JP3907240B2 - Carrier tape - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a carrier tape used for supplying or transporting an electronic component to a mounting apparatus, and more particularly to a carrier tape suitable for a semiconductor package such as a QFP (Quad Flat Package) including a mold part and leads.
[0002]
[Prior art]
As a conventional carrier tape, for example, one described in Japanese Patent Publication No. 4-42260 is known. As shown in FIG. 7 and FIG. 8, this Japanese Patent Publication No. 4-42260 discloses a strip-like long carrier tape in which a plurality of pockets 2 having a rectangular concave shape in plan view are formed. A pedestal 3 having a rectangular shape in plan view is formed apart from the two peripheral surfaces, a lead receiving groove 4 is formed between the pedestal 3 and the peripheral surface of the pocket 2, and partition ribs 5 are projected on the upper surface periphery of the pedestal 3. Are listed.
[0003]
In such a carrier tape, the semiconductor package P is accommodated in the pocket 2 by placing the lead Pb in the lead accommodating groove 4 and placing the mold part Pa inside the partition rib 5 on the upper surface of the base 3. . Then, after this carrier tape accommodates the semiconductor package P in the pocket 2, a cover tape (not shown) is bonded to the opening surface side of the pocket 2.
[0004]
[Problems to be solved by the invention]
However, in the carrier tape described in Japanese Patent Publication No. 4-42260 described above, when a bending moment is applied during handling by an operator, the lead receiving groove 4 is deformed between the pocket 2 and the base 3. There is a problem in that the accompanying distortion occurs and the peripheral surface of the pocket 2 may come into contact with the lead Pb and the lead Pb may be bent.
[0005]
That is, as shown in FIG. 8a, when a bending moment that causes relative displacement in the longitudinal direction between the opening side (front surface) of the pocket 2 and the bottom side (back surface) of the pocket 2 acts on the carrier tape, As shown in FIG. 8b, when a bending moment that causes the carrier tape to be convex is applied to the carrier tape, as shown in FIG. 8c, the carrier tape is bent so that the back surface is convex. When a bending moment is applied, the lead Pb of the semiconductor package P may be pressed against the peripheral surface of the pocket 2 to cause bending.
[0006]
Also, such carrier tape is formed by pressure forming, vacuum forming, press forming or the like using a mold or the like, and a fine rib is formed on the mold and a partition rib is formed by the protrusion. There is also a problem in that the resin tape is closely attached to the protrusions at the corners of the ribs, the mold release property is hindered, and the molded carrier tape has problems such as deformation.
The present invention has been made in view of the above problems, and even when an external force is applied to the carrier tape, there is no inconvenience such as bending in the lead of the electronic component stored in the pocket, and the mold release property at the time of molding It is an object to provide a carrier tape that can be improved.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, according to the present invention, a rectangular pedestal is bulged and formed on a bottom surface of a pocket formed at a predetermined interval in the longitudinal direction at a distance from the peripheral surface to form a pedestal and the pocket peripheral surface. In the carrier tape in which a lead receiving groove is formed between and a partition rib projectingly formed in the pocket inward direction on the periphery of the seat surface of the base,
An auxiliary rib that is continuous with the partition rib at the corner of the seating surface and extends to the pocket side wall toward the diagonally outer side of the seating surface is formed in the lead receiving groove, and the height of the auxiliary rib from the seating surface is The height of the partition rib is the same as the height from the seat surface over the entire length, or the diagonally inner end of the auxiliary rib is the same as the height from the seat surface of the partition rib, a carrier tape, characterized in that the hand was gradually Hesi as towards the height diagonally outward.
[0008]
The carrier tape according to the present invention, prior Symbol auxiliary rib width b is the aspect (Claim 2) in the range defined by the following equation with respect to the width a of the partition ribs. The relational expression is a ≦ b ≦ 2 × a × cos 45 ° (formula) . Furthermore, the auxiliary rib can be configured to have an aspect in which the diagonally outer portion, that is, the portion continuous with the pocket peripheral surface or the lead receiving groove bottom surface is widened (Claim 3 ).
[0009]
An electronic component has a lead extending from a mold part (electronic component main body) or the like, and is typified by a semiconductor package such as the above-described QFP.
In the carrier tape, a large number of pockets are formed at regular intervals, and a plurality of feed holes are formed at regular intervals on one side or both sides as necessary. This carrier tape is manufactured by molding a thermoplastic resin sheet such as polystyrene, polyvinyl chloride resin, polyethylene terephthalate, or polypropylene by compressed air, pressing, or vacuum forming.
The pocket is composed of, for example, a rectangular recess in a plan view corresponding to the electronic component, for example, a rectangular parallelepiped or a cubic recess opening on one surface (surface).
[0010]
The pedestal has a quadrangular shape whose upper surface corresponds to (for example, similar to) the mold part of the electronic component, for example, a square shape.
The partition ribs are formed at least at the four corners of the upper surface of the base. The partition ribs may be continuous or intermittent, but are preferably formed continuously in a rectangular frame shape.
The lead receiving groove is defined by the standing wall of the pedestal and the side wall of the pocket around the entire periphery of the pedestal to receive the lead of the electronic component, and the depth and width thereof are determined according to the lead of the electronic component.
[0011]
The auxiliary rib has one end (inner end) continuous to the corner partition ribs on the base and extending diagonally outward from the base, and the other end is the bottom surface of the lead receiving groove or the side or top of the pocket (tape surface) Is continuous. The auxiliary rib, the height is equal to the partition ribs over the entire length height, or that lessen gradually toward diagonally outward. As a desirable form, this auxiliary rib has a width dimension method (width dimension of the base portion) b within the range defined by the above-mentioned formula with reference to the width dimension a of the partition rib, and the portion outside the diagonal line is widened. Then, it continues with a large area on the bottom surface of the lead receiving groove and the side surface of the pocket.
[0012]
[Action]
In the carrier tape according to the present invention, the auxiliary rib extends from the partition rib on the periphery of the upper surface of the pedestal to the diagonal side of the pedestal to the side surface of the pocket, the bottom surface of the lead receiving groove, etc., and the rigidity of the lead receiving groove is improved. For this reason, even if a bending moment as shown in FIGS. 8a, 8b, and 8c described above is applied, deformation of the lead receiving groove can be suppressed, and bending of the lead or the like can be prevented from occurring in the electronic component housed in the pocket. And since an auxiliary rib continues to the corner | angular part of a partition rib, the mold release property in the case of shaping | molding is improved, and generation | occurrence | production of a deformation | transformation etc. of a molded product can also be prevented.
[0013]
In particular, the carrier tape according to the second aspect of the present invention has the height of the auxiliary rib substantially the same as the height of the partition rib, so that higher rigidity can be obtained and the deformation of the lead receiving groove can be prevented more reliably.
Similarly, since the carrier tape according to the fourth aspect of the present invention widens the end of the auxiliary rib on the outer side of the pedestal diagonal so as to be continuous with the side wall of the pocket in a large area, higher rigidity is obtained.
[0014]
Further, the carrier tape according to the invention of claim 3 can ensure sufficient rigidity because the width dimension b of the auxiliary rib is not less than the width dimension a of the partition rib and not more than 2a · cos π / 4. It is possible to prevent the lead of the electronic component housed in the interference with the auxiliary rib. That is, if the width b of the auxiliary rib is less than the value a, the shape retaining property of the lead receiving groove cannot be secured sufficiently, and conversely, if the width is larger than the value (2a · cos π / 4), the lead protrudes into the lead storing area. Although it interferes, a sufficient shape can be maintained by setting the width in the above range, and interference with the lead can be prevented.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
1A and 1B show a carrier tape according to an embodiment of the present invention, in which FIG. 1a is a plan view and FIG. 1b is a cross-sectional view taken along line A-O-A in FIG. 1a.
[0016]
In the figure, reference numeral 1 denotes a carrier tape. A large number of cavities 10 are formed on one surface (surface) of the carrier tape 1 at regular intervals in the longitudinal direction, and a large number of feed holes 20 are constant in the longitudinal direction on both sides in the width direction. Formed at intervals. Although not shown and detailed description is omitted, the carrier tape 1 has a known cover tape bonded to the surface of the pocket 10 with a semiconductor package (electronic component) P such as QFP accommodated in the pocket 10. The opening is closed.
[0017]
The pocket 10 is formed of a concave portion that opens in a square shape on the surface of the tape 1, and a pedestal 11 having a square shape in plan view that protrudes at a predetermined interval from a peripheral side surface is bulged and formed on the bottom portion. In the pocket 10, a lead receiving groove 12 is formed around the pedestal 11 by the standing wall of the pedestal 11 and the side wall of the pocket 10. The lead accommodating groove 12 has a substantially square frame shape in plan view, and accommodates the lead Pb of the semiconductor package P in which the mold part Pa is placed on the pedestal 11.
[0018]
The pedestal 11 has a trapezoidal cross-sectional shape in which the side walls (standing walls) are inclined toward each other toward the upper part, and the upper surface has a plan view shape (square in the present embodiment) that is substantially the same as the mold part Pa. . In this pedestal 11, partition ribs 13 that are continuous over the entire periphery of the upper surface are integrally projected, and a detection hole 19 for detecting an electronic component is formed through the center of the upper surface. The partition rib 13 bulges the upper surface periphery of the base 11 and extends in a square side shape along the upper surface periphery of the base 11.
[0019]
Further, in the pocket 10, auxiliary ribs 17 are bulged and formed on the upper surface of the pedestal 11 from the four corners of the partition rib 13 toward the diagonally outward direction of the pedestal 11. The auxiliary ribs 17 have diagonally inward end portions (inner end portions) of the pedestal 11 that have the same height from the seating surfaces of the partition ribs 13 and the pedestal 11, are continuous with the partition ribs 13, and are diagonally outward. gradually decreases in height from the seat surface as it unsuitable, the outer end portion is continuous in the vicinity of the side walls of the pocket 10 to the bottom surface of the lead receiving groove 12. The auxiliary rib 17 is formed to have a value in a range where the root width dimension b is determined by the following formula with respect to the width dimension a of the partition rib 13. a ≦ b ≦ 2 × a × cos 45 ° (formula)
[0020]
In the carrier tape 1 according to this embodiment, the semiconductor package P is accommodated in each pocket 10, and a cover tape that closes the opening of each pocket 10 is bonded to the surface. Here, in the semiconductor package P accommodated in the pocket 10, the mold part Pa is placed on the pedestal 11, and the lead Pb is positioned in the lead accommodating groove 12.
[0021]
In the pocket 10, auxiliary ribs 17 are continuous with the four corners of the partition rib 13, and these auxiliary ribs 17 extend outward in the diagonal direction on the top surface of the pedestal 11 so that the pocket 10 is formed on the bottom surface of the lead receiving groove 12. It continues in the vicinity of the side wall. For this reason, the lead accommodating groove 12 has high shape retention, that is, high rigidity, and deformation of the lead accommodating groove 12 is small even when the bending moment acts as shown in FIGS. Therefore, even if a bending moment acts, the lead Pb of the semiconductor package P and the side wall of the pocket 10 do not come into contact with each other, and bending of the lead Pb due to this contact or the like is prevented.
[0022]
Further, in the carrier tape 1, the width dimension of the auxiliary rib 17 has a value satisfying the following expression with respect to the width dimension of the partition rib 13.
a ≤ b ≤ 2 · a · cos 45 ° (Formula)
For this reason, the rigidity can be sufficiently improved, and the auxiliary rib 17 does not protrude into the region between the lines along the inner surface of the partition rib 13, that is, the lead frame accommodating region, and the lead Pb of the semiconductor package P Interference with the auxiliary rib 17 can also be prevented.
[0023]
Further, the carrier tape 1 is formed by pressure forming or the like using a mold, and partition ribs 13 are formed by fine protrusions or the like formed on the mold. As described above, since the partition ribs 13 have a square frame shape during molding, the partition ribs 13 are in close contact with the mold at the corners, and the releasability between the partition ribs 13 and the mold is hindered. However, the auxiliary ribs 17 are continuous with the four corners of the partition ribs 13 and the auxiliary ribs 17 are formed at the same time as the partition ribs 13. Therefore, the releasability is improved and the release can be performed smoothly.
[0024]
2A and 2B show a carrier tape according to another embodiment of the present invention, in which FIG. 2a is a partially enlarged plan view, and FIG. 2b is a cross-sectional view taken along line B-O-B in FIG. 2a.
In this embodiment and each embodiment described later, the same parts as those of the carrier tape described above are denoted by the same reference numerals and description thereof is omitted.
[0025]
In this embodiment, the auxiliary ribs 17 are continuous with the same height from the seating surface of the partition ribs 13 , and maintain this height, i.e., maintain a uniform height. Consecutive corners. Similar to the embodiment described above, the auxiliary rib 17 has a value in which the width dimension b is defined by the above-described formula.
[0026]
In this embodiment, the auxiliary rib 17 has the same height as the partition rib 13 over the entire length, and the inner end portion is continuous with the partition rib 13 and the outer end portion is continuous with the corner portion of the pocket 10. For this reason, the shape retaining property of the lead receiving groove 12 is more excellent, the deformation of the lead receiving groove 12 is further suppressed, and the releasability at the time of molding is improved.
[0027]
FIG. 3 shows a carrier tape according to a reference embodiment of the present invention, and is a cross-sectional view corresponding to a cross section taken along the line B-O-B in FIG. 2a. In this reference form, the auxiliary rib 17 has an inner end continuous to the partition rib 13 at the same height, an outer end continuous to the upper portion of the corner of the pocket 10, and the height is diagonally outward. It gradually increases to.
[0028]
Also in this reference embodiment, the shape retention of rie de accommodating groove 12 is excellent, it can prevent such bending of the wall and lead Pb pocket 10, also releasing property is improved during molding.
[0029]
FIG. 4 shows a carrier tape according to still another embodiment of the present invention. FIG. 4a is a partially enlarged plan view, and FIG. 4b is a cross-sectional view taken along the line CC in FIG. 4a.
The carrier tape 1 according to this embodiment forms a groove 18 adjacent to the partition rib 13 on the periphery of the upper surface of the base 11. The groove 18 extends in a square frame shape similar to the partition rib 13.
[0030]
In this embodiment, even when the rising part inside the partition rib 13 is curved, the lower edge part of the mold part Pa of the semiconductor package P does not interfere with (climb on) the rising part. The lift of the semiconductor package P due to the interference between Pa and the rising portion of the partition rib 13 is prevented.
[0031]
FIG. 5 shows a carrier tape according to still another embodiment of the present invention, in which FIG. 5a is a partially enlarged plan view, and FIG. 5b is a sectional view taken along the line DD in FIG. 5a.
The carrier tape 1 according to this embodiment projects symmetrically with four convex portions 16 as pedestals 11 on the bottom surface of the pocket 10. These convex portions 16 have a rectangular shape in plan view with a flat upper surface (top surface), and have a protruding height equivalent to the pedestal 11 in each of the above-described embodiments. Further, the partition rib 13 is divided at the center position of each side of the pocket 10 and is formed in a substantially Y shape at the four corners of the pocket 10.
[0032]
In this embodiment, since the mold part Pa of the semiconductor package P is placed on each convex part 16, even if the inner base end part (base part) of the partition rib 13 is curved, the mold part Pa is separated from the mold part Pa. The ribs 13 do not interfere with each other, so that the semiconductor package P is prevented from being lifted, and the semiconductor package P can be accommodated in an appropriate posture, that is, in a posture in which the mold portion Pa is parallel to the tape.
[0033]
In each of the above-described embodiments, the reinforcing rib 17 is formed to have a uniform width, but the outer end portion can be widened as shown in FIGS. 6a and 6b. That is, in the embodiment shown in FIG. 6a, the outer end portion continuous with the wall portion of the pocket 10 of the reinforcing rib 17 shown in FIGS. 2 and 3 is linearly (linear function) widened, that is, widened in a C chamfered shape. .
Similarly, in the embodiment shown in FIG. 6b, the outer end portion of the reinforcing rib 17 has a quadratic function characteristic, that is, the side edge of the outer end portion is widened as a curved surface. 6a and 6b, since the outer end portion of the reinforcing rib 17 is widened and continues to the wall of the pocket 10 with a large area, the shape retaining property of the lead receiving groove 12 can be further improved. In addition, the releasability is further improved.
[0034]
Further, in the embodiment of FIG. 4 described above, the groove 18 is formed on the peripheral edge of the upper surface of the pedestal 11, but instead of this groove 18, an inclined portion inclined downward toward the base end of the partition rib 13 is provided. It can also be formed on the upper surface. In the embodiment of FIG. 5, the planar shape of the convex portion 16 can be arbitrarily selected.
[0035]
【Example】
Next, examples will be described.
In this example, a test sample 1 corresponding to the embodiment of FIG. 1 and a test sample 2 corresponding to the embodiment of FIG. 2 are prepared by the following test sample preparation method. A drop test and a mounting test were conducted by the following test methods.
[0036]
・ Test sample preparation method Thermo-sheet EC (trade name, manufactured by Denki Kagaku Kogyo Co., Ltd.) with a thickness of 0.3 mm is molded into the carrier tape by the compressed air molding method, and the semiconductor package (LQFP100P) is housed as an electrical component. Then, 10 reels wound around a PS injection reel having an outer diameter of 330 mm and an inner diameter of 100 mm were prepared, and these were housed in a cardboard box to prepare test samples.
However, the carrier tape according to the test sample 1 has a depth of the pocket 10 of 2.0 mm, the carrier tape according to the test sample 2 has a depth of the pocket 10 of 3.5 mm, and both the test sample 1 and the test sample 2 The number of semiconductor packages stored on one reel is 1000.
[0037]
Test method 1) Drop test According to JIS Z0202, a drop from a height of 75 cm was performed.
2) Mounting test The sample subjected to the drop test was mounted with a tact time of 0.2 seconds using a mounting machine CP-6 manufactured by Fuji Machine Manufacturing Co., Ltd.
[0038]
Regarding the test sample 1 and the test sample 2 described above, the bending of the lead Pb of the semiconductor package P after the drop test was visually evaluated, but the bending could not be found, and the mounting test could be performed without causing a mounting failure. The carrier tape was proven to be excellent.
[0039]
【The invention's effect】
As described above, according to the carrier tape according to the present invention, a pedestal having a rectangular shape in plan view is formed in a pocket to form a lead receiving groove around the pedestal, and at the periphery of the upper surface of the pedestal. A partition rib is formed to protrude, and an auxiliary rib that is continuous with the pocket side wall is formed diagonally outward from the corner of the partition rib. Therefore, rigidity is improved and shape retention of the lead receiving groove is improved. The bending of the lead due to the contact of the metal and the like can be prevented, and the mold releasability of the mold during molding is improved.
[0040]
In addition , the carrier tape according to the invention of claim 2 can prevent interference between the auxiliary rib and the lead while sufficiently securing the shape retaining property of the lead receiving groove ,
In addition, the carrier tape according to the invention of claim 3 can more reliably prevent the bending of the lead, etc., because the shape retention property of the lead receiving groove is further improved, and the releasability from the molding die can be improved. It can be improved.
[Brief description of the drawings]
FIG. 1 shows a carrier tape according to an embodiment of the present invention, in which a is a partially enlarged plan view and b is a cross-sectional view taken along line A-O-A.
FIGS. 2A and 2B show a carrier tape according to another embodiment of the present invention, in which a is a partially enlarged plan view and b is a cross-sectional view taken along line B-OB in FIG.
FIG. 3 is a cross-sectional view showing a carrier tape according to a reference embodiment of the present invention and corresponding to a BOB arrow view of FIG. 2a.
FIG. 4 shows a carrier tape according to still another embodiment of the present invention, in which a is a partially enlarged plan view, and b is a cross-sectional view taken along the line CC in FIG.
FIG. 5 shows a carrier tape according to still another embodiment of the present invention, in which a is a partially enlarged plan view, and b is a cross-sectional view taken along line D-O-D of a.
FIGS. 6A and 6B are enlarged plan views of a part of a carrier tape according to another embodiment of the present invention.
7 shows a conventional carrier tape, in which a is a partially enlarged plan view, and b is a EE arrow view of a. FIG.
8 is a cross-sectional view corresponding to the EE arrow line of FIG. 7a for explaining the problems of the conventional carrier tape.

Claims (3)

A rectangular pedestal is swelled from the peripheral surface of the bottom surface of the pocket formed at a predetermined interval in the longitudinal direction to form a lead receiving groove between the pedestal and the pocket peripheral surface, and In the carrier tape which formed the partition rib in the pocket inward direction at the periphery of the seat surface of the base,
An auxiliary rib that is continuous with the partition rib at the corner of the seating surface and extends to the pocket side wall toward the diagonally outer side of the seating surface is formed in the lead receiving groove, and the height of the auxiliary rib from the seating surface is The height of the partition rib is the same as the height from the seat surface over the entire length, or the diagonally inner end of the auxiliary rib is the same as the height from the seat surface of the partition rib, carrier tape, characterized in that the hand was gradually Hesi as towards the height diagonally outward. The carrier tape according to claim 1, wherein the auxiliary rib width b is a value determined by the following formula with respect to the width a of the partition rib.
(Formula) a ≦ b ≦ 2 × a × cos 45 °   3. The carrier tape according to claim 1, wherein the auxiliary rib widens a portion continuous with the pocket peripheral surface or the bottom surface of the lead receiving groove. 4.

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