JPS59152652A - Manufacture of heat pipe structure ic substrate - Google Patents

Abstract

PURPOSE:To improve the working efficiency and to enhance the heat sink by separately manufacturing and baking an IC substrate formed in a wick structure on one side, an opposite plate, and a supporting frame having wick material filling hole interposed between the substrate and the opposite plate, then assembling and bonding or bonding the frame and the opposite plate in the steps, then baking them and then bonding the sintered substrate. CONSTITUTION:A manufactured circuit substrate A is covered with metal Au on the surface, and a copper pipe is soldered to the position of a wick solution filling hole 23. Silicone resin adhesive is coated on the outer peripheral end of capillary slot 21a forming surface of an opposite plate C, a supporting frame B is superposed and bonded thereon, and dried and cured. Then, glass fiber is filled in ten wick material filling holes 22 of the frame B. The adhesive is coated on the upper surface of the frame B except the filled parts, an IC substrate B is superposed and bonded thereon, followed by curing.

Description

[Detailed description of the invention] It is related to.

In recent years, many IC boards have been seen that utilize heat pipes to improve the heat dissipation of power transistor circuits and the like that generate high heat density.

IC board with conventional heat pipe structure on the 1st floor! ! The perspective view of Figure A is an IC board for mounting electronic components (hereinafter referred to as I).
(abbreviated as C board), the diagonal #A diagram in the opening diagram is a heat pipe. A perforated portion IO is provided on the upper surface of the heat pipe 5, and a circuit mounting (element mounting printing portion 3) is provided in the perforated portion IO.
, the printed wiring portion 4) is inserted into the IC board 1, placed on the protruding support portion s, and bonded. In this manufacturing method, green sheets were processed, laminated and bonded, and then sintered to form a heat pipe 5 structure, and an IC board 1 with circuit wiring was separately manufactured and sintered.

According to the above method, in order to configure the heat pipe 5 having the internal space 11 in the raw stage of the green sheet,
The green sheet sag during manufacturing or baking, and after baking, the surface was uneven and not flat.

Therefore, not only problems occur when printing or vapor-depositing the wiring circuit 9 after sintering, but also the adhesion stability with the IC substrate 1 is poor, and the efficiency of heat dissipation during use is reduced.

Furthermore, since the heat pipe 5 and the IC board 1 are made with an inset structure, extra materials such as the installation of the protruding support part 8 of the heat pipe and high processing costs are required, and the pass rate is low because the surface is not flat. Ta.

The present invention has been made to eliminate the above-mentioned drawbacks, and the gist thereof can be described as shown in the exploded perspective view of FIG. 2. A facing plate C and a supporting frame B having a wick material filling hole 22 interposed between the substrate A and the facing plate C are manufactured separately and then assembled and bonded together after firing, or the supporting frame B and It is characterized in that it is manufactured by bonding the opposing plate C in the main process, and then bonding the sintered A substrate after firing.

In the present invention, it is advantageous for the characteristics and manufacturing cost of the heat pipe structure IC board to make the IC board A, the support frame B, and the opposing plate C from the same ceramic material, but mixing different ceramic materials is advantageous. For example, the IC board A can be made of glass ceramic, and the support frame B and the opposing plate C can be made of other ceramic or metal materials with excellent thermal conductivity. The bonding methods used for these assemblies include means such as organic or inorganic adhesives, solder, and laser, and the optimum bonding method can be selected depending on the material and purpose of use.

The present invention provides a method for forming a green sheet having a wick structure, a method for sintering each component, and then assembling it by adhesion, or a support frame B.
A method of adhering and assembling the sintered IC board A by bonding and sintering the wick of the IC board A and the opposing board C in the main process, or attaching the wick of the IC board A and the opposing board C to the inner hole of the support frame B. In order to establish a connection with the material, a method such as filling a wick material such as organic fiber, glass fiber, or ceramic fiber is used.

For the above reasons, the manufacturing method of the present invention can create sintered flat substrates, making adhesive assembly easy, and is also suitable for wiring printing, vapor deposition, bonding welding of thin metal wires, etc. after adhesive assembly. There were no problems and almost no defects occurred. In addition, the heat pipe structure can be made simpler than the conventional structure, improving the work efficiency of the process, and at the same time, it is possible to further improve the heat dissipation performance of the substrate A, making it possible to produce products with high reliability and uniform quality at low cost. was completed.

Hereinafter, embodiments will be described in detail based on the perspective views of FIGS. 2 and 3, but the present invention is not limited thereto without exceeding the gist of the present invention.

A green sheet is cast using a doctor blade method using a slurry with an alumina content of 96% on a polyethylene carrier film (manufactured by Sambic Corporation, No. 400) whose transfer surface forms capillary grooves. After 12 hours of natural drying,
Two types were molded: one with a thickness of Q, 5 mm, and one with a thickness of Q, 9 m, in which a net-like capillary groove was formed on the peeled surface after being peeled off from the film.

Separately, two types of green sheets with a thickness of 0.3 mm and a thickness of 0.9 mm were formed using the same slurry as above using a commonly used carrier film having a flat surface.

Thickness 0.6 tm and 0.6 tm with capillary grooves formed on one side.
9 Tsuru sheets and both sides flat thickness Q, 3mm and 0.9mm
The sheet was cut into a size of 120 x 60 mm, and each i sheet was prepared. Next, the internal wiring of the IC board was formed by screen printing on a 0.6 mm thick flat surface with capillary grooves on one side using a paste prepared with W metal powder, etc. A through hole for connection with the internal wiring formed above is formed in the sheet, and the hole is filled with metal paste, and a mounting part 24 for IC elements etc. and a wiring circuit part 25 are formed on the top surface of the sheet using the same metal as above. It was formed by screen printing with paste. These two printed sheets are glued together with a solvent so that the upper surface is the printed surface for mounting IC elements, etc., and the lower surface is the capillary groove forming surface. A hole 23 was drilled. After removing the resin, it was fired at 1550°C in a non-oxidizing atmosphere, and the size was 10.
0 x 50 Xo, 75 t*@0:) Substrate A was obtained. In the figure, 21 is a capillary groove on the opposite side (not shown).

After removing the resin from the cut sheet with a thickness of Q and 9 m @ having capillary grooves on one side, it was fired in an oxidizing atmosphere at 1550°C to obtain a counter plate C with dimensions of 100 x 50 xo and 75" m. Inside 218 is a capillary groove.

In addition, the outer dimensions of the cut 9 mm sheet with a flat thickness of Q on both sides are 120 x 60 m, and the inner dimensions are 96 x 3611 + 1.
It was punched out to form a window frame shape, and a total of 10 holes were punched at predetermined positions in the window frame portion to serve as the wink material filling holes 22 of the 7Φ crane. After removing the resin from this, it was fired in an oxidation value atmosphere of 1550'C, and the external dimensions were 100 x 5.
0 Xo, 75 A support frame B with internal dimensions of 76 x 26 fi was obtained with the award amount.

The surface of the circuit board A prepared above was coated with a metal such as Au, and a 20×1.2 Φ copper vibrator was soldered to the wink liquid injection hole 23 position.

As described above, a silicone resin adhesive was applied to the outer peripheral edge of the capillary groove 21a forming surface of the opposing plate C, and the support frame B was layered and bonded thereon, and dried and cured at a temperature of 50°C. Next, 10 locations of the wink material filling holes 22 of the support frame B are filled with glass fibers, a silicone resin adhesive is applied to the upper surface of the support frame B except for the filled portions, and the IC board A is placed on top of the glass fibers. They were overlapped and bonded, and cured and bonded at 50°C.

Next, vacuum degassing was performed, wick liquid was injected, and the 26 holes of the injection tube were sealed with solder. This heat pipe structure IC
It was completed by mounting electronic components such as silicon semiconductor ICs and capacitors on the board.

In the above, the support frame B and the opposing plate C were sintered separately and assembled together by bonding, but the method of bonding these two together in the main process and then bonding and assembling the sintered IC board A after sintering is also the same. A good product was obtained.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a conventional structure, in which the A diagram shows an IC board and the B diagram shows a heat pipe section. Fig. 2 is an exploded perspective view of the present invention, in which Fig. A is an IC board, Fig. B is a support frame, Fig. 0 is a counter plate, and Fig. 3 is an assembled perspective view. 1...IC board, 2.6 Old...ceramic,
3.24...Element loading printing section, 4,9.25.
...Wiring printing section, 5...Heat pipe section, ? , 21゜21a... Capillary groove, 8...
・Protruding support part, IO...Drilling part, 41...
...inner space, 12.26...metal pipe,
13 glass fiber, 22...wink material filling hole,
23... Wick liquid injection hole Figure 1 Figure 3 Figure 2

Claims (1)

[Claims] 1) A method for manufacturing an IC board with a heat pipe structure in which a board on which electronic components are mounted is installed on a plate-shaped heat pipe, in which a wick structure is provided on one side for mounting electronic components. An IC board A, a plate C facing the board A, and a support frame B having a wink material filling hole interposed between the board A and the board C are manufactured separately, and after firing, they are assembled and bonded. Alternatively, a method for manufacturing a heat pipe structure IC board, characterized in that the support frame B and the opposing plate C are bonded in an earlier step, and after firing, the A substrate is bonded. 2) The method for manufacturing a heat pipe structure 10 substrate according to claim 1, wherein the Wifuku material is organic fiber, glass fiber, or ceramic fiber. 3) The above-mentioned bonding after baking can be done using organic or inorganic adhesive, solder,
A method for manufacturing a heat pipe structure IC substrate according to claim 1, wherein the bonding is performed by means such as a laser. 4) The method for manufacturing a heat pipe structure IC substrate according to claim 1, wherein the substrate material is an alumina ceramic or a glass ceramic.