JP2740430B2 - Sealing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seal for joining electronic circuit components and the like used in general electronic equipment such as a computer with a low melting point brazing material such as solder and hermetically sealing the internal space of the joint. It relates to the stopping method.

[0002]

Conventionally, electronic circuit components used in the electronic computer or the like as shown in the sectional view of FIG. 7, for example, Al ₂
For the ceramic substrate 1 made of Al ₂ O ₃ or mullite material on which a large number of iCs (integrated circuits) 18 made of O ₃ or SiC material are mounted, copper for removing heat generated from the iC 18 from the cooling side is used. A cooling component 19 made of an alloy or the like is provided,
Further, in order to support the cooling component 19 and to make the atmosphere around the iC 18 an inert and heat-transferring gas atmosphere such as He, a material such as a copper alloy or AlN surrounded on four sides is used. There is an electronic circuit component in which the cap 2 is pressed and joined with the solder 15 and hermetically sealed so that the periphery of the iC 18 is maintained in a gas atmosphere such as He.

In such an electronic circuit component, when the ceramic substrate 1 and the cap 2 are pressed and joined by the solder 15, conventionally, since the airtightness is emphasized,
Both the ceramic substrate 1 and the cap 2 are subjected in advance to metallization processing capable of diffusing the solder 15 made of a low melting point brazing material such as Sn-Pb material on the opposing surfaces, and the solder 15 is adhered thereto. Thereafter, the entire body is heated by a carbon heater or the like, and the solder 15 is joined together by pushing up the ceramic substrate 1 or pushing down the cap 2 in a predetermined temperature state in which the solder 15 is melted stably. Is hermetically sealed such that the gas is maintained in a gas atmosphere such as He.

In this case, the cooling part 19 and the iC 18 which are vertically suspended from the inner ceiling surface of the cap 2 are brought into contact with each other, and the iC 18
The heat generated from 18 is transmitted to the cap 2 via the cooling component 19, and the cap 2 is further cooled by forced cooling means such as water cooling or air cooling.

[0005] The control of the shape of the solder 15 is dealt with by controlling the amount of solder, adjusting the pressure after pressing the metallized shape, and the like.

[0006] As a document describing a related technique, refer to the IBM Journal "No. 1 January 1982".
There is.

[0007]

However, in the above-mentioned conventional sealing method, the solder 15
In the process from the pressing start position of the cap 2 to the solder 15 and the pressing end position, as shown in FIG. 8, the internal pressure P3 of the cap 2 gradually increases as the pressing progresses, while the external pressure P2 of the cap 2 increases. Is constant, the solder 15 existing on the facing surface of the ceramic substrate 1 and the cap 2 at the final point of the pressing is extruded outward to form a “bulging solder” 20, and the solder on the facing surface Is almost eliminated. Then, the facing surfaces are joined with a small thickness of solder, so when shipped as a product and actually operated, thermal stress is applied to the facing surfaces and cracks occur in the solder on the facing surfaces However, there is a problem that the airtightness inside the cap is broken.

Also, if the solder 15 is pushed out during the pressing, the solder 2 that cannot be completely held at the joint portion
1 scatters outside and adheres to a power supply pattern or the like formed on the outer peripheral portion of the substrate 1, causing a problem of causing an electrical short circuit accident.

In this case, a method is considered in which the external pressure P2 is increased by a predetermined amount immediately after the sealing and the solder 21 protruding outward is returned to the inside immediately after the internal pressure P3. Since the timing at which the solder 15 is sealed is uncertain, the internal pressure P3 at the final pressing position becomes non-uniform, and the sealing shape becomes various only by increasing the external pressure by a predetermined amount. The problem that the solder 15 is lost occurs.

A first object of the present invention is to provide a sealing method capable of reliably maintaining airtightness between members to be joined and preventing the brazing material as a joining material from scattering.

A second object of the present invention is to provide a sealing method capable of appropriately setting the cross-sectional shape of a brazing filler metal at a joint in order to reliably maintain airtightness between members to be joined for a long time. It is to provide.

[0012]

SUMMARY OF THE INVENTION In order to achieve the first object, the present invention relates to a method for melting a brazing material such as solder previously supplied to a portion where at least two members are joined. In a method of hermetically sealing the space formed inside the joint by pressing the member, after melting the brazing material, the sealing mating surface of one member with respect to the sealing mating surface of the other member, The pressing is started from a state where the inclination is a predetermined angle, and the pressing is performed while gradually decreasing the inclination angle so that the entire surface is finally in a parallel state.

Further, in order to achieve the second object, the present invention is to press a member such as a solder or the like previously supplied to a portion where at least two members are to be joined, after melting the material. In the method for hermetically sealing the space formed inside the joint by means of melting the brazing material, the sealing mating surface of one member is inclined at a predetermined angle with respect to the sealing mating surface of the other member. Start pressing from the state,
Finally, after pressing while gradually decreasing the inclination angle so that the entire surface is in a parallel state, the external pressure of the two members is increased by a predetermined amount.

[0014]

According to the above-mentioned means, after the brazing material is melted, at least one member is inclined and pressed against the mating surface of the other members so that the molten solder existing on the mating surface is still in a contact state. The molten solder that is not drawn is drawn toward the contact portion by the surface tension of the contact portion. Then, when one member is pressed from this state so that the inclination angle is gradually parallel to the other members, the solder drawn to the contact part is joined to the mating surface while being pushed out in the direction of the non-contact part. Go.

Therefore, the two members are gradually joined from one end to the other end. That is, the joining surfaces of the two members are not joined at the same timing. As a result, the pressure rise inside the member during the process up to the final pressing position is reduced, so that the brazing material at the joint is prevented from scattering and the confidentiality between the members can be reliably maintained.

Further, even when the movement of the brazing material due to surface tension cannot be expected, the pressure rise from the complete adhesion of the brazing material to the final pressing position can be reduced to almost half, so that immediately after sealing, The follow-up control of the external pressure applied from the outside of the member is facilitated, and the follow-up control is performed, that is, after pressing while gradually decreasing the inclination angle so that the entire surface is finally in a parallel state, the two member external pressures are increased by a predetermined amount. By performing the raising control, the sealing cross-sectional shape can be made appropriate.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

FIG. 1 is a partial sectional view showing an embodiment of a mechanism for carrying out the sealing method of the present invention.
Printed circuit board 1 made of l ₂ O ₃ or mullite material etc. and AlN
A spare solder 15 that can be solder-connected to each other is provided on the cap 2 made of metal such as metal or 42 alloy.

In this case, the printed board 1 and the cap 2 are held at a predetermined interval so that the spare solder 15 is not connected to each other when the spare solder 15 is in a molten state.

A copper alloy is provided around the printed circuit board 1 and the cap 2 for uniformizing heat from the heater 5 such as carbon to transfer the heat to the members (the printed circuit board 1 and the cap 2) and for mechanical protection. Cap protection jig 3
And a substrate protection jig 4.

Further, after sealing the ceramic substrate 1 and the cap 2, He
A chamber 6 is provided for increasing the pressure by such a gas.

Below the ceramic substrate 1, there is provided a pressing mechanism 7 having two pairs of left and right member contact portions 11 projecting upward. The member contact portion 11 of the pressing mechanism 7 is such that the height of the member contact portion 11 on the right side of the drawing is higher by y, and when the substrate protection jig 4 is pushed upward, the right side of the substrate protection jig 4 is pushed up first. The ceramic substrate 1 can be pressed against the cap 2 from a state where the ceramic substrate 1 is inclined at a predetermined angle.

In this case, as shown in FIG. 2, the member contact portion 11 has a spring 12 which can expand and contract in the axial direction, and further has a needle-like member protruding at the tip so as to position the substrate protection jig 3. It has a positioning part 13.

As shown in FIG. 3, the substrate protection jig 4 and the cap protection jig 3 can be moved up and down during tilting pressing, and have pins 9 and positioning holes 10 for positioning. ing.

In this case, the directions in which the pins 9 and the positioning holes 10 are installed are not limited. Although a plurality of member contact portions 11 of the pressing mechanism 7 are required, the number of the contact portions may not be four and may be any shape. Further, the difference y in height between the left and right member contact portions 11 may be any value as long as the ceramic substrate 1 can be inclined.
The direction does not matter.

Next, before describing the operation, the solder 1
The cause of the change of the solder paste 5 is described with reference to FIG. 4. When the solder paste 15 of the ceramic substrate 1 and the cap 2 is melted by the heater 5 and then pressed, the spare solders 15 are temporarily connected to each other during the pressing. When the state is further pressed from the state to the final position, the original pressure P shown in FIG. 4 (a) is further pressed and the internal volume is reduced, and as shown in FIG. As a result, the solder 15 is pushed outward and the solder is scattered.

Therefore, in order to return the extruded solder 15 to the inside, it is necessary to apply a pressure of ΔP to the outside of the members 1 and 2 to return to the original state. However, the pressure control is not easy because ΔP tends to fluctuate, and the shape is not determined even if it is returned by a predetermined ΔP later.

On the other hand, in the present invention, when the ceramic substrate 1 and the cap 2 are joined by the above-described mechanism, they are joined in the steps shown in FIG. FIG. 5
6 shows a cross section when the solder surfaces of the ceramic substrate 1 and the cap 2 shown in FIG.

First, after melting the solder 15, FIG.
In the initial state in which the joint surface between the ceramic substrate 1 and the cap 2 is inclined at a predetermined angle in FIG.
, And one end (the right end in the drawing) of the two joining surfaces is brought into contact as shown in FIG.

Then, of the molten solders 15 existing on the joining surface, the molten solders 15 that have not yet come into contact with each other.
Is drawn toward the contact portion as shown in FIG. 5C by the surface tension of the contact portion. Therefore, when the pressing mechanism 7 is gradually pushed up from this state, the rise of the right member contact portion 11 of the two pairs of member contact portions 11 is suppressed, and only the left member contact portion 11 rises. The tool 4 rises as if the inclination angle is gradually reduced, and finally becomes a parallel state.

Since the state of the ceramic substrate 1 changes in the same manner, the solder 15 drawn to the contact portion in FIG. 5C joins the mating surfaces while being pushed out toward the non-contact portion.

When the joining surfaces are in a parallel state, the pressing is completed. In this case, at the pressing end position, the constant of the spring 12 is set so that the pressing force of the two pairs of member contact portions 11 is the same, and the joining force at the left and right ends is made uniform.

Accordingly, the ceramic substrate 1 and the cap 2 are gradually joined from one end to the other end.
That is, the joining surfaces of the ceramic substrate 1 and the cap 2 are not all joined at the same timing. As a result, the pressure inside the member rises in the process up to the final pressing position after the timing when the two joining surfaces are bonded, and until immediately before this, the internal pressure and the external pressure are the same, and at one end during that time. Since the internal volume is reduced by the drawn solder 15, the rise of the internal pressure is reduced.

As a result, the joint has a cross-sectional shape as shown in FIG. 5D, prevents the solder 15 from scattering, and ensures that the confidentiality between the members is maintained.

Further, even when the movement of the solder 15 due to the surface tension cannot be expected, the pressure rise from the complete adhesion of the solder 15 to the final pressing position can be reduced to almost half, that is, the internal volume is reduced. Almost 1 change
/ 2, so that the follow-up control of the external pressure applied from the outside immediately after the sealing is facilitated, and after the follow-up control, that is, after the pressing is performed so that the entire surface finally becomes a parallel state, the two members are controlled. By performing control to increase the external pressure by a predetermined amount, the sealing cross-sectional shape can be made more appropriate.

In this case, the external pressure can be increased by using a pressure sensor such as baratron or pyranine and supplying a predetermined amount of He gas.

In the above embodiment, the ceramic substrate is raised, but the cap may be lowered.

[0038]

As described above, according to the present invention, when the space formed inside the joint is hermetically sealed by pressing at least two members, after the brazing material such as solder is melted. Then, the pressing is started from a state where the sealing mating surface of one member is inclined at a predetermined angle with respect to the sealing mating surface of the other member, and the inclination angle is gradually reduced so that the entire surface is finally in a parallel state. While pressing
The airtightness between the members to be joined can be reliably maintained, and the brazing material as the joining material can be surely prevented from scattering.

Further, after pressing while gradually decreasing the inclination angle so that the entire surface is finally in a parallel state, the external pressure of the two members is increased by a predetermined amount. There is an effect that the shape can be made appropriate.

[Brief description of the drawings]

FIG. 1 is a partial sectional view showing an embodiment of a mechanism for performing a sealing method of the present invention.

FIG. 2 is a detailed perspective view of a pressing mechanism.

FIG. 3 is a detailed perspective view of a member protecting jig.

FIG. 4 is an explanatory diagram of a pressure increase due to sealing.

FIG. 5 is an explanatory view showing a process of bonding members in the present invention.

FIG. 6 is a plan view showing a solder surface of the member.

FIG. 7 is a cross-sectional view of an electronic circuit component requiring a sealing connection.

FIG. 8 is an explanatory diagram showing a problem of the related art.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Ceramic substrate, 2 ... Cap, 3 ... Cap protection jig, 4 ... Board protection jig, 5 ... Heater, 6 ... Chamber, 7 ... Press mechanism, 8 ... Press gap, 9 ... Pin,
10 positioning hole, 11 member contact part, 12 spring, 1
3: Member positioning portion, 15: Solder, 18: iC, 19
... cooling parts, 20 ... blunt solder, 21 ... scattering solder.

Claims (2)

(57) [Claims] After melting a brazing material such as solder previously supplied to a portion where at least two members are joined,
In a method for hermetically sealing a space formed inside a joint portion by pressing the member, after melting the brazing material, the sealing mating surface of one member with respect to the sealing mating surface of another member. A sealing method characterized in that pressing is started from a state in which it is inclined by a predetermined angle, and pressing is performed while gradually decreasing the inclination angle so that the entire surface is finally in a parallel state. 2. After melting a brazing material such as solder previously supplied to a portion where at least two members are joined,
In a method for hermetically sealing a space formed inside a joint portion by pressing the member, after melting the brazing material, the sealing mating surface of one member with respect to the sealing mating surface of another member. Pressing is started from a state in which the two members are inclined at a predetermined angle, and the two members are externally pressure increased by a predetermined amount after the pressing is performed while gradually decreasing the inclination angle so that the entire surface is finally in a parallel state. Sealing method.