JPH06302627A - Alignment method for wiring board and lead frame - Google Patents

Abstract

PURPOSE:To provide a method which aligns a semiconductor device lead frame with a wiring board with accuracy and precision. CONSTITUTION:A quarter disk-shaped notched part 12 is installed to four corners of a square-shaped wiring board. As the notched part is formed at the same time when a through hole or the like is formed, a definite spacing is maintained between both the parts. Two penetration holes 22 are installed to an outer frame of a lead frame 20. Four cylinder-shaped projected parts 32 are installed to an alignment base 30 so as to meet with the notched part of the wiring board. A projected part 33 is installed to the alignment base in such a state that the lead frame 20 may be aligned with and fixed with the wiring board where the notched part is inserted into the projected part. The notched part of the wiring board is inserted into the projected part 32 of the alignment base and fixed. The penetration hole of the lead frame is inserted into the wiring board and placed on the wiring board and contact- bonded with the application of pressure, which makes it possible to align both the parts with higher accuracy.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of aligning a wiring board and a lead frame for mounting electronic parts,
In particular, the present invention relates to a method for accurately aligning a fine pitch lead frame with a wiring board on which a highly integrated integrated circuit chip or the like is assembled.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 7, a method of aligning a wiring board and a lead frame of this type is one in which a rectangular recess 4 is provided on an alignment base 3 and two sides 4a, 4 of the recess 4 are provided.
The wiring board 1 is arranged by end face alignment in which the two sides 1a and 1b of the wiring board 1 are aligned with b, and the cylindrical projection 5 for alignment provided at the reference position of the alignment base 3 is provided with the lead frame 2 through The hole 2a was fitted and aligned with the wiring board 1.

[0003]

By the way, the above-mentioned wiring board is usually formed in a batch on a multi-piece board for mass production, and then separated into a single board. When the processing deviation occurs, the relative position from the end face of the wiring board to the through hole provided in the wiring board or the conductor circuit is misaligned. When the lead frame is aligned and fixed to the wiring substrate thus displaced, the positional displacement may hinder the work and reduce the product yield in the subsequent wire bonding process and the like. . The present invention is intended to solve the above problems, and an object of the present invention is to provide a positioning method capable of easily and precisely positioning a wiring board for an electronic component mounting device and a lead frame. .

[0004]

In order to achieve the above object, the structural feature of the invention according to claim 1 is that arcuate notches are formed at the four corners of a rectangular wiring board. At least two through holes are provided at the reference position of the frame of the lead frame, and the first tubular projection portion and the first tubular projection portion are aligned with the notch portion on the alignment base. And a second tubular projection portion into which a through hole of the lead frame is inserted so that the lead frame is properly aligned in a state in which the wiring board is arranged by fitting the portions. The wiring board is arranged by fitting the notch to the cylindrical projection of No. 1, and the through hole is fitted to the second cylindrical projection, and the lead frame is arranged on the wiring board. It is in.

In addition, the structural feature of the invention according to claim 2 is that the board through holes are provided at least at two reference positions at the four corners of the rectangular wiring board, and the reference positions of the frame of the lead frame are set. At least two through holes are provided, and the first cylindrical protrusion and the first cylindrical projection that are aligned with the substrate through holes are provided on the alignment base.
A second cylindrical projection portion into which the through hole of the lead frame is inserted so that the lead frame is properly aligned in a state where the board through hole is fitted into the cylindrical projection portion of Is provided, the wiring board is arranged by fitting the board through hole into the first cylindrical projection of the alignment table, and the through hole is fitted into the second cylindrical projection and the wiring board is superposed and leaded. It is to arrange the frame.

Further, according to the third aspect of the present invention, the arc-shaped board cutouts are provided at the four corners of the rectangular wiring board at the reference positions, and the board cutouts are provided on the alignment table. A cylindrical projection is provided in accordance with the above, and the frame of the lead frame is arranged so that the lead frame is properly aligned in a state where the board notch is fitted to the cylindrical projection and the wiring board is arranged. The lead is provided with a notch that fits into the tubular protrusion, the board notch is fitted into the tubular protrusion of the alignment base, the wiring board is placed, and the notch is attached to the tubular protrusion. The reason is that the lead frame is arranged so as to be fitted and overlapped with the wiring board.

[0007]

In the invention according to claim 1 configured as described above, since the notch portion of the wiring board can be formed at the same time during the precision machining of the through hole etc. by the machine tool, the notch portion The position accuracy and the processing accuracy are high, and the distance between the notch, the through hole and the conductor wiring is always kept constant. Therefore, by fitting the wiring board having the accurate positioning notches at the four corners between the four first cylindrical projections for board positioning of the positioning table, The wiring board is placed at the reference position on the alignment table without misalignment. Then, the lead frame is accurately aligned with the wiring board by inserting the through hole of the lead frame into the second tubular projection portion for aligning the lead frame of the alignment table and superposing it on the wiring board. In this state, the two are bonded and fixed using an adhesive or the like, so that the wiring board provided with the lead frame is accurately aligned in the subsequent bonding process and the like, and as a result, the final product, the electronic product, is obtained. The component mounting device is manufactured with high yield and at low cost. Further, conventionally, when the outer shape of the wiring board was processed, chamfers of 45 ° were provided at the four corners of each wiring board in order to improve the flow of the mold resin. However, in the invention according to claim 1, the above alignment is performed. Since the notch portion for use corresponds to a conventional chamfer, it is not necessary to purposely provide a chamfer, so that the processing time can be shortened and the processing cost can be reduced.

Further, in the invention according to claim 2 configured as described above, since the substrate through holes of the wiring substrate can be simultaneously formed at the time of precision processing of the through holes by the machine tool, the substrate through holes are located. Both accuracy and processing accuracy are high, and the mutual distance between the substrate through hole and the through hole or the conductor wiring is always kept constant. Therefore, by fitting the wiring board having the board through-holes for positioning with high accuracy in at least two corners between the first cylindrical projections for board positioning of the positioning table, wiring can be performed. The substrate is placed at the reference position on the alignment table without misalignment. And
The lead frame is accurately aligned with the wiring board by inserting the through hole of the lead frame into the second cylindrical protrusion for aligning the lead frame of the alignment table. In this state, the two are bonded and fixed using an adhesive or the like, so that the wiring board provided with this lead frame is accurately aligned in the subsequent bonding step, etc. Manufactured with high yield.

Further, in the invention according to claim 3 configured as described above, the four board notches for alignment provided at the four corners of the wiring board are provided on the alignment table to be fitted. Since the cylindrical protrusion is also used for aligning the lead frame, the frame or the lead of the lead frame is provided with a notch to be fitted into the cylindrical protrusion. Then, after the wiring board is arranged by fitting the board cutout portion of the wiring board into the cylindrical projection portion of the alignment table, the cutout portion of the lead frame is aligned with the same cylindrical projection portion where the wiring board is aligned. By inserting and stacking on the wiring board,
The lead frame is accurately aligned with the wiring board.
In this state, the two are bonded and fixed using an adhesive or the like, so that the wiring board provided with the lead frame is accurately aligned in the subsequent bonding step and the like, and as a result, the electronic component which is the final product is obtained. The on-board device is manufactured with high yield and at low cost. In addition, since it is not necessary to provide a tubular projection dedicated to the lead frame on the alignment table, it is possible to obtain an effect that the alignment table can be easily formed.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a wiring board 10 for a square flat package type semiconductor chip mounting device to which the present invention is applied, a multi-cavity lead frame 20, and a positioning table 30 used for positioning the wiring board 10 and the lead frame 20.
FIG. 2 is a schematic exploded perspective view of FIG.

As shown in FIG. 1 (b), the wiring board 10 is a square printed wiring board having a square semiconductor chip mounting recess 11 in the central portion and the main portions of the present invention at the four corners. Arc-shaped notch 1 for certain alignment
Equipped with 2. In this wiring board 10, a semiconductor chip mounting cavity 11 is formed at a predetermined position by a precision machining tool such as an NC router on a multi-piece substrate, and a through hole (not shown) is formed at a predetermined position by a precision cutting tool such as an end mill. A circular hole for alignment is provided along with the formation of. After that, the multi-piece substrate is cut by a punching die to obtain an individual wiring substrate 10 having symmetrical quarter circle cutouts 12 at four corners. As described above, the cutout portion 12 of the wiring board has high positional accuracy and processing accuracy for alignment, and the distance between the cutout portion 12 and the through hole provided in the wiring board 10 or the conductor wiring is always constant. To be kept.

As shown in FIG. 1A, the lead frame 20 is formed in a four-piece arrangement in which four single lead frames 21 are arranged, and reference positions before and after the outer frame of the single lead frame 21 are formed. A pair of through-holes 22 for alignment are provided at the same time when the leads and the like are etched. Therefore, both the positional accuracy and the processing accuracy of the through hole 22 are appropriate for alignment. In this embodiment, two lead holes 22 are provided for each single lead frame 21, but one lead hole 21 may be provided. That is, in this embodiment, four lead frames 20 are taken, and at least two through holes are required for positioning the lead frame 20, but as a result, four through holes 22 are formed as a whole.
This is because each of the through holes is sufficient for alignment.

As shown in FIG. 1C, the alignment table 30 is provided with four alignment parts 31 according to the number of lead frames 20 to be taken. Each of the alignment parts 31 is provided with four cylindrical protrusions 32 for alignment of the cutout parts 12 at the four corners of the wiring board 10 and two for alignment of the through holes 22 of the lead frame 21. A cylindrical convex portion 33 is provided.

The alignment of the wiring board 10 and the lead frame 20 using the alignment base 30 constructed as described above will be described. First, the wiring board 10 having an adhesive applied to predetermined positions on the front surface side is fitted into the cylindrical projection 32 of the alignment board 30 by inserting the notches 12 at the four corners thereof. Next, as shown in FIG. 2, the lead frame 20 is inserted into the cylindrical convex portion 33 of the positioning substrate 30, the through hole 22 is inserted, and the lead frame 20 is superposed on the wiring substrate 10, and then pressure is applied from above. The wiring board 10 and the lead frame 20 are pressure-bonded and temporarily fixed. As described above, in this embodiment, since the quarter-circle notch for positioning the wiring board and the mutual distance between the through hole and the conductor wiring are always kept constant, the lead frame and When aligning the wiring board with the alignment stand,
Both are precisely aligned. As a result, by using the wiring board to which the lead frame is fixed, the alignment is properly performed in the subsequent wire bonding process and the like, and the semiconductor chip mounting device is manufactured with high yield. Further, conventionally, in order to improve the flow of the mold resin during the outer shape processing of the wiring board, four wirings are provided at the four corners of each wiring board.
Although a chamfer of 5 ° was provided, in the above embodiment,
Since the notch for alignment corresponds to a conventional chamfer, it is not necessary to purposely provide a chamfer, so that the processing time of the wiring board can be shortened and the processing cost can be reduced.

Next, a second embodiment of the present invention will be described with reference to the drawings. FIG. 3 is a wiring board 40 for a QFP type semiconductor chip mounting device and a wiring board 40 according to the second embodiment.
2 is an exploded perspective view schematically showing an alignment table 50 used for aligning the lead frame 20 and the lead frame 20. FIG. The lead frame 20 is the same as that described in the first embodiment.

As shown in FIG. 3A, the wiring board 40 is a printed wiring board having a square shape with four corners cut out at 45 ° with respect to each side, and a square semiconductor chip is mounted in the central portion. In addition to having a concave portion 41 for use, a circular through hole 42 for alignment, which is an essential part of the present invention, is provided at two corners on the diagonal. The manufacturing method of the wiring board 40 is the same as that of the first embodiment, and the description thereof is omitted. However, the through hole 42 of the wiring board is precisely formed in terms of positional accuracy and processing accuracy. The mutual distance between the through holes and the conductor wirings provided on the substrate 40 is always kept constant.

As shown in FIG. 3B, the alignment table 50 is provided with four alignment parts 51 according to the number of lead frames 20 to be taken. Each of the alignment portions 51 is provided with two cylindrical protrusions 52 for aligning the through holes 12 at the two corners of the wiring board 40, and two for aligning the through holes 22 of the lead frame 20. Cylindrical convex part 3
3 is provided.

The alignment of the wiring board 40 and the lead frame 20 using the alignment base 50 constructed as described above will be described. First, the wiring board 40 having the adhesive applied to predetermined positions on the front surface side is fitted into the cylindrical convex portion 52 of the positioning board 50, and the through holes 42 at the two corners thereof are fitted. Next, as shown in FIG. 4, the lead frame 20 is inserted into the cylindrical convex portion 33 of the positioning substrate 50 with the through hole 22 thereof being superposed on the wiring substrate 40, and then pressure is applied from above. The lead frame 20 and the wiring board 40
It is crimped to and temporarily fixed. As described above, also in the second embodiment, the lead frame and the wiring board can be accurately aligned, as in the first embodiment. As a result, by using this wiring board, the alignment in the wire bonding process and the like is properly performed, and the semiconductor chip mounting device is manufactured with a high yield.

Next, a third embodiment of the present invention will be described with reference to the drawings. FIG. 5 is a wiring board 10 for a QFP type semiconductor chip mounting device according to the third embodiment, and a wiring board 10.
FIG. 3 is a plan view showing a part of a state in which the lead frame 60 and the lead frame 60 are aligned with the alignment table 70. The wiring board 10 is the same as that described in the first embodiment, and a description thereof will be omitted. Alignment table 70
Is provided with only four cylindrical convex portions 71 for aligning the cutout portions 12 at the four corners of the wiring board 10. Next, the lead frame 60, which is the main part of the present embodiment, has projecting portions 62 provided at four corners of the frame of the single lead frame 61 and its tip 62a is cut out in an arc shape, and The protrusion 62 is aligned with the wiring board 10.
The tip 62a of the is fitted into the cylindrical convex portion 71 of the alignment table 70.

In the third embodiment configured as described above, the cylindrical convex portion 71 of the alignment base 70 is connected to the wiring board 10.
And the lead frame 20 can be used for alignment, and both are shared by the same cylindrical convex portion 71.
The position can be adjusted with high accuracy. Therefore, similarly to the first and second embodiments, the alignment is properly performed in the subsequent wire bonding process and the like, and the semiconductor chip mounting device is manufactured with a high yield. As a modified example of the third embodiment, as shown in FIG. 6, the lead portion 82 may be used to align the lead frame with the cylindrical convex portion 71 of the alignment base 70. That is, by forming arc-shaped recesses 82a on the side surfaces of a pair of opposing lead portions 82 at the four corners of a single lead frame 81 and fitting the recesses 82a into the cylindrical protrusions 71, the lead frame is wired. The substrate 10 can be accurately aligned. This also provides the same effect as the third embodiment.

The shapes and the like of the wiring board, the lead frame, and the alignment portion of the alignment base shown in each of the above embodiments are examples, and the shapes can be appropriately changed according to the application.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a lead frame, a wiring board, and an alignment table to which a first embodiment of the present invention is applied.

FIG. 2 is a plan view showing a state in which a lead frame and a wiring board are superposed on an alignment base in the embodiment.

FIG. 3 is an exploded perspective view showing a wiring board and an alignment table to which a second embodiment of the present invention is applied.

FIG. 4 is a plan view showing a state in which a lead frame and a wiring board are superposed on an alignment base in the embodiment.

FIG. 5 is a partially enlarged plan view showing a state in which a lead frame and a wiring board are superposed on an alignment base in the third embodiment.

FIG. 6 is a partially enlarged plan view showing a state in which a lead frame and a wiring board are superposed on an alignment base in a modification of the third embodiment.

FIG. 7 is an exploded perspective view showing a lead frame, a wiring board, and an alignment base according to a conventional example.

[Explanation of symbols]

10, 40; Wiring board, 11, 41; Semiconductor chip mounting portion, 12, 82a; Cutout portion, 20, 60, 80; 4
Individually picked lead frame, 21, 61, 81; lead frame, 22; through hole, 30, 50, 70; alignment table, 31, 51; alignment portion, 32, 33, 52, 7
1-shaped convex portion, 62; protruding portion, 82; lead.

Claims (3)

[Claims] 1. A rectangular wiring board is provided with arcuate notches at reference positions at four corners thereof, and at least two through holes are provided at reference positions of a frame of a lead frame. Same as the first tubular projection part that is aligned with the cutout part
Second tubular shape in which the through hole of the lead frame is inserted so that the lead frame is properly aligned in a state where the cutout portion is fitted to the tubular projection portion of A protrusion, and the first of the alignment table
The notch is fitted to the cylindrical protrusion of the wiring board, the through hole is fitted to the second cylindrical protrusion, and the lead frame is arranged on the wiring board. A method for aligning a wiring board and a lead frame, characterized in that 2. A positioning board is provided with at least two through-holes at the four corners of a rectangular wiring board at the reference positions, and at least two through-holes at the reference positions of the frame of the lead frame. A first tubular projection portion aligned with the board through hole, and the lead frame properly aligned in a state where the board through hole is fitted into the first tubular projection portion and the wiring board is arranged. And a second cylindrical projection portion into which the through hole of the lead frame is inserted as described above, and the wiring board is arranged by fitting the board through hole into the first cylindrical projection portion of the alignment base. Then, the through hole is fitted into the second tubular protrusion, and the lead frame is arranged so as to overlap with the wiring board, and the method for aligning the wiring board and the lead frame. 3. A rectangular wiring board is provided with arc-shaped board cutouts at reference positions at four corners, and cylindrical projections are provided on the alignment table so as to match the board cutouts. The tubular notch is fitted to the frame or the lead of the lead frame so that the lead frame is properly aligned with the wiring board arranged by fitting the board notch to the protrusion. And a wiring board is arranged by fitting the board notch to the tubular projection of the alignment table, and the wiring is provided by fitting the notch to the tubular projection. A method for aligning a wiring board and a lead frame, characterized in that the lead frame is arranged on the board.