JP2001036231A - Solder removing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solder removing device which can remove a large quantity of solder without affecting a metallized layer, etc., formed on the solder removing surface. SOLUTION: A solder 111 adhering to a cooling jacket 100 is heated at a melting point or higher by a heater 10 for heating substrate, and it is melted. A squeegee 20 heated by a heater 30 for heating squeegee is moved horizontally apart a specified distance from the cooling jacket 100, and an excessive amount of solder is moved and removed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solder removing apparatus for removing solder from a substrate or the like, and more particularly to a solder removing apparatus suitable for use in a repair operation.

[0002]

2. Description of the Related Art Conventionally, in modules used in electronic computers, for example, as described in JP-A-4-314358 and JP-A-4-147656,
A water-cooled jacket with radiating fins is attached to a ceramic substrate on which a large number of SIs are mounted, and a liquid cooling medium having a heat transfer effect is sealed in the module to generate heat from the LSI, etc. Heat is radiated to the outside through However, with the miniaturization and processing speed of the high-density computer, the LSI mounted in the module has been increasing in density and integration.
The calorific value of I is increasing. As a result, the conventional cooling structure via the cooling medium and the radiation fins cannot provide sufficient cooling.

[0003] Therefore, for example, Japanese Patent Application Laid-Open No. 8-172148.
As described in Japanese Patent Application Laid-Open Publication No. H10-209, there is known a method of improving cooling efficiency by fixing an LSI and a jacket with a solder material or the like.

Here, as described in Japanese Patent Application Laid-Open No. 8-172148, in a module employing a structure in which an LSI and a jacket are fixed with a solder material or the like, if a sealing failure or the like occurs, the fixing is performed. It is necessary to perform a repair operation of melting the solder as a material, releasing the fixation between the LSI and the jacket, and then re-fixing. In this repair work, a solder removing device for removing the solder attached to the jacket is required. As a conventional solder removing apparatus, for example, a contact-type solder removing system using a Cu material is known. In this method, a Cu material is brought into contact with a molten solder so that the Cu material is sucked up.

[0005]

However, when the solder in the cooling jacket was removed using the contact-type solder removal method using a Cu material, it was found that the solder could not be sufficiently removed. That is, in the contact-type solder sucking method using the Cu material, the solder can be uniformly removed, but the amount of removal is relatively small. On the other hand, when the cooling jacket and the LSI are fixed by soldering, assuming that the size of the cooling jacket is 150 mm square, for example, 20 LSIs having a size of 20 mm square are fixed to the jacket. The amount of solder used is also large, and the contact-type solder removal method using Cu
It was found that it was not suitable for removing a large amount of solder material. In particular, if the LSI is removed after the solder between the jacket and the LSI is melted while the LSI is mounted on the jacket, most of the solder (about 90% of the total solder usage) becomes It will remain on the jacket side.

Accordingly, the present inventors have studied a method of melting the solder attached to the jacket and then sucking the melted solder with a vacuum pipe or the like. However, in the vacuum pump method, the amount of suction increases,
It has been found that there is a problem that the metallized layer formed on the surface of the jacket to improve the wettability with the solder is also removed together. In repair work,
After removing the solder, it is necessary to fix the solder between the jacket and the LSI again. At this time, if the metallized layer is removed, the solder between the jacket and the LSI cannot be fixed.

[0007] For example, as described in JP-A-11-42763, a system using a squeegee for printing cream solder is known. In this method, a cream squeegee is used to fill the opening of the mask with cream solder using a filling squeegee, and to scrape off excess solder. here,
The squeegee for scraping is to contact the mask surface and remove the cream solder protruding from the top of the mask, but in removing the molten solder as in the present invention, the squeegee is brought into contact with the cooling jacket, If an attempt is made to remove excess solder, the metallized layer formed on the surface of the cooling jacket is also removed, so that soldering of the jacket and the LSI becomes impossible during repair work.

An object of the present invention is to provide a solder removing apparatus which can remove a large amount of solder without affecting a metallized layer or the like formed on a surface from which solder is removed.

[0009]

In order to achieve the above object, the present invention provides a solder removing apparatus for removing solder attached to a substrate, wherein the solder attached to the substrate is heated to a melting point or higher to melt the solder. A substrate heating heater, and a squeegee that moves in a horizontal direction at a predetermined distance from the substrate and is heated to a melting point of the solder or more, and the squeegee is melted by the substrate heating heater. , And the excess solder is moved and removed. With this configuration, since the squeegee does not directly contact the substrate, a large amount of solder can be removed by moving the squeegee without peeling off an adhesive layer such as a metallized layer on the substrate surface.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration and operation of a solder removing apparatus according to an embodiment of the present invention will be described below with reference to FIGS. First, the overall configuration of the solder removing apparatus according to the present embodiment will be described with reference to FIG.

The cooling jacket 100 to which the solder 111 is attached at a plurality of places is placed on the substrate heater 10 with the surface to which the solder 111 is attached facing upward. The substrate heater 10 heats the cooling jacket 100 and the solder 111 to a temperature equal to or higher than the melting point of the solder 111 to melt the solder 111.

The squeegee 20 for removing solder is attached to the squeegee heater 30 so as to be vertically movable, and is heated by the heater 30 to a temperature equal to or higher than the melting point of the solder 111 to be removed. The squeegee heater 30 for fixedly supporting the squeegee 20 is supported by a support post 40. A gap management roller 50 is attached to the lower end of the column 40. Roller for gap management 5
0 can travel on the roller receiving portion 60.

The squeegee 20 removes excess solder from the solder 111 adhered on the cooling jacket 100 by moving the gap management roller 50 on the roller receiving portion 60.

Next, the structure of a module from which solder is to be removed using the solder removing apparatus according to the present embodiment will be described with reference to FIG. The plurality of LSIs 106 constituting the module 130 are connected and fixed to the ceramic multilayer wiring board 104 by solder balls 116. As a material of the solder ball 116, for example, a tin-silver eutectic solder (Sn3Ag) having a melting point of 221 ° C. is used. The size of the LSI 106 is, for example, 20 m
In the case of m square, the solder ball 116 having a diameter of 170 μm is
About 5000 pieces are used. A frame 105 is fixed to the multilayer wiring board 104 by, for example, a tin-silver-based solder having a high melting point.

The LSI 106 and the cooling jacket 100 are
It is fixed by solder 111. Cooling jacket 1
00 is, for example, made of aluminum nitride (AlN). The solder 111 has a lower melting point than the solder ball 116,
For example, a tin-lead eutectic solder having a melting point of 185 ° C. (Sn37P
b) is used. If the size of the LSI 106 is, for example,
In the case of a 20 mm square, the LSI 106 and the cooling jacket 1 are formed by using a 150 μm thick solder sheet of 200 mm square.
00 is fixed. When the size of the cooling jacket 110 is, for example, 150 mm square, the number of LSIs 106 built in the module 130 is 20, so that
Twenty 200 mm square solder sheets having a thickness of 150 μm are also used. The total amount of solder 111 used is about 15
It is as large as 0 mm ³ .

The cooling jacket 100 and the frame 1
05 is fixed by solder 114. Solder 1
14 has, for example, a melting point of 185, like the solder 111.
℃ tin-lead eutectic solder (Sn37Pb) is used. Although not shown, the LSI 106 has a cap fixed on a substrate on which a semiconductor circuit is formed with high melting point solder to hermetically seal the semiconductor circuit. The melting point of the solder used for fixing the cap is, for example, 280 ° C.

Accordingly, the entire module 130 must have a melting point of the solder 111 and the solder 114 (for example, 185 ° C.) or more and a melting point of the solder ball 116 (for example, 22 ° C.).
1 ° C.) or less, so that the solder 111, 1
By melting only 14, the cooling jacket 100 can be separated from the frame 105 and the LSI 106.

Further, on the side surface of the frame 105, a hermetically sealed hole 118 is formed on the side surface of the frame 105. A port screw 120 is attached to the hermetic sealing hole 118 by a module sealing device (not shown). A sealing material 122 such as an O-ring is attached to the port screw 120.
By tightly contacting the side surface of the module 18, the inside of the module 130 can be hermetically sealed.

A leak test is performed in a state where the inside of the module 130 is hermetically sealed.
The solder 111 and 114 are melted, and the cooling jacket 10 is melted.
0, and a repair operation for attaching the cooling jacket 100 again is required. At this time, the cooling jacket 1
The solder removing device according to the present embodiment is used to remove the excess solder 111 attached to the 00 side.

In the case where the LSI 106 used inside the module 130 is upgraded to a new high-performance LSI, the solders 111 and 114 are also used.
After the cooling jacket 100 is removed,
A repair operation for replacing the SI and attaching the cooling jacket 100 is required. Also at this time, the solder removing device according to the present embodiment is used in order to remove excess solder 111 attached to the cooling jacket 100 side.

Next, referring to FIG.
The configuration of the solder fixing portion between the LSI and the LSI 106 will be described. Note that the same reference numerals as those in FIG. 2 indicate the same parts. A plurality of LSIs 106 constituting the module 130
Are connected and fixed to the multilayer wiring board 104 made of ceramics by solder balls 116.

On the upper surface of the LSI 106, Ti / Ni / A
A metallized layer 112 composed of each plating layer of u is formed. Since the cap of the LSI 106 is made of aluminum, it has poor wettability with the solder.
Is provided, the fixing force with the solder is increased.
The metallized layer 112 is an adhesive layer for improving wettability with solder, and a metal layer other than the metallized layer can be used. The portion of the lower surface of the cooling jacket 100 that is fixed to the LSI 106 by soldering is also provided with Ti.
Metallized layer 113 composed of each plating layer of / Ni / Au
Are formed. Since the cooling jacket 100 is made of aluminum nitride and has poor wettability with the solder, the metallization layer 113 is provided to enhance the bonding strength with the solder. The LSI 106 and the cooling jacket 100
It is fixed with solder 111 via metallization layers 112 and 113.

In the illustrated state, the cooling jacket 100
Are arranged on the upper side and the LSI 106 is arranged on the lower side. When the cooling jacket 100 is detached from the LSI 106, the upper and lower sides of the drawing are reversed, that is, the cooling jacket 100 is arranged on the lower side, and the LSI 106 is arranged on the lower side. Are arranged on the upper side. After heating the cooling jacket 100 and the LSI 106 to melt the solder 111, the LSI 106 side is lifted up, so that the cooling jacket 100 and the LSI
The solder fixation between 106 can be released. At this time, most (about 90%) of the solder 111 is attached to the cooling jacket 100 side, and the cooling jacket 1
At 00, a large amount of solder is attached. In addition, the height of the solder that has been cooled and solidified thereafter is not uniform, and may be too high when the cooling jacket 100 and the LSI 106 are fixed again.
It is necessary to remove the solder remaining at zero. At this time, if an attempt is made to remove all the solder, the metallized layer 113 is removed.
Will also be removed. Since it is difficult to form a metallized layer again on the cooling jacket 100 during the repair work, when removing the solder 111,
It is necessary to leave a certain amount of solder and level the height to the same level. For this purpose, the solder removing apparatus according to the present embodiment is used.

Next, the operation of the solder removing apparatus according to the present embodiment will be described with reference to FIGS. In addition,
The same reference numerals as those in FIG. 1 indicate the same parts. As shown in FIG. 4, an XY stage 80 is arranged in the gas purge chamber 70. On the XY stage 80, the substrate heater 10 and the roller receiver 60 are placed.

The substrate heater 10 has a recess 10A as shown in FIG. Cooling jacket 100
Is housed in the recess 10A. The recess 10A has an opening 10B communicating with the lower portion, and the cooling jacket 100 is vacuum-sucked into the recess 10A via the opening 10B.

On the roller receiving portion 60, a gap management roller 50 is movably mounted. Squeegee 2
The squeegee heater 30 fixedly supports the support 4
Supported by 0. A gap management roller 50 is attached to the lower end of the column 40.

The squeegee 20 for removing the solder is moved in the Z direction shown in FIG.
The cooling jacket 10
It is possible to adjust the gap t1 between 0 and the squeegee 20. The gap t1 is adjusted to be, for example, 40 μm.

The material of the squeegee 20 is, for example, SUS which has poor wettability with solder and high strength. Note that, other than SUS, ceramic or aluminum can also be used. As shown in FIG. 4, the squeegee 20 has a rectangular cross section and a thickness T1 of, for example, 10 mm.

Next, the overall operation of the solder removing apparatus according to the present embodiment will be described with reference to FIG. On the substrate heater 10 in the gas purge chamber 70, a cooling jacket 100 from which solder is to be removed is fixedly supported. Next, an inert gas, for example, a nitrogen gas is introduced into the gas purge chamber 70, and the inside atmosphere is exhausted, whereby the gas purge chamber 7 is exhausted.
0 is a low oxygen concentration atmosphere. The oxygen concentration is, for example, 100 ppm or less.

Next, using the substrate heater 10 and the squeegee heater 30, the solder 111 attached to the cooling jacket 100 is heated to a melting point or higher and melted. After the solder 111 is melted, the squeegee 20 is moved at a constant speed V1 in the direction of the arrow, leaving the solder 111 having a predetermined thickness t1 on the cooling jacket 100,
Remove excess solder. The removed solder is moved by the squeegee 20 to the surplus solder discarding section 90 and discarded. By heating and melting the solder 111 in a low oxygen concentration atmosphere, formation of an oxide film on the solder surface can be prevented.

When the excess solder is removed, the heating by the substrate heater 10 and the squeegee heater 30 is stopped, and after cooling and curing of the solder, air is introduced into the gas purge chamber 70 to perform the solder removing operation. finish.

Next, the solder removing step using the solder removing apparatus according to the present embodiment will be explained with reference to FIG. Note that the same reference numerals as those in FIG. 4 indicate the same parts.
As shown in FIG. 6A, the cooling jacket 100 is housed and held in the recess 10A of the substrate heater 10. On the cooling jacket 100, solder 1
11A, 111B, and 111C are scattered and attached in an island shape. As described with reference to FIG. 3, metallization layers 113 and 112 are provided on the cooling jacket 100 so as to oppose each other in order to improve the wettability of the solder 111 when the solder is fixed to the LSI 106. The solder 11 attached to the cooling jacket 100
1A, 111B and 111C are left only on the metallized layers 113A, 113B and 113C, respectively.

Using the substrate heater 10, the solders 111 A, 111 B, 1 adhered to the cooling jacket 100.
While heating 11C above the melting point, the squeegee 20 for removing the solder is also heated above the melting point temperature using the squeegee heater 30 shown in FIG. When the solder 111 melts, the squeegee 20 moves at a speed V1 in the direction of the arrow. As described in FIG. 4, the gap t1 between the cooling jacket 100 and the squeegee 20 is, for example, 40
μm, so that the solder 111A
When the squeegee 20 comes into contact with the squeegee 20, the solder having a thickness of 40 μm remains at that position, and the excess solder is
In the direction of travel. Here, the metallized layer 1
The thickness of 13A is 1 μm or less.

Further, when the squeegee 20 moves, FIG.
As shown in (B), the solder 1 which has been flattened by the squeegee 20, has a uniform thickness, and is leveled.
11A ′ remains, and the excess solder 111A displaced by the squeegee 20 becomes adjacent solder 1A.
Fuse with 11B.

Further, when the squeegee 20 moves and the squeegee 20 moves toward the solder 111B, FIG.
As shown in (C), the leveled solder 111
A ′ is separated from the solder 111B during leveling. This is because the metallization layers 113A, 113A,
113B is formed in an island shape, and the solder 111
The metallization layer 113 has good wettability, but has poor wettability with aluminum nitride (AlN), which is the material of the cooling jacket 100. Therefore, the solder 111 does not remain on the portion where the metallization layer 113 is not formed, and Layer 113
A, 113B only, solder 111A ', 111B
Is to remain.

Further, when the squeegee 20 moves and the squeegee 20 moves toward the solder 111C, FIG.
As shown in (D), the leveled solder 111
A ′ and 111B ′ remain, and leveling of the solder 111C is performed.

Further, as shown in FIG. 6 (E), an excessive solder waste portion 90 is provided at the end of the squeegee 20 in the moving direction.
Is provided, the excess solder 111Z removed by the squeegee 20 is discarded by the surplus solder disposal unit 90, and the leveled solders 111A 'and 111 are provided.
B ′ and 111C ′ are formed. The leveled solders 111A ', 111B', and 111C 'are formed to have a predetermined thickness, so that the metallized layer 113 can be left. Easy cooling jacket and LS
I can be fixed.

The present inventors have determined that the moving speed V of the squeegee 20 is
As a result of examining No. 1, 5 mm / s to 50 mm
In the range of / s, it was confirmed that the remaining solder could be leveled to a predetermined thickness. Assuming that the moving speed V1 of the squeegee is, for example, 25 mm / s, it is possible to remove excess solder from the surface of the 200 mm square cooling jacket in a short time of 8 seconds.

Although the above description has been made on the assumption that the solder adhered on the cooling jacket is removed, a case where a large amount of solder is removed, for example, a case where a large amount of solder adhered on the multilayer wiring board is removed The solder removing apparatus according to the present embodiment can be applied to the above.

As described above, according to the present embodiment, a large amount of solder can be removed without affecting the metallized layer or the like formed on the surface from which the solder is to be removed. Can be done.

[0041]

According to the present invention, a large amount of solder can be removed without affecting the metallized layer formed on the surface from which the solder is removed.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an entire configuration of a solder removing apparatus according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing the structure of a module from which solder is to be removed using the solder removing apparatus according to one embodiment of the present invention.

FIG. 3 illustrates a configuration of a solder fixing portion between a cooling jacket and an LSI.

FIG. 4 is a side view illustrating the operation of the solder removing device according to the embodiment of the present invention.

FIG. 5 is a front view illustrating the operation of the solder removing device according to the embodiment of the present invention.

FIG. 6 is an explanatory diagram of a solder removing step using the solder removing apparatus according to one embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Substrate heater 20 ... Squeegee 30 ... Squeegee heater 50 ... Gap management roller 60 ... Roller receiving part 70 ... Gas purge chamber 90 ... Excess solder waste part 100 ... Cooling jacket 111 ... Solder 112, 113 ... Metallized layer

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takeshi Takahashi 1st Horiyamashita, Hadano-shi, Kanagawa Prefecture, Hitachi, Ltd. Enterprise Server Division (72) Inventor Eiichi Kiryu 1st Horiyamashita, Hadano-shi, Kanagawa, Hitachi, Ltd. F-term in the Enterprise Server Division of Mfg. (Reference) 5E319 CD57

Claims (2)

[Claims] 1. A solder removing apparatus for removing solder attached to a substrate, comprising: a substrate heating heater for heating the solder attached to the substrate to a melting point or higher to melt the solder; A squeegee that moves in the horizontal direction and is heated to a temperature equal to or higher than the melting point of the solder. The squeegee comes in contact with the solder melted by the substrate heating heater to move and remove excess solder. A device for removing solder. 2. The solder removing apparatus according to claim 1, wherein the solder adheres on an adhesive layer for improving wettability with the substrate, and the adhesive layer is scattered on the substrate. A solder removing device characterized by being formed.