JPH08148624A - Manufacture of semiconductor device and semiconductor device and lead frame - Google Patents

Abstract

PURPOSE: To obtain a high-quality product without being affected by dross in a semiconductor device, which permits bending and forming for outer leads and cutting for dam bars while maintaining highly accurate shapes for narrow- pitch and multi-pin lead frames. CONSTITUTION: After sealing a semiconductor chip and lead frame as a united body with resin molding, outer leads 3 coupled with a dam bar 4 and a coupling portion 5 are bent and formed as an united body. At this time, an outer frame portion 7 is fixed and smoothly bent and formed by utilizing elongation deformation of a deforming portion 6 provided between the coupling portion 5 and the outer frame portion 7. Next, dam bars 4 are cut by laser, and dross generated is almost fully removed by a chemical treatment. Thereafter, solder plating is performed for the outer lead 3 and the coupling portion 5 is cut off.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a semiconductor device in which a semiconductor chip is mounted on a lead frame and then sealed with a resin mold, and particularly, outer lead bending and dam bar cutting are performed in a highly accurate lead frame shape. The present invention relates to a semiconductor device manufacturing method performed while maintaining the above, a semiconductor device manufactured by the manufacturing method, and a lead frame used for the semiconductor device.

[0002]

2. Description of the Related Art Recently, in a semiconductor device in which a semiconductor chip is mounted on a lead frame, the inner leads of the lead frame are connected to respective terminals of the semiconductor chip, and they are integrally sealed by resin molding, the size and size of the semiconductor device are reduced. There is a demand for higher performance, and for this reason, the processed shape of the lead frame is also required to be fine and highly precise (hereinafter, such a semiconductor device will be referred to as a resin-molded semiconductor device as appropriate,
Or simply called a semiconductor device).

In the above resin mold type semiconductor device, a dam bar for connecting outer leads is provided in the lead frame in order to prevent positional deviation between the leads of the lead frame and to restrain the resin mold. The dam bar is cut and removed after sealing with the resin mold.

Conventionally, the dam bar has been mainly cut by punching using a punch or the like (hereinafter, referred to as a punch press method) (hereinafter, referred to as first prior art).

Further, in Japanese Patent Laid-Open No. 4-157761, a part of a resin mold (referred to as resin burr) sticking out to a dam bar and adhered thereto is irradiated with a laser beam in advance to melt or decompose the resin, and then the punch press method is used. Discloses a method of cutting a dam bar (hereinafter referred to as a second conventional technique).

Further, as described in Japanese Patent Laid-Open No. 2-301160, a method of cutting the dam bar by irradiating laser light (hereinafter referred to as laser cutting as appropriate) has been proposed (hereinafter referred to as the third prior art). ).

Further, as disclosed in Japanese Patent Application Laid-Open No. 6-232309, a method has been proposed in which the dam bar is laser-cut after the outer leads around the resin mold portion are bent and formed. Here, a connecting portion is provided on the outer periphery of the outer lead, and the connecting portion is cut and removed before or after laser cutting of the dam bar (hereinafter, referred to as a fourth portion).
Of conventional technology).

[0008]

In the first prior art, that is, the conventional general method of cutting the dam bar only by the punch press method, a resin burr formed in the vicinity of the dam bar is used after being integrally sealed with a resin mold. The punch life is greatly reduced. Further, there is a limit to cutting a fine portion by the punch press method, and it is difficult to cut a dam bar in a recent resin mold type semiconductor device having a large number of leads and a narrow lead pitch interval (narrow pitch and a large number of pins). It's getting harder.

In the second prior art, the problem due to the resin burr is solved, but since the dam bar is cut by the punch press method, there is a limit to cutting a fine portion like the above, and a narrow pitch is obtained. Therefore, it is difficult to cut the dam bar in a multi-pin semiconductor device.

In the third conventional technique, that is, the conventional technique of cutting the dam bar by laser processing, fine processing is possible by focusing the laser beam in an extremely small amount. Also,
The laser processing is a non-contact processing and can be processed without giving unnecessary deformation or distortion to the lead frame during the processing, so that the processing accuracy can be maintained. Further, in the laser processing, even if there is the resin burr described above, the processing size and the processing accuracy are not affected. However, this conventional technique has the following problems different from the case of using the punch press method.

That is, the laser processing is a method of locally and instantaneously heating a portion to be cut by a laser beam focused in a small size, and melting the heated portion to cut it. It solidifies and attaches as dross to the end surface of the cut part. If a semiconductor device with dross attached to it is mounted on an electronic device in this way, the dross can easily peel off and become a major cause of performance defects such as short circuits. Also, the surface of the outer lead that is joined to other components (such as electronic circuit boards) If the dross adheres to the adhesive, the adhesion at the time of joining will deteriorate.

In the fourth prior art, the rigidity of the outer lead is maintained by the connecting portion on the outer periphery of the dam bar or outer lead, and the outer lead can be bent while maintaining its width and pitch, and laser cutting is performed after the bending. Dross does not hinder the bending process,
It is possible to prevent the mutual displacement of the outer leads after the bending and forming, and to improve the bending and forming accuracy.

However, in this conventional technique, no consideration is given to positively avoiding the influence of dross adhesion, and the dross remains attached to the lead frame (outer lead) after the bending molding. Similar to the above-described third conventional technique, after mounting on an electronic device, they may be peeled off to cause a performance defect such as a short circuit, or the adhesiveness at the time of joining outer leads may be deteriorated to deteriorate the quality.

It is an object of the present invention to enable outer lead bending and dam bar cutting while maintaining a highly accurate shape of a lead frame having a narrow pitch and a large number of pins.
A method of manufacturing a semiconductor device that can obtain good product quality without being affected by dross, a semiconductor device manufactured by the manufacturing method, and a lead frame used for the semiconductor device. .

[0015]

In order to achieve the above object, according to the present invention, in a method of manufacturing a semiconductor device in which a semiconductor chip is mounted on a lead frame and then sealed by resin molding, the semiconductor chip is mounted on the lead frame. A first step of electrically connecting the inner lead of the lead frame and a terminal of the semiconductor chip and then integrally sealing the inner lead and the semiconductor chip with a resin mold; and the first step. And a second step of bending the outer lead of the lead frame into a gull wing shape, and a third step of cutting the dam bar of the lead frame by laser light irradiation after the second step, and the third step. And the fourth step of removing the dross formed by the irradiation of the laser beam by a chemical treatment after the step of. The method of manufacturing a semiconductor device according to claim Rukoto is provided.

In the method for manufacturing a semiconductor device described above, preferably, prior to the first step, the lead frame is provided with a connecting portion for connecting the outer peripheries of the outer leads to each other, and the chemical step in the fourth step is performed. After removing the dross by processing, the connecting portion on the outer periphery of the outer lead is cut and removed.

Further, preferably, immediately after the dross removal by the chemical treatment in the fourth step, the outer lead is plated.

Preferably, the outer leads are plated before the bending and forming of the outer leads in the second step.

Further, preferably, in the fourth step, the dross is chemically treated until its height becomes 5 μm or less.

Further, preferably, after the first step, the resin burr generated during the integral sealing by the resin mold is melted or decomposed by the irradiation of laser light to be removed.

[0021] Preferably, the resin mold portion and the outer lead are coated with a water-resistant and chemical-corrosion-resistant coating either before or after the bending of the outer lead in the second step.

In order to achieve the above-mentioned object, according to the present invention, there is provided a semiconductor device manufactured by the method for manufacturing a semiconductor device as described above.

Further, in order to achieve the above-mentioned object, according to the present invention, an inner lead electrically connected to a terminal of a semiconductor chip, an outer lead continuous to the outer side of the inner lead, and an outer lead thereof are provided. In a lead frame having a dam bar that connects the semiconductor chips and the inner lead with each other to prevent the resin mold from flowing out at the time of sealing with the resin mold, a connecting part that connects the outer peripheries of the outer leads to each other, and the connecting part. There is provided a lead frame, comprising: an outer frame portion that supports the outer periphery of the outer lead portion; and a deforming portion that connects between the connecting portion and the outer frame portion and that expands and deforms during bending of the outer lead. It

[0024]

In the present invention having the above-described structure, first, the semiconductor chip is mounted on the lead frame, the inner leads of the lead frame and the terminals of the semiconductor chip are electrically connected, and then the inner lead and the semiconductor chip. And are integrally sealed by a resin mold. The steps up to this point are almost the same as the conventional general semiconductor device manufacturing method.

Subsequently, in the present invention, after the above steps, the outer leads of the lead frame are bent and formed into a gull wing shape. At this time, the dam bar still exists in the lead frame without being cut, and the outer leads connected by the dam bar are integrally formed by bending with the outer peripheral shape of the resin mold portion as a reference. When such bending is performed, the outer lead behaves like a single plate and is bent in the out-of-plane direction with high in-plane rigidity, so that the outer leads have almost the same shape after forming. In addition, even if the processed shape or cross-sectional shape of each lead frame (outer lead) is slightly different, the shape after bending is hardly affected. That is, the outer lead is bent in a state where good bending accuracy can be easily achieved, and the shape accuracy after bending can be improved. Further, the accuracy of the lead pitch in the original lead frame is maintained without being impaired.

After the bending and forming process, the dam bar is laser-cut. Since this laser cutting is a cutting method that can accurately and reliably cut the dam bar of a lead frame with a large number of pins and a narrow pitch as described above, and is a non-contact cutting method with respect to the work piece, most of the work piece is not deformed. Never give. Thereby, the shape accuracy after the outer lead is bent and formed is maintained. Further, unlike the conventional punch press method, it is not necessary to manufacture a dedicated metal mold or jig for each semiconductor device, and the size to be processed can be arbitrarily changed with one laser processing device. It is possible to deal with a dam bar of a semiconductor device. Further, it is not necessary to press the cutting blade securely to the position to be cut while ensuring high positioning accuracy, and the dam bar can be easily cut only by irradiating the laser beam.

Next, after the laser cutting step, the dross formed by laser light irradiation is removed by chemical treatment. In this chemical treatment, for example, the dross can be easily and surely removed by immersing at least the portion to which the dross is attached in the chemical treatment liquid and holding it for a predetermined time. In addition, it is possible to remove dross in a recessed portion such as a valley fold portion of the outer lead, which is difficult to remove mechanically. Further, the chemical treatment is a treatment method that does not contact the work piece, so that the work piece is hardly deformed, and the shape accuracy after bending the outer lead is maintained even in this step. To be done.

By the way, in a semiconductor device which is a product after the outer lead is bent and formed, the bottom variation of the bent portion of the outer lead with respect to the surface to be joined to the electronic circuit board is called coplanarity. Although it is caused by a slight variation, it is very important to reduce the variation, and hence the coplanarity, in order to secure the shape accuracy of the semiconductor device as a product. In the present invention, the outer lead is bent and formed to a high shape accuracy, and the dam bar is cut and the dross is removed while maintaining the shape accuracy, so that the coplanarity is minimized and the state is maintained to a high shape accuracy. It becomes possible to manufacture the semiconductor device.

Furthermore, since the dross is almost completely removed by the chemical treatment which is a characteristic treatment method of the present invention, performance defects such as short circuit due to the dross peeling off and deterioration of adhesion at the time of joining the outer leads, etc. Therefore, it is possible to obtain good product quality without being affected by dross.

Further, since the lead frame is provided in advance with the connecting portion for connecting the outer peripheries of the outer leads to each other, the in-plane rigidity of the outer leads is further enhanced, and the shape accuracy after bending can be further improved. . It is desirable that the connecting portion on the outer circumference of the outer lead is finally cut after all the steps are completed in order to maintain the shape accuracy after the outer lead bending. Therefore,
This connecting portion is cut and removed after the dross is removed by a chemical treatment, whereby the outer leads are individually cut off to form a semiconductor device as a product.

Since the outer lead surface immediately after the dross removal by the chemical treatment is finished in a clean and smooth state, a sound and uniform plating layer is formed immediately after the chemical treatment by an appropriate plating treatment. Can be formed. This improves the bondability of the outer leads when the semiconductor device is mounted on the electronic circuit board. Moreover, since this plating process is performed before cutting and removing the connecting portion on the outer periphery of the outer lead, that is, in a state where the in-plane rigidity of the outer lead is high, there is no need to worry about deformation due to the plating process.

Further, even if the plating treatment is performed before the outer lead is bent and formed, the same thing can be said.

Further, according to an experiment conducted by the present inventors using a lead frame having a multi-pin and a narrow pitch of 0.3 mm pitch with a plate thickness of about 0.1 to 0.2 mm, ordinary laser cutting was performed. In this case, the height of the dross is 0.02-0.05m
The height of the dross, which is about m, which is not a problem when the semiconductor device is surface-mounted on the electronic circuit board, is about 0.005 mm at the maximum on one side. Therefore, if the dross generated by laser cutting is chemically treated until its height becomes 0.005 mm or less, that is, 5 μm or less, there is no practical problem. Furthermore, the thickness of the plating layer determined by the standard of the semiconductor device is 0.02 m in total on both sides.
However, if the dross is chemically processed to have a height of 5 μm or less as described above, there will be no problem when a plating layer is subsequently applied.

Further, the resin burr generated at the time of the integral sealing by the resin mold is melted or decomposed by the irradiation of the laser beam and removed to obtain a higher shape precision and obtain a better product quality. It becomes possible.

Further, in the present invention, the resin mold portion and the outer leads are coated with a water resistant and chemical corrosion resistant coating. By coating the resin mold part with the above coating, the resin mold part is protected from the chemical treatment liquid and the water used during cleaning after the chemical treatment, etc. It prevents the mold part from cracking and breaking. At the same time, by coating the outer lead with the above-mentioned coating, it is possible to prevent the surface of the outer lead material from being thinned by the chemical treatment liquid. Further, by coating this coating either before or after the outer lead is bent, that is, before the laser cutting of the dam bar, the adhesion of dross to the outer lead during the laser cutting of the dam bar can be prevented to some extent. This coating may be removed after the dross is removed by the chemical treatment.

Further, in the lead frame, an outer frame portion for further supporting a connecting portion on the outer periphery of the outer lead from the outer periphery is provided, and the connecting portion and the outer frame portion are connected to each other so that the lead frame is stretched and deformed during bending of the outer lead. By providing the portion, when the outer lead is bent while the outer frame is being fixed, the deformable portion is stretched and deformed with respect to the fixed outer frame, and the material is smoothly drawn in. That is, the deformation portion absorbs the deformation corresponding to the amount of material drawn. As a result, the outer leads and the outer frame portion are not irregularly deformed during bending, and high shape accuracy can be obtained.

[0037]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A semiconductor device manufacturing method, a semiconductor device and a lead frame according to an embodiment of the present invention will be described with reference to FIG.
From now on, referring to FIG.

FIG. 1 is a diagram for explaining the processing state of the outer leads and dam bars according to this embodiment, and FIG. 2 is a flow chart for explaining the manufacturing process of the method for manufacturing a semiconductor device according to this embodiment. First, in step S100 of FIG. 2, a metal plate such as steel, copper alloy, 42 alloy, and Kovar is placed on a leveler and processed into a predetermined thickness. Next, in step S101, the metal plate is processed to form a lead frame. Further, the inner end of the lead frame processed as described above is subjected to gold plating in order to facilitate bonding with the terminals of the semiconductor chip.

Next, in step S102, an adhesive is applied to a die pad (not shown) for mounting the semiconductor chip at the center of the lead frame, and the semiconductor chip (not shown) is mounted and bonded. Next, in step S103, each terminal of the semiconductor chip and each lead of the lead frame are electrically connected by wire bonding.

Next, in step S104, the semiconductor chip and the lead frame bonded as described above are integrally sealed with a resin mold. The state in which this step is performed is shown in FIG. In FIG. 3, the resin mold 2 is arranged in the center of the lead frame 1, and the outer leads 3 of the lead frame 1 project from the resin mold 2 in four directions. Further, a dam bar 4 that connects the respective leads of the outer lead 3 is provided at a position near the resin mold 2 inside the outer lead 3. The dam bar 4 plays a role of preventing the positional deviation between the leads of the outer lead 3 and preventing the resin mold 2 from flowing out. A connecting portion 5 that connects the outer leads 3 to each other is provided on the outer periphery of the outer lead 3, and an outer frame portion 7 is provided on the outer periphery of the connecting portion 5 via a deforming portion 6. Deformation part 6 is outer lead 3
Is a portion that is stretched and deformed during the bending and shaping of. In addition, the outer frame portion 7 is provided with a positioning hole 8 for fixing the outer frame portion 7 during fixing of the lead frame 1 during processing, positioning during mounting of a semiconductor chip, and bending of the outer lead 3. It is used for things.

Next, in step S105 of FIG.
Of the lead frame 1, four corner portions (portions indicated by broken lines 3a in FIG. 3) outside the resin mold 2 are cut by pressing or the like. This cut portion is an unnecessary portion in the final product. Even after the corner portion 3a is cut, the outer peripheral tip of the outer lead 3 is still connected by the connecting portion 5. Then, the appearance at this point is inspected.

Next, in step S106, the outer lead 3 is bent and formed into a predetermined gull wing shape. At this time, the outer leads 3 connected by the dam bar 4 and the connecting portion 5 are integrally and integrally bent from the vicinity of the dam bar 4 with reference to the shape of the outer periphery of the resin mold portion 2. When such bending is performed, the outer lead 3 behaves like a single plate and is bent in the out-of-plane direction with high in-plane rigidity, so that the outer lead 3 has almost the same shape after molding. Become. Further, even if the processed shape and the cross-sectional shape of each outer lead 3 are slightly varied during the manufacture of the lead frame 1, the shape after the bending is hardly affected. Therefore, the outer leads 3 are bent in a state where good bending accuracy can be easily achieved, the shape accuracy after bending can be improved, and the accuracy of the lead pitch in the original lead frame 1 is maintained without being impaired. .

Further, this bending is performed with the outer frame portion 7 fixed, and at that time, the deformable portion 6 is deformed with respect to the outer frame portion 7.
Stretches and deforms, and the material is drawn in smoothly. That is,
The deformation corresponding to the amount of material drawn in is absorbed by the deformation portion 6. As a result, the outer leads 3 and the outer frame portion 7 are not irregularly deformed during bending. After the bending and forming is completed, the deformable portion 6 and the outer frame portion 7 are cut off and divided into individual semiconductor devices 100. This step S106
1 is a partial enlarged view of the outer lead 3 after the completion of
(A). Strictly speaking, the semiconductor device at this stage is in the process of manufacturing, but in the present invention, a device in such a process of manufacturing is also referred to as a semiconductor device for simplicity.

Next, in step S107, the dam bar 4 is cut by irradiation with laser light. The laser processing device for generating the laser beam used at this time may be a general one known in the art. An example of the optical system of this laser processing apparatus is shown in FIG.

In FIG. 4, the laser beam 52 generated by the laser oscillator 51 is incident on a bending mirror 54 provided in the processing head 53 and guided toward the metal plate 1. Then, the laser light 52 is incident on the condenser lens 56 in the nozzle 55, is sufficiently condensed so as to have a required energy density that enables processing, and is processed from the tip of the nozzle 55 to the processing position X of the lead frame 1. (Dam bar 4) is irradiated. Further, the nozzle 55 has an assist gas supply port 5
7 is provided, and assist gas 58 is supplied from the tip of the nozzle.
Are ejected coaxially so as to enclose the laser beam 52.

In such a laser processing apparatus, first, various conditions such as the oscillation period and energy density of the laser light 52, the focal position of the condenser lens 56, the pressure of the assist gas, the processing position, etc. are set, and then the dam bar 4 is set. Laser cutting is performed. At this time, since the dam bar 4 after the outer lead 3 is bent and shaped is cut in a good state, the laser light 52
It is necessary that the tip of the nozzle 55 that emits is close to the dam bar 4 as much as possible. Therefore, when laser cutting is performed, laser light is emitted from the mountain fold side of the outer lead 3.

Further, at this time, by using a laser beam having an elongated elliptical cross section, as shown in FIGS.
As shown in FIG. 5, the spot 52A on the dam bar 4 becomes elliptic, and the dam bar 4 can be cut by irradiating the laser beam once or several times. Can be cut well. The laser cutting may be inferior in processing efficiency to the conventional punch press method, but if the laser beam having the elongated elliptical cross section as described above is used, the processing efficiency can be improved to the level of the conventional method. it can. However, a laser beam having an elongated elliptical cross section as shown in FIG. 5 can be obtained by passing a laser beam having a circular cross section output from a laser oscillator through a cylindrical lens. Alternatively, a laser beam having a rectangular cross section output from a slab type laser oscillation medium may be used.

The fine pulsed continuous pulse laser light is reflected by a galvanometer mirror, which is a reflection optical system capable of high-speed scanning, or a rotary reflection optical system that rotates the optical axis at a high speed, and is traced on the cutting position of the dam bar. A method of moving the laser light along with high speed and accuracy may be adopted.

Further, as shown in FIG. 5A, the resin 2a inside the dam blocked by the dam bar 4 and the resin burr 2b which is the resin flowing out to the surface of the lead frame 1 are attached near the dam bar 4. However, in FIG. 5A, the resin 2a in the dam and the resin burr 2b are indicated by diagonal lines. Almost all of the resin burr 2b is melted or decomposed by heat input by the irradiation of the laser beam 52, and the resin 2a in the dam is also extremely small. As a result, higher shape accuracy can be obtained and better product quality can be obtained. However, since the resin burr 2b is only thinly attached to the surface of the lead frame,
It can be easily removed by simply irradiating the laser beam which is defocused to some extent.

FIG. 6 is a view conceptually showing a cross section of the workpiece (dam bar 4) to be laser-cut at this time. In FIG. 6, the laser beam 52 is condensed by the condenser lens 56 so as to supply sufficient heat energy, and the metal plate 1
The irradiated portion of the surface is melted, and this serves as a heat source, and this melting progresses sequentially from the surface in the depth direction, and eventually the dam bar 4 is cut and removed. Since the laser light 52 can be condensed in an extremely small amount, it is suitable for fine processing, and the dam bar 3 in the lead frame 1 having a large number of pins and a narrow pitch can be cut accurately and surely. Moreover, since this laser cutting is a non-contact cutting method with respect to the workpiece, almost no unnecessary deformation or distortion is given to other parts of the lead frame 1 such as the outer lead 3 during cutting, and the outer lead 3 The shape accuracy after bending and shaping is maintained.

Further, unlike the conventional punch press method, it is not necessary to manufacture a dedicated die or jig for each semiconductor device, and if there is one laser processing device, the size to be processed can be arbitrarily changed. Therefore, it can be applied to the dam bars of all semiconductor devices. Further, it is not necessary to press the cutting blade securely to the position to be cut while ensuring high positioning accuracy, and the dam bar can be easily cut only by irradiating the laser beam.

Further, at this stage, the outer lead 3
Since the outer periphery of the outer lead 3 is still connected by the connecting portion 5, the in-plane rigidity of the outer lead 3 is still maintained, and the shape accuracy after bending can be maintained. This step S1
FIG. 1B is a partially enlarged view of the outer lead 3 after the laser cutting of 07 is completed.

Most of the molten metal generated by the laser light irradiation as described above is blown off by the assist gas and falls from the back surface of the lead frame 1, but a part of the molten metal that remains remains on the outer leads 3 (lead frame 1). Then, it solidifies and becomes a dross 10 as shown in FIG. In this embodiment, since the laser light is emitted from the mountain-folded side of the outer lead 3, the dross 10 is on the side opposite to the side irradiated with the laser light, that is, the outer lead 3.
Many adhere to the valley fold side of the back surface of. Further, the molten metal by laser light irradiation is solidified on the side wall after cutting the dam bar 4 to form the re-solidified layer 11. The dross 10 is peculiar to laser processing, which is heat processing. As described above, the dross 10 is peeled off after mounting on an electronic device to cause a performance defect such as a short circuit, or the adhesiveness at the time of joining outer leads is It will deteriorate and the quality will be impaired.

Next, in step S108, the dross 10 generated by laser cutting and attached to the outer leads 3 is removed by a chemical treatment. Since the lead frame having a large number of pins and a narrow pitch has a fine and highly accurate shape, it is generally not easy to mechanically remove the dross 10 attached to the valley fold side of the outer lead 3 after the fold forming. However, when using a chemical treatment method such as an etching method using a ferric chloride solution or a cupric chloride solution or a chemical polishing method, any portion can be treated as long as the treatment liquid can penetrate. Can do the dross 1
It is possible to easily remove 0.

Here, the mechanism of the chemical treatment of the dross 10 will be described. However, what will be described below is a chemical treatment by an etching method in which the semiconductor device 100 is immersed in a ferric chloride solution, a cupric chloride solution, or the like. According to the investigation conducted by the present inventor, as shown in FIG. 7A, the dross 10 is not entirely bonded to the back surface of the outer lead 3 but is in contact with the back surface of the outer lead 3 10 a. On the outer periphery of the metal oxide (10 μm
It is expected that most of them are attached via a thickness of about 15 μm). That is, the contact surface 1 between the dross 10 and the outer lead 3 with sufficient oxygen supply.
It is considered that the two are in a kind of bonded state via the oxide 12 formed on the outer peripheral portion of 0a, and the inner portion of the contact surface 10a does not adhere very strongly. Due to the presence of the oxide 12, it is not easy to mechanically remove the dross 10 from the outer lead 3. However, it is considered that the same oxide as the oxide 12 is naturally formed on the surface of the dross as a layer.

When the etching liquid is supplied in the vicinity of the portion where the dam bar 4 is removed by laser cutting, the dross 1
0 was gradually corroded from the oxide layer on the surface, and the height thereof was H ₀ shown in FIG. 7 (a) from H ₁ shown in FIG. 7 (b) to H ₂ shown in FIG. 7 (c). It becomes gradually lower (however, H ₀ > H ₁ > H ₂ ). At the same time, dross 10
The oxide 12 formed on the outer peripheral portion of the contact surface 10a between the outer lead 3 and the outer lead 3 is also corroded, and the width of the oxide 12 starts at the beginning of FIG.
What was L ₀ shown in FIG. 7 is changed from L ₁ shown in FIG.
It becomes gradually thinner to L ₂ shown in (c) (however, L ₀ > L ₁
> The L _2). Then, when the corrosion progresses to some extent, the oxide 12 that joins the dross 10 to the outer lead 3 is removed, so that the dross 10 is stripped off and removed cleanly as shown in FIG. 7D. Further, the portion including the re-solidified layer 11 and the like formed on the side wall after cutting the dam bar 4 is also corroded by etching, the thickness thereof becomes thin, and the side wall of the slit is slightly sagged, but this is not a problem. In FIG. 7, the direction in which the etching process proceeds is indicated by an arrow.

In the present embodiment, etching is performed until the time when the stripping of the dross 10 that occurs as described above is completed. As a result, most of the dross can be removed by stripping. Hereinafter, the results of an experimental examination of the situation of the dross 10 coming off will be described with reference to FIG. In addition, the following experimental results are also the basis for the fact that the above-mentioned adhesion state of the dross 10 is expected to be as shown in FIG. 7A.

FIG. 8 is a diagram showing the relationship between the etching processing time and the average value of the dross height. The black circles in the figure represent the average value of the dross height. Here, a SUS304 stainless steel plate of 18 mm square and a thickness of 0.15 mm was used as the metal plate of the material. As an experimental method, the metal plate was laser-cut and then masked with two Teflon plates. The sample was dipped in a ferric chloride solution at 45 ° C., the height of a predetermined number of dross was measured every predetermined etching processing time (2 min in FIG. 8), and the average value was obtained. The metal plate is not covered with the resist film before laser cutting. Also,
At the same time, the thickness of the metal plate was measured, and the results are shown by white circles in the figure. However, in FIG. 8, the vertical axis on the left side is a scale of the average value H (μm) of the dross height, and the vertical axis on the right side is attached to the plate thickness T (μm) of the metal plate and the metal plate. The scale of dross ratio γ (%) is taken.

In FIG. 8, in the area A, the decreasing rate of the average value of the dross height (hereinafter, simply referred to as the dross height) H is 1.5 μm / min, and the decreasing rate of the plate thickness T of the metal plate. It is almost the same as 1.6 μm / min. However, since the metal plate is corroded from both sides at the same time, while the dross is corroded from one side, the corrosion rate from the surface of the dross is actually twice the corrosion rate from the surface of the metal plate. The corrosion rate is from the decrease rate of plate thickness T of 1.6μm / mi
It is 0.8 μm / min which is half of n. This means that the dross is selectively corroded to some extent as compared with the metal plate material. Further, in the region B, the reduction rate of the dross height H is 8.3 μm / min, which is significantly faster than in the region A, and in the region C, the reduction rate of the dross height H is 1 It becomes 0.3 μm / min, and it decreases at almost the same speed as the area A.

From these results, it is considered that the dross is gradually corroded from the surface in the initial stage of corrosion, that is, the region of A in FIG. 8, and the stage where the corrosion has advanced, that is, the region of B in FIG. Then, it is considered that the dross starts to peel off, and the amount of dross removed by peeling off gradually increases, so that the average value of the dross height suddenly decreases. It is considered that in the region C, the dross was almost completely stripped off and the remaining dross was subsequently corroded little by little from the surface.

It is considered that the ratio γ of the dross adhering to the metal plate corresponding to each of the regions A to C changes and decreases as shown by the one-dot chain line in the figure. In addition, the change of the dross height H in the area of B is extrapolated up to the horizontal axis, and the extrapolation point is D
Then, the extrapolation point D is considered to be the time when the dross is almost completely removed. Each dross has various dimensions, but the behavior of the dross may be evaluated based on the average value thereof as shown in FIG.

If a straight line (shown by a broken line in the figure) parallel to the change in dross height H in the area A is drawn from the extrapolation point D and the intersection with the left vertical axis is E, this point E is It is considered that it represents the net thickness that is gradually corroded from the surface until the dross is completely removed, and the oxide 12 formed on the outer peripheral portion of the contact surface 10a with the outer lead 3 (see FIG. 7).
Is considered to represent the thickness of the. That is, 10 μm to 1
When the oxide layer having a thickness of about 5 μm is removed, the dross 10 having the outer peripheral portion joined with the oxide 12 is almost removed and removed.

As described above, in this embodiment, most of the dross 10 is peeled off and removed by the chemical treatment, so that the performance loss such as a short circuit due to the dross 10 peeling off and the deterioration of the adhesion at the time of joining the outer leads 3 are deteriorated. It is possible to obtain good product quality without being affected by the dross 10.

Further, since the etching process is stopped when the dross 10 is almost completely stripped off, most of the dross 10 can be removed by stripping and the outer lead 3 can be minimized in thickness. Therefore, by performing the etching process, the adverse effect of dross can be eliminated, and this etching process can be suppressed to the necessary minimum, so that lean meat can be suppressed as much as possible. In addition, the time required for etching processing can be significantly reduced.

Although the dross in the joined state shown in FIG. 7 (a) has been described here, the dross in which the inner portion of the contact surface with the metal plate adheres relatively strongly is removed by peeling as described above. There is no such thing. However, since the number of them is very small, and the size is reduced to some extent by the etching process, there is almost no obstacle in the manufacturing process of the semiconductor device. Furthermore, such dross adheres strongly to the metal plate. Since it does not fall off, its adverse effects can be almost ignored.

In order to verify how small the dross adhered relatively strongly should be,
According to the experiments conducted by the inventors of the present invention using a multi-pin and narrow-pitch lead frame with a plate thickness of approximately 0.2 mm and a pitch of 0.3 mm, the dross height is 0 when ordinary laser cutting is performed. The height of the dross was about 0.02 to 0.05 mm, which was not a problem when the semiconductor device was surface-mounted on the electronic circuit board. Therefore, it is considered that there is no practical problem if the chemical treatment is performed until the height of the dross becomes 5 μm or less. Further, the thickness of the plating layer (plating processing will be described later in step S109 of FIG. 2) determined by the standard of the semiconductor device is 0.02 mm in total on both sides, but the height of the dross is as described above. If it is chemically treated to have a thickness of 5 μm or less, there will be no problem when a plating layer is applied.

After completion of the above chemical treatment, washing and drying are performed. Outer lead 3 at this point
A partially enlarged view of is shown in FIG. By the chemical treatment of step S108, the dross 10 is removed, and the side wall 3A of the dam bar 4 after laser cutting becomes a smooth and clean surface.

Even at this stage, since the outer peripheries of the outer leads 3 are still connected by the connecting portion 5, the in-plane rigidity of the outer leads 3 and, therefore, the shape accuracy after bending is maintained.

Next, in step S109 of FIG.
The outer lead 3 is coated with a low melting point metal, that is, solder-plated, and then an external appearance inspection is performed. Immediately after the dross 10 is removed by the chemical treatment in step S108, the surface of the outer lead 3 is finished in a clean and smooth state. It is possible to form layers. This improves the bondability of the outer leads when the semiconductor device is mounted on the electronic circuit board. Moreover, this plating process is performed with the connecting portion 5 on the outer periphery of the outer lead 3.
Is left, that is, in a state where the in-plane rigidity of the outer lead 3 is high, there is no need to worry about deformation due to the plating process.

As the low melting point metal, tin, lead or the like may be used in addition to the solder as described above. Further, the plating process may be performed before the bending forming of the outer lead 3 in step S106. Furthermore, in step S102, the surface of the lead frame 1 before mounting the semiconductor chip may be plated beforehand.

Following the solder plating as described above, in step S110, the connecting portion 5 connecting the outer peripheral tips of the outer leads 3 is cut. That is, as shown in FIGS. 9A and 9B, the outer leads 3 are individually cut off by cutting the connecting portions 5 on the four sides of the lead frame to form the final semiconductor device shape. At this time, it is preferable to use a cutting method that is less likely to deform the outer lead 3 so as not to impair the bending accuracy of the outer lead 3 as much as possible. Further, as shown in FIG. 1, if the notch 5a is provided in advance along the cutting line C for cutting the connecting portion 5, the connecting portion 5 can be easily cut along the cutting line C. it can.

In this way, the laser cutting of the dam bar 4 and the chemical treatment of the dross 10 are performed with the connecting portion 5 left, and the connecting portion 5 is processed after the processing up to step S109 which is a processing step other than the inspection is completed. The reason for cutting is to maintain the shape accuracy of the outer lead 3 after bending.

After the connection portion 5 is cut, in step S111, the connection between each lead of the semiconductor device and the semiconductor chip is inspected, the shape of the outer lead 3 and its appearance are inspected, and finally the package is shipped.

Here, the shape accuracy of the outer lead 3 after bending in the semiconductor device as a product will be described. The coplanarity, which is the bottom variation of the bent portion of the outer lead 3 with respect to the surface joined to the electronic circuit board, is caused by a slight variation in the bent shape. However, reducing this coplanarity is a product. Is very important for ensuring the shape accuracy of the semiconductor device as described above. For example, 0.3m
In the m-pitch QFP type semiconductor device, the allowable coplanarity is 0.05 mm. That is, if the coplanarity becomes even worse (the variation is large), the number of joint defects increases significantly when the semiconductor device is surface-mounted on the electronic circuit board. Therefore, in an electronic circuit board having a fine circuit pattern, even if the coplanarity of only one semiconductor device is poor, it is difficult to repair the joint defect caused thereby, and the electronic circuit board and the mounted electronic circuit board are mounted. All of the electronic components will be wasted. As described above, although it is difficult to process the outer lead 3 with high dimensional accuracy and shape accuracy, the quality of the accuracy affects the quality of the semiconductor device itself.

For example, the semiconductor device 1 shown in FIG.
00, the variation of the end surface of the outer lead 3 after bending and forming viewed from the B direction will be compared. As shown in FIG. 10B, there is no vertical displacement of the outer leads 3 after bending and the bottom surfaces of the bent portions of the outer leads 3 (which also serve as the bottom surface of the semiconductor device 100 itself) are all the same. If it is on a flat surface, when placed on the surface of an electronic circuit board, no gap is generated between the bottom surface of any outer lead 3 and the electronic circuit board. Therefore, in this state, the outer leads 3 and the electronic circuit board can be satisfactorily surface-mounted by soldering. However, in FIG. 10A, the pitch of the outer leads 3 is represented by p.

On the other hand, as shown in FIG.
When the outer leads 3 after bending and forming are displaced in the vertical direction, the bottom surface of the bent portion of the outer leads 3 is displaced upward or downward from the reference plane determined at the time of design, and placed on the electronic circuit board surface. In that case, a gap is generated between the bottom surface of the outer lead 3 and the electronic circuit board. When this gap is small, the solder will fill the gap to some extent, which will not result in a joint defect. However, when the gap becomes large, the solder cannot fill the gap, resulting in a joint defect. The equipment will be defective. However, in FIG. 10B, the variation (coplanarity) of the bottom surface of the outer lead 3 after the bending molding is represented by Δ.
It was represented by h.

However, in the present embodiment, as described above, the outer lead 3 is bent and formed with high shape accuracy, and while maintaining the shape accuracy, the dam bar 4 is cut and the dross 5 is removed. It becomes possible to manufacture the semiconductor device with high shape accuracy by minimizing the coplanarity which is the bottom surface variation of the bent portion of 3 and maintaining the state.

By the way, even if the outer lead is bent with high precision and the product is manufactured while maintaining its shape precision, the dimensional precision is impaired before the surface mounting on the electronic circuit board. And joint defects cannot be reduced. In particular, in a semiconductor device using a lead frame having a large number of pins and a narrow pitch, the rigidity and strength of the lead frame must be low, and therefore the latest care must be taken in handling the product. Therefore, it is necessary to process the product as accurately as possible at the product shipping stage and to maintain the accuracy until surface mounting on the electronic circuit board. As one method, for example, if the outer leads 3 are reinforced with a heat-resistant insulating film such as a polyimide film, the outer leads 3 are prevented from being deformed, and the handling of the semiconductor device can be improved.

According to this embodiment as described above, since the outer leads 3 connected by the dam bar 4 and the connecting portion 5 are integrally formed by bending, the accuracy of shape of the outer leads 3 after bending is improved. Therefore, the accuracy of the lead pitch in the original lead frame 1 is maintained without being impaired. Further, since the dam bar 4 is cut by using the laser beam, even the dam bar 4 of the lead frame 1 having a large number of pins and a narrow pitch can be cut accurately and surely, and a dedicated metal mold like the conventional punch press method is used. It is possible to easily cut the dam bars of all semiconductor devices without the need for manufacturing jigs and jigs. Further, the dross 10 can be easily and surely removed by the chemical treatment, and the dross 10 such as the valley fold portion of the outer lead 3 which is difficult to mechanically remove can also be removed.

Further, since the laser cutting and the chemical treatment are both non-contact treatment methods for the workpiece,
Almost no deformation is given to the outer lead 3 after bending and the shape accuracy is maintained. Therefore, the coplanarity of the outer lead 3 after bending and forming can be minimized and the state can be maintained to manufacture a semiconductor device with high shape accuracy.

Further, since the dross 10 is stripped off by chemical treatment and is almost completely removed, performance defects such as short circuit due to the stripping of the dross 10 and deterioration of adhesion at the time of joining the outer leads are avoided, and a good product is obtained. You can get quality. On the other hand, the dross that adheres relatively strongly is not removed by flaking, but the number is very small.
Since the size is also small and it hardly peels off, its adverse effect can be almost ignored.

Further, since the plating layer is formed on the clean and smooth outer lead surface immediately after the removal of the dross 10 by the chemical treatment, a sound and uniform plating layer can be formed. This improves the bondability of the outer leads 3 when the semiconductor device is mounted on the electronic circuit board.

Further, since the chemical treatment is performed until the height of the dross 10 generated by laser cutting becomes 5 μm or less, there is no practical problem when the semiconductor device is surface-mounted on the electronic circuit board. Furthermore, there is no problem in applying the plating layer.

Further, since the resin burr 2b is melted or decomposed and removed by irradiation of laser light, higher shape accuracy can be obtained and better product quality can be obtained.

Further, since the deformable portion 6 is provided between the connecting portion 5 and the outer frame portion 7, the outer frame portion 7 is fixed and the outer lead 3 is fixed.
When the bending molding is performed, the deformable portion 6 does not expand and deform, and the material is smoothly drawn in, so that the outer lead 3 and the outer frame portion 7 are not irregularly deformed.

Further, since the laser beam having the elongated elliptical cross section is used, the dam bar 4 can be cut by irradiating the laser beam once or several times, and the processing efficiency can be made equal to the conventional method. .

Next, another embodiment of the method of manufacturing a semiconductor device according to the present invention will be described with reference to FIG.

As shown in the sectional view of FIG. 11, in the present embodiment, the outer lead 3 in step S106 of FIG.
Before or after the bending and molding, the water-resistant and chemical-corrosion resistant coating (hereinafter referred to as a resist film) 20 is coated on the entire semiconductor device 100 including the resin mold 2. The resist film 20 on the surface of the dam bar is removed by the heat when the dam bar is laser-cut. Further, after removing the dross by the chemical treatment, the resist film 20 may be removed by a suitable solvent or the like before the cleaning step. However, FIG. 11B is an enlarged view of the portion B of FIG. 11A, and shows a situation in which the plating layer 30 is formed on the surface of the lead frame 1 and the resist film 20 is coated thereon. The configuration other than the above is the same as the embodiment described with reference to FIGS.

In this embodiment as described above, the resin mold 2 is covered with the resist 20 film.
Are protected from the chemical treatment liquid and the water used at the time of cleaning after the chemical treatment, and the resin mold 2 is prevented from cracking due to the invasion of the chemical treatment liquid and the water. At the same time, since the outer lead 3 is covered with the resist film 20, it is possible to prevent the surface of the material of the outer lead 3 from being thinned by the chemical treatment liquid. Further, the resist film 20 prevents the dross from adhering to some extent during laser cutting of the dam bar.

The outer lead is bent and formed into a rough shape to some extent within a range where the shape accuracy is maintained in the dam bar laser cutting process and the dross removing process, and the dross generated by the laser cutting and the chemical treatment of the dam bar is removed. After the removal, the outer leads may be bent and formed while being precisely corrected to the final shape. This makes it possible to control the shape accuracy after the outer lead bending molding in the final step, and improve the shape accuracy.

Further, in the above-mentioned embodiments, the dross after the laser cutting of the dam bar is mainly treated, but according to the present invention, not only the dross but also the spatter can be treated similarly.

[0092]

According to the present invention, the outer leads connected by the dam bar are integrally formed by bending, so that the shape accuracy of the outer leads after bending can be improved and the original lead frame can be formed. The accuracy of the lead pitch is also maintained without being impaired. Also,
The laser cutting can easily cut the dam bar of the lead frame having a large number of pins and a narrow pitch, and the chemical treatment can easily and surely remove the dross. Further, since the laser cutting and the chemical treatment are both non-contact treatment methods with respect to the workpiece, the outer leads after bending and forming are hardly deformed, and the shape accuracy thereof is maintained. . Therefore, it is possible to manufacture the semiconductor device having a lead frame with a large number of pins and a narrow pitch with high shape accuracy while minimizing the variation of the outer leads after bending and maintaining the state.

Further, since the dross is almost completely removed by the chemical treatment, it is possible to avoid performance defects such as short circuit and deterioration of adhesion at the time of joining outer leads, and to obtain good product quality.

Further, since the connecting portion for connecting the outer peripheries of the outer leads to each other is provided, the shape accuracy after bending can be further improved.

Further, since the plating layer is formed on the clean and smooth outer lead surface immediately after the dross removal by the chemical treatment, a sound and uniform plating layer can be formed.
The outer leads can be bonded well when the semiconductor device is mounted on the electronic circuit board.

Further, since the chemical treatment is performed until the height of the dross becomes 5 μm or less, there is no practical problem when the semiconductor device is surface-mounted on the electronic circuit board. Furthermore, there is no problem in applying the plating layer.

Further, since the resin burr is melted or decomposed by the irradiation of the laser beam and removed, higher shape accuracy can be obtained and better product quality can be obtained.

Further, since the resin mold portion and the outer leads are coated with a water resistant and chemical corrosion resistant film,
The resin mold portion is protected from chemical treatment liquid and water used during cleaning after chemical treatment to prevent cracking, and it is possible to prevent the surface of the outer lead material from being thinned by the chemical treatment liquid. Further, the coating prevents dross from adhering to some extent.

Further, since the deforming portion is provided between the connecting portion on the outer periphery of the outer lead and the fixing outer frame portion, the outer lead and the outer frame portion are not irregularly deformed.

Therefore, according to the present invention, a semiconductor device of high shape accuracy and high quality can be manufactured with good processing efficiency and low cost, so that mass production can be realized. Further, by using the semiconductor device of the present invention, it is possible to produce a highly reliable electronic device because the occurrence of a junction defect during the production of an electronic device can be avoided, and it is possible to improve the product yield thereof. Further, it is possible to realize high-density mounting of electronic devices.

[Brief description of drawings]

FIG. 1 is a view for explaining a processing state of an outer lead and a dam bar according to an embodiment of the present invention, FIG. 1A is a partially enlarged view of the outer lead after bending and forming are completed,
(B) is a partially enlarged view of the outer lead after the laser cutting of the dam bar is completed, and (c) is a partially enlarged view of the outer lead after the chemical treatment is completed.

FIG. 2 is a flowchart illustrating a manufacturing process of a semiconductor device according to an embodiment of the present invention.

FIG. 3 is a view showing a state in which a semiconductor chip and a lead frame are integrally sealed with a resin mold, and is an external view of a semiconductor device during manufacturing.

4 is a diagram showing an example of an optical system of a laser processing apparatus used in step S107 of FIG.

5A and 5B are diagrams showing a situation in which a dam bar is cut by laser light, in which FIG. 5A is a plan view and FIG.
It is B sectional drawing.

FIG. 6 is a view conceptually showing a cross section of a workpiece (dam bar 4) to be laser-cut.

7 is an enlarged view of part VII of FIG. 6, (a)-
(C) is a diagram showing a state in which dross is gradually corroded from the oxide layer on the surface by etching, and (d) is a diagram showing a state in which the dross is peeled off.

FIG. 8 is a diagram showing the results of an experimental investigation of the state of dross flaking off.

9A and 9B are views showing a situation in which a connecting portion on the outer periphery of the outer lead is cut, in which FIG. 9A is a plan view and FIG. 9B is B in FIG. 9A.
It is a sectional view of the -B direction.

FIG. 10 is a diagram illustrating coplanarity, which is a bottom surface variation of a bent portion of the outer lead, (a).
Is a cross-sectional view of the semiconductor device, (b) is a view as seen from the direction B of (a), and shows a case where there is no vertical displacement of the outer leads after bending, and (c) is (a) FIG. 8B is a view as seen from the direction B in FIG. 9B, showing the case where the outer leads after bending have a vertical displacement.

FIG. 11 is a diagram illustrating a method of manufacturing a semiconductor device according to another embodiment of the present invention, in which (a) is a semiconductor device 100 including a resin mold 2 including a resist film having water resistance and chemical corrosion resistance. Sectional drawing which shows the state which covered the whole, (b) is a B section enlarged view of (a).

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Lead frame 2 Resin mold 3 Outer lead 4 Dam bar 5 Connecting part 6 Deformation part 7 Outer frame part 8 Positioning hole 10 Dross 10a (Contact surface between dross 10 and outer lead 3) 11 Re-solidified layer 12 (Outer periphery of contact surface 10a) Oxide 20 formed on the part 20 Water-resistant and chemical-corrosion resistant resist film 30 Plating layer 51 Laser oscillator 52 Laser light 52A Spot 53 Processing head 54 Bending mirror 55 Nozzle 56 Condenser lens 57 Assist gas supply port 58 Assist Gas 100 Semiconductor device C Cutting line of connecting part 5 p Pitch of outer lead 3 Δh Variation of bottom surface of outer lead 3 (coplanarity)

Front Page Continuation (72) Inventor Yoshiyuki Uno 1-9-15-3 Nishizaki, Okayama City, Okayama Prefecture

Claims (9)

[Claims] 1. A method of manufacturing a semiconductor device in which a semiconductor chip is mounted on a lead frame and then sealed by a resin mold, wherein the semiconductor chip is mounted on the lead frame and the inner leads of the lead frame and terminals of the semiconductor chip are electrically connected. A first step of integrally sealing the inner lead and the semiconductor chip with a resin mold after connecting to the second step, and a second step of bending the outer lead of the lead frame into a gull wing shape after the first step. And a third step of cutting the dam bar of the lead frame by irradiation of laser light after the second step, and a dross formed by irradiation of the laser light after the third step is chemically removed. A fourth step of removing by processing, a method of manufacturing a semiconductor device. 2. The method of manufacturing a semiconductor device according to claim 1, wherein, prior to the first step, a connecting portion for connecting outer peripheries of the outer leads to each other is provided on the lead frame, and the fourth portion is provided. A method of manufacturing a semiconductor device, characterized in that after the dross is removed by the chemical treatment in the step, the connecting portion on the outer periphery of the outer lead is cut and removed. 3. The semiconductor device manufacturing method according to claim 1, wherein the outer lead is plated immediately after the dross is removed by the chemical treatment in the fourth step. Device manufacturing method. 4. The method of manufacturing a semiconductor device according to claim 1, wherein the outer lead is plated before the bending and forming of the outer lead in the second step. Manufacturing method. 5. The method for manufacturing a semiconductor device according to claim 1, wherein in the fourth step, the dross is chemically treated until its height becomes 5 μm or less. And a method for manufacturing a semiconductor device. 6. The method for manufacturing a semiconductor device according to claim 1, wherein after the first step, resin burrs generated during integral sealing by the resin mold A method of manufacturing a semiconductor device, characterized by melting or decomposing and removing by irradiation of light. 7. The method of manufacturing a semiconductor device according to claim 1, wherein the resin mold portion and the outer portion are provided before or after the bending of the outer lead in the second step. A method of manufacturing a semiconductor device, comprising coating a lead with a water-resistant and chemical-corrosion-resistant coating. 8. A semiconductor device manufactured by the method for manufacturing a semiconductor device according to claim 1. Description: 9. An inner lead electrically connected to a terminal of a semiconductor chip, an outer lead continuous to the outer side of the inner lead, and the outer lead are connected to each other and a resin mold for the semiconductor chip and the inner lead. In a lead frame having a dam bar that dams the resin mold flowing out at the time of sealing by, a connecting portion that connects the outer peripheries of the outer leads to each other,
A lead frame, comprising: an outer frame portion that supports the connecting portion from the outer circumference; and a deforming portion that connects the connecting portion and the outer frame portion and that expands and deforms when the outer lead is bent and formed. .