JPH0817959A - Manufacturing jig of solder ball and the solder ball manufacturing method and the forming method of solder bump on a semiconductor package jig - Google Patents

Abstract

PURPOSE:To provide a forming method of a solder ball manufacturing jig efficiently in excellent evenness in diameter, a manufacturing method of solder ball using the jig, and a forming method of solder bump on a semiconductor package using said jig. CONSTITUTION:A jig having multiple blind holes made in required lattice points mounted on a hardly solder wettable metallic plate 1 with the blind holes on the jig surface filled up with solder paste is heated upto the solder melting temperature. Next, leaving the solder balls mounted on the jig intact, a semiconductor package wiring board 9 to form bumps with the positions of the bump forming land and jig holes aligned is mounted on the jig to be heated in such a state to the solder melting temperature thereby enabling the bump forming land of the wiring board 9 to be junctioned with solder.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a jig for manufacturing a solder ball used in a ball grid array, a method for manufacturing a solder knot using the same, and a method for forming a solder bump on a semiconductor package using the jig. .

[0002]

2. Description of the Related Art As a package for a semiconductor device, a leadless chip carrier having a conductor formed on a part of the outside of the package is disclosed in JP-A-59-15.
It is disclosed in Japanese Patent No. 8579. Manufacturing a pin grid array having terminal pins for connecting to through holes of a wiring board is disclosed in Japanese Patent Publication No. 58-11100. A ball grid array is provided in which solder balls are provided instead of the terminal pins of the pin grid array, and the ball grid array is mounted by soldering.
It is disclosed in Japanese Patent Publication No. 00. Further, Japanese Patent Publication No. 58-26828 discloses a method of forming an automated tape carrier in which a terminal portion is first formed and insulated with a tape-shaped insulating film.

Many of such semiconductor devices use ceramics as an insulating material for a package, and a semiconductor chip is mounted on these chip carriers by wire bonding. However, as an organic insulating material, a semiconductor chip is used. Was used to seal after mounting. Further, using the technology of the multilayer wiring board, a pin grid array having terminal pins for connecting to through holes of the wiring board is mounted as a chip carrier for mounting a semiconductor chip and connecting to a circuit formed on the wiring board. Manufacturing is disclosed in Japanese Examined Patent Publication No. 3-25023.

Among them, the ball grid array using solder balls can achieve high-density wiring connection from the mounted semiconductor to the wiring board to be mounted, and the mounting method is also mounted on the semiconductor and exposed to high temperature hot air. As a result, it is a semiconductor package that has been attracting attention in recent years because it can be efficiently manufactured. The method of manufacturing the solder balls used in this ball grid array is to melt the solder alloy by casting, to melt the molten metal out of the pores in a fixed amount into oil, and use the surface tension of the molten solder alloy in high temperature oil. The method of spheroidizing is generally used.

Further, a method of forming solder bumps in which solder balls are mounted on a ball grid array is such that the solder balls formed by the above method are aligned by a vibration aligner, transferred and transferred to a wiring board, and solder melted. The method of forming by heating to a temperature is common.

[0006]

By the way, a conventional method for manufacturing such a solder ball is a container for containing high temperature oil, a device for controlling the temperature of the high temperature oil, and a device for collecting and cleaning solder balls. Manufacturing equipment of
When changing the composition of the solder alloy, it takes time to set up, and in order to obtain a solder ball with a uniform diameter,
There was a problem that it was necessary to select by a sieve. Also, regarding the method of mounting the solder balls on the ball grid array, there is a problem in that a solder ball aligner and a device for mounting the solder balls on the wiring board are required, and further, the mounting process requires time. Furthermore, the tip shape of the solder balls of the ball grid array to be bonded to the conventional wiring board is spherical, and the flatness of each solder bump formed on the grid is the size of the solder ball and the surface accuracy of the wiring board. There was a problem that was affected by.

The present invention is directed to a jig for manufacturing solder balls having excellent diameter uniformity and efficiency, a solder ball manufacturing method using the same, and a semiconductor package efficiently using the jig. It is an object of the present invention to provide a method for forming solder bumps on a substrate.

[0008]

As shown in FIG. 1, a solder ball manufacturing jig according to the present invention comprises a plurality of blind holes 2 formed at required grid points on a metal plate 1 which is hard to get wet with solder. It is characterized by having.

To manufacture solder balls using this solder ball manufacturing jig, as shown in FIG. 3A, paste-shaped solder 6 is individually applied from a dispenser by silk screen printing. Alternatively, the paste-like solder is spread directly on the jig, and a flat plate 7 as shown in FIG.
Then, as shown in FIG. 3C, the jig surface is ground to uniformly supply paste-like solder to each hole,
By heating the jig to the solder melting temperature,
As shown in (d), solder balls 8 can be formed.

After that, the jig is cooled and the obtained solder balls are aligned by a vibration aligner as in the conventional method.
It can also be formed by transferring and transferring it onto a wiring board and heating it to the solder melting temperature. However, as shown in FIG. The semiconductor package wiring board 9 on which bumps are to be formed is placed with the bump forming land and the jig hole positioned through a spacer 11 for adjusting the thickness, and a load 10 on the substrate 10 that does not move during heating. Then, the bump-forming lands of the wiring board 9 and the solder are bonded to each other by heating to a solder melting temperature in this state, and the solder is cooled as it is. As shown in FIG. 9 can be taken out, which is efficient.

As the metal plate 1 which is hard to get wet with solder used in the present invention, for example, a titanium plate or a stainless plate can be used. The shape and dimensions of the blind hole provided in the jig are
Depending on the size of the solder ball to be formed, it can be designed to have a pre-calculated volume, and the grid position of this blind hole is designed according to the position required for the semiconductor package. The shape of this hole is, for example, as shown in FIG.
Holes as shown in (b) and (c) can be formed.

The shape of the solder bumps can be changed by changing the thickness of the spacer 11 shown in FIG.
It can be changed by adopting a hole shape in which the hole bottom surface is flat as shown in FIG. For example, when the spacer 11 is thickened, the tip shape of the bump 12 becomes spherical as shown in FIG. 5A, and when the spacer is thinned or removed to a certain extent, the solder ball is formed as shown in FIG. 5B. Crumbling, bump-shaped bump 13 with a flat tip shape
Since the flatness of the tip surface of each bump is corrected by the hole bottom surface of this jig, high accuracy can be obtained.

[0013]

According to the present invention, the paste-like solder can be gathered into a spherical shape on the plate surface at the time of heating and melting, and the grid-like uniform blind holes 2 are formed. It prevents people from joining each other. By using paste-like solder, the solder can be easily pushed into the holes of the jig. By using paste-like solder, any commercially available paste-like solder can be easily made into solder balls by using this jig.

By aligning the hole positions of the jig of the present invention with the grids of the bump lands of the wiring board on which solder bumps are to be formed, bumps can be formed simultaneously with ball formation. In addition, bumps can be formed without transferring balls.

The blind hole shape of this jig is processed so that the bottom surface is flat and the flatness of the bottom surface of each hole is sufficiently accurate, and the solder balls are forced to the bottom surface of the hole. By heating and melting while pressing, and then cooling as it is, drum-shaped bumps having a highly accurate flatness can be formed.

[0016]

【Example】

Example 1 A flat plate made of titanium having a thickness of 4 mm was arranged in 19 rows and 18 columns in a grid position with a pitch of 1.5 mm, a diameter of 1.2 mm and a depth of 0.
A solder ball manufacturing jig having 361 6 mm cylindrical holes is prepared. The paste-like solder was a eutectic solder, and a solder paste having a flux of 11 wt% was used. The hole size was set so that the ball diameter was 750 μm when the solder balls were formed. The wiring board for the semiconductor package is a glass epoxy board with an outer diameter of 29 mm x 2
9mm, thickness 1mm, bump forming land diameter 0.5
A land having gold-plated bumps formed thereon was used in a grid pattern of 19 mm in length and 19 mm in length and width. First, apply the solder paste onto the solder ball manufacturing jig and slide the solder paste into the blind hole using a stainless steel plate with a width of 60 mm and a thickness of 0.5 mm to slide the jig on the jig. Push in without walls and repeat stretching several times, and finally remove excess solder paste by scraping the surface of the jig with the same stainless steel plate. Next, a spacer with a thickness of 0.5 mm is fixed on the jig in a well-balanced manner at four places so as not to cover the holes. Put it in the right position. Further, a weight of 50 g is placed on the center of the semiconductor package wiring board. 240 ° C in advance
The jig set as described above is placed as it is on the hot plate heated to 1, and heated for 40 seconds. It is placed on a table at room temperature from the hot plate as it is, cooled and disassembled. As a result of this work, a 361
As a result, spherical bumps having an average height of 775 μm were obtained from the end of the wiring board.

Example 2 In Example 1, the wiring board for semiconductor package was directly placed on the jig without using the spacer having the thickness of 0.5 mm, and the other conditions were the same. By this work, the height from the edge of 361 wiring boards to the wiring board is 683μ.
A drum-shaped bump having a flatness of m and a variation of 32 μm (3σ) was obtained.

[0018]

According to the present invention, a uniform solder ball can be easily manufactured from a paste-like solder, and a solder bump can be efficiently formed on a wiring board for a semiconductor package. The shape has a highly accurate flatness.

[Brief description of drawings]

FIG. 1 is a top view of a solder ball manufacturing jig showing an embodiment of the present invention.

2A to 2C are cross-sectional views each showing a shape of a hole portion of a jig showing an embodiment of the present invention.

3A to 3D are cross-sectional views for explaining a solder ball forming process using a jig showing an embodiment of the present invention.

4A and 4B are cross-sectional views for explaining a process of forming bumps on a wiring board for a semiconductor package using a jig showing an embodiment of the present invention.

5A and 5B are cross-sectional views showing the shapes of solder bumps for explaining the effect of the present invention.

[Explanation of symbols]

1. Metal plate that does not easily get wet with solder 2. Hole 3. Conical hole 4. Conical deep hole 5. Cylindrical hole 6. Paste-like solder 7. Flat plate 8. Solder balls 9. Wiring board before bump formation 10. Load 11. Spacer 12. Spherical solder bump 13. Drum-shaped solder bumps

Claims (14)

[Claims] 1. A solder ball manufacturing jig comprising a plurality of blind holes 2 provided on required grid points on a metal plate 1 which is hard to get wet with solder. 2. A titanium plate or a stainless plate is used as the metal plate 1 which is hard to get wet with solder.
Solder ball manufacturing jig described in. 3. The solder ball manufacturing jig according to claim 1, wherein the blind hole 2 has a cylindrical shape. 4. The solder ball manufacturing jig according to claim 1, wherein the blind hole 2 is in the shape of a skirt. 5. The solder ball manufacturing jig according to claim 1, wherein the blind hole 2 has a shape of a skirt and the bottom top is flat. 6. The jig for producing a solder ball according to claim 1, wherein the blind hole 2 has a cylindrical shape at the edge of the hole and a tapered shape. 7. A paste 6 is supplied to a jig having a plurality of blind holes 2 provided on required grid points on a metal plate 1 which is hard to get wet with solder, and a flat plate 7 is used. A method of manufacturing a solder ball, which comprises: uniformly scraping the surface of a jig to uniformly supply paste-like solder to each hole and heating the jig to a solder melting temperature. 8. The method of manufacturing a solder ball according to claim 7, wherein paste solder is individually supplied from the dispenser to the position of the blind hole. 9. The method of manufacturing a solder ball according to claim 7, wherein a silk screen printing method is used to supply the paste-like solder to the position of the blind hole. 10. The method of manufacturing a solder ball according to claim 7, wherein the paste-like solder is directly supplied onto the jig. 11. The method of manufacturing a solder ball according to claim 7, wherein a titanium plate or a stainless plate is used as the metal plate 1 which is hard to get wet with solder. 12. A jig having a plurality of blind holes 2 provided on required grid points on a metal plate 1 which is hard to get wet with solder, and paste-like solder 6 is placed at the blind holes at a dispenser. To spread the paste solder individually and scrape the surface of the jig with the flat plate 7 to uniformly supply the paste solder to each hole and heat the jig to the solder melting temperature. To form solder balls, cool the jig, align the resulting solder balls with a vibration aligner, transfer and transfer to the semiconductor package wiring board, and heat to the solder melting temperature. A method of forming solder bumps on a featured semiconductor package. 13. A jig having a plurality of blind holes 2 provided on required grid points on a metal plate 1 which is hard to get wet with solder, and a paste-like solder 6 at the blind hole position, a dispenser. To spread the paste solder individually and scrape the surface of the jig with the flat plate 7 to uniformly supply the paste solder to each hole and heat the jig to the solder melting temperature. Solder balls are formed by, and with the solder balls still on the jig, the semiconductor package wiring board 9 on which the bumps are to be formed is mounted on the jig via the spacer 11 for height adjustment. And the jig hole are positioned and placed, and a load 10 is applied on the jig hole so that the substrate does not move during heating. In this state, the solder is heated to the solder melting temperature to bond the bump forming land of the wiring board 9 and the solder, As it is Retirement, and a method of forming solder bumps on the semiconductor package, characterized in that retrieving the wiring board 9 formed bumps from the jig. 14. The method for forming solder bumps on a semiconductor package according to claim 13, wherein a titanium plate or a stainless plate is used as the metal plate 1 which is hard to get wet with solder.