| 摘要 |
A printed circuit board includes a plurality of lands thereon. The size D2 of the outer land 3 in the direction along the outside array is less than the size D1 of the inner land 1 in the direction along the inside array. Therefore, it is possible to pass the pattern 4 with enough clearance against the outer land 3. The outer lands 3 are formed with an oval, elliptical or oblong shape. Namely, the size D3 of the outer land 3 in the direction perpendicular to the direction of the outside array is greater than the size D2. Then, it is possible to ensure a sufficient reliability of a soldered part. Preferably, the connected area 5 between the inner land 1 and the pattern 4 and the connected area 7 between the outer land 3 and the pattern 6 are formed as a shape of a tear-drop. Then, the patterns 4, 6 cannot be easily cut by a thermal stock or a heat cycle. The solder resist 8 is coated, around the outer land 3, from an outer area to an inner area of the outer land 3, except for the central area 3A. The resist 8 is further coated, around the inner land 1, from an outer area to an inner area of the inner land 1, except for the central area 1A. Then, each area 5, 7 is reinforced by the resist 8. Further, since a clearance between exposed areas 1A and a clearance between exposed areas 3A are widened, a bridge of solder does not easily occur.
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