JP2750500B2 - Pre-processing method and apparatus for electronic component manufacturing frame and electronic component manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for pretreating a frame for manufacturing an electronic component, and a method for manufacturing an electronic component.

[0001]

2. Description of the Related Art A resin package type electronic component represented by a semiconductor device such as an IC or an LSI is manufactured using a manufacturing frame called a lead frame.

As the degree of integration of such semiconductor devices has increased, the number of external leads has been increased and the pitch of fine leads has been increased. FIGS. 15 to 18 show an example of a manufacturing frame F for a semiconductor device in which such fine pitch has been advanced. As is apparent from FIG. 15, for each of the four side dam bars a defining the region to be resin-packaged, the external lead b and the internal lead c, each of which has a narrow interval between the pitches, are integrally formed to extend. ing. At the center of the area defined by the four dam bars, an island d to which a semiconductor chip is to be bonded is formed so as to be supported by the support frame h.

As can be seen from FIG. 1, the inner leads c extending inward from the dam bar a have their tips gathered on the respective sides of the island d. Are even smaller.

A semiconductor device is manufactured by subjecting the above-described manufacturing frame F to the following processes. First, a semiconductor chip (not shown) is bonded on the island d. Then, the terminal pads on the upper surface of the chip thus bonded and the tips of the internal leads c are connected by wire bonding. Next, a rectangular area defined by the dam bar a is resin-molded and packaged. And, while punching out unnecessary parts of the dam bar to make each lead independent, and cutting the external lead from the frame,
Predetermined lead forming is performed. Of course, during this time, a solder plating process on the lead frame, a mark on the resin package, or a predetermined inspection process is performed.

By the way, as described above, as the pitch of the lead terminals becomes finer, the interval between the tips of the internal leads c becomes extremely small. Therefore, the internal leads c are easily deformed by an external force. When the internal lead c is deformed, not only wire bonding to the chip is not properly performed, but also adjacent internal leads come into contact with each other to cause a short circuit failure.

Therefore, the following countermeasures have conventionally been taken in the process of manufacturing a semiconductor device using the manufacturing frame F. That is, the tips of the internal leads c are connected to each other by a connecting bar e as shown in detail in FIG. 16, and the intermediate portion of each internal lead is also restrained by a resin tape f or the like as shown in FIG. Then, after that, the above-mentioned leading end connecting portion is cut off to make each internal lead independent as shown in FIG.

[0007] Then, the distance between the internal leads c is defined by the resin tape f.
The deformation of the tip of the internal lead c can be prevented to some extent.

[0008] However, even if the above method is adopted, the following problem still remains.

A frame F for manufacturing a semiconductor device having a fine pitch as described above has a thickness of 0.2 mm.
Generally, it is manufactured by either a method of manufacturing by punching out a conductive metal sheet of a degree by a press or a method of manufacturing by etching the metal sheet. It is clear that the production method by press punching is advantageous in terms of cost and efficiency. However, the following serious problems have been pointed out, especially when a manufacturing frame formed by press punching is used for a semiconductor device having a fine pitch as described above.

That is, when press stamping is performed,
Due to the external force applied from the die and the punch, a residual stress remains particularly at the internal lead portion. And
As shown in detail in FIG. 17, a return or burr g inevitably occurs in the lead due to punching.

Residual stress may give tension to the entire lead frame F and cause sticking. In addition, as described above, after connecting the internal leads c with the resin tape f, a portion connecting the tips is connected. When cut, the residual stress is released, and the tip of the internal lead c may be displaced.

[0012] Then, even if the measures for preventing deformation of the internal leads using the resin tape are taken as described above, finally the tip of each internal lead is displaced to cause inconvenience in wire bonding, Or short-circuit failure due to contact between the tips of the two.

[0013] If any one of a large number of internal leads causes a short circuit as described above, the entire product becomes defective, and the yield is significantly reduced due to this.

Further, since the post-process is performed while leaving the return and burrs generated by the punching without any countermeasure as described above, when the soldering is performed on the lead frame, the solder does not averagely adapt. In some cases, a solder defect may occur or moisture may enter the resin mold package from burrs or return portions.

When the frame is manufactured by etching, the above-mentioned problems do not occur. However, as described above, the manufacturing of the frame by the etching has another disadvantage that it takes time and costs.

The present invention has been conceived in view of the above circumstances, and uses a manufacturing frame obtained by press-punching an electronic component having an external lead and an internal lead having a fine pitch. In manufacturing, it is an object of the present invention to eliminate various problems caused by residual stress generated at the time of press punching, and at the same time to eliminate various problems caused by return and burrs generated at the time of press punching. It is.

[0017]

In order to solve the above-mentioned problems, the present invention employs the following technical means.

The invention described in claim 1 of the present application is a method for pre-treating a frame for manufacturing an electronic component by press punching, wherein the frame for manufacturing an electronic component has an average particle size of 100 μm or less, preferably 50 μm or less. It is characterized in that spheres or granules are blown on a high-speed air stream.

The high-speed air flow is preferably a low-pressure large-flow air flow obtained by a low-pressure blower or the like (claim 2). The air flow obtained by the low-pressure blower has a flow velocity of 100 m / sec or more. Can be achieved, and depending on the conditions, it is not impossible to reach 200 m / sec (claim 3).

As described above, glass beads are the most suitable spheres that are currently available as very small spheres having a particle size of 100 μm or less, and even 50 μm or less (claim 4).

The invention described in claim 5 of the present application is a method for manufacturing an electronic component using the manufacturing frame pretreated as described above. Such a manufacturing method includes processing steps such as chip bonding, wire bonding, and resin molding.

According to a sixth aspect of the present invention, it is specified that the above-mentioned pre-processing method is performed using a blast device. The blast device has a basic configuration in which it has a blast chamber in which a blast nozzle is disposed. However, in the invention of the present application, as a polishing material to be sprayed on a high-speed air flow from a blast nozzle, a sphere or a particle such as a glass bead of 100 μm or less, preferably 50 μm or less is used for a frame for electronic component production by press punching. It blows against.

The low-pressure, high-speed air flow injected from the blast nozzle is preferably generated by a low-pressure blower, and its discharge pressure is 0.3 to 0.6.
Atmospheric pressure (gauge pressure) is set to a low pressure (claim 7). The low-pressure, high-speed air flow may be obtained by reducing high-pressure compressed air generated by a compressor to 0.3 to 0.6 atm.

Also in this case, when an air flow is generated by the low-pressure blower, a 10-
Air can be injected at a high speed of 0 m / sec or more (claim 9).

Further, the invention according to claim 10 is a pretreatment apparatus for performing each of the above pretreatment methods, and utilizes a blast apparatus, and is 100 μm or less, preferably 50 μm or less.
A sphere or particle having an average particle diameter of μm or less is put on a low-pressure, high-speed air flow and jetted from a blast nozzle, and is continuously applied to an electronic component manufacturing frame conveyed by a conveying mechanism. Things. By adopting such a configuration, it is possible to automatically perform pre-processing on the manufacturing frame.

Also in this case, glass beads are suitable as the sphere (claim 11).

In the pretreatment apparatus for a frame for manufacturing an electronic component according to the present invention, it is preferable to provide at least two blast nozzles for processing both front and back surfaces of the manufacturing frame to be conveyed.

[0028]

In short, the present invention is applied at the time of press punching when a frame for manufacturing an electronic component, particularly a frame for manufacturing an electronic component with a finer pitch is formed by press punching. It is an object of the present invention to provide a new method for performing an appropriate pre-process on a frame before chip bonding so as to eliminate the influence of residual stress and the effects of burrs and return. Therefore, in the present invention, processing by air blast is basically adopted.

In adopting air blast, the present invention is basically characterized in that spheres (beads) or particles having an extremely small particle size are blown on a high-speed air flow as the abrasive. Can be As a method using a sphere as an abrasive material, conventionally, there is a so-called shot peening, in which a steel ball is blown off by compressed air and applied to a work, but the method of the present invention employs the following so-called shot peening. The difference is overwhelming.

First, the particle diameter of the sphere as the abrasive to be used is 100 μm or less, preferably 50 μm or less.
Secondly, they are of a very small particle size, and secondly, the small-sized spheres or particles are blown not by a compressed air flow but by a low-pressure high-speed air flow.

As a method for generating a high-speed airflow, a low-pressure blower is preferably used in the present invention. An example of a low-pressure blower is a Roots blower, in which the airflow generated by such a blower is a low-pressure, large-flow airflow while that generated by the compressor is a high-pressure, small-flow airflow. Greatly differ. Further, the speed of the air flow can easily be 100 m / sec or more at the tip of the nozzle, and depending on the conditions, it is easy to make the flow speed of the air flow as high as 200 m / sec. This high-speed air flow can be obtained by converting a high-pressure small-flow air flow generated by a compressor into a high-speed large-flow air flow while reducing the pressure by introducing secondary air or the like. .

Furthermore, in addition to the extremely small particle size as described above, glass beads having a smaller specific gravity than steel balls are preferably used as the spheres.

The particle size and material as the above-mentioned abrasive material are appropriately selected according to the thickness of the electronic component manufacturing frame to be pretreated. A manufacturing frame for an electronic component having a fine pitch has a relatively thin shape of, for example, 0.2 mm, and a pitch interval of, for example, 0.5 m.
In the case of m, the interval between the tips of the internal leads has a smaller pitch. In such a case, for example, glass beads having a minimum particle size that can be produced by the current technology, more specifically, glass beads having a particle size of about 30 μm are suitably adopted.

Compared to using a high-pressure air flow in conventional shot peening, when a high-pressure air with a low pressure and a large flow rate is used as in the present invention, the cross section of the nozzle is enlarged to mix the abrasive material. Since the air flow cross-sectional area can be enlarged, it is suitable for treating a wide area on average. That is, even if it is a manufacturing frame for fine pitch as described above by blasting,
It is less likely to damage it.

As described above, when a large amount of glass beads having an extremely small particle diameter are jetted onto a manufacturing frame at a high speed of 100 m / sec or more and the flow cross section is enlarged, residual glass is produced by the following action. The effects of stress can be eliminated, and burrs and return can be suitably removed.

First, the so-called peening effect can be obtained without damaging the frame by applying a sphere or a particle such as glass beads having a small specific gravity and an extremely small particle diameter to the frame at high speed. Can be given. In other words, the fine glass beads hit the frame surface at high speed, so that the surface can be moderately hardened while releasing the residual stress in the frame, thereby reducing the residual stress generated inside during press molding. It can be substantially removed. Then, even in the case of a manufacturing frame for fine pitch, it is possible to effectively prevent the tip of the internal lead from being deformed due to the release of the residual stress and causing short-circuit failure and wire bonding failure. .

Further, in addition to the peening effect as described above, a polishing effect can be expected. The reason is that although beads are used as an abrasive, they are applied to the frame at a very high speed, so that burrs and returns formed by punching the frame can be conveniently removed. In this regard, the bead material, which is appropriately crushed during repeated collisions with the frame and has a sharp crushed surface, also helps the above-mentioned cleaning effect.

As described above, according to the present invention, the above-mentioned residual stress is substantially removed in the frame for manufacturing an electronic component in which the residual stress remains after the press punching, and the press punching inevitably causes the residual stress. Also, burrs and edges generated on the surface are removed.

In particular, when a manufacturing frame corresponding to a fine-pitch electronic component is manufactured by press punching, internal leads are deformed due to the influence of residual stress to cause short-circuiting or bonding failure. Such a situation can be effectively avoided, and the yield of a fine-pitch, multi-terminal resin packaged electronic component can be significantly improved. In this way, a manufacturing frame formed by press punching, which can be manufactured at low cost, can be used without any problem, and the cost of manufacturing electronic components can be reduced overall.

In addition, since the burrs and return formed on the leads are removed, the solder is well-familiar when the leads are plated with solder, which may result in poor soldering when mounted on a circuit board. It is reduced.

Further, since the surface is cleaned,
In the case where a solder or other coating layer is formed on a manufacturing frame by plating, it is possible to omit the degreasing process which has been required in the past, and this plating process is simplified.

[0042]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below.
This will be specifically described with reference to the drawings.

The pretreatment method for a frame for manufacturing an electronic component according to the present invention can be carried out by using the structure of the blast device 1. FIGS. 1 to 12 show a pretreatment device for a frame for manufacturing an electronic component according to the present invention using a blast device. This apparatus 1 is basically sprayed from a blast nozzle 4 onto a manufacturing frame F which is conveyed in a blast chamber 2 in a horizontal direction or a substantially horizontal direction by a conveying mechanism 3 with a low-pressure, high-speed, large-flow airflow. The spheres or granules having a small particle diameter are applied.

In the blast chamber 2, a plurality of blast nozzles 4 are arranged vertically so as to face the manufacturing frame F which is transported in the horizontal direction by the transport mechanism 3 as described above. An air supply pipe 5 to which air sent from a low-pressure air generation source (not shown) such as a roots blower is supplied is disposed above the blast chamber 2. The air supply pipe 5 branched from the air supply pipe 5 is provided. The hoses 5a are connected to the base ends of the blast nozzles 4, respectively. A polishing material supply hose 6 is connected to the base end of each blast nozzle 4.

The blast nozzle 4 is supplied from the air supply hose 5a and sucked by an air flow passing through the inner hole of the blast nozzle at a high speed. Those configured to be mixed can be used. The blast nozzle 4
The specific configuration of will be described later.

An umbrella-shaped dust collecting hood 7 is disposed above the blast chamber 2. The upper portion of the dust collecting hood 7 is connected to the outside of the blast chamber 2 via a dust collecting pipe 8. It is connected to a dust collection device 9 (FIG. 2) arranged adjacently. The dust collecting device 9 generates a suction force by a suction blower 11 installed at an upper portion of the dust collection tube 10, and the dust-mixed air is introduced from the dust collection tube 8 into the dust collection tube 10 by the suction force. A well-known device configured to remove dust by a filter can be used.

On the other hand, the lower part of the blast chamber 2 is reduced in diameter like a hopper, and a polishing material collection container 13 is connected below the hopper 12. In the apparatus of the present embodiment, the abrasive material S accumulated in the abrasive material collecting container 13 connected to the lower part of the blast chamber 2 is blasted through the abrasive material supply hose 6 as follows. The cleaning material S is sent to the nozzle 4 so that it can be recycled.

That is, as shown in FIGS. 3 and 4, one side wall 13a of the blasting material collecting container 13 has the blasting material suction pipe 14 penetrated and supported, while the other side wall 13b of the collecting container 13 has An air supply pipe 15 is supported in a penetrating manner so as to have the same axis as each of the suction pipes 14, and the outer end of each of the suction pipes 14 is connected to the outer end of the suction pipe 14 through the abrasive supply hose 6 as described above. The blast nozzle 4 is connected to the base end of the blast nozzle 4, and the base end side of each of the air supply pipes 15 is connected to a blowing unit 16.

In this embodiment, each of the suction pipes 14
Is a boss 17 formed through one side wall of the collection container 13.
The position after the adjustment can be held by a set screw 18 screwed from the side wall of the boss 17.

Further, each of the air supply pipes 15 is also inserted and supported in a boss portion 19 supported on the other side wall of the collection container 13 so as to be able to adjust the sliding position in the horizontal direction. The position of each air supply pipe 15 after adjustment in the axial direction is held by the set screw 20.

By adjusting the axial position of one or both of the suction pipes 14 and the air supply pipes 15 as described above, the inner end opening of the suction pipes 14 and the air supply pipes 15 are adjusted. The size and the axial length of the annular gap 21 between the tip and the end of the annular gap 21 can be appropriately adjusted.

As described above, the base end side of each air supply pipe 15 is connected to the air supply means 16, but in this embodiment, as shown in FIG. The end is connected to a surge tank 23 via a hose 22, and the surge tank 23 is connected to a blower 24. Therefore, the air from the blower 24 is sent into each air supply pipe 15 through the surge tank 23 or each hose 22.

When the above-described apparatus is in the operating state, the dust collecting device 9 is in the operating state, and the suction force is applied to the dust collecting hood 7 above the blast chamber 2. Then, air from an air source such as a roots blower (not shown) is sent to each blast nozzle 4 via an air supply pipe 5. Then, as described above, in the cleaning material collection container 13, air from the blower 24 is supplied to each air supply pipe 15 by each suction pipe 1.
4 is fed toward the inner end opening.

When air is sent into each suction pipe 14 through each air supply pipe 15 in the collection container 13, the abrasive material S collected in the lower portion of the collection container 13 is drawn by the air flow. The suction pipe 14 is drawn into the suction pipe 14 through the annular gap 21 between the suction pipe 14 and the air supply pipe 15. The abrasive material thus drawn into the suction pipe 14 is given a dynamic pressure by the air flow from the air supply pipe 15, and generates a negative pressure generated by high-speed air flowing through the air supply pipe 5 into each blast nozzle 4. Due to the action of the pressure, it is sent to each blast nozzle 4 via the abrasive supply hose 6 and then mixed with the high-speed air flow in the blast nozzle 4 and jetted again. In other words, the abrasive material drawn into the suction pipe 14 has a pumping force due to an air flow from the air supply pipe 15,
By the synergistic action with the negative pressure generated in the blast nozzle 4, the blast nozzle 4 is conveniently transported to the blast nozzle 4 at a higher position through the abrasive supply hose 6.

Further, by adjusting the size and the axial length of the annular gap 21 formed by the suction pipe 14 and the air supply pipe 15, suction can be performed according to the particle size or specific gravity of the abrasive used. The amount of the abrasive material sent to the blast nozzle 4 through the pipe 14 and the abrasive material supply hose 6 and circulated and used can be appropriately adjusted.

On the other hand, the transport mechanism 3 capable of transporting the manufacturing frame F in the horizontal direction so as to penetrate the blast chamber 2 basically has two transfer mechanisms disposed on the left and right with respect to the transport direction. It comprises a set of endless belts 25,26.
Each of the endless belts 25 and 26 has an inlet portion 27 and an outlet portion 2 formed on the front and rear facing side walls of the blast chamber 2.
8 is wrapped around belt pulleys 29a and 29b rotatably mounted about a horizontal axis.

As shown in FIG. 12, a pair of left and right endless belts 25 and 26 used in the transport mechanism 3 are used to transmit power by being wrapped around a belt pulley having a plurality of V-grooves formed on the outer periphery. The endless belt is used with its inside and outside reversed. That is, the direction in which the V-groove which should be looped around the belt pulley with the V-groove is formed is turned outward, and the flat portion which should be positioned on the outer side is looped around the flat belt pulleys 29a and 29b. ing. By making such a pair of belts face each other, as shown in FIG. 12, both side edges of the manufacturing frame F are locked in the V-grooves of the belt. Can be conveniently transported.

Each of the belts 25 and 26 is adapted to run by rotating an outlet belt pulley 29b, and to drive both belt pulleys 2b on the inlet side.
By adjusting the gap between the belt pulleys 29a and 29b and the gap between the belt pulleys 29b and 29b on the outlet side, the gap between the belt running portions to which the both side edges of the manufacturing frame F are to be locked is adjusted as described above. It can be changed.

When the manufacturing frame F is transported by using the belt as described above, since the belts 25 and 26 are usually formed of rubber, the manufacturing frame F to be transported is transported.
Even if is a thin plate, it is possible to effectively avoid inadvertently damaging it. As described later, the manufacturing frame F conveyed in the horizontal direction while the side edges are locked by the V-grooves of the pair of left and right belts 25 and 26 in this manner is subjected to the processing by the abrasive material from the blast nozzle. However, since the belt itself is not subjected to the blasting action by the blasting material, it becomes a very suitable long-life transport mechanism in the blast chamber.

The structure in which the endless belts 25 and 26 are wound will be described below by dividing the structure into an inlet side 27 and an outlet side 28.

FIGS. 5 to 7 show the left and right endless belts 2.
5 shows a support structure at the entrance side of the fifth and the 26th. A spindle 3 having the belt pulleys 29a, 29a attached to the upper end.
Reference numerals 0 and 30 are vertically supported by support members 31 and 31 that can slide in the left and right directions with respect to the transport direction. As shown in FIG. 6, each of the support members 31, 31 is engaged with guide members 32, 32 arranged in the front and rear in the inlet container 27a, so that they can be individually slid in the left-right direction. ing. Each of the support members 31, 31 has a through hole 33, 3 in the left-right direction.
3 are provided.

On the other hand, a male screw portion 35a formed on the rotating shaft 35 is screwed to the female screw member 34 (FIG. 7) attached to the side wall of the inlet container 27a. The inner small diameter portion 35b of the rotating shaft 35 is inserted through the through hole 33 in the left-right direction of the support member 31, and a large diameter portion 35c is formed at the inner end of the rotating shaft 35. Have been. Further, a tool engaging means 35d is formed on the outer end 35a of the rotating shaft 35.

Therefore, when the rotating shaft 35 is rotated by applying an appropriate tool to the outer end tool engaging means,
Male screw portion 35 of rotating shaft 35 with respect to female screw member 34
The rotary shaft 35 reciprocates in the axial direction due to the screw feed action due to the rotation of a. Then, this rotating shaft 3
The supporting members 31, 31 through which the small-diameter portion 35b is inserted.
Are moved in the left-right direction with the axial movement of the rotary shaft 35.

The belt pulleys 29a, 29a on the inlet side corresponding to the left and right endless belts 25, 26 are supported by the independent supporting members 31, 31 as described above. Are also provided for each of the left and right. Therefore, the interval between the belt pulleys 29a, 29a supporting the entrances of the left and right endless belts 25, 26 can be adjusted by moving the support members 31, 31 in the left-right direction as described above. .

In FIGS. 5 and 6, reference numeral 36 indicates that the manufacturing frame F is attached to the left and right endless belts 2.
It is an introduction guide for introducing between 5 and 26.

FIGS. 8 to 11 show the left and right endless belts 2.
5 shows the support structure at the outlet side 28 of 26. A vertical support shaft 37 having belt pulleys 29b, 29b at the upper ends thereof around which the outlet portions of the endless belts 25, 26 are looped,
37 is rotatably mounted on support members 38, 38 which are supported in the outlet container 28a so as to be position-adjustable in the left-right direction.

The positions of the support members 38, 38 can be independently adjusted in the left-right direction. The mechanism for enabling the position adjustment is the same as the above-described adjustment mechanism for the belt pulley on the inlet side. The same is true.

That is, the supporting members 38, 38 are provided with through holes 39, 39 penetrating in the left-right direction.
In the through holes 39, 39, an inner small diameter portion 40 of a rotary shaft 40 supported so as to be capable of screwing and retracting on the side wall of the outlet container 28a.
The small diameter part 40b is formed at the inner end of the small diameter part 40b. Therefore, by rotating the rotary shaft 40 to reciprocate in the left-right direction with respect to the side wall of the outlet container 28a, the support member 3
The distance between the belt pulleys 29b, 29b supported by the vertical shafts 37, 37 can be adjusted as appropriate.

In this embodiment, the endless belts 25, 26 are run by rotating belt pulleys 29b, 29b around which the outlets are wound. Further, both belt pulleys 29b, 29b need to be synchronously rotated in the opposite direction at a constant speed, and in the present embodiment, this is configured as follows.

As shown in FIGS. 8 and 11, a belt pulley 29 around which the endless belts 25 and 26 are wound
Driven sprockets 41, 41 are attached to the lower ends of the spindles 37, 37 with the upper ends b, 29b attached. Of course, the diameters of the driven sprockets 41, 41 to be attached to both support shafts are the same.

On the other hand, the front and rear two sprockets 43 and 44 are rotatably mounted on the stationary member 42 in the outlet container 28a, and one of them (the right side in FIG. 9).
Is driven to rotate by a motor 45 with a speed reduction mechanism. As described above, the two sprockets 43, 44 to be arranged in the front-rear direction are arranged at the same height position as the driven sprockets 41, 41, and these four sprockets 41, 41, 4
A driving endless chain 46 is wrapped around 3,44.

However, since the driven sprockets 41 need to rotate in the reverse direction due to the travel of the driving endless chain 46, the driving endless chain 46 is wound around as shown in FIG. You. By doing so, when the sprocket 44 attached to the spindle of the motor 45 is driven to rotate in the direction of the arrow in FIG.
The driving endless chain 46 travels in the direction of the arrow in FIG. 11, whereby the left and right driven sprockets 41 are rotationally driven in opposite directions. As a result, the left and right endless belts 25, 26 run parallel to each other.
6a is driven synchronously by being pulled from the entrance side to the exit side at a constant speed.

In order to achieve a straight running property by applying an appropriate tension to the parallel running portions 25a and 26a of the left and right endless belts 25 and 26, the support member 3 on the entrance side is required.
Tension pulleys 49, 49 are attached to guides 50, 50 which are arranged so as to span between the support members 1, 31, and the outlet side support members 38, 38.

Further, the guides 50, 50 are provided with backup guides 48 for backing up the manufacturing frame F which is conveyed with the both side edges engaged and supported between the endless belts 25, 26 at an appropriate portion in the conveying direction. , 48 are fixedly mounted. More specifically, as described above, in the blast chamber 2, the blast nozzle 4 facing the upper surface of the manufacturing frame F transported as described above and the blast nozzle 4 facing the lower surface are preferably in the transport direction. Are alternately arranged, but at a portion where the blast nozzle 4 facing the upper surface is arranged, a backup guide 48 for backing up the back surface of the manufacturing frame F is provided, and at a portion where the blast nozzle 4 facing the lower surface is arranged. Is to provide a backup guide 48 for backing up the upper surface of the manufacturing frame F.

The backup guides 48, 48 preferably have an elastic member such as rubber adhered to the surface thereof. The reason for this is to prevent the glass beads as the abrasive material from colliding with the backup guide and causing unnecessary crushing, and to moderate the abrasive effect of the abrasive material to reduce the thin manufacturing frame. This is to prevent unnecessary damage to the manufacturing frame when processing is performed on F.

The electronic component manufacturing frame F before the chip bonding step, which is input from the inlet side input guide 36,
Both edges are engaged and supported in opposed V-grooves of the left and right endless belts 25 and 26 running parallel to each other,
As the belt runs, it is conveyed horizontally toward the exit.

As shown in FIG. 13 and FIG. 14, the blast nozzle 4 has a low-pressure, high-speed, large-flow air flow introduced from an air supply hose 6 and an abrasive material supply pipe 5 inside. In this embodiment, the abrasive is mixed with the abrasive material and injected from the end of the nozzle. In the present embodiment, the nozzle piece 47 whose end nozzle hole has a long hole shape as shown in FIGS. It is attached to. And
As shown in FIG. 12, the nozzle piece 47 is oriented such that the major axis is orthogonal to the transport direction of the manufacturing frame F transported as described above. The reason for doing this is
This is because the entire width region of the manufacturing frame F having a certain width can be averagely processed.

The nozzle piece 47 has secondary air introduction holes 51, 51 formed at the base end thereof, so that the air flow flowing forward from the nozzle body does not decelerate, and is vigorously sharpened. The air flow mixed with the cleaning material can be jetted.

It is desirable that the nozzle piece 47 be formed of an elastic member such as rubber as a main material in order to prevent abrasion by the abrasive material.

In the pretreatment method and apparatus for a frame for manufacturing an electronic component according to the present invention, the abrasive material to be jetted from the blast nozzle 4 in a high-speed air stream as described above, A sphere or particle of 200 μm or less, preferably 100 μm or less, more preferably 50 μm or less is employed. It has been found that glass beads are desirable for processing the thin manufacturing frame F because the specific gravity of the sphere is smaller than that of metal.

In the case of glass beads, the specific gravity is generally about 2 to 4, and the Vickers hardness of the surface is 50.
It is about 0 to 700 kg / mm ² . It is considered that the particle size of the glass beads is desirably as small as possible, but at present, it is about 30 μm (about 4 μm).
(Equivalent to 00 mesh) is readily available.
The particle size of the glass beads may be appropriately selected depending on the thickness of the electronic component manufacturing frame to be processed, particularly, the degree of fine pitch.

Hereinafter, a test example in which the manufacturing frame F was processed by the method of the present invention will be shown for reference. As the manufacturing frame F, the short side is 49 mm and the long side is 164 mm
The lead pattern shown in FIG. 15 was used. The thickness of the frame is 0.2 mm, and the pitch of the external leads is 0.5 mm. A 4 × 30 mm nozzle piece 47 of the blast nozzle 4 was used. Also,
Glass beads equivalent to about 400 mesh, that is, those having an average particle diameter of 38 μm were used as the abrasive material. The transport speed of the transport mechanism is 164 mm for the long side.
Was set to pass in 3 seconds.
Discharge pressure of Roots blower as air generator is 0.3
The output of the blower was set so as to be 5 kg · f / cm ² . In this case, the velocity of the air flow injected from the blast nozzle 4 is theoretically as high as 200 m / sec.
00 m / s. The distance from the end of the nozzle piece of the blast nozzle to the manufacturing frame F transported by the transport mechanism was set to 200 mm. Under these conditions, the front side and the back side of the manufacturing frame F were processed once each, and the findings of the manufacturing frame F were as follows.

The surface of the frame had a fine satin finish. Before the treatment, there was a slight stickiness tendency, but after the treatment, the stickiness tendency disappeared. When the connecting bar connecting the tips of the internal leads was cut, almost no deformation of each internal lead was observed. Before the treatment, burrs or returns were present on the back surface by press punching, but such burrs or returns had disappeared cleanly.

As glass beads, a particle diameter of 50 μm was used.
When the same test was conducted by changing the diameter to m and 100 μm, a considerable effect was obtained even if the glass beads having the particle diameter of 38 μm were not used. Thus, it is considered that more preferable results can be obtained by further reducing the particle size of the glass beads.

From the above, it can be said that, when the treatment according to the present invention was performed under the above conditions, the stress remaining inside each lead due to press punching was substantially eliminated. The reason for this is that fine glass beads having a relatively small specific gravity collide at an extremely high speed, so that the surface of the lead is work-hardened while releasing internal stress due to the so-called peening effect, and the internal stress is substantially reduced. It is supposed that this is due to a synergistic effect between the fact that it was considered that the burr and the return had been neglected.
In addition, the above-mentioned return and the disappearance of burrs are caused because, although the abrasive material is spherical beads, it has a very small particle diameter and is driven at an extremely high speed,
It is considered that this is because the cleaning effect was exhibited.

As described above, according to the present invention, even if a manufacturing frame corresponding to an electronic component having a fine pitch is manufactured by press punching, if the pretreatment of the present invention is performed, press punching is performed. The internal stress that sometimes remains is substantially removed to prevent deformation of the internal lead,
The occurrence of short-circuit failure and wire bonding failure can be effectively prevented, the yield of electronic components can be significantly improved, and the manufacturing cost can be reduced.

Conventionally, when a manufacturing frame F as shown in FIG. 15 is used, before cutting the tie bars connecting the tips of the internal leads to make each internal lead independent, the intermediate portion of the internal lead is electrically nonconductive. However, if the processing of the present invention is performed, such complicated processing can be omitted. However, since residual stress is generated in the frame at the time of punching and forming, it is considered that it is still necessary to form a connecting bar connecting the tips of the internal leads c in a frame corresponding to fine pitch.

Further, according to the present invention, the internal stress of the manufacturing frame can be substantially removed as described above, and the burrs and the return formed by press punching can be eliminated conveniently, so that the lead It is possible to effectively prevent the occurrence of a solder failure at the time of solder plating on a substrate or at the time of solder mounting on a circuit board.

Further, since the burrs of the leads have been eliminated, the conventional problem that water enters into the resin mold package from the burrs and causes a circuit failure can be solved conveniently.

Further, since the surface is formed with a matte surface, it is possible to omit the degreasing process when plating with solder or the like, thereby simplifying the plating process and expecting cost reduction. There is an additional effect.

Of course, the scope of the present invention is not limited to the embodiment described above. As a configuration of the blast device, a method of injecting high-speed air mixed with the abrasive material from the blast nozzle is not limited to the method as in the embodiment. As high-speed air, it is required to inject high-pressure, low-pressure air generated by a low-pressure air source such as a roots blower at a high speed. However, it is also possible to reduce the pressure of the compressed air generated by the compressor to obtain a high-speed airflow with a low pressure and a large flow rate, and use this. Also, the number of blast nozzles may be set to an appropriate number depending on the transfer speed of the frame transfer mechanism. That is, in the embodiment shown in the drawings, four blast nozzles are provided, two on the upper side and two on the lower side, but if the conveying speed is further increased, the number of blast nozzles may be increased.

The mechanism for transporting the manufacturing frame also includes a pair of left and right belts as described above, and is described in Japanese Patent Application No. 4-265545 already filed by the applicant of the present invention. Or a frame transport mechanism also described in Japanese Patent Application No. 4-17785. Further, when the manufacturing frame is formed by press punching, the manufacturing frame conveyed from the press punching apparatus is continuously loaded into the pretreatment device of the present invention, so that the semiconductor device manufacturing line is further increased. Serialized,
It is considered that the efficiency of semiconductor device manufacturing is further improved.

Further, in the embodiment shown in the figure, the manufacturing frame is held horizontally between the left and right endless belts. However, the endless belts are arranged vertically and the lead frame is vertically You may make it convey. Needless to say, in this case, the blast nozzles for blowing the high-speed air mixed with the abrasive material to the manufacturing frame conveyed in this way are arranged on both sides thereof.

Further, as a manufacturing frame, besides a strip-shaped lead frame, there is also a hoop-shaped frame in which this is connected in the longitudinal direction, and the present invention can be applied to any frame. .

Further, in the above-described embodiment, a manufacturing frame for an electronic component having a fine pitch is assumed, but the manufacturing frame to which the present invention is applied is not limited to this.

Further, as a sphere or a particle to be blown on a frame for manufacturing electronic parts by being placed in a high-speed air flow,
Not only glass beads, but as technology advances,
As long as resin beads (spheres) having a particle diameter of 100 μm or less, preferably 50 μm or less can be produced, use of such resin beads is also included in the scope of the present invention.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an overall schematic configuration of an embodiment of an apparatus for carrying out a method of the present invention.

FIG. 2 is a sectional view taken along the line II-II in FIG.

FIG. 3 is a sectional view taken along line III-III in FIG. 2;

FIG. 4 is a sectional view taken along line IV-IV in FIG. 3;

FIG. 5 is a schematic plan view showing a configuration of an entrance of a frame transport mechanism of the apparatus of FIG. 1;

FIG. 6 is a sectional view taken along the line VI-VI in FIG. 5;

FIG. 7 is a sectional view taken along line VII-VII in FIG. 6;

FIG. 8 is a schematic plan view showing a configuration of an outlet of a frame transport mechanism of the apparatus shown in FIG. 1;

FIG. 9 is a sectional view taken along line IX-IX in FIG. 8;

FIG. 10 is a sectional view taken along line XX of FIG. 9;

11 is a view in the direction of arrows XI-XI in FIG. 9;

FIG. 12 is an enlarged sectional view taken along line XII-XII of FIG. 1;

FIG. 13 is a longitudinal sectional view of an example of a blast nozzle.

FIG. 14 is a view as seen in the direction of the arrow XIV in FIG. 13;

FIG. 15 is a partially enlarged plan view of an example of an electronic component manufacturing frame processed by the method of the present invention.

16 is a plan view showing a part of the frame shown in FIG. 15 in a further enlarged manner.

FIG. 17 is an enlarged sectional view taken along line XVII-XVII of FIG. 16, showing burrs or return generated at the time of press punching on the back surface of the lead.

FIG. 18 is a plan view showing a state in which a connecting bar connecting the tips of the internal leads has been removed from the state shown in FIG. 16;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pre-processing apparatus of electronic component manufacturing frame 2 Blast chamber 3 Transport mechanism 4 Blast nozzle F Electronic component manufacturing frame b External lead c Internal lead g Burr

Claims (12)

(57) [Claims] 1. An electronic component manufacturing frame formed by press punching is formed in a thickness of 100 μm or less, preferably 50 μm or less.
A method for pre-treating a frame for manufacturing electronic components, wherein a sphere or a particle having an average particle diameter of not more than m is blown on a high-speed air stream. 2. The method of claim 1, wherein the high-speed airflow is a low-pressure, high-flow airflow generated by a low-pressure blower or obtained by decompressing compressed air generated by a compressor. 3. The method according to claim 2, wherein the flow velocity of the high-speed air flow is 100 m / sec or more. 4. The method according to claim 1, wherein the sphere is a glass bead. 5. An electronic device, comprising: performing a process including chip bonding, wire bonding, and resin molding using an electronic component manufacturing frame preprocessed by the method according to claim 1. The method of manufacturing the part. 6. A blasting apparatus comprising a blast chamber and a blast nozzle disposed in the blast chamber, wherein the blast nozzle is used to press an electronic component manufacturing frame by press punching and introduced into the blast chamber. A method for pre-treating a frame for manufacturing electronic components, wherein a sphere or a particle having an average particle diameter of 100 μm or less, preferably 50 μm or less is blown on a low-pressure high-speed air flow. 7. The method of claim 6, wherein said low pressure, high speed air flow is an air flow generated by a low pressure blower at a discharge pressure of 0.3 to 0.6 atmospheres. 8. The low pressure, high speed air flow comprises compressed air generated by a compressor of 0.3 to 0.6.
7. The method of claim 6, wherein the air stream is obtained by reducing the pressure to atmospheric pressure. 9. The method according to claim 7, wherein the air stream fluid ejected from the blast nozzle has a flow rate of 100 m / sec or more. 10. A blast chamber, a blast nozzle disposed in the blast chamber and blowing a sphere or a particle having an average particle diameter of 100 μm or less, preferably 50 μm or less on a low-pressure high-speed air flow, and electronic component manufacturing. And a transfer mechanism for introducing the frame into the blast chamber, and a large amount of the spheres or granules mixed into the high-speed air injected from the blast nozzle, into the electronic component manufacturing frame transferred by the loading mechanism. A pretreatment device for a frame for manufacturing an electronic component, wherein the pretreatment device is continuously applied to the frame. 11. The apparatus of claim 10, wherein said sphere is a glass bead. 12. The apparatus according to claim 10, further comprising a nozzle facing one surface of the manufacturing frame transported by the transport mechanism and a nozzle facing the other surface.