JPH0448762A - Semiconductor substrate for electronic apparatus - Google Patents

Abstract

PURPOSE:To improve cooling performance due to proper array of IC chip groups and to further activate a board by arranging the groups of both-side mounting at the upstream side of cooling fluid from the group of one-side mounting. CONSTITUTION:If IC chip 2 groups of one-side mounting 3 and IC chip 2 groups of both-side mounting 4 are mixed, the groups of the mounting 4 are arranged at the upstream side and the groups of the mounting 3 are arranged at the downstream side to suppress the highest temperature of the chip to a relatively low value. The reason is because, if the groups of the mounting 4 are arranged at the upstream side, cooling air having not large air temperature rise can be activated. Since the groups of the mounting 3 at the downstream side occupies a large weight of heat dissipating from a board, the rise of the chip temperature can be suppressed to a small value even by considering the air temperature rise due to the groups of the mounting 4 at the upstream side. Further, in order to improve cooling performance, when the IC chip 2 groups are arranged in a zigzag manner, the effect is further large.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a board in which single-sided and double-sided IC chip groups are mixed in electronic devices such as computers.

[Conventional technology]

In the substrate arrangement of IC chip groups in electronic devices such as computer computers, there are almost no known examples of a case in which double-sided mounting and single-sided mounting of the substrate are mixed. Note that related to this type of device, for example, Japanese Patent Application Laid-Open No. 59-214246 can be cited.

Also, the method for cooling IC chips is disclosed in Japanese Patent Application Laid-open No. 1-115198.
As described in the above publication, it had a duct for conducting cooling air, and this duct was provided with blow-off holes to send cooling air only to the heat-generating parts, thereby performing collision cooling.

[Problem to be solved by the invention]

The above conventional technology does not take into consideration the arrangement of the substrate, and there is room to consider the arrangement of the IC chips on the substrate from the viewpoint of reducing the temperature rise of the IC chips on the downstream side of the substrate and ensuring reliability. was there.

The purpose of the present invention is to improve the cooling performance by optimizing the arrangement of single-sided and double-sided IC chip groups mounted on a board in a computer, and to improve the cooling performance of the -layer by utilizing the board. The aim is to improve this.

[Means to solve the problem]

In order to achieve the above object, the arrangement of single-sided mounting and double-sided mounting IC chip groups mounted on the board is such that the double-sided mounting IC chip group is provided on the upstream side, and the single-sided mounting IC chip group is provided on the downstream side. This is designed to reduce the maximum temperature of the IC chip.

Furthermore, we have further improved the cooling performance of the IC chip group and
In order to equalize the temperature of the chip, small holes for air inflow are provided in the substrate so that the diameter increases as you go downstream.
It is equipped with an inclined slit.

[Effect]

By arranging the double-sided mounted IC chip group on the upstream side and the single-sided mounted IC chip group on the downstream side, it is possible to suppress a local increase in air temperature. As a result, the maximum temperature of the IC chip can be reduced, improving the cooling performance of the IC chip and ensuring reliability. Furthermore, by arranging the IC chip groups in a staggered manner, cooling air can be utilized, thereby improving the cooling performance of the IC chips. Furthermore, by utilizing the board and taking in cooling air, it is possible to suppress the rise in air temperature. As a result, the maximum temperature of the IC chip can be reduced, further improving the cooling performance of the IC chip.
Reliability can also be greatly ensured.

〔Example〕

Hereinafter, one embodiment of the present invention will be explained with reference to FIG. 1. This figure shows a computer IC chip group 1 in which an IC chip 2 with single-sided mounting 3 is brought to the downstream side and an IC chip 2 with double-sided mounting 4 is brought to the upstream side. , is an example of a staggered arrangement. The value inside the IC chip 2 is the surface temperature TLsr of the IC chip 2.
and the inflow air temperature Ta5r, ΔT (= Tt, sr
Tier).

The maximum temperature of ΔT was 45.8 degrees, and the temperature distribution of the IC chip 2 was also kept almost uniform. The reason for this is
By using a staggered arrangement, it is difficult to receive air whose temperature has increased due to heat dissipation from the IC chip 2 in front, that is,
This is because the effect of fresh cooling air can be taken into account.

Next, the IC chip 2 of double-sided mounting 4 on the upstream side of FIG.
An example of the case where the group arrangement is seen as the base is shown in Figure 2, 8T.
The maximum temperature was 46.6 degrees, which is 0.8 degrees higher than in the staggered arrangement shown in Figure 1. This is the front I
This is due to the cooling effect of the air at the C-chip 2 whose temperature has increased. but.

The temperature distribution of the IC chip 2 is kept almost uniform as in the case of FIG.

Next, FIG. 3 shows an example in which, contrary to FIG. 2, two groups of IC chips with double-sided mounting 4 are brought on the downstream side and two groups of IC chips with single-sided mounting 3 are brought on the upstream side.

The maximum temperature of ΔT is 48.8 degrees, which is higher than in the case of FIG. 2, and the temperature distribution of the IC chip 2 also becomes more non-uniform.
Lacks reliability.

In addition, two groups of IC chips mounted on one side 3 are placed below the substrate 1,
FIG. 4 shows an example in which two groups of IC chips mounted on both sides 4 are arranged above the substrate 1. The maximum temperature of ΔT is 50.5
This is even higher than in the case of Figure 3. Also, I
The temperature distribution of the C chip 2 is also extremely non-uniform.

The reason for this is that in the case of single-sided mounting 3, the heat dissipation from the board 1 accounts for a large amount of weight, whereas in the case of double-sided mounting 4, there is almost no heat dissipation from the board 1, and as you go downstream, the air temperature increases. Due to the rising air, the maximum temperature of ΔT is also high. Therefore, the reliability of the IC chip 2 is lost.

A summary of the above is shown in Figure 5, where the vertical axis shows Δ
T, the horizontal axis shows the distance from the upstream side to the downstream side.6 Although the temperature distribution in the examples in Figures 1 and 2 has waves, it is relatively uniform and the maximum temperature is low. ing. On the other hand, the temperature distribution in the examples shown in FIGS. 3 and 4 is non-uniform, and as is clear from the phenomenon of 0 or more where the maximum temperature is high, two groups of IC chips with single-sided mounting 3 and Double-sided mounting 4
If two groups of IC chips are mixed, double-sided mounting 4 is installed on the upstream side.
By arranging two groups of IC chips with single-sided mounting 3 on the downstream side, the maximum chip temperature can be kept relatively low. The reason for this is that double-sided mounting 4
If two groups of IC chips are arranged on the upstream side, cooling air that does not cause a large increase in air temperature can be used, and in addition, for the two groups of single-sided mounted IC chips on the downstream side, heat radiation from the board occupies a large portion. Therefore, the IC chip 2 of double-sided mounting 4 on the upstream side
Even if the increase in wind temperature caused by the group is taken into consideration, the increase in chip temperature can be suppressed to a small level. Furthermore, in order to improve the cooling performance, if the two groups of IC chips are arranged in a staggered manner, the negative layer effect is large.

As mentioned above, the arrangement of the two groups of IC chips is such that the two groups of IC chips with double-sided mounting 4 are brought to the upstream side and further arranged in a staggered manner, which improves the cooling performance and improves the temperature distribution of the two groups of IC chips. This is most effective in ensuring the reliability of the IC chip 2 by making it substantially uniform.

In the embodiment shown in FIG. 6, in order to improve the cooling performance of the two groups of IC chips and to make the temperature distribution uniform, the diameter of the small holes 5 for air inflow into the substrate 1 is increased toward the downstream side. Furthermore, a slit plate 6 is provided in order to control the amount of air flowing in. The slit plates 6 (a) and 6 (b) are placed parallel to the substrate 1, but as the temperature of the IC chip 2 rises, the air temperature also rises, and the inflow amount can be controlled in response to this. , slit plate 6(a).

A spring 7 made of shape memory alloy is provided at one end of 6(b). Due to the expansion and contraction of the spring 7, the slit plate 6 (a
) and the substrate 1, the air expands and the pressure decreases as it goes downstream, and between the substrate 1 and the slit plate 6(b), the air compresses and the pressure increases as it goes downstream. Become. Due to the pressure difference in this open area, air whose temperature has not risen at all passes through the small hole 5 of the substrate 1 and reaches the IC chip 2.
The temperature boundary layer 8 is disturbed, and the IC chip 2
It is possible to suppress the temperature rise of the IC chips and achieve uniform temperature distribution of the two groups of IC chips.

FIG. 7 shows a multilayer version of the substrate 1 of the embodiment shown in FIG. This example shows the applicability to case mounting.

The embodiments shown in FIGS. 8 and 9 are not limited to the two groups of IC chips;
This is a device for making the temperature distribution of the chip 9 of the substrate 1 uniform. By combining these, the temperature distribution of the chip 9 can be made uniform and the cooling performance can be improved. The embodiment shown in FIG. 10 is a case where the board 1 of the embodiment shown in FIG. It is. In addition to two groups of IC chips, one or more semiconductor packages 11 are also mounted on the substrate 1. The board 1 is held in a housing 12, the slit plate 6 is variable by a shape memory alloy spring 7, and a fan 13 is installed on the top of the housing 12 to cool the board 1. In the example, the temperature distribution of the IC chip 2 on the board 1 becomes uniform, there is no wasted cooling air, and it also helps to reduce the load on the fan 13.
This also leads to a reduction in the noise generated by the rotation of No. 3.

〔Effect of the invention〕

Since the present invention is configured as described above, it produces the effects described below.

Same speed, single-sided IC chip group 1 double-sided IC
When chip groups are mixed, cooling air can be used effectively by arranging the IC chip groups, with double-sided mounting IC chips on the upstream side and single-sided mounting IC chip groups on the downstream side, and a staggered arrangement. The reliability of the IC chip can be ensured. In addition, small holes for air inflow are provided on the substrate so that the diameter increases toward the downstream side, and a slit plate is installed using a spring made of a shape memory alloy to even out the temperature distribution of the chips on the substrate. control and achieve improved cooling performance.

[Brief explanation of drawings]

FIG. 1 is a front view (a) and a cross-sectional view (b) of an embodiment of the present invention, FIG. 2 is a front view (a) and a cross-sectional view (b) of an application example of the present invention, FIG. 4 is a front view (a) and a sectional view (b) of another different embodiment of the present invention, and FIG. 5 is a temperature distribution diagram in the flow direction of an IC chip according to an embodiment of the present invention.
FIG. 6 is an explanatory diagram of an application example where the temperature distribution of an IC chip group is made uniform according to an embodiment of the present invention, and FIG. 7 is an application example when the substrate of the embodiment of FIG. 6 is multilayered. Explanatory diagram, No. 8
9 are explanatory diagrams of an application example in which the guide plate of the present invention is incorporated, and FIG. 10 is an explanatory diagram of an application example in which an IC chip group is mounted in a casing. DESCRIPTION OF SYMBOLS 1... Board, 2... IC chip, 3... Single-sided mounting, 4... Double-sided mounting, 5... Small hole, 6... Slit plate, 7... Spring. 8... Temperature boundary layer, 9... Chip, 1o... Small high performance electronic computing machine, 11... Semiconductor package, 12
...Housing, 13...Fan, 14...Fin, 15...Guide plate・Figure 2 (α) Fruit shell U = 2 DMy/. Bulky ox illustration cow white side with a small hole, , , , , , , , , , , , , , , , , , , , , , , , , , , , , , other winter i * ii * , 13 - 1 - Faso cow -- −Fiso

Claims (1)

[Claims] 1. In a semiconductor device consisting of a group of IC chips arranged on a substrate and having a mixture of single-sided mounting and double-sided mounting, the IC chip group that is double-sided mounted is cooled more than the IC chip group that is single-sided mounted. A semiconductor substrate for electronic equipment characterized by being arranged on the upstream side of a fluid.