JP2003002360A - Carrier tape - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a carrier tape in which a conventional small-sized QFN package does not contact with the side surface and side bottom portion and also the bottom center part of a component part, and in which the QFN package does not get into touch with a housing recessed portion to the utmost. SOLUTION: In a carrier tape 1 in which a number of housing recessed portions 5 opened on the surface are formed at predetermined intervals in the longitudinal direction and which houses an electronic component 10 in the housing recessed portion 5, three points of protruded portions 1 are provided on an inner bottom surface 2 of the housing recessed portion 5, and the portion of the barycenter of the inside bottom surface 2 is positioned inside a flat triangle formed by the three points of the protruded portions 1.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a carrier tape having a plurality of storage recesses for storing electronic components in a longitudinal direction. 2. Description of the Related Art In recent years, in order to increase the surface mounting density of semiconductors, a QFN package (Quad Flat non-package) has no leads on the sides of the package and has electrode pads on all four sides and the bottom of the four sides. leded
package) has been used. However, when such a semiconductor package is stored and transported, if the electrode pad directly contacts the carrier tape, there is a possibility that the electrode terminal may be contaminated. In addition, the bottom also functions as a heat sink or the like, and it is necessary to minimize contact with the carrier tape. For this purpose, a shelf formed at four corners of a storage recess as disclosed in Japanese Patent Application Laid-Open No.
There is known a carrier tape which mounts four corners of a QFN package and prevents the bottom surface of the storage recess from coming into contact with an electrode terminal. [0004] Such a carrier tape is formed by air pressure molding,
The housing recess is formed by vacuum molding or press molding. In general, the dimensions of the carrier tape storage recess are determined by the dimensional accuracy of the component, the dimensional accuracy of the storage recess, the necessity of a punch taper by a die on the side of the storage recess, the necessary allowance that comes from the mechanical accuracy at the time of component insertion, etc. Generally, each dimensional accuracy is required to be about ± 0.1 mm. [0005] For this reason, this method can solve the problem in a large QFN package in which the size of the shelf at the four corners is sufficiently large. If the contactable parts at the four corners are extremely small due to the need to form electrode pads on the back side, the actual dimensions of the part are on the minimum side, and the actual dimensions of the storage recess are close to the maximum side, etc. An example of falling off occurred. [0006] Further, as disclosed in the above publication, a method of providing a slope on a side surface and fixing the position to a central portion to prevent falling off is disclosed in QFN.
In the package, the electrode pads are exposed at the bottom of the side surface and come into contact with the carrier tape, so that the problem cannot be solved. [0007] Thus, a small QF
In the N package, there has been a need for a carrier tape having a storage structure in which the QFN package does not come into contact with the side and bottom of the component, does not contact with the bottom center as much as possible, and does not rattle in the storage recess. The present invention solves the above-mentioned problems by the following means. That is, a large number of storage recesses opened on the surface are formed at regular intervals in the longitudinal direction, and three points of protrusions are provided on the inner bottom surface of the storage recess in a carrier tape that stores electronic components in the storage recess. The carrier tape is characterized in that the center of gravity of the inner bottom surface is located inside a triangular planar shape formed by the three projections. The carrier tape of the present invention is provided with three projections on the inner bottom surface of the storage recess, and is provided inside the triangle on the plane formed by the vertices of the three projections. It is characterized in that it is provided so that the position of the center of gravity of the planar shape of the storage recess is entered. [0010] By adopting a structure in which the QFN package is supported by the three points of projections, the contact portion with the bottom of the component can be minimized, and since the three points are supported, there is no play at all. The projections do not come into contact with the electrode pads if the electrode pad portions on the bottom surface are skipped. Further, by setting the positions of the three points so that the center of gravity of the planar shape of the storage recess is located inside the triangle on the plane formed by the vertices of the three projections, the component can be placed in the storage recess. Even if it swings, the center of gravity of the part is inside the triangle formed by the three projections, so that the original horizontal state can be maintained without being inclined. The storage recess has substantially the same planar shape as the storage component to prevent rotation of the component. Therefore, the position of the center of gravity of the storage component is located at a position substantially equal to the position of the center of gravity of the planar shape of the storage recess. Even in such a case, the parts can be returned to the horizontal state when they stand still, thereby preventing a take-out error when taking out the parts. There is no particular limitation on the shape of the projection, but if it is a substantially hemispherical projection, the contact becomes a point contact and can be supported with a minimum contact area, and the installation position can be easily selected. Yes, it is easy to form it on the bottom of the storage recess. The storage recess 5 is made of a thermoplastic resin such as polystyrene, polyvinyl chloride, amorphous polyester,
It is obtained by press molding, vacuum molding, air pressure molding, vacuum pressure molding, or air pressure plug assist molding of a resin sheet such as polycarbonate. An embodiment will be described below in detail with reference to the drawings. FIG. 1 is a plan view of a carrier tape according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view showing a state cut along line CC in FIG. [0015] The carrier tape according to the embodiment of the present invention comprises:
This is an embossed carrier tape having a plurality of storage recesses 5 formed at predetermined intervals in the length direction and a plurality of feed holes 4 formed at one end in the width direction at predetermined intervals. After the electronic component 10 is stored in the storage recess 5, a top tape (not shown) is attached to the carrier tape. The storage recess 5 is a substantially rectangular parallelepiped portion for storing the electronic component 10, and as shown in FIG. 1, the opening has a substantially square shape. The center of the wall is retracted so that it does not touch. Therefore, when rotating on a plane, the QFN package is fixed to these four corners and does not contact the side surface. The storage recess 5 has a bottom surface 2 and a bottom surface 2.
Three projections (1a, 1b, 1c) projecting from
An inner peripheral surface 6 and an opening 11 are provided. As shown in FIG. 2, the electronic component 10 is a substantially rectangular parallelepiped QFN package having terminals and the like on the side surface and the side bottom. Therefore, according to the present embodiment, the electrode pads on the side and bottom sides of the QFN package do not come into contact with each other, and the contact portions on the bottom have the minimum necessary three points of contact. It was possible to obtain a carrier tape in which the parts were kept in a horizontal position when parts were removed without rattling. According to the present invention, there is no contact with the electrode pads on the side and bottom sides of the QFN package, and the contact portions on the bottom are the minimum necessary three points of contact. There was no play in the parts, and a carrier tape was obtained in which the parts always kept a horizontal position when the parts were taken out.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of a carrier tape according to an embodiment of the present invention. FIG. 2 is a sectional view showing a state cut along a line CC in FIG. 1; [Description of Signs] 1 Protrusion 2 Inner bottom surface of storage recess 3 Carrier tape 4 Feed hole 5 Storage recess 6 Inner peripheral surface 10 Electronic component 11 Opening

   ────────────────────────────────────────────────── ─── Continuation of front page    (72) Inventor Junichi Haga             2-13-1 Daidai, Kamakura-shi, Kanagawa             Gaku Co., Ltd. F term (reference) 3E067 AA11 AB41 AC04 BA34A                       BB14A EE60 FC01 GD03                 3E096 AA06 BA08 CA15 CC02 DA23                       DB06 DC01 EA02 FA09 FA27                       FA31 GA05

Claims (1)

Claims: 1. A carrier tape for accommodating electronic components in a plurality of storage recesses formed at regular intervals in a longitudinal direction, the storage recesses being open on a surface thereof. Three projections are provided, and the center of gravity of the inner bottom surface is
A carrier tape, wherein the carrier tape is arranged inside a triangular planar shape formed by the three projections.