JPH10120075A - Carrier tape - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a received area-type package such as a BGA package from rattling to allow a shelf to be machined technically easily and to have sufficient strength by making an angle θ between a housing side wall and a mounting face of a carrier tape to be a specific value. SOLUTION: An angle between a housing side wall 2 of a carrier tape 1 and a surface of a shelf 3 is made to be θ<90 deg., whereby a contact between a received package 4 and the shelf 3 is in a line contact, wherein by supporting by the line contact, rattling of the package due to smoothness of the shelf 3 can be prevented. In addition, the shelf can be in a flat structure, and a sheet can be thick, thereby being advantageous in strength and also advantageously facilitating machining by molding metal. The angle θ is preferably 70 to 85 deg..

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a BGA (ball grid array) package (LSI package in which solder balls are arranged in a lattice pattern on the lower surface) and a CSP (chip size) which are classified into area type packages in electronic components. Μ) in which solder balls are arranged in a lattice pattern at the bottom in an LSI chip size package called
BGA (micro ball grid array) package,
The present invention also relates to a bump chip having bumps for wiring connection formed on an LSI chip, and a carrier tape useful for transporting, storing and mounting a bare chip.

[0002]

2. Description of the Related Art As a carrier tape for accommodating a BGA package, the applicant has previously proposed a carrier tape having a structure in which a shelf is provided in a storage section (Japanese Patent Laid-Open No. Hei 8-11930).
issue). In order to avoid the conventional inconvenience that the stored BGA package is tilted by climbing on the rounded portion that forms the boundary between the storage portion side wall and the mounting shelf, the carrier tape is provided at the boundary between the storage portion side wall and the mounting shelf. A groove is formed, and a round portion is located in the groove.

[0003]

However, when attempting to store a package having a small flange portion such as a μBGA package in the above-described carrier tape, the width of the mounting shelf is inevitably reduced due to the presence of the groove. When trying to process such a narrow mounting shelf and groove with the conventional technology,
Technically very difficult. Further, there is a disadvantage that the thickness of the mounting shelf after processing becomes thinner than that of the mounting shelf without the groove due to the groove, and the strength is weakened.

[0004] Further, even when the width of the mounting shelf is sufficient,
In the structure of the carrier tape described above, when the package is stored, the flange portion of the package and the mounting shelf come into surface contact with each other, so that if there is a factor that impairs the smoothness of the mounting shelf surface, such as shrinkage during molding, the mounting is performed. Irregularities occur on the shelf, and this is the stored B
This causes rattling due to the inclination or lifting of the GA package.

The present invention solves the above-mentioned problem, and prevents rattling of an area type package (hereinafter simply abbreviated as a package) such as a stored BGA package, and processing of a mounting shelf is facilitated. It is an object to provide a carrier tape which is technically easy and has sufficient strength.

[0006]

In order to solve the above-mentioned problems, in the carrier tape of the first aspect, the angle θ between the side wall of the storage section and the surface of the mounting shelf is set to θ <90 °. As a result, the flange portion of the stored package is held in line contact with the mounting shelf, preventing rattling of the package due to the smoothness of the mounting shelf, and preventing the boundary between the storing portion side wall and the mounting shelf. The inconvenience that the package touches the rounded portion of the vehicle and runs over is prevented. Further, in the carrier tape according to the second aspect, at least one protrusion protruding inward is provided on a side wall of the storage section of the carrier tape to facilitate positioning of the package in the storage section.

[0007]

Embodiments of the present invention will be described below with reference to the accompanying drawings. 1A and 1B are diagrams of an example of the carrier tape of the present invention, in which FIG. 1A is a partial plan view showing a storage section, FIG. 1B is a cross-sectional view taken along line XX, and FIG.
It is the elements on larger scale sectional view. FIGS. 2 to 4 are views each showing an example of a storage portion of the carrier tape of the present invention.
(A) is a plan view and (b) is a perspective view.

First, according to the first aspect of the present invention, as shown in FIG.
Is set to θ <90 °, the contact portion between the stored package 4 and the mounting shelf 3 is changed from the conventional surface contact to line contact. In the conventional carrier tape storage unit, if the surface smoothness of the mounting shelf is impaired due to distortion during molding, shrinkage, uneven thickness of the sheet, etc., the storage inside the storage unit due to inclination or lifting of the package stored It was a cause of rattling. To avoid this, it is conceivable to reduce the contact area between the package 4 and the mounting shelf 3, but if the contact area is small, it is difficult to stably store the package. In consideration of the above, by supporting the stored package 4 by line contact at the periphery of the mounting shelf 3, it is possible to prevent rattling of the package due to the smoothness of the mounting shelf 3. .

Further, by setting the angle θ between the storage part side wall 2 and the surface of the mounting shelf 3 to be θ <90 °, the round part A forming the boundary between the storage part side wall 2 and the mounting shelf 3 can be formed. Package 4
Since the lower end edge of the package 4 does not run over the rounded portion A and tilts, the package 4 can be in contact with the side wall 2 of the storage portion, thereby preventing rattling of the package in the storage portion and improving the package. Position control becomes easy.

In this case, as shown in FIG. 1C, when the upper edge α of the round portion, the contact point β between the mounting shelf 3 and the package 4 and the lower end edge of the package 4 and the contact point γ of the storage portion side wall 2 are connected. Since a right triangle is formed, the dimensions of the sides αβ and αγ are automatically determined when the angle θ and the dimension of the effective mounting shelf dimension βγ are determined. From this, the structure of the mounting shelf of the molding die can be easily designed.

In the carrier tape of the present invention, since the mounting shelf 3 may have a flat structure, a conventional structure is provided in which a sheet is stretched at the time of pressing to form a groove at the boundary between the storage portion side wall 2 and the mounting shelf 3. Since the thickness of the sheet can be increased as compared with the conventional method, the sheet is advantageous in terms of strength, and has an advantage that processing with a molding die is easier as compared with a conventional groove structure. Further, if the angle θ between the storage unit side wall 2 and the mounting shelf 3 is 85 ° or more, the lower end edge of the package 4 approaches the round part that borders the storage unit side wall 2 and the mounting shelf 3 and If the package is less than 70 °, the dimensions of the effective mounting shelf become unnecessarily long, and the thickness of the sheet becomes thin and the strength becomes weak.
゜ is preferred.

The relationship between the angle and the length of the sheet will be described in more detail. From the effective mounting shelf dimension βγ and the angle θ between the mounting shelf and the side wall of the storage section, the mounting shelf dimension αβ and a part of the side wall Has the following relationship. αβ = βγ / sinθ αγ = βγ / tanθ The length of γαβ after molding is as follows: γαβ = αβ + αγ = βγ / sinθ + βγ / tanθ = (1 / sinθ + 1 / tanθ) βγ = ((1 + cosθ) / sinθ) βγ . From this, it can be seen that when the angle θ between the mounting shelf and the storage unit side wall is set to an arbitrary angle, the length of γαβ when θ is 90 ° is ((1 + cos θ) / sin θ) times. This is an item that affects the thickness after molding. Specifically, when θ = 70 °, it is about 1.43 times, and θ = 65
゜ is 1.57 times. If it exceeds 1.5 times, it is considered that the thickness becomes thin and the strength becomes weak. Therefore, it can be said that the value of θ is preferably 70 ° <θ <85 °.

Next, FIG. 2 to FIG.
As shown in FIG. 5, by providing the projecting portion 4 protruding inward at at least one position of the housing portion side wall 2, the package storage position is inside the projecting portion 4, so that the position of the package in the housing portion is restricted. This makes it easier to prevent the package from tilting and rattling. Regarding the relationship between the projection and the dimensions of the mounting shelf, the dimension from the tip of the projection 4 to the edge of the mounting shelf 3 is the dimension for mounting the package,
The effective dimension is smaller than the width. This means that even if the mounting shelf such as μBGA is narrow, it is necessary to design the mounting shelf wider than the effective dimension, so that there is also an advantage that it becomes technically easy to process the shelf structure. .

The size of the projection 4 may be sufficient to regulate the position of the package. Usually, the projection 4 is formed so as to protrude inward from the side wall of the housing by 1 to 3 mm. In addition, the shape of the protrusion 4 is not the side and the surface of the package.
A structure in which the contact is made in a line or a point is preferable. However, a structure in which the protrusion is formed in a shape as shown in FIGS. Can be avoided. Further, in the case of a shape in which a radius occurs at the boundary between the projection 4 and the mounting shelf 3, the projection 4 and the mounting shelf 3 are divided as shown in FIG. A completely open structure allows the radius to escape.

[0015]

【Example】

[Example 1] The dimensions of the package were 27 mm x 27 mm
± O. 2mm, width of flange margin is 2.5mm ± O. 1
A carrier tape similar to that shown in FIG. 1 was produced as a carrier tape for accommodating a BGA package of mm. The effective dimension of the mounting shelf 3 was 1.5 mm, and the angle θ between the storage unit side wall 2 and the surface of the mounting shelf 3 was 80 °.

[Embodiment 2] Next, a carrier tape according to the embodiment 1 has a size of an opening of 29 mm × 29 m.
m, a carrier tape having a mounting shelf dimension of 2.5 mm and a protrusion length of 1 mm was prepared.

Example 3 Further, as a structure incorporating the above two features, a carrier tape having a protrusion having a protrusion of θ = 80 ° and a protrusion length of 1 mm was manufactured. The dimensions of the opening were designed according to the second embodiment. When the BGA package was stored using these three types of carrier tapes, there was no rattling of the BGA package in the storage section and no inclination due to riding on the round section.

[0018]

According to the present invention, even if the area type package is stored in the package of the carrier tape according to the present invention, the looseness of the package in the stored state is prevented, so that the breakage of the package in the carrier tape can be prevented. In addition, since the position of the package is regulated by the projection on the side wall of the storage section in the state of being stored in the carrier tape, the package can be easily positioned at the time of mounting, and mounting defects can be eliminated.

[Brief description of the drawings]

FIG. 1 is a view of an example of a carrier tape of the present invention, in which (a) is a plan view showing a storage portion, and (b) is an X-
X-ray sectional view, (c) is a partially enlarged sectional view thereof.

FIG. 2A is a plan view showing a storage section of an example of the carrier tape of the present invention, and FIG. 2B is a perspective view thereof.

FIG. 3A is a plan view showing a storage section of an example of the carrier tape of the present invention, and FIG. 3B is a perspective view thereof.

FIG. 4A is a plan view showing a storage section of an example of the carrier tape of the present invention, and FIG. 4B is a perspective view thereof.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Carrier tape 2 Storage part side wall 3 Mounting shelf 4 Projection part 5 Package

Claims (2)

[Claims] 1. To store an area type package,
A carrier tape having a mounting shelf structure in which the height is kept constant from the bottom surface along the side wall of the storage unit, wherein the angle θ between the side wall of the storage unit and the surface of the mounting shelf is θ <90 °. A carrier tape characterized by the following. 2. The carrier tape according to claim 1, wherein at least one portion of the side wall of the storage portion has a protrusion protruding inward.