JPH0379040A - Manufacture of spot-shaped partial clad material - Google Patents

Abstract

PURPOSE:To obtain a spot-shaped partial clad material with high-accuracy pitch and dimensions by cutting a metal foil at a fixed interval in the longer direction by a rotary cutter and then by eliminating the metal foil which is not welded and placing a metal foil piece of specified dimensions at a fixed interval on a substrate material and by performing pressure welding and rolling of the tentatively fixed metal foil piece and the substrate material. CONSTITUTION:A substrate material 10 and a metal foil 11 are superposed and the metal foil 11 is subjected to supersonic welding at a fixed interval in the longer direction of the substrate material 10 by a supersonic vibration- applying board 15 at the surface side of a metal foil piece and a directed material 14 on the rear side of the substrate material 10. Further, after cutting the metal foil 11 in the width direction at a fixed interval in the longer direction by a rotary cutter 16, a metal foil piece which is not welded is eliminated and a metal foil piece 12 of specified dimensions is placed at a specified interval on the substrate material 10, and then the tentatively fixed metal foil piece 12 and the substrate material 10 are subjected to pressure welding and rolling, thus achieving a highly accurate alignment with a lead frame material for continuous tentative fixing and for cladding.

Description

[Detailed description of the invention] Industrial field of application The present invention relates to a method for manufacturing spot-shaped partial cladding materials by overlapping pressure welding and rolling, in which metal foil and substrate material fed by a fixed length are continuously ultrasonically welded at predetermined intervals. After temporary fixing, cut the metal foil at predetermined intervals with a rotary cutter to remove the metal foil pieces that are not fixed, or cut the metal foil that has been fed to a fixed length with a punch, and at the same time cut the metal foil to be fed to a fixed length. A manufacturing method for obtaining a spot-shaped partial cladding material having highly accurate pitch and dimensions by temporarily fixing the plate material by ultrasonic welding using an excitation plate for ultrasonic welding built into a punch, and then pressing and rolling it. Regarding.

Background Art In recent years, there has been a strong demand for miniaturization of devices using integrated circuits, and flat packages have come to be frequently used.

A lead frame (3) for such a flat package as shown in FIG. 5 in which terminal portions are provided in the four circumferential directions is coated with a metal (AI, Ag, Cu, etc.) for good bonding on the part where wire bonding is to be performed. It is necessary to provide a section.

Conventionally, in order to provide such a metal-deposited portion in advance, after processing the lead frame, a) a vapor deposition method, and b) a plating method were used, but a method with better mass productivity was desired.

That is, (a) the vapor deposition method not only requires expensive equipment, but also requires masking of unnecessary parts, resulting in slow vapor deposition speed and low productivity; and (b).

Some metals cannot be plated using plating methods, and there are limits to the thickness that can be plated efficiently.

In addition, in order to provide the metal deposited portion in advance, as shown in FIG. A method of forming by etching is considered.

For example, a technology has been proposed in which Al or Ag foil is provided in stripes on a lead frame strip by rolling pressure, and then the unnecessary parts are mechanically or chemically removed to form the desired spot shape. -1078 Publication) However, the yield of deposited metal is poor, the efficiency is poor as it involves masking the parts that need to be deposited and removing unnecessary parts, and it is also difficult to perform spot-like deposition at the required pitch and size with high precision. It was difficult to establish one.

In addition, it is possible to manufacture a spot-shaped partial cladding material of a certain length by overlapping metal foil pieces of a certain size at a certain position on a certain length of substrate material, rolling, and pressure-welding, but Because it is not possible to continuously return, cut the metal foil to be adhered to a predetermined size and length with high precision, align it with high precision, and temporarily fasten it continuously at the required pitch, the spot-like parts Industrial mass production of cladding materials was thought to be impossible.

On the other hand, a lead frame has been proposed (Japanese Patent Publication No. 60-227456) in which AI foil is fixed on the lead frame material by spot welding and then made into a cladding.
No specific manufacturing method has been proposed for aligning metal foils with high precision at a predetermined pitch and temporarily fixing them continuously, making it difficult to put them into practical use.

Furthermore, if the temporary fixing is done simply by spot welding, the AI
The foil is restrained at the welded portion, causing a problem in its rollability, and there is also the problem that the required pitch and dimensional accuracy cannot be increased simply by rolling and pressure welding.

Purpose of the Invention In view of the current situation, the present invention is to cut a metal foil to be adhered to a predetermined size and length with high precision, align it with a lead frame material with high precision, and continuously temporarily cut the metal foil to a predetermined length. The object of the present invention is to provide a method for producing spot-shaped partial cladding material that can be fixed and cladded.

Summary of the Invention This invention involves superimposing a substrate material and a metal foil, and applying ultrasonic waves to the metal foil at regular intervals in the longitudinal direction of the substrate material using an ultrasonic excitation plate on the front side of the metal foil piece and a support material on the back side of the substrate material. Weld the metal foil, then cut the metal foil in the width direction at regular intervals in the longitudinal direction using a rotary cutter, and then remove the metal foil pieces that are not welded to the base material. This is a method for producing a spot-shaped partial cladding material, which is characterized by arranging foil pieces, and then pressing and rolling the temporarily attached metal foil pieces and the substrate material.

Furthermore, the present invention provides a method for manufacturing a spot-shaped partial cladding material in which pieces of metal foil of a predetermined size are crimped onto a substrate material at predetermined intervals, including the step of: The metal foil is sandwiched and cut into a predetermined size by the die and a vertically moving punch that maintains a minimum clearance with the end face of the die, and the vibration plate for ultrasonic welding attached to the descending punch is cut. After sandwiching and cutting, the metal foil piece is pressed onto the strip material, and the metal foil piece is temporarily fixed by ultrasonic welding to one or more points in the width direction of the substrate material using a support material that is in contact with the back side of the strip material. This is a method for producing a spot-shaped partial cladding material, which is characterized in that the temporarily fixed metal foil piece and the substrate material are then pressure-welded and rolled.

This invention involves continuously ultrasonic welding the metal foil and substrate material fed to a fixed length at the required intervals to temporarily fix them, and then cutting off unnecessary parts with a rotary cutter and cutting the metal foil into the required size at a high precision pitch. The pieces were temporarily fixed, or the metal foil that had been fed to a fixed length was sandwiched between a punch and cut, and at the same time, the pieces were temporarily fixed by ultrasonic welding using an ultrasonic welding excitation plate attached to the punch on the substrate material that was fed to a fixed length. After obtaining the material, the rolling load is controlled so as to obtain a predetermined thickness during subsequent pressing and rolling. For example, constant load control and constant elongation control are cascade controlled, and the pitch after rolling is detected to adjust the target load. This is a manufacturing method that allows ultra-high precision plate thickness control and obtains spot-shaped partial cladding materials with highly accurate pitch and dimensions.

Composition of the invention Specifically, this invention: ■Feed the metal foil and substrate material by a fixed length and overlap them.

■The metal foil is sandwiched between the vibrating plate for ultrasonic welding on the front side and the support material on the back side of the substrate material, and ultrasonic vibration is applied with the required pressing force to perform ultrasonic welding.

By such fixed size feeding and ultrasonic welding, metal foils of a predetermined width are overlapped at a predetermined position and temporarily fixed at regular intervals in the longitudinal direction of the substrate material.

(2) For example, a pair of rotating cutters held at regular intervals cut the metal foil in the width direction at regular intervals.

■After cutting, remove the part that is not welded.

(2) By repeating this process, metal foil pieces of a predetermined size can be stacked continuously on the substrate material at a predetermined pitch.

Furthermore, the process includes pressing and rolling to obtain a spot-shaped partial cladding material that is excellent in mass productivity.

To be more specific, this invention provides the following features: (1) A predetermined length of a metal foil strip of a predetermined width is fed into a pinch cutting mechanism, and is cut by a pinch cutter, and this process is repeated to obtain metal foil of a predetermined size with high precision and continuously. .

■A vibration plate for ultrasonic welding is incorporated into the punch, and immediately after cutting the metal, ultrasonic vibration is applied with the required pressing force to perform ultrasonic welding.

■By such metal foil cutting and ultrasonic welding, metal foils of predetermined dimensions are overlapped in a predetermined position and temporarily fixed to the substrate material,
The substrate material is sent out by a predetermined length.

(2) By repeating this process, metal foil pieces of a predetermined size can be stacked continuously on the substrate material at a predetermined pitch.

(2) After this, the process consists of pressure welding and rolling to obtain a spot-shaped partial cladding material that is excellent in mass production.

In this invention, known methods and devices can be applied to ultrasonic welding.
Ultrasonic vibrations of 6 kHz were applied to a vibrating plate that was brought into contact with a pressing force of approximately ION in the direction of the bonding thickness between the metal foil and the substrate material. Hold for 1-1 seconds to complete welding.

In this invention, any known material such as the 42Ni-Fe system used as lead frame material can be applied to the substrate material serving as the clad base material, and the metal foil to be pressure-welded in a spot shape can be Ag, Ag-Cu, etc. Known brazing materials such as Ag brazing material, Al, Cu, etc. can be used.

Based on the Drawings <Disclosure of the Invention Figures 1a, b, d, and f are schematic explanatory diagrams showing the manufacturing process of a rolled material, and Figures 1c and 1e are schematic illustrations of a welding device and a cutting machine viewed from the line direction. It is an explanatory diagram.

2A to 2E are schematic explanatory diagrams of an embodiment of a fixed-size feeding and welding device showing the manufacturing process of a rolled material, and FIG. 2A is an explanatory diagram as seen from the line direction.

FIG. 3 is a schematic explanatory diagram of a rolling mill showing the rolling pressure welding method according to the present invention.

Configuration 1 The substrate material (10) unwound from the coil is sent to the ultrasonic welding device (13) in predetermined lengths by a fixed size feeding device (not shown), and the metal foil (11) is similarly fed from above to a fixed size. The device sends out a predetermined length at a time.

Further, on the downstream side of the ultrasonic welding device (13), there is provided a cutting device using a pair of circular cutters (16), which is used to wind the coil into a coil after welding, which will be described later.
Welding and rolling are performed using a rolling device installed on the downstream side.

Although the device for feeding the substrate material (10) and the metal foil (20) to fixed lengths is not shown, any known configuration can be used as long as it can feed the substrate material (10) and the metal foil (20) in predetermined lengths.

As shown in Figure b, the ultrasonic welding device has a supporting member (14) movably disposed on the back side of the substrate material (10) at the position where the metal foil (11) is to be crimped, in this case at the center of the lower surface. Further, an ultrasonic vibration plate (15) is arranged on the metal foil (11) side.

That is, the support material (14) is moved by a feeding device provided with a mechanism for guiding the substrate material (10) to a predetermined position.
) and the ultrasonic vibration plate (15) can be opened and closed, and the substrate material (
10) and the metal foil (11) are fed a fixed length and overlapped at a predetermined position, the support material (14) and the ultrasonic vibration plate (15) are moved to separate the substrate material (10) and the metal foil. (11)
It is configured to vibrate and perform ultrasonic welding when it comes into contact with the

As shown in Figure 0, the cutting device consists of circular cutters (16) held at predetermined intervals and rotated by a drive motor (not shown), and is configured to cut the moving metal foil (11) in its width direction.

As shown in Figure 1, the metal foil (11) is guided by the guide mechanism to the substrate material (10).
The substrate material (10) and the metal foil (11) are fed into an ultrasonic welding device (13) whose electrodes can be opened and closed by the device. At this time, the predetermined feed amount needs to take into account the amount of deformation due to pressure rolling and finish rolling (see figure a).

■When the support material (14) is raised and the ultrasonic vibration plate (15) presses the metal foil (11) against the substrate material (10), the ultrasonic vibration plate (15) applies pressure and vibration. The metal foil is welded (see figures b and e).

In particular, as shown in Figure 3C, it is best to weld two points at both ends of the metal foil piece (11) in the width direction of the substrate material (10), and only the tip side that will be caught in the roll during rolling in the subsequent process. By temporarily fixing and leaving the rear end free, pressure welding and rolling properties are improved.

■The metal foil (11) fixed to the substrate material (10) part located at an integral multiple of the predetermined pitch is cut into a predetermined length by the circular cutter (16) arranged at a predetermined interval by the above-mentioned welding device. 11) Perform the shaping (see figures d and e).

At this time, it is necessary to take into account the amount by which the predetermined length will be deformed by pressure rolling and finish rolling.

(2) After cutting, by removing the unwelded portion, it is possible to obtain a metal foil piece (12) of a predetermined size that is temporarily fixed by ultrasonic welding and has a good shape (see box).

For example, by repeating the cycle of simultaneously performing the above-mentioned step (1) and then simultaneously performing the
) are continuously temporarily fixed at a required pitch to obtain a substrate material (10).

Sekiya 1 The substrate material (10) unwound from the coil is sent out to the ultrasonic welding device in predetermined lengths by a fixed size feeding device (not shown), and the metal foil (11) is attached and removed by a suction device near the welding device. A mechanism is installed to feed the metal foil in predetermined lengths, and a clamping and cutting device is installed.The metal foil can be wound into a coil after welding (described later), or it can be welded by pressure using a rolling device installed downstream. Roll.

Here, the fixed size feeding device for metal foil (11) is such that a band-shaped metal foil (11) of a predetermined width is sucked by a suction machine (21), and the metal foil (11) is provided on a material guide (20). It is configured to be slid on the bottom surface of the four-part groove by one stroke of the suction device (21).

Although the fixed size feed device for the substrate material (10) is not shown, any known structure can be used as long as it can feed the substrate material by a predetermined length.

As shown in FIG. 2, the pinch cutting device uses the material guide (
The downstream end of 20) serves as a lower fixed die, and the punch (22) is driven vertically by a hydraulic cylinder or servo motor.
and the end face of the die.

In addition, the pinch cutting device is designed to maintain the distance from the die end surface (
Since the punch holder is pressed by a spring or the like so that the clearance (clearance) becomes 0, clogging is less likely to occur.

The ultrasonic welding device is capable of welding a metal foil piece (11) of a substrate material (10).
A support roller (23) is arranged in contact with the back side of the planned crimping position, that is, the center of the lower surface, and in combination with the punch (22) equipped with an ultrasonic vibration plate, the metal is cut after the sandwiching and cutting. When the punch (22) and the foil piece come into contact with the substrate material (10), pressure and vibration are applied to perform ultrasonic welding.

Operation As shown in FIG. 4, a predetermined amount of metal foil (11) of a predetermined width is fed into the cutting device by a fixed size feeding device having an attachment/detachment mechanism using a Φ suction machine (21). (See figure 0) ΦWhen the metal foil (11) of a predetermined length overhangs the end face of the guide (20), lower the punch (22) to cut the metal foil (11) to form a piece of metal foil (11). Nasu. (d
(See figure) When the metal foil piece (12) cut by the punch (22) is pressed against the substrate material (10), the metal foil piece (12) is pressed and vibrated with an ultrasonic vibration plate. Weld (see figure 0). The welding conditions at this time are preferably the same as those described above.

Φ After the ultrasonic welding is completed, the substrate material (10) is sent by a predetermined amount using a fixed size feeder, that is, an amount that takes into account the amount of deformation due to pressure rolling and finish rolling.

For example, by repeating the cycle of simultaneously performing the ΦΦ process and then performing the φΦ process, a substrate material (10) in which metal foil pieces (12) are continuously temporarily fixed at a required pitch is obtained.

Next, a method of pressure rolling the obtained substrate material (10) and metal foil piece (12) will be explained.

As shown in FIG. 3, the rolling mill (30) has a configuration in which a backup roll (32) is brought into contact with a pair of work rolls (31) to pressurize the rewound substrate material (10), and the load is detected. It is equipped with a device and a plate thickness gauge, and the rolling load control device performs constant load control.

Furthermore, a metal foil piece pitch measuring machine is installed on the exit side of the rolling mill (30).
Here, an optical sensor (33), a high-precision encoder (
34) is provided.

The control method consists of the following steps.

■Based on the measured value of the rolling load and the measured value of the absolute position of the metal foil piece from the required origin at that time, determine the quantitative relationship between the fluctuation of the rolling load and the fluctuation of the pitch and absolute position, and the control model, ■Predetermined position By calculating the target rolling load to obtain accuracy, ■ By outputting the rolling load as a control standard ■ In addition, the position measurement results of the metal foil pieces are fed back to the rolling force control device to prevent control errors. , modify the control model as appropriate and perform comprehensive correction.

With such control, it is possible to control the plate thickness with ultra-high precision during rolling, and the desired high-precision pitch control can be achieved.

In addition, in II, the absolute position measurement value of the metal foil piece before rolling from the required origin is fed forward, and the target setting value of the rolling load can be corrected at all times or as appropriate.

Effects of the Invention The present invention has made it possible to manufacture spot-shaped partial cladding materials by rolling, which is superior in mass productivity compared to vapor deposition and plating methods.

The spot-shaped partial cladding material produced by the manufacturing method of the present invention has a metal part such as a brazing filler metal formed in a predetermined position with high precision and a predetermined size, so it has excellent shape accuracy and mass productivity when forming a lead frame. ing.

In the case of pinch cutting, there is no waste in the metal foil pieces to be adhered, and for example, when Ag or the like is used as a metal with good bonding properties for lead frames, the yield is greatly improved.

In addition, since this invention uses rotary cutting or pinch cutting to cut the metal foil, clogging is less likely to occur.
For example, whereas the conventional punching method that maintains the clearance between 2 and 311 m gets clogged after about 2,000 times, it has the advantage of being virtually maintenance-free.

Because ultrasonic welding is used for temporary welding of metal foil,
It has the advantage of excellent bondability, short welding time, and high efficiency.

[Brief explanation of drawings]

Figures 1a, b, d, and f are schematic explanatory diagrams showing the manufacturing process of a rolled material, and Figures 1c and e are schematic explanatory diagrams of a welding device and a cutting machine as seen from the line direction. 2A to 2E are schematic explanatory diagrams of an embodiment of a sizing feed and welding device showing the manufacturing process of a rolled material, and FIG. 2A is an explanatory diagram as seen from the line direction. FIG. 3 is a schematic explanatory diagram of a rolling mill showing the rolling pressure welding method according to the present invention. FIG. 4 is a perspective explanatory view of a spot-shaped partial cladding material. FIG. 5 is an explanatory diagram showing an example of a lead frame. DESCRIPTION OF SYMBOLS 10... Substrate material, 11... Metal foil, 12... Metal foil piece, 13... Welding device, 14... Supporting material, 15...
...Ultrasonic vibration plate, 16...Circular cutter, 20...
・Material guide, 21...Adsorption machine, 22...Punch,
23... Support roller, 30... Rolling machine, 31...
Work roll, 32...Backup role, 33.
...Optical sensor, 34...High precision rotary encoder.

Claims (1)

[Claims] 1. A method for manufacturing a spot-shaped partial cladding material in which metal foil pieces of a predetermined size are crimped onto a substrate material at predetermined intervals, the substrate material and the metal foil being superimposed, and the front side of the metal foil pieces being ultrasonically applied. The metal foil is ultrasonically welded at regular intervals in the longitudinal direction of the substrate material using the shake plate and the support material on the back side of the substrate material.Furthermore, after cutting the metal foil in the width direction at regular intervals in the longitudinal direction with a rotary cutter, It is characterized by arranging metal foil pieces of a predetermined size at predetermined intervals on the substrate material by removing the metal foil pieces that are not welded, and then pressing and rolling the temporarily fixed metal foil pieces and the substrate material. A method for manufacturing a spot-shaped partial cladding material. 2. In a method for manufacturing a spot-shaped partial cladding material in which metal foil pieces of a predetermined size are crimped onto a substrate material at predetermined intervals, a die end face provided at the end of a material guide that feeds the metal foil by a fixed distance on the substrate material. The metal foil is sandwiched and cut into a predetermined size by a vertically moving punch that maintains a minimum clearance between the metal foil and the die, and an ultrasonic vibrating plate attached to the descending punch is used to sandwich and cut the metal foil into pieces. is pressed onto the strip material, and the metal foil piece is temporarily fixed by ultrasonic welding at one or more points in the width direction of the substrate material using the supporting material that is in contact with the back side of the strip material. A method for producing a spot-shaped partial cladding material, which comprises press-welding and rolling a foil piece and a substrate material.