JPS58105556A - Mounting method of lsi package module to printed circuit board - Google Patents

Abstract

PURPOSE:To improve packaging density by providing a heat sink to the rear side of LSI package and mounting it to a printed circuit board through a hole of heat sink of said printed circuit board. CONSTITUTION:When a through hole is provided to a multi-wiring substrate 3 and a heat sink 2 is mounted to the rear side of LSI1 through said through hole, the height B is lower as much as the height of lead terminal 4 than that when it is mounted on the substrate 3 like a conventional one and thereby when it is stacked, the interval of printed circuit boards can be reduced and the packaging density can also be improved. Moreover, the cooling air flow F is uniformly in contact with both sides of LSI, resulting in excellent cooling effect.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for mounting a high-density IC on a printed circuit board, and more particularly, a method for mounting a high-density IC on a printed circuit board.
The method of attaching the module to the printed circuit board is related to the method.

As a high-quality work 0, there is an L8 Eva as shown in FIG. 1, in which a heat sink 2 is mounted on a cage 1. The LSI is attached to the printed circuit board 3 (part of which is shown in FIG. 1) by soldering the lead terminals 4 extending around the L8 battery to the printed wiring on the printed circuit board 3. be exposed.

Here, the height after mounting to the nine printed board 3 including Heaton/Li 2 is A. Therefore, when stacking printed boards on which LSIs are mounted, a minimum interval of A is required between the printed boards. At the same time, the air flow for forced air cooling flows between the printed boards, so that the heat generated by the LSI is cooled only on the side where the heat sink 2 is attached.From this point of view, in the present invention, the printed boards are overlapped. Reduction in printed board spacing when implemented, and! The object of the present invention is to provide a method for mounting an L-day package module on a printed board, which enhances the cooling effect by applying air flow from one side to the heat generated by +8cm. The feature is that the heat V/R is used to attach the sheet sink to the printed board of the IIBX package wall formed on the LSI package.
The seat sink is provided on the back side of the 8-e package, and a hole is formed in the printed board through which the seat sink passes.

The embodiments of the present invention will be described in detail above.

FIG. 2 shows an embodiment of the present invention, and the same parts as in FIG. 1 are given the same numbers. In Fig. 2, ((A) is a later perspective view of installing L8 work 1 to printed board 3, and Fig. 2(B) is a cross-sectional view on the c-c' plane.The installation in Fig. 1 is The difference from the method is that a hole is provided in the printed board (here, a multi-circuit board) 3 through which the sheet sink 2 passes, so that the heat sink 2 on the back side of the L8 workpiece 1 can be attached.
By doing this, the size including the heat sink 2 becomes the size B, and compared to the conventional method, the buried terminal 4
It is smaller by the height of , and the relationship B is established. Therefore, even when printed boards are stacked and mounted, the interval between printed boards can be reduced, and the packaging density can be increased.

Further considering the cooling air, as shown in FIG. 3, the flow indicated by 1 is obtained by the method of the present invention. Therefore, the cooling air can come into contact with both surfaces of L81 evenly, resulting in a good cooling effect.

As described above, the method of the present invention enables high-density packaging of LAN and provides a good cooling effect, making it an extremely useful technique for the hardware configuration of computers.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of a conventional method, FIG. 2 is an embodiment of the present invention, and FIG. 3 is an explanatory diagram of the effect of the embodiment of the present invention. In the figure, l is L8, 2 is heat sink, (111
1) Mr. Commissioner of the Japan Patent Office 1.l Indication of IQ Patent Application No. 204289 of 1982 Supplement 11 Relationship with +ll I↑- Patent issuer Address 1015 Odanaka, 11, Nakahara-ku, Yozaki City, Kanagawa Prefecture (522)
Name: Fujitsu Limited 4 Representative: Ir: Address: I-/1/1/H, Nakausei-ku, Yozaki City, Kanagawa Prefecture] Naka 1015 No. jya 8 Contents of the amendment Attachment O 1) The scope of the present specification and claims is as follows: Correct the text like this. LB where the heat sink is formed on the L8 package.
A method for attaching an e-package module to a printed circuit board, characterized in that a heat sink t-I is provided on the back surface of the 81 package, and a hole is formed in the printed board through which the heat sink passes. How to attach the module to the printed board. 2) Page 3, line 15, page 2, line 19 and 2 of the specification of the present application
0 line and 3rd page, 9th line, "Heat sink" is corrected to "Heat sink". 3) The "hole" in the first and ninth lines of page 3 of the specification of the present application is changed to "hole".
□ 4) Replace Figure 3 in the drawings of this specification with an appropriate drawing with explanatory characters deleted.

Claims (1)

[Claims] According to the method of attaching the L8 package module to the printed board, in which the heat sink is formed on the LSI package, a sheet sink is provided on the back side of the L8 package, and the sheet sink penetrates the printed board. This is a method for attaching the L8 package module to a printed board, which is characterized by forming holes.