JPH06188347A - Method and device for manufacturing lead frame - Google Patents

Abstract

PURPOSE:To prevent the generation of failure, by correcting feed and performing baking positioning, when a residual lead pattern is formed by etching, on lead frame material on which a part of the lead pattern is formed. CONSTITUTION:When lead frame material 1 on which a part of a lead pattern is formed with a press is intermittently carried, and the residual pattern is formed by etching, the length between intermittently carried guide holes 3 is measured, and the feed length is calculated. The measured guide hole 3 is made to coincide with a mask reference arranged at a backward specified position, and the lead pattern is baked. The junction part of the baked lead pattern and the previously formed pattern with the press is image-sensed, and the difference of conformation degree is obtained. In order to eliminate the difference, a difference signal is fed back, and the feed is corrected. Then the lead pattern is baked and etched. Thereby the failure due to imperfect conformation can be evaded.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for manufacturing a lead frame by using both press and etching.

[0002]

2. Description of the Related Art A semiconductor device has a semiconductor integrated circuit chip (hereinafter referred to as a chip) mounted on a pad portion of a lead frame, and a chip terminal and an inner lead are connected by a wire such as a gold wire or an aluminum wire, or an inner wire. It is manufactured by directly connecting the lead and the chip terminal and enclosing them with resin or ceramic.

A semiconductor device is indispensable for an electric equipment device applied to each industrial field, and its technical progress is remarkable, and it is important to make it highly functional, highly integrated, and miniaturized.

Under such circumstances, lead frames having 100 pins or more are manufactured.
As the number of pins increases, the width and pitch of the leads become smaller,
Above all, the inner leads are fine.

As one of manufacturing a multi-pin lead frame, a method using both punching by a press and etching is proposed. For example, Japanese Patent Publication No. 3-6663 discloses a method of manufacturing a lead frame in which the inner lead portion and the pad portion are formed by etching and the outer lead portion is formed by pressing. This has the advantages of both a fine etching action by etching and a high-speed and stable punching action by a press, and has the effect that a multi-pin lead frame can be manufactured relatively inexpensively.

[0006]

When a part of the lead pattern is formed by pressing, for example, an outer lead is formed and then the remaining lead pattern is formed by etching, it is important to align the two. Is intermittently conveyed and positioned with reference to the guide hole provided in the guide rail, and the remaining lead pattern is baked, developed, and etched. However, the exactness of the positioning accuracy of baking, which determines the degree of alignment with the lead pattern previously formed, was not known until after etching. For this reason, even if the positioning accuracy of the lead pattern printing is lowered for some reason, there is a case where the shape is defective while it comes out of the etching line.

In practice, the spacing between the guide holes formed in the guide rails of the lead frame material may have an error when viewed in detail, for example, on the order of microns, and also in the intermittent transportation of the lead frame material, The feed length may fluctuate due to wear of the drive system, deterioration over time, and the like, causing misalignment in the lead pattern.

According to the present invention, the baking positioning accuracy is not deteriorated, and even if the accuracy is lowered, it is caught before etching and the lead pattern is positioned with good consistency, and the multi-pin lead frame is excellent in shape. Is manufactured without damage, and its manufacturing device is intended.

[0009]

SUMMARY OF THE INVENTION The gist of the present invention is a method of manufacturing a lead frame, wherein a part of the lead pattern is formed by pressing and the remaining lead pattern is formed by etching. The lead frame material is intermittently conveyed at a length several times as long as the unit lead frame, the length between the guide holes that have been intermittently conveyed is measured, and the measured value is added up to calculate the feed length. , The lead pattern is baked by feeding the guide hole in accordance with the mask reference arranged at a predetermined position behind the threading line, and the above-mentioned baked lead pattern is formed by press in advance from the baking position at the predetermined rear side. An image of the bonded portion of the formed lead pattern is imaged, the difference in the degree of matching is measured, the feed is corrected so as to eliminate the difference, and the baking etching is performed. In the manufacturing method of the lead frame. Another point is that in a lead frame manufacturing apparatus in which a part of a lead pattern is formed by pressing and the remaining lead pattern is formed by etching, a spacing of a predetermined number of unit lead frame lengths is set on a sheet passing line. An apparatus for imaging the guide holes at both ends of the lead frame material that is intermittently conveyed and provided, an image processing unit that outputs an intermittently conveyed feed length signal from an image signal of the imaging apparatus, and the feed length signal is input in advance. A feed control device that outputs a feed signal that aligns the imaging guide hole with the arranged mask reference position, a lead pattern printing device that is provided at a predetermined distance behind the plate passing line, and a burned lead pattern is formed first. A device for picking up an image of the bonded portion of the lead pattern, an image processing unit for inputting an image of the bonded portion and outputting a difference signal of the degree of matching, and sending the difference signal. In apparatus for manufacturing a lead frame to perform the corrected feed as fed back to the control device eliminate the difference.

[0010]

According to the present invention, when the lead frame material having a part of the lead pattern formed by pressing is intermittently conveyed and baked to form the remaining lead pattern by etching, the length between the guide holes conveyed intermittently is measured. Then, the measured value is counted and added for each intermittent transport to calculate the feed length from the measurement position, and the lead pattern is fed by combining the measured guide holes with the mask reference placed at a predetermined rear position. Bake, image the joint part of the lead pattern burned and the lead pattern previously formed by pressing at a predetermined rear from the bake position to obtain a difference in matching degree, and feed back a difference signal so as to eliminate the difference. Then, the feed is corrected and the lead pattern is baked and etched. Therefore, even if the uniformity of the drilling of the guide holes is deteriorated or the conveyance or the like fluctuates, and the accuracy of printing and positioning the lead pattern is deteriorated, it can be recognized at an early stage before the etching and the positioning is immediately corrected. However, damage due to improper alignment cannot be performed, and a lead frame having an excellent shape can be manufactured by using both pressing and etching.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the drawings based on one embodiment. In the drawing, 1 is a lead frame material, and a part of a lead pattern, for example, an outer lead 2 and a guide hole 3 are formed by pressing as shown in FIG. Reference numeral 4 is a lead pattern forming region in the etching process, and in this embodiment, inner leads, pads, support bars, and tie bars are formed by etching.

Reference numeral 5 is an image pickup device such as cameras 5-1 and 5-2 provided at intervals, and images the guide holes 3-1 and 3-2 at both ends of the lead frame material 1 which is intermittently conveyed, and the images thereof are shown. The signal is input to the image processing unit 5A and the feed length is measured from the difference in image position. When the length of intermittent conveyance of the lead frame material 1 is, for example, three unit lead frames 6, the cameras 5-1 and 5-2 have guide holes 3-1 and 3 at both ends within the intermittent conveyance length. -2 as imaging guide holes are arranged at predetermined intervals so as to be placed in the visual field.

Reference numeral 7 denotes a feed control device, which is the image processing unit 5A.
From the feed length signal of the lead frame material 1 intermittently conveyed from the image pickup guide hole 3-1 of the lead frame material 1 which is intermittently conveyed to a mask reference position separately input.
Output a feed signal to align 3-2.

Reference numeral 8 denotes the remaining lead pattern printing apparatus, which is provided behind the cameras 5-1 and 5-2, for example, an integral multiple of the intermittent transport length. In this embodiment, the inner pattern as shown in FIG. Lead 9, pad 10, support bar 1
The pattern No. 1 is printed on a photoresist film (not shown) attached to the lead frame material 1. Reference numeral 12 is a mask reference previously arranged in the field of view of the lead pattern printing apparatus 8, and the imaging guide holes 3-1 and 3 are provided at the time of feeding.
-2 is the standard for matching.

A pattern imaging device 13 is provided behind the lead pattern printing device 8 in a predetermined predetermined position, for example, in the rear of an integral multiple of the length of the unit lead frame 6,
An image of the joint between the baked lead pattern and the lead pattern formed by pressing, for example, the joint between the inner lead 9 and the outer lead 2, is imaged, the degree of matching between the two is detected by the image processing unit 5A, and the difference signal is output. . The difference signal is fed back to the feed control device 7, and the feed of the lead frame material 1 is corrected so that there is no difference in the degree of alignment.

Reference numeral 14 is a conveying device for the lead frame material 1,
Grips 15 are provided at intervals, and this connecting member 16
Connected by. Reference numeral 17 denotes a conveyance driving device, which is, for example, a servo motor, and conveys the lead frame material 1 according to a signal from the feed control device 7. In addition, 18 is a conveyance roll.

The apparatus configuration is as described above. Next, the method will be described together with the operation. Imaging guide hole 3-1 of the lead frame material 1 captured by the cameras 5-1 and 5-2,
From the image position difference 3-2, the length of intermittent conveyance is sequentially added by the image processing unit 5A to obtain the length.

When the lead frame material 1 is intermittently conveyed a predetermined number of times, the lead pattern is printed on the assumption that the image pickup guide hole 3-1 coincides with the mask reference 12 which is arranged in the predetermined rear side in advance.

In such baking, the alignment with the outer leads 2 previously formed may be unsuitable. For example, in a lead frame having 160 pins or more, the lead width,
This is a problem because both pitches are fine. The poor degree of alignment is caused by the existence of an error when the guide hole 3 is pierced at a micron order, a feed error during conveyance, and the like. In order to prevent such misalignment from being detected at an early stage, the present invention uses a pattern imaging device 13 provided behind the lead pattern printing device 8 to image the joint portion of the lead pattern and measure the degree of alignment between the outer lead 2 and the inner lead 9. The difference, for example, the amount of deviation from the picked-up image as shown in FIG.
Is detected and the alignment degree deviation amount x is calculated as (a + b) / 2, and the feed of the lead frame material 1 is corrected so as to eliminate the deviation amount.

In addition to the above-mentioned feed correction, intermittent conveyance is performed and the lead pattern is printed. As a result, the lead patterns of the inner leads 9, the pads 10 and the support bars 11 are printed in alignment with the outer leads 2 previously formed by pressing.

After that, a developing process is performed to remove the photoresist film other than the exposed area through the lead pattern to form an etching mask, and an etching solution is sprayed to etch the inner lead 9, the pad 10, The support bar 11 and the tie bar 19 are formed to form the entire pattern of the lead frame.

The difference between the matching patterns of the two patterns is not limited to the method of the above-described embodiment, and, for example, a reference pattern may be stored in the image processing section 5A and image processing such as a matching method may be employed.

[0023]

As described above, according to the present invention, when the remaining lead patterns are formed by etching on the lead frame material on which a part of the lead patterns has been formed by pressing as described above, baking positioning is performed, so that both patterns are highly accurate. To match. Moreover, even during unmanned production,
The degree of alignment of the printed lead pattern is caught by image processing, and even if the alignment state deteriorates, the correction is directly performed, so that no damage occurs. Furthermore, this function has the effect that the initial positioning becomes simple and can be performed in a short time even when the setup work is changed to another product having a different shape.

[Brief description of drawings]

FIG. 1 is a diagram showing a device configuration according to an embodiment of the present invention.

FIG. 2 is a diagram showing a lead pattern formed by pressing in one example of the present invention.

FIG. 3 is a diagram showing a baked lead pattern during etching in one example of the present invention.

FIG. 4 is a diagram showing a lead frame having a completed lead pattern according to an embodiment of the present invention.

[Explanation of symbols]

 1 Lead Frame Material 2 Outer Lead 3 Guide Hole 4 Lead Pattern Forming Area 5 Imaging Device 5A Image Processing Unit 6 Unit Lead Frame 7 Feed Control Device 8 Lead Pattern Burning Device 9 Inner Lead 10 Pad 11 Support Bar 12 Mask Reference 13 Pattern Imaging Device 14 carrier device 15 grip 16 connecting material 17 carrier drive device 18 carrier roll 19 tie bar

[Procedure amendment]

[Submission date] November 26, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Figure 5

[Correction method] Added

[Correction content]

FIG. 5 is a diagram for explaining the amount of misalignment between the outer lead and the inner lead.

Claims (2)

[Claims] 1. A method of manufacturing a lead frame in which a part of a lead pattern is formed by pressing and the remaining lead pattern is formed by etching. Intermittently conveyed at a length of a predetermined number of times, measure the length between the guide holes that have been intermittently conveyed, count and add the measured lengths to calculate the feed length, and set a predetermined value behind the threading line. The lead pattern is baked by feeding the guide hole in accordance with the mask reference arranged at the position, and the junction between the baked lead pattern and the lead pattern previously formed by the press is imaged at a predetermined rear from the baking position and its image is taken. Measure the difference in the degree of matching, correct the feed to eliminate the difference,
A method for manufacturing a lead frame, which comprises baking and etching. 2. A lead frame manufacturing apparatus in which a part of a lead pattern is formed by pressing and the remaining lead pattern is formed by etching. An apparatus for imaging the guide holes at both ends of the lead frame material that is intermittently conveyed and provided, an image processing unit that outputs an intermittently conveyed feed length signal from an image signal of the imaging apparatus, and the feed length signal is input in advance. A feed control device that outputs a feed signal that aligns the imaging guide hole with the arranged mask reference position, a lead pattern printing device that is provided at a predetermined distance behind the plate passing line, and a burned lead pattern is formed first. A device for picking up an image of the bonded portion of the lead pattern, an image processing unit for inputting an image of the bonded portion and outputting a difference signal of the degree of matching, and sending the difference signal. A lead frame manufacturing device that feeds back to a control device and performs feed correction so as to eliminate the difference.