Since the cut portion 3 suppresses the area variation of the land pattern portions 6a and 6b due to the coating of the resist 5, the exposed area of the land pattern portions 6a and 6b does not change greatly due to the displacement. Therefore, even if such a positional shift occurs, the tensile strength by solder between the two land pattern portions 6a and 6b is not greatly affected.

Other Embodiments As shown in FIG. 1, the position of the lead-in portion 6e provided between the two pattern cut portions 3a and 3b is limited by the arrangement position of the pattern cut portions 3a and 3b. In FIG. 2, pattern cut portions 3c, 3d, and 3e that are divided and arranged in three are provided, and a lead-in portion 6e ′ different from that in FIG. 1 is formed. In this way, even if a pattern cut part is provided around the land pattern part by changing the pattern cut part provided around the land pattern part according to the position of the lead-in part, it can be freely changed as in the conventional board design. It is possible to lay out the wiring pattern.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic top view showing an electronic component mounting structure according to an embodiment of the present invention. It is a general | schematic upper surface block diagram which shows the mounting structure of the electronic component concerning the other Example of this invention. It is a general | schematic upper surface block diagram which shows the mounting structure of the conventional electronic component. FIG. 4 is a schematic cross-sectional configuration diagram taken along line 1-1 in FIG. 3. It is another general | schematic top surface block diagram which shows the mounting structure of the conventional electronic component. FIG. 6 is a schematic cross-sectional configuration diagram along a line 2-2 in FIG. 5 showing a change in the solder adhesion area.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electronic component 2 Wiring board 3 Pattern cut part 4 Solder 5 Resist part 6 Wiring pattern 6a, 6b Land pattern part 6c Wide area pattern part

Claims (3)

In a mounting structure of an electronic component formed of a conductive member and having a land pattern portion to which an electronic component is joined by solder, and a resist covering a part of the wiring pattern formed on a substrate,
Provided with a pattern cut part where no conductive member exists in a part of the periphery of the land pattern part,
The electronic component mounting structure is characterized in that the resist does not cover the land pattern portion and the pattern cut portion. 2. The electronic component mounting structure according to claim 1, wherein the land pattern portion and the pattern cut portion are provided in a wide area pattern made of a conductive material. 3. The electronic component mounting structure according to claim 1, wherein the pattern cut portion is divided into two or more around the land pattern portion.

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