JPH0743018U - Board noise pattern structure - Google Patents

Abstract

(57) [Abstract] [Purpose] To prevent the warp of the board when the noise countermeasure pattern is formed on the back surface of the board on which the wiring pattern is formed. [Structure] A substrate 1 is formed of a glass epoxy material, and a wiring pattern 2 is formed on a front surface 1a of the pattern material made of copper. The noise countermeasure pattern 3 is formed in a striped pattern with an interval in the direction in which it is likely to warp during reflow over the entire back surface of. [Effect] Since the pattern areas on the front and back sides are made approximately equal, it is possible to prevent warpage due to thermal stress during reflow.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a noise countermeasure pattern structure of a substrate, and more particularly to a noise countermeasure pattern structure of a substrate having a wiring pattern formed on the front surface and a noise countermeasure pattern formed on the back surface of the substrate.

[0002]

[Prior art]

 Conventionally, in a hybrid IC, etc., where a desired wiring pattern is formed on a substrate made of ceramics etc., as a countermeasure against external noise, a pattern material is reflowed over the entire back surface of the substrate to form a noise countermeasure pattern. There is something I did. On the other hand, in order to reduce the weight, there is one in which the substrate is made of a synthetic resin material such as a glass epoxy material.

However, in the above-mentioned synthetic resin substrate, when the area of the noise countermeasure pattern is relatively larger than the area of the wiring pattern, for example, the expansion / shrinkage rate of the copper pattern material and the substrate are different, There was a problem that the substrate was greatly warped due to thermal stress during reflow.

[0004]

[Problems to be solved by the device]

 In view of the above problems of the prior art, a main object of the present invention is to provide a pattern structure for noise suppression of a substrate, which can prevent the warp of the substrate.

[0005]

[Means for Solving the Problems]

 According to the present invention, such an object is characterized in that the noise countermeasure pattern formed on the back surface of the substrate having the wiring pattern formed on the front surface is formed in approximately the same area as the wiring pattern. This is achieved by providing a pattern structure for noise suppression of the substrate. Particularly, it is preferable that the noise countermeasure pattern is formed in a striped pattern with an interval in the direction in which it easily warps when formed on the entire back surface.

[0006]

[Action]

 By thus forming the pattern material having approximately the same area on the front surface and the back surface of the substrate, the effects of thermal expansion and contraction of the pattern material on the front and back surfaces of the substrate can be made substantially equal. In particular, when the pattern material is formed on the entire back surface of the substrate, the pattern is formed in a striped pattern with intervals in the direction in which the pattern material is easily warped, so that the effect of thermal expansion and contraction due to the noise countermeasure pattern can be reduced.

[0007]

【Example】

 Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a plan view of a substrate 1 of, for example, a hybrid IC to which the present invention is applied. (A) shows a front surface 1a of the substrate 1 and (b) shows a back surface 1b of the substrate 1.

A wiring pattern 2 made of a conductor film, a resistor film, etc. is formed on the surface 1 a of the substrate 1 by a pattern material made of copper, for example. The wiring pattern 2 has an electrode portion region on which a chip or the like is placed.

On the back surface 1b of the substrate, a noise countermeasure pattern 3 is formed by using the same pattern material as the wiring pattern 2. The noise countermeasure pattern 3 is formed by reflow in the step after the wiring pattern 2 is formed, but is formed in a vertical striped pattern in the figure by using a pattern material in the same amount as that of the wiring pattern 2. There is.

When the substrate 1 is made of a synthetic resin material such as a glass epoxy material and a pattern is formed on the entire back surface 1b, the coefficient of thermal expansion / contraction between the substrate 1 and the pattern material is large. Because of the difference, in the embodiment, the warp tends to occur by bending the longitudinal direction in the drawing.

In the substrate 1, the noise countermeasure pattern 3 is arranged such that the stripes are spaced in the longitudinal direction, and the ratio of the area of the noise countermeasure pattern 3 in the direction of easy warping should be reduced. You can Further, the pattern area of the entire back surface 1b is approximately the same as that of the front surface 1a, and when the noise countermeasure pattern 3 is reflowed, due to the influence of the difference in the thermal expansion / contraction rate between the substrate 1 and the pattern material, It is possible to prevent 1 from following along. Although the entire back surface 1b is not covered with the pattern material, in this embodiment in which the pattern areas of the front surface 1a and the back surface 1b are approximately the same as described above, there is no change in the noise resistance performance. , No warpage occurred.

[0013]

[Effect of device]

 As described above, according to the present invention, even if there is a large difference in the coefficient of thermal expansion / contraction between the substrate material and the pattern material, the noise countermeasure pattern on the back surface can be provided to the wiring pattern on the front surface. Since the areas are approximately the same, the influence of the thermal stress on the board due to the thermal stress during the reflow of the noise countermeasure pattern can be made equal on both the front and back sides, and the warpage of the board can be prevented. In particular, by forming the noise countermeasure pattern in a striped pattern with intervals in the direction in which warpage is likely to occur, it is possible to make the area ratio approximately the same as the surface pattern in the direction in which warpage is likely to occur, and to A pattern can be formed over the entire back surface, and the noise resistance does not deteriorate.

[Brief description of drawings]

FIG. 1 is a plan view of a substrate to which the present invention is applied,
(A) shows the front surface and (b) shows the back surface.

FIG. 2 is a partially enlarged sectional view taken along the line II-II in FIG.

[Explanation of symbols]

 1 substrate 1a front surface 1b back surface 2 wiring pattern 3 noise countermeasure pattern

Claims (2)

[Scope of utility model registration request] 1. A noise countermeasure pattern structure for a substrate, wherein a noise countermeasure pattern formed on the back surface of a substrate having a wiring pattern formed on the front surface is formed in approximately the same area as the wiring pattern. . 2. The noise suppression pattern is formed in a striped pattern with a gap in the direction in which it easily warps when formed on the entire back surface. Pattern structure for noise suppression on the board.