JPH10132755A - Faulty section detecting method of solder pattern on solder carrier - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to smoothly and speedily detect faulty sections in a solder pattern formed on a solder carrier. SOLUTION: In this method, a solder carrier where a solder pattern is formed on a carrier film and an inspection film with a pattern, where light passes through a part corresponding to the solder pattern, and where light does not pass through the remaining part are stacked, so that the inspection film may come into contact with either of the surface where the solder pattern of the solder carrier is formed or the surface where it is not formed. By irradiating either one of the surface where the inspection film of the solder carrier is stacked or the surface where it is not stacked with light, faulty sections in the solder pattern of the solder carrier is detected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detecting a defective portion of a solder pattern of a solder carrier, and more particularly to a method for detecting a defective portion of a solder pattern on a substrate on which a plurality of pads for mounting connection terminals of a semiconductor element by soldering are mounted. The present invention relates to a method for detecting a defective portion of a solder pattern of a solder carrier used for supplying solder to each pad.

[0002]

2. Description of the Related Art In recent years, as a method of forming solder bumps for flip-chip mounting on a printed wiring board, a solder carrier having a solder pattern formed on a carrier film is mounted on a pad of a printed wiring board coated with flux. A so-called solder transfer method of transferring the solder by heating the same has been proposed (JP-A-6-69640). The solder pattern on the solder carrier is generally manufactured by a punching method or an etching method, but the solder pattern manufactured by such a method has a disadvantage that a part of the solder pattern is separated from the solder carrier, When a solder carrier from which such a solder pattern has been detached is used for a solder transfer method, the obtained package substrate becomes defective.

Therefore, it is necessary to inspect whether the solder pattern is formed on the solder carrier as designed. However, the solder bumps usually cluster together to form one site, the one site being 1000-3000.
It is composed of solder bumps, and on a work-sized board, there are 100 or more solder bumps.
It was virtually impossible to perform a visual inspection.

Therefore, as a method of inspecting a solder carrier, an image of a solder pattern formed on a solder carrier is read by using a CCD camera, and this is calculated by a calculation unit by setting a solder pattern forming area to 1 and a non-forming area to 0. Binarized or multi-valued, stored in the storage unit as image data,
Next, a method of comparing and determining whether or not a solder image as designed is obtained by a logical operation of image data of a solder pattern input in advance has been adopted.

However, in the above method, a camera and a computer are required, so that the cost is high. In addition, a fixing jig for fixing the solder carrier is required to have high accuracy. In order to insert the solder carrier, it is necessary to perform a complicated operation of cutting the solder carrier, and furthermore, since the solder pattern is different for each product lot, the design value of the solder pattern according to each product lot is created. However, it takes time and effort to enter it, and it takes a lot of time to inspect all the work size solder carriers because the camera is brought close to each site and reading is done, etc. There is.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above prior art, and is capable of easily and quickly detecting a defective portion of a solder pattern formed on a solder carrier. An object of the present invention is to provide a method for detecting a defective portion of a solder pattern of a carrier.

[0007]

The gist of the present invention is to provide (1)
A solder carrier in which a solder pattern is formed on a carrier film, and an inspection film in which a pattern in which a light beam is transmitted in a portion corresponding to the solder pattern and a light beam is not transmitted in other portions are formed. The inspection film is laminated so that at least one of the surface where the solder pattern is formed and the surface where the solder pattern is not formed and the inspection film are in contact with each other, and the surface where the inspection film of the solder carrier is laminated or the surface where the inspection film is not laminated And (2) contacting the solder carrier and the test film with the surface of the solder carrier on which the solder pattern is not formed and the test film. Irradiate the light beam on the surface of the solder carrier on which the inspection film is laminated. (1) The method for detecting a defective portion of a solder pattern of a solder carrier according to the above (1), and (3)
The portion corresponding to the solder pattern has a similar shape to the solder pattern of the solder carrier, and the area thereof is 60 to 90% of the solder pattern of the solder carrier. The present invention relates to a method for detecting a defective portion.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method for detecting a defective portion of a solder pattern of a solder carrier according to the present invention will be described in detail. The method for detecting a defective portion of a solder pattern of a solder carrier according to the present invention is, as described above, a solder carrier in which a solder pattern is formed on a carrier film, and a light beam is transmitted through a portion corresponding to the solder pattern. In the part, an inspection film in which a pattern through which light does not pass is formed, and the inspection film is laminated so that at least one surface of the surface where the solder pattern of the solder carrier is formed and the surface where the solder pattern is not formed is in contact with the inspection film, Light is applied to the surface of the solder carrier on which the inspection film is laminated or the surface on which the inspection film is not laminated.

The carrier film used in the present invention comprises:
There is no particular limitation, for example, a glass cloth is impregnated with a resin solution obtained by dissolving a resin such as an epoxy resin, a polyimide resin, and a bismaleimide triazine resin in a solvent such as diethylene glycol dimethyl ether, and then dried to form a so-called B-stage. Prepreg in a state. The thickness of the carrier film is not particularly limited, but is usually preferably about 0.05 to 0.2 mm, more preferably about 0.1 to 0.12 mm.

[0010] The solder carrier used in the present invention includes:
There is no particular limitation. As such a solder carrier, for example, a solder foil having a thickness of 15 to 40 μm is laminated on a carrier film, and the carrier film and the solder foil are integrated by heating and pressing. Form a so-called positive resin layer on the solder foil where the part not irradiated with the light beam is cured without performing, so that the light beam does not pass through the part corresponding to the predetermined solder pattern on the positive resin layer. To do so, for example, by laminating a photomask film made of polyethylene terephthalate or the like on which a light opaque pattern such as a black circle is formed, exposing, developing and forming an etching resist, and then performing an etching resist process And those on which a predetermined solder pattern is formed. In the present invention, when a solder carrier is manufactured in this manner, data of a photomask film used for forming an etching resist can be used when manufacturing an inspection film described later.

The inspection film used in the present invention is, for example, a resin film made of polyethylene terephthalate or the like, and has a pattern in which a light beam is transmitted at a portion corresponding to a solder pattern and a light beam is not transmitted at other portions. It has been formed. The thickness of the inspection film is not particularly limited, but is preferably 0.2 to 0.1.
About 5 μm, more preferably 0.25 to 0.35 μm
Desirably.

The portion of the inspection film corresponding to the solder pattern through which the light beam passes is similar in shape to the solder pattern of the solder carrier, and the area thereof is preferably 60 to 90%, more preferably 60% to 90% of the solder pattern of the solder carrier. Is desirably 70 to 80%. This is because if the pattern for transmitting the light beam of the inspection film is exactly the same size as the solder pattern on the solder carrier, the light beam may be transmitted due to a slight displacement of the inspection film. Note that a deviation between the light transmission pattern of the inspection film and the solder pattern within a range where the light beam does not leak becomes an allowable error of the alignment between the solder carrier and the inspection film.

As a method of forming a pattern on the inspection film in which a light beam is transmitted at a portion corresponding to a solder pattern and a light beam is not transmitted at other portions, for example, a predetermined pattern is formed by so-called CAD (computer aided desig).
n) etc., a method of drawing with a drawing device, a method of printing a predetermined pattern with ink, and the like. Among these methods, pattern data of a photomask film used when manufacturing a solder carrier is used. , Zoom in, zoom out,
Inspection films can be easily manufactured by performing data conversion such as inversion, so that predetermined patterns can be
A drawing method using a drawing device such as D is preferable.

At this time, when a so-called negative resin, which cures a portion irradiated with light rays, is used as a raw material resin of a photomask film for forming an etching resist used in manufacturing a solder carrier. By correcting the data used to produce the photomask film so that the portion corresponding to the solder pattern has a similar shape of preferably about 60 to 90% of the solder pattern area of the solder carrier, It can be used for fabrication. Further, when a so-called positive type resin is used, in which a portion of the photomask film that is not irradiated with light is cured, a negative is obtained by reversing the positive / negative of the data used for producing the photomask film. By making the same modifications as in the case of using the mold resin, the data can be used for producing an inspection film.

In the present invention, the solder carrier and the inspection film are laminated so that at least one of the surface of the solder carrier on which the solder pattern is formed and the surface on which the solder pattern is not formed is in contact with the inspection film; By irradiating a light beam on the surface where the inspection film of the solder carrier is laminated or the surface where the inspection film is not laminated, it is possible to inspect whether the solder pattern is formed on the solder carrier as designed. .

In the present invention, among the above methods,
A method in which a solder carrier and an inspection film are laminated such that the surface where the solder pattern of the solder carrier is not formed and the inspection film are in contact with each other, and a method of irradiating a light beam to the surface of the solder carrier where the inspection film is laminated is preferable. .
This is because, by fixing the inspection film and the light source of the light beam, the inspection can be performed only by laminating the solder carrier on the inspection film, and the continuous inspection of the solder carrier becomes possible.

The light beam used in the present invention is not particularly limited, but a visible light beam is preferably used because a defective portion of the solder pattern can be easily detected by visual observation.

According to the method for detecting a defective portion of a solder pattern of a solder carrier according to the present invention, when a light beam is applied to the surface of the solder carrier on which the inspection film is laminated or the surface on which the inspection film is not laminated, Is transmitted through the solder carrier in a portion of the solder carrier where the solder pattern is not formed, but is shielded in a portion of the inspection film where the light beam does not transmit, and does not reach the opposite surface of the surface irradiated with the light beam. Further, in the solder pattern forming portion of the solder carrier, the light beam is transmitted in a portion corresponding to the solder pattern of the inspection film, but in the solder carrier, the light beam is shielded by the solder pattern itself. Does not reach the surface opposite to the surface irradiated with. Therefore,
When the solder carrier is a non-defective product having a solder pattern formed as designed, the light beam is blocked by the solder carrier and the inspection film, and does not reach the surface opposite to the surface irradiated with the light beam.

However, if there is a defect such as detachment in at least a part of the solder pattern of the solder carrier, or if the solder pattern is not formed as designed, the light beam will not In this case, light passes through the portion corresponding to the solder pattern and the defective portion of the solder pattern, so that light leaks from the defective portion on the surface opposite to the surface irradiated with the light, and when visible light is used as such light, it leaks visually. Since the emitted light can be easily and quickly grasped, it is possible to easily and quickly detect a defective portion of the solder pattern formed on the solder carrier. In addition, when the transmitted light can be image-recognized by, for example, a CCD sensor or the like, it becomes possible to automate the detection of a defective portion.

[0020]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the present invention.

Example 1 A glass cloth was impregnated with a resin solution obtained by dissolving an epoxy resin in diethylene glycol dimethyl ether, and then dried at 60 ° C. for 30 minutes to form a B stage to prepare a 0.1 mm-thick carrier film. . Next, a 40-μm-thick solder foil was laminated on the obtained carrier film, and heated and pressed at 150 ° C. for 6 hours to cure the resin, and the solder foil was brought into close contact with the carrier film.

A positive type liquid resist film (trade name: HL-020B,
(Fuji Banks Co., Ltd.) was placed on the surface, and the layers were integrated by heating and pressing. After that, the surface was made of polyethylene terephthalate (hereinafter referred to as PET) with a thickness of 0.5 by CAD.
A photomask film in which a black circle having a diameter of 250 μm was drawn with black ink was laminated on a portion corresponding to the solder pattern of the μm translucent film, and the photomask film was irradiated with ultraviolet rays. Curing the UV-irradiated part without curing the UV-irradiated part of the positive type liquid resist film,
It was developed and subjected to an etching resist treatment to produce a solder carrier on which a solder pattern having a diameter of 190 μm was formed.

On the basis of the CAD data of the photomask film, an inspection film of PET having a thickness of 0.5 μm was prepared. Since a positive-type liquid resist was used for the photomask film, the data obtained by inverting the positive-negative of the photomask film was used so that the portion corresponding to the solder pattern had a diameter of 160 to 170 μm, and was used by CAD. A pattern in which a light beam was transmitted at a portion corresponding to the solder pattern and a light beam was not transmitted at other portions was drawn on the inspection film. In the above-mentioned pattern, a portion through which light does not pass was drawn using black ink.

Next, using the prepared inspection film,
Whether or not the solder pattern was formed as designed on the solder carrier was examined according to the following method. That is, FIG.
As shown in FIG. 2, a test film 3 having a black ink layer 3b formed on a PET film 3a is placed on a ground glass plate 4 having a thickness of 5 mm with the PET film 3a facing down. The solder carrier 1 on which the solder pattern 2a was formed was placed thereon. Next, a fluorescent lamp (40) is placed on a surface of the ground glass plate 4 on which the inspection film 3 is not placed, from a position 3 cm away from the ground glass plate 4.
W, a white fluorescent lamp) in the direction of arrow A in FIG.

As a result, in the portion where the solder pattern is formed as designed, the light beam transmitted through the inspection film 3 is shielded by the solder pattern 2a in the solder carrier 1, so that the light beam is irradiated on the surface opposite to the surface irradiated with the light beam. Was not observed. However, the defective portion 2b of the solder pattern
Since the light transmitted through the inspection film 3 was further transmitted through the solder carrier 1, the sample looked bright. From this, according to the method of the first embodiment, it is possible to easily and quickly grasp the light leaked from the defective portion such as the detachment of the solder pattern, so that the defective portion of the solder carrier can be easily and quickly determined. It can be seen that it can be detected.

[0026]

According to the method for detecting a defective portion of a solder pattern of a solder carrier according to the present invention, it is possible to easily and quickly detect a defective portion of a solder pattern formed on a solder carrier. Is played.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view showing one embodiment of a method for detecting a defective portion of a solder pattern of a solder carrier according to a first embodiment of the present invention.

[Description of Signs] 1 Solder carrier 2a Solder pattern 2b Defective portion of solder pattern 3 Inspection film 3a PET film 3b Black ink layer 4 Ground glass plate

Claims (3)

[Claims] 1. A solder carrier having a solder pattern formed on a carrier film, and an inspection film having a pattern formed by transmitting light at a portion corresponding to the solder pattern and not transmitting light at other portions. Are laminated such that the test film is in contact with at least one of the surface on which the solder pattern of the solder carrier is formed and the surface on which the solder film is not formed, and the surface or the test film on which the test film of the solder carrier is laminated is formed. A method for detecting a defective portion of a solder pattern of a solder carrier, which comprises irradiating a light beam onto a non-laminated surface. 2. A solder carrier and an inspection film are laminated so that the surface of the solder carrier where the solder pattern is not formed and the inspection film are in contact with each other, and a light beam is applied to the surface of the solder carrier on which the inspection film is laminated. 2. The method according to claim 1, wherein the irradiation is performed. 3. A solder carrier according to claim 1, wherein a portion corresponding to the solder pattern has a similar shape to the solder pattern of the solder carrier, and has an area of 60 to 90% of the solder pattern of the solder carrier. A method for detecting a defective portion of a pattern.