JPH098206A - Lead frame and bga resin sealed semiconductor device - Google Patents

Abstract

PURPOSE: To provide a lead frame which can cope with the further increased number of terminals and can be used as a core material for forming a circuit by forming external terminals so that their two faces can be on the surface of the material of the lead frame and the other two faces can be projected to the outside of each external terminal section from the inside. CONSTITUTION: The front end section 110A of an inner lead has a nearly square cross section and four surfaces and the first surface 110Aa of the inner lead is in the same plane with one surface of a thick external terminal section 120 on the surface of the material of a lead frame. The second surface 110Ab of the inner lead is composed of an etched surface, but is almost flat and wire bonding can be easily performed on the surface. The third and fourth surfaces 110Ac and 110Ad are recessed toward the inside of the inner lead so as to increase the strength of the inner lead even when the width of the second surface 110Ab is reduced. An external terminal 120 has a nearly square cross section and four surfaces. The paired facing two surfaces 120a and 120b of the terminal 120 are projected toward the outside of the terminal 120 from the inside.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lead frame member for a surface mounting type resin-sealed semiconductor device in which a circuit is formed using a lead frame as a core material, and more particularly to a BGA (Ba
The present invention relates to a method for manufacturing a lead frame member for an ll grid array type semiconductor device.

[0002]

2. Description of the Related Art In recent years, semiconductor devices have become more highly integrated and more functional, as typified by LSI ASICs, due to the trend toward higher performance, lighter, thinner, shorter, and smaller electronic devices (current trends). . In a highly integrated and highly functional semiconductor device, the inductance in the package cannot be neglected for high-speed processing of signals. In order to reduce the inductance in the package, the power supply and the ground have to be reduced. This has been addressed by increasing the number of connection terminals and lowering the substantial inductance. For this reason, high integration and high functionality of the semiconductor device increase the total number of external terminals (pins), and require more and more terminals (pins). Multi-terminal (pin) ICs, especially ASICs represented by gate arrays and standard cells, microcomputers, DSPs (Digital Signal Proc)
In order to use a semiconductor device such as an Essor), a device using a lead frame includes a QFP (Quad Flat P).
surface mount type packages such as package) and QFPs up to 300-pin class have been put to practical use. The QFP uses the single-layer lead frame 1410 shown in FIG. 14 (b).
As shown in the sectional view in FIG. 1, the semiconductor element 1420 is mounted on the die pad 1411 and the inner lead tip portion 1412A and the semiconductor element 1420 which have been subjected to a treatment such as gold plating.
After being connected to the terminal (electrode pad) 1421 of with a wire 1430, it is sealed with resin 1440, the dam bar portion is cut, and the outer lead 1413 portion is bent into a gull wing shape. Such a QFP has a structure in which outer leads for electrically connecting to an external circuit are provided in four directions of the package, and has been developed as a device capable of coping with multiple terminals (pins). The single layer leadframe 1410 used herein is typically a Kovar, 4
FIG. 14B shows a metal plate having excellent conductivity and large strength such as 2 alloy (42% Ni-iron) and copper alloy by an etching method or stamping method using the photolithography technique. It was manufactured by processing into such a shape. 14B and 14B are sectional views taken along line F1-F2 of FIG. 14B and FIG. 14A, which are plan views of the single-layer lead frame.

However, in recent years, the higher speed and higher performance (function) of signal processing of semiconductor devices requires more terminals. On the other hand, in QFP, the number of external terminals can be increased by narrowing the external terminal pitch. However, if the external terminal pitch is narrowed, the width of the external terminal itself must be narrowed and the external terminal strength is reduced. Will be made. As a result, a problem occurs in the positional accuracy or flatness accuracy of terminal molding (gull wing formation). In QFP, the outer lead pitch is 0.4m.
As the pitch is further narrowed to m and 0.3 mm, the mounting process of these narrow pitches becomes difficult, and there are obstacles (problems) such as the need to realize advanced board mounting technology.

In order to avoid the problems of the mounting efficiency and mountability of these conventional QFP packages, a plastic package semiconductor called BGA (Ball Grid Array) which is a surface mounting type package in which solder balls are replaced by external terminals of the package. Devices have been developed. The BGA is a generic name of a surface-mounted semiconductor device (plastic package) in which external terminals are arranged on a back surface in a matrix (array) of solder balls. Normal,
In order to increase the number of input / output terminals, this BGA has a semiconductor element mounted on one side of a double-sided wiring board, and an external terminal electrode with a spherical solder attached on the other side. Continuity with the test electrode. By arranging the spherical solder in an array, the terminal pitch can be made wider than that of a semiconductor device using a conventional lead frame. As a result, the mounting process of the semiconductor device is not made difficult and the number of input / output terminals is increased. I was able to deal with. B
GA generally has a structure as shown in FIG. FIG.
11B is a view seen from the back surface (substrate) side of FIG. 11A, and FIG. 11C shows the through hole 1150 portion. This BGA is BT resin (bismaleimide resin)
Heat-resistant flat plate (resin plate) substrate 11 represented by
02 has a die pad 1105 on which a semiconductor element 1101 is mounted and a bonding pad 1110 electrically connected to the semiconductor element 1101 by a bonding wire 1108, and the other surface of the die pad 1105 electrically and physically connects an external circuit and a semiconductor device. Connection terminal 1 formed of solder balls arranged in a grid or zigzag for physical connection
106, the wiring 1104 and the through hole 115 are provided between the external connection terminal 1106 and the bonding pad 1110.
0, the wiring 1104A is electrically connected. However, this BGA is provided with a circuit for connecting a semiconductor element to be mounted and a wire, and electrodes for external terminals for mounting on a printed circuit board after being made into a semiconductor device on both sides of a base material 1102, and these are through holes 1150.
It has a complicated structure in which the through holes 1150 are electrically connected to each other through the resin, and the through hole 1150 may be broken due to the thermal expansion of the resin, and there are many problems in terms of reliability in manufacturing.

Therefore, in order to simplify the manufacturing process and to avoid deterioration of reliability, in addition to the structure shown in FIG. 11 described above, various types in which a circuit is formed using a lead frame as a core material have been proposed in recent years. Came. BGA packages using these lead frames are generally resin-sealed by fixing the lead frame 1210 on an insulating film 1260 having a predetermined hole at a position corresponding to the external terminal portion 1214 of the lead frame 1210. Figure 12 (a)
The structure shown in FIG. 12 or the structure shown in FIG. A lead frame used in a BGA package using the above lead frame is conventionally manufactured by an etching processing method as shown in FIG.
Both the external terminal portion 1214 and the inner lead 1212 were manufactured in the thickness of the lead frame material. Here, FIG.
The etching method shown in 3 will be briefly described. First, a thin plate made of a copper alloy or 42% nickel-iron alloy and having a thickness of about 0.25 mm (lead frame material 131
0) is thoroughly washed (FIG. 13A), and then a photoresist 1320 such as a water-soluble casein resist using potassium dichromate as a photosensitizer is uniformly applied to both surfaces of the thin plate. ((FIG. 13B)) Next, after exposing the resist portion with a high-pressure mercury lamp through a mask on which a predetermined pattern is formed, the photosensitive resist is developed with a predetermined developing solution (FIG. 13C). ), A resist pattern 1330 is formed, and a film hardening process, a cleaning process, etc. are performed as necessary, and the thin plate (lead frame material 1310) is sprayed onto the thin plate (lead frame material 1310) with an etching solution containing a ferric chloride aqueous solution as a main component. Then, the resist film is sprayed to have a predetermined size and shape so as to be penetrated (FIG. 13D). Then, the resist film is stripped (FIG. 13E), and after cleaning, a desired lead frame is obtained and an etching process step is performed. In this way, the lead frame manufactured by the etching process is further subjected to silver plating in a predetermined area, etc. Then, after undergoing treatments such as washing and drying, the inner frame is finished. The tape part is taped with an adhesive-attached polyimide tape for fixing, and if necessary, the tab suspension bar is bent and the die pad part is down-set. In addition to the plate thickness direction of the plate to be processed, it also advances in the plate width (plane) direction. Therefore, in the etching processing method as shown in FIG. was there.

[0006]

As described above, in the BGA type resin-sealed semiconductor device using the lead frame as the core material, the semiconductor device using the single-layer lead frame shown in FIG. 14B is used. Compared to, the external terminal pitch for connecting to an external circuit with the same number of terminals can be widened, and it was possible to cope with an increase in input / output terminals without complicating the mounting process of the semiconductor device. Was required to reduce the pitch of the inner leads, which was required. SUMMARY OF THE INVENTION The present invention is intended to provide a BGA type semiconductor device having a circuit formed by using a lead frame as a core material, which is capable of coping with further increase in the number of terminals. At the same time, it is intended to provide a lead frame for manufacturing such a semiconductor device.

[0007]

The lead frame of the present invention is for a BGA type semiconductor device in which the thickness of the tip of the inner lead is externally processed by a two-step etching process to be thinner than the thickness of the lead frame material. An outer terminal portion for electrically connecting at least an inner lead and an external circuit that is integrally connected to the inner lead and is two-dimensionally arranged along the inner lead forming surface. And the tip portion of the inner lead has a substantially square cross section, and has a first surface, a second surface, and a third surface.
The first surface and the fourth surface, and the first surface is flush with one surface of the other portion having the same thickness as the lead frame material and faces the second surface. The third surface and the fourth surface are formed in a shape that is recessed toward the inner side of the inner lead, and the external terminal portion has a substantially rectangular cross-section and has four surfaces. It is characterized in that it is on the frame material surface, and the other one set of two surfaces is convex from the inside to the outside of the external terminal portion. In the above, the entire inner lead portion is characterized in that the outer shape is processed to be thinner than the thickness of the lead frame material. In addition, the BG of the present invention
The A type semiconductor device is a BGA type resin-sealed semiconductor device using the lead frame of the present invention, and a terminal for connecting to an external circuit made of solder or the like on the surface of the external terminal portion of the lead frame. The semiconductor element is fixed to the first surface side of the inner lead via an insulating adhesive so that the electrode section fits between the inner leads on the surface on the electrode section (pad) side. The electrode portion (pad) is electrically connected to the second surface side of the inner lead by a wire. A BGA type semiconductor device of the present invention is a BGA type resin-sealed semiconductor device using the lead frame of the present invention, wherein an external circuit made of solder or the like is provided on the surface of the external terminal portion of the lead frame. A terminal portion for connection is provided, and the semiconductor element is electrically connected to the second surface of the inner lead through a bump of the semiconductor element. The second surface at the tip of the inner lead is recessed toward the inner lead side. A BGA type semiconductor device of the present invention is a BGA type resin-sealed semiconductor device using the lead frame of the present invention, wherein an external circuit made of solder or the like is provided on the surface of the external terminal portion of the lead frame. A terminal part for connecting is provided,
The lead frame has a die pad portion,
In addition, the die pad portion is sized to fit between the electrode portions (pads) of the semiconductor element and has the same thickness as the inner lead tip portion. The surface of the inner lead and the second surface of the inner lead are oriented in the same direction, and the surface on the electrode part (pad) side is fixed on the die pad with an adhesive material to form the electrode part (pad).
Is electrically connected to the second surface side of the tip of the inner lead by a wire. A BGA type semiconductor device of the present invention is a BGA type resin-sealed semiconductor device using the lead frame of the present invention, wherein an external circuit made of solder or the like is provided on the surface of the external terminal portion of the lead frame. A terminal portion for connection is provided, the lead frame has a die pad portion, and in the semiconductor element, the electrode portion (pad) of the semiconductor element and the second surface of the tip of the inner lead are in the same direction. The surface opposite to the electrode part (pad) side is fixed on the die pad with an adhesive so that the electrode part (pad) is electrically connected to the second surface side of the inner lead tip with a wire. It is characterized by being.

[0008]

The lead frame of the present invention, by having the above-mentioned structure, enables the production of the BGA type resin-sealed semiconductor device of the present invention which can cope with a further increase in the number of terminals. . More specifically, the lead frame of the present invention is formed by the two-step etching process so that the thickness of the tip of the inner lead is thinner than the thickness of the lead frame material, that is, FIGS. By the etching processing method as shown in (3), the outer lead can be processed so that the thickness of the tip portion of the inner lead is thinner than the thickness of the material, and the inner lead can be made narrower in pitch. Further, the lead frame is provided with the external terminal portion for connecting to the external circuit integrally coupled with the inner lead, which is arranged two-dimensionally along the surface of the lead frame, thereby providing a BGA type semiconductor device. It is supposed to be compatible. By making the inner leads thinner than the lead frame material, it is possible to cope with not only the narrow pitch of the inner lead tip portions but also the narrow spacing between the inner lead portions.
In addition, the tip of the inner lead of the lead frame is
The cross-sectional shape is substantially rectangular and has four surfaces, that is, a first surface, a second surface, a third surface and a fourth surface, and the first surface has a thickness that is the same as the thickness of the material that is not a thin portion. Since it is flush with one surface and faces the second surface, and the third and fourth surfaces are formed in a concave shape toward the inner side of the inner lead, the wire bonding of the tip of the inner lead is performed. The strength is also stronger than the width. The external terminal portion of the lead frame has a substantially rectangular cross section and has four faces, one set of two facing faces is on the lead frame material face, and the other set of two faces is the external terminal. The convex shape from the inside to the outside of the portion ensures sufficient strength. The BGA type resin-encapsulated semiconductor device of the present invention uses the lead frame of the present invention, and is configured as described above to be compatible with a further increase in the number of terminals.

[0009]

EXAMPLE An example of a lead frame of the present invention will be described with reference to the drawings. First, a first embodiment of the lead frame of the present invention will be described. FIG. 1A is a schematic plan view showing the lead frame of the first embodiment, and FIG.
1A is an enlarged view of about 1/4 portion, FIG. 1C is a cross-sectional view of the inner lead tip, and FIG. 1D is A of FIG.
It is sectional drawing which showed a part of cross section in 1-A2.
Note that FIG. 1A is a schematic diagram, and the number of inner leads and the number of external terminal portions are smaller than those in FIG. 1B in order to make the whole easy to understand. In the figure, 100 is a lead frame, 110 is an inner lead, 110A is an inner lead tip portion, 120 is an external terminal portion, 140 is a dam bar, 1
50 is a suspension bar, 160 is a frame (frame portion), and 170 is a jig hole. The lead frame of Example 1 has 42%
A lead frame for a BGA type semiconductor device made of a nickel-iron alloy by the etching method shown in FIG. 8 and integrally connected to an inner lead 110 as shown in FIG. 1 (a). External terminal part 120
Are arranged two-dimensionally along the inner lead forming surface (lead frame surface), and the inner lead tip 1
Not only the 10A portion but the entire inner lead is formed thinner than the thickness of the lead frame material. The external terminal portion 120 is formed to the thickness of the lead frame material.
The thickness t of the inner lead 110 is 40 μm, and the thickness t ₀ of the portions other than the inner lead portion 110 is 0.15 mm, which is the plate thickness of the lead frame material. Further, the pitch of the inner lead tip portions 110A is as narrow as 0.12 mm, which is adapted to the multi-terminal of the semiconductor device. As shown in FIG. 1 (c), the tip portion 110A of the inner lead has a substantially rectangular cross section and has four surfaces. The first surface 110Aa is the lead frame material surface and is not the thin terminal portion 120A. Coplanar with one surface of the. The second surface 110Ab is an etched surface (corroded surface), but has a substantially flat shape that facilitates wire bonding, and the third surface 110Ac and the fourth surface 110Ad are recessed toward the inner side of the inner lead. The second surface 110Ab (wire bonding surface) has a narrow shape and is strong in strength even if it is narrowed. The external terminal section 120 is shown in FIG.
As shown in (d), the cross-sectional shape is substantially rectangular and has four surfaces, and a pair of opposed two surfaces 120a and 120b are convex from the inside to the outside of the external terminal. Further, as shown in FIG. 1D, the cross-sectional shape of the inner lead portion 110 is the same as that of the inner lead tip portion 110 shown in FIG.
It has the same shape as the cross-sectional shape of A. In the lead frame 100 of this embodiment, the external terminal portion 120 is integrally connected to the dam bar 140.

Next, a second embodiment of the lead frame of the present invention will be described. 2A is a schematic plan view showing the lead frame 100A of the second embodiment, and FIG. 2B is an enlarged view of about 1/4 part of FIG. 2A, and FIG. )
2A is a sectional view of the inner lead tip, and FIG.
(B) is a cross-sectional view showing a cross section of the inner lead 110 at C1-C2 in FIG. Figure 2 (c)
(C) is the external terminal portion 1 at C1-C2 in FIG.
It is sectional drawing which showed the cross section of 20. Note that FIG. 2A is a schematic diagram, and the number of inner leads and the number of external terminal portions are smaller than those in FIG. 2B in order to make the whole easy to understand. The lead frame of Example 2 is also a lead frame for a BGA type semiconductor device, which is made of 42% nickel-iron alloy as a raw material and manufactured by the etching processing method shown in FIG. 8, and as shown in FIG. In addition, the external terminal portion 120 integrally connected to the inner lead 110 can be two-dimensionally arranged along the surface of the lead frame. However, unlike the lead frame of the first embodiment, the inner lead tip portion 11
Only the 0A part is formed thinner than the thickness of the lead frame material. As shown in FIGS. 2C and 2A, the cross section of the inner lead tip portion 110A is almost the same as that of the first embodiment. As shown in FIGS. 2 (c) and (b), unlike the lead frame of the first embodiment, since the semiconductor element and the electrode portion (pad) are connected by wire bonding, except the inner lead tip portion 110A including the bonding area. Like the external terminal portion 120, it is formed to the thickness of the lead frame material. Therefore, the inner lead tip 1
A narrow pitch cannot be obtained as compared with 110A. FIG.
As shown in (c) and (c), the cross section of the external terminal portion 120 is formed to the thickness of the lead frame material as in the lead frame of the first embodiment. Also in the lead frame 100A of this embodiment, the external terminal portion 120 is integrally connected to the dam bar 140.

In the lead frames of Examples 1 and 2, if the lead frame is directly etched into the shape shown in FIG. As shown in FIG. 3 (a), after etching the inner lead tip portion with the connecting portion 110B fixed, the inner lead 110 portion is fixed with the reinforcing tape 190 (FIG. 3 (b)), followed by pressing or the like. At
The unnecessary connecting portion 110B was removed when the semiconductor device was manufactured (FIG. 2A), and was formed. In the case of the lead frame of Example 2, the unnecessary portions may be cut after the etching processing is performed so that the tip ends of the inner leads are directly connected to the die pad.

A method for etching the lead frame of the first embodiment will be described with reference to FIG. 8A to 8C are cross-sectional views of each step for explaining the method for etching the lead frame of Example 1 shown in FIG. 1, which are taken along line A1-A of FIG.
It is a manufacturing-process figure in the cross-section part of 2 parts. In FIG. 8, 81
0 is a lead frame material, 820A and 820B are resist patterns, 830 is a first opening, 840 is a second opening, 850 is a first recess, 860 is a second recess, 87
Reference numeral 0 indicates a flat surface, and 880 indicates an etching resistance layer. Further, 110 is an inner lead, and 120 is an external terminal portion. First, after applying a water-soluble casein resist using potassium dichromate as a photosensitizer to both surfaces of a lead frame material 810 having a thickness of 0.15 mm and made of 42% nickel-iron alloy, a predetermined pattern plate was used. Then, resist patterns 820A and 820B having a first opening 830 and a second opening 840 having a predetermined shape were formed. (FIG. 8
(A)) The first opening 830 forms the shape of the external terminal portion in the subsequent etching process, and the lead frame material 810 in the inner lead forming region is solidly formed from this opening and is thinner than the lead frame material. The second opening 840 of the resist is for forming the shapes of the inner lead portion and the external terminal portion. Then, using a ferric chloride solution having a liquid temperature of 57 ° C and a concentration of 48Be ^' , a spray pressure of 2.5 kg / cm
^{At 2} , the both sides of the lead frame material 810 having the resist pattern formed thereon are etched, and the depth h of the first recess 850, which is corroded into a solid (flat) shape, reaches 1/3 of the lead frame member. At that point the etching was stopped. (FIG. 8B) In the first etching described above, both sides of the lead frame material 810 were simultaneously etched, but it is not always necessary to simultaneously etch from both sides. At least, a predetermined amount of etching is performed in the corroded inner lead portion forming region from the side where the resist pattern 820B having the opening of the predetermined shape is formed, in order to form the inner lead portion shape. I just need to be able to process and stop. The reason for simultaneously etching both sides of the lead frame material 810 in the first etching as in the present embodiment is to shorten the second etching time to be described later by etching from both sides, and the resist pattern 82
Compared with the case of single-sided etching only from the 0B side, the total time of the first etching and the second etching is shortened. Then, a hot-melt type wax having etching resistance as an etching resistance layer 880 in the corroded first concave portion 850 on the first opening 830 side (acid wax manufactured by The Inktech Co., model number MR-WB6). Was applied using a die coater and embedded in the first recess 850 which was corroded into a solid (flat) shape. The resist pattern 820A was also applied to the etching resistance layer 880. (FIG. 8C) The etching resistance layer 880 is formed by using a resist pattern 820A.
Although it is not necessary to apply it to the entire upper surface, it is difficult to apply it only to a part including the first concave portion 850. Therefore, as shown in FIG. An etching resistance layer 880 was applied to the entire surface of the portion 830 side. The etching resistance layer 880 used in this example is an alkali-soluble wax, but it is preferable that the etching resistance layer 880 is basically resistant to an etching solution and has some flexibility during etching, and is particularly limited to the above wax. Not UV
A hardening type may be used. Thus, the etching resistance layer 8
80 is the first recessed portion 850 in which the pattern for forming the shape of the inner lead tip portion is formed and which is corroded on the surface side.
By embedding it in the substrate, the first concave portion 850 is prevented from being corroded during the etching in a later process so as to be large, and the mechanical strength is reinforced for high-definition etching processing, and the spray pressure is increased. High (2.5 kg
/ Cm ² or more), which facilitates the etching to proceed in the depth direction. After that, the second etching is performed to etch the lead frame material 810 from the side where the second concave portion 860, which is corroded in a concave shape, is formed.
The inner lead 110 and the external terminal portion 12 are penetrated.
Formed 0. (FIG. 8D) The etched surface 870 produced by the first etching process is flat, but the two surfaces sandwiching this surface are recessed toward the inner lead. Next, cleaning, removal of the etching resistance layer 880, and removal of the resist film (resist patterns 820A and 820B) were performed, and the inner lead 110 and the external terminal portion 120 were processed.
The lead frame shown in (a) was obtained. Etching resistance layer 880 and resist film (resist patterns 820A, 82
OB) was removed by dissolution with an aqueous sodium hydroxide solution.

The etching method of the lead frame shown in FIG. 8 is a manufacturing process diagram in the cross section of the A1-A2 portion of FIG. 1 (b), and the inner lead tip shown in FIG. 1 (a). The portion 110A is also formed in the same manner as the inner lead 110 portion shown in FIG. By etching the entire inner lead to be thinner than the lead frame material by the etching method shown in FIG. 8, it is possible to make the pitch narrower at the tip of the inner lead and to narrow the space between the inner leads even at a place other than the tip of the inner lead. Allows spacing. In particular, as shown in FIG. 1C, the first surface 110Aa at the tip of the inner lead is made flush with the other surface having the same thickness as the lead frame material other than the thin portion and the second surface 110Ab.
And the third surface 110Ac and the fourth surface 110Ad can be concave toward the inner lead side.

The lead frame of Example 2 shown in FIG. 2 can be manufactured by partially changing the etching processing method shown in FIG. That is, the inner lead tip portion 110A is formed thinner than the thickness of the lead frame material 810 as in the inner lead portion 110 shown in FIG. 8, and the outer terminal portion 120 shown in FIG. As with the creation of
By forming the lead frame material 810 to have the same thickness as that of the lead frame material 810, the lead frame of Example 2 in which only the inner lead tips are thinner than the lead frame material can be manufactured by etching.

A semiconductor element is mounted on the second surface 11 of the inner lead by using a bump as in the semiconductor device of Example 2 described later.
In the case of mounting on No. 0b and electrically connecting to the inner leads, it is better to form the second surface 110b in a shape recessed toward the inner leads because the tolerance at the time of bump connection becomes larger, and therefore, as shown in FIG. An etching processing method is adopted. The etching processing method shown in FIG. 9 is the same as the method shown in FIG. 8 up to the first etching step, but after the etching resistance layer 880 is embedded in the second recess 860 side, the first recess 850 is formed. The difference is that the second etching is performed from the side and the etching is performed. As shown in FIG. 5B, the sectional shape of the inner lead including the inner lead tip of the lead frame obtained by the etching method shown in FIG. 9 is a concave shape in which the second surface 110b is dented toward the inner lead side. .

Incidentally, an etching processing method in which etching is divided into two stages like the etching processing method shown in FIGS. 8 and 9 is generally called a two-stage etching processing method, which is advantageous for fine processing. It is a processing method. In the method of etching the lead frame 110 of the first embodiment shown in FIG. 1 and the lead frame of the second embodiment shown in FIG.
The two-step etching method and the method of performing outer shape processing while partially thinning the lead frame material by devising the pattern shape are adopted together, and in the portion where the lead frame material is thin, Especially, it is possible to perform fine processing. In the above method shown in FIGS. 8 and 9, the miniaturization of the inner lead tip portion 110 depends on the thickness t of the finally obtained inner lead tip portion. Is reduced to 50 μm, the flat width W1 shown in FIG.
m, the inner lead tip pitch p is 0.15 m
Fine processing is possible up to m. If the plate thickness t is reduced to about 30 μm and the flat width W1 is set to about 70 μm, fine processing can be performed to the inner lead tip end pitch p of about 0.12 mm. However, depending on how to set the plate thickness t and the flat width W1, the inner lead The tip pitch p can be made to a narrower pitch.

Next, an example of a BGA type resin-sealed semiconductor device of the present invention will be described with reference to the drawings. First, Example 1 of the BGA type resin-encapsulated semiconductor device of the present invention will be described. FIG. 4A is a cross-sectional view of the resin-sealed semiconductor device according to the first embodiment, and FIGS. 4B and 4C are semiconductor device thicknesses of the inner lead tip portion and the external terminal portion, respectively. It is sectional drawing of a direction. In FIG. 4, 200 is a semiconductor device, 210 is a semiconductor element, 211 is an electrode part (pad), 220 is a wire, 240 is a sealing resin, 250 is a reinforcing tape, 260 is an insulating adhesive, and 270 is a terminal part. Is. The semiconductor device of the first embodiment is a BGA type resin-sealed semiconductor device using the lead frame of the first embodiment, and is connected to an external circuit made of solder on the surface of the external terminal portion 120 of the lead frame. Terminal part 27 for
Zeros are arranged two-dimensionally on one surface of the semiconductor device. In the first embodiment, the semiconductor element 210 has the inner lead 110 on the surface on the electrode portion (pad) 211 side.
The electrode portion 211 is fixed to the first surface 110a side of the inner lead 110 via an insulating adhesive material 260 so that the electrode portion 211 is accommodated between the electrode portion (pad) 211 and the wire 2.
At 20, the wire is electrically connected to the second surface side 110b of the inner lead 110. The semiconductor device according to the first embodiment is resin-encapsulated with the encapsulating resin 240 to have a size substantially equal to the size of the semiconductor element.
It can also be said to be a Size Package). Further, since the tip portion of the inner lead 110 connected by the wire 220 is formed thinner than the lead frame material, it is possible to make the semiconductor device thinner.

The sectional shape of the inner lead portion 110 of the lead frame used in the semiconductor device of the first embodiment is as shown in FIG. 10 (a) (a), and the etching flat surface (second surface). The width W1 on the 110Ab side is almost flat and slightly larger than the width W2 of the opposite surface 110Aa (first surface). Both W1 and W2 (about 100 μm) are wider than the width W of the middle portion in the plate thickness direction. Is also getting bigger. In this manner, both surfaces of the tip of the inner lead have a broadened cross-sectional shape, and the third surface 110Ac and the fourth surface 110A.
Since d has a shape recessed toward the inner lead side, the semiconductor element (not shown) and the inner lead tip portion 110 can be formed by using either the first surface 110Aa or the second surface 110Ab.
The connection (bonding) by A and the wire is stable and the bonding is easy, but in the case of the semiconductor device of Example 1, the etching surface side (FIG. 10B).
(A)) is used as the bonding surface. 110A in the figure
b is a flat surface (second surface) by etching, 110A
a is a lead frame material surface (first surface), 1020A is a wire, and 1021A is a plated portion. In addition, since the flat etching surface 110Ab (second surface) is a surface free from arabic, in the case of (a) of FIG. 10B, the suitability for connection (bonding) is particularly excellent. FIG. 10C shows a connection (bonding) between the inner lead tip portion 1010B of the lead frame manufactured by the processing method shown in FIG. 13 and the semiconductor element (not shown). Both sides of the lead tip portion 1010B are flat,
It cannot be as large as the width of this part in the plate thickness direction. Further, since both surfaces are lead frame material surfaces, the suitability for connection (bonding) is inferior to the flat etching surface of this embodiment. In FIG. 10D, the inner lead tips 1010C and 1010D are processed by etching after thinning the inner lead tips by pressing (coining), but connection (bonding) with a semiconductor element (not shown).
In this case, since the press surface side is not flat as shown in the figure, whichever surface is used for connection (bonding), (a) in FIG. 10 (d),
As shown in (b), the stability is poor at the time of connection (bonding), which often causes a problem in terms of quality. 1010
Ab is a coining surface and 1010Aa is a lead frame material surface.

Next, a second embodiment of the BGA type resin-sealed semiconductor device of the present invention will be described. FIG. 5A is a cross-sectional view of the resin-sealed semiconductor device according to the second embodiment, and FIGS. 5B and 5C are semiconductor device thicknesses of the inner lead tip portion and the external terminal portion, respectively. It is sectional drawing of a direction. FIG.
Inside, 200 is a semiconductor device, 210 is a semiconductor element, 212
Is a bump, 240 is a sealing resin, 250 is a reinforcing tape, and 270 is a terminal portion. The semiconductor device according to the second embodiment is made of 42 alloy (42% nickel-iron alloy).
A 15 mm-thick lead frame material is formed by the etching method shown in FIG. 9 so that the entire inner lead is thinner than the material of the lead frame, with the same appearance as in Example 1 shown in FIGS. 1 (a) and 1 (b). A BGA type resin-encapsulated semiconductor device using the lead frame, wherein a terminal portion 270 for connecting to an external circuit made of solder is two-dimensionally formed on one surface of the semiconductor device on the surface of the external terminal portion 120 of the lead frame. Are arranged in a line. In the second embodiment, the semiconductor element 210 is electrically connected to the second surface 110b at the tip of the inner lead 110 via the bump 212. The reinforcing tape 250 is provided at a position near the tip of the inner lead 110, but when the lead frame is thin and sufficient strength cannot be ensured, it may be attached over the entire surface of the lead frame.

The sectional shape of the inner lead portion 110 of the lead frame used in the semiconductor device of the second embodiment is as shown in FIGS. 10A and 10B, and the width W1A on the etching flat surface 110Ab side. Is almost flat and slightly larger than the width W2A of the opposite surface. W1A, W2A
(Approximately 100 μm) Width W of this part in the thickness direction middle part
It is larger than A. As shown in FIGS. 10 (a) and 10 (b), both surfaces of the tip portion of the inlay lead have a widened cross-sectional shape, the first surface 110Aa is flat, and the second surface 110 is
Since Ab has a recessed shape on the inner lead side, and the third surfaces 110Ac and 110Ad also have a recessed shape on the inner lead side, it is easy to perform stable bump connection on the second surface 110Ab. I am supposed to.

In the semiconductor device of the second embodiment,
A lead frame manufactured by the etching method shown in FIG. 9 in which the entire inner lead is formed thinner than the lead frame material is used, as shown in FIG.
As shown in, the second surface 110b of the inner lead 110 including the tip of the inner lead is recessed toward the tip of the inner lead to increase the bump connection tolerance.

Next, a third embodiment of the BGA type resin-sealed semiconductor device of the present invention will be described. FIG. 6A is a cross-sectional view of the resin-sealed semiconductor device according to the third embodiment. FIG. 6B and FIG. 6C h show the thickness of the semiconductor device at the tip of the inner lead and the external terminal, respectively. It is sectional drawing of a direction. Figure 6
Inside, 200 is a semiconductor device, 210 is a semiconductor element, 211
Is a wire, 220 is a wire, 240 is a sealing resin, 25
Reference numeral 0 is a reinforcing tape, 260 is a conductive adhesive, 270 is a terminal portion, 280 is a protective frame portion, and 290 is an adhesive material. The semiconductor device of the third embodiment is a BGA using the lead frame having the die pad in the lead frame of the first embodiment.
A resin-sealed semiconductor device of the type described above, in which terminal portions 270 for connecting to an external circuit made of solder are two-dimensionally arranged on one surface of the semiconductor device on the surface of the external terminal portion 120 of the lead frame. There is. The lead frame used was prepared by the etching method shown in FIG.
The entire inner lead and die pad 130 are formed thinner than the lead frame material.
The material, appearance, and the like are the same as those of the lead frame of the first embodiment except for 30 and parts related thereto. In the semiconductor device of the third embodiment, the die pad portion 130 is sized to fit between the electrode portions (pads) 211 of the semiconductor element, and the semiconductor element 210 includes the surface of the semiconductor element on the electrode portion 211 side and the inner lead 110. The electrode portion (bump) is formed on the die pad 130 so that the second surface 110b faces the same direction.
The surface on the 211 side is fixed by a conductive adhesive 260, and the electrode portion (bumps) 211 is connected to the inner lead 11 by a wire.
0 is electrically connected to the second surface 110b side. With this configuration, the semiconductor device can be made thinner than in the first embodiment or the fourth embodiment described later. Also,
The conductive adhesive is used here to dissipate the heat generated by the semiconductor element through the die pad.
Furthermore, if a terminal portion is provided below the die pad and a ground line or the like is connected, heat can be effectively dissipated. The protective frame 280 is made of an adhesive material 29 so as to cover the outer periphery of the semiconductor device.
Although it is provided through 0, it is useful when the semiconductor device is particularly thin and the strength is insufficient, and is not always necessary. In this way, by connecting the die pad and the semiconductor element via the conductive adhesive material, when the die pad is connected to the ground line, not only the heat radiation effect but also noise countermeasures can be obtained.

Next, a fourth embodiment of the BGA type resin-sealed semiconductor device of the present invention will be described. FIG. 7A is a cross-sectional view of the resin-sealed semiconductor device of the fourth embodiment, and FIGS. 7B and 7C show a semiconductor device of the inner lead tip portion and the external terminal portion, respectively. It is sectional drawing of the thickness direction. In FIG. 7, 200 is a semiconductor device, 210 is a semiconductor device, and 21.
1 is a wire, 220 is a wire, 240 is a sealing resin, 2
Reference numeral 50 is a reinforcing tape, 260 is a conductive adhesive, and 270 is a terminal portion. Like the semiconductor device of the third embodiment, the semiconductor device of the fourth embodiment uses the 42% alloy (42% nickel-iron alloy) and the entire inner lead 110 and the die pad 130 are framed by the etching processing method shown in FIG. A BGA type resin-encapsulated semiconductor device using a lead frame made thinner than the thickness of the material, and a terminal portion 270 for connecting to an external circuit made of solder or the like on the surface of the external terminal portion 120 of the lead frame. Is provided. The die pad 130 is larger than that of the third embodiment and has substantially the same size as the semiconductor element 210. Semiconductor element 2
10 is such that the electrode portion (pad) 211 of the semiconductor element and the second surface 110b of the inner lead 110 face the same direction, and the electrode portion (pad) 2 is formed on the die pad 130.
The surface opposite to the 11 side is fixed by a conductive adhesive 260, and the electrode portion (pad) 211 is electrically connected to the second surface 110b side of the inner lead 110 by a wire 220.

In each of the semiconductor devices of Examples 1 to 4 described above, the two-step etching method as shown in FIGS. It is thinner, and can support more multi-terminals than the conventional BGA type resin-sealed semiconductor device using a lead frame as a core material as shown in FIG. By forming the part thinner than the lead frame material, it is possible to make the semiconductor device thinner.

[0025]

As described above, the lead frame of the present invention is manufactured by a two-step etching process so that at least the inner lead tips are thinner than the plate thickness of the lead frame material, and the external terminals are formed on the lead frame surface. A BG using a lead frame in which the tip end portions of the inner leads are externally processed with the thickness of the lead frame material as shown in FIG. 12 due to the two-dimensional arrangement along the BG.
Compared to the A type semiconductor device, it is possible to further increase the number of terminals B
It is possible to provide a GA type resin-sealed semiconductor device. In addition, the BGA type resin-encapsulated semiconductor device of the present invention uses the lead frame of the present invention as described above, and is capable of further increasing the number of terminals and making the device thinner. It is possible to provide the semiconductor device.

[Brief description of drawings]

FIG. 1 is a schematic view of a first embodiment of a lead frame of the present invention.

FIG. 2 is a schematic view of a second embodiment of the lead frame of the present invention.

FIG. 3 is a diagram for explaining a lead frame of the present invention.

FIG. 4 is a sectional view of a BGA type semiconductor device according to a first embodiment of the present invention.

FIG. 5 is a sectional view of a BGA type semiconductor device according to a second embodiment of the present invention.

FIG. 6 is a sectional view of a BGA type semiconductor device according to a third embodiment of the present invention.

FIG. 7 is a sectional view of a BGA type semiconductor device according to a fourth embodiment of the present invention.

FIG. 8 is a process drawing for explaining the method of manufacturing the lead frame of the present invention.

FIG. 9 is a process drawing for explaining the lead frame manufacturing method of the present invention.

FIG. 10 is a diagram for explaining the connectivity of the lead frame of the present invention with a semiconductor element.

FIG. 11 is a diagram for explaining a conventional BGA semiconductor device.

FIG. 12 is a schematic view of a BGA type semiconductor device using a conventional lead frame.

FIG. 13 is a process drawing for explaining a conventional lead frame manufacturing method.

FIG. 14 is a diagram of a single-layer lead frame and a semiconductor device using the same.

[Explanation of symbols]

100, 100A Lead frame 110 Inner lead 110A Inner lead tip portion 120 External terminal portion 140 Dam bar 150 Hanging bar 160 Frame (frame portion) 170 Jig hole 200 Semiconductor device 210 Semiconductor element 211 Electrode portion (pad) 220 Wire 240 For sealing Resin 250 Reinforcing tape 260 Insulating adhesive 270 Terminal portion 810 Lead frame material 820A, 820B Resist pattern 830 First opening 840 Second opening 850 First recess 860 Second recess 870 Flat surface 880 Etching Resistance layer 1010B, 1010C, 1010D Inner lead tip part 1020A, 1020B, 1020C Wire 1021A, 1021B, 1021C Plating part 1010Aa Lead frame material surface 1010Ab Inning surface 1101 Semiconductor element 1102 Base material 1103 Molded resin 1104, 1104A Wiring 1105 Die pad 1108 Bonding wire 1106A External connection terminal 1118 Plated part 1150 Through hole 1151 Thermocouple via 1200, 1200A Semiconductor device 1210 Lead frame 1211 Die pad 1212 External lead inner terminal 1212 Part 1220 Semiconductor element 1221 Electrode part (pad) 1230 Wire 1240 Encapsulating resin 1260 Insulation film 1310 Lead frame material 1320 Photo resist 1330 Resist pattern 1340 Inner lead 1400 Semiconductor device 1410 (single layer) lead frame 1411 Die pad 1412 Inner lead 1412A Inner lead tip Part 1413 Outer lead 1414 Dam bar 1415 Frame portion 1420 Semiconductor element 1421 Electrode portion (pad) 1430 Wire 1440 Sealing resin

Claims (7)

[Claims] 1. A lead frame for a BGA type semiconductor device, wherein at least the inner lead is processed by a two-step etching process so that the thickness of the tip of the inner lead is thinner than the thickness of the lead frame material. And an external terminal portion that is integrally connected to the inner lead and that is electrically connected to an external circuit that is two-dimensionally arranged along the inner lead forming surface. The section has a substantially rectangular cross section, and has a first surface,
It has four surfaces, a second surface, a third surface, and a fourth surface, and
The surface is flush with one surface of the other portion having the same thickness as the lead frame material and faces the second surface, and the third and fourth surfaces are concave toward the inner side of the inner lead. The external terminal portion has a substantially rectangular cross-section and has four faces. One set of two facing faces is on the lead frame material face, and the other set of two faces is the outside. A lead frame, which is convex from the inside to the outside of the terminal portion. 2. The lead frame according to claim 1, wherein the entire inner lead portion is externally processed to be thinner than the thickness of the lead frame material. 3. A BGA type resin-sealed semiconductor device using the lead frame according to claim 1 for connecting to an external circuit made of solder or the like on a surface of an external terminal portion of the lead frame. The terminal portion is provided, and the semiconductor element is fixed to the first surface side of the inner lead via an insulating adhesive so that the electrode portion fits between the inner leads on the surface on the electrode portion side. A BGA type resin-encapsulated semiconductor device, wherein the electrode portion is electrically connected to the second surface side of the inner lead by a wire. 4. A BGA type resin-sealed semiconductor device using the lead frame according to claim 1 for connecting to an external circuit made of solder or the like on the surface of the external terminal portion of the lead frame. A terminal portion is provided, and the semiconductor element is electrically connected to the second surface of the inner lead via a bump of the semiconductor element.
GA type resin-sealed semiconductor device. 5. The resin-encapsulated semiconductor device according to claim 4, wherein the second surface at the tip of the inner lead of the lead frame is recessed toward the inner lead. 6. A BGA type resin-sealed semiconductor device using the lead frame according to claim 1 for connecting to an external circuit made of solder or the like on a surface of an external terminal portion of the lead frame. A terminal portion is provided, the lead frame has a die pad portion, and the die pad portion is sized to fit between the electrode portions on the electrode portion side of the semiconductor element and has the same thickness as the inner lead tip portion. The semiconductor element is fixed on the die pad with an adhesive so that the surface of the semiconductor element on the electrode portion side and the second surface of the tip of the inner lead face the same direction. , The electrode part is a wire of the inner lead second
BGA characterized by being electrically connected to the surface side
Type resin-encapsulated semiconductor device. 7. A BGA type resin-sealed semiconductor device using the lead frame according to claim 1 for connecting to an external circuit made of solder or the like on a surface of an external terminal portion of the lead frame. A terminal portion is provided, the lead frame has a die pad portion, and the semiconductor element is mounted on the die pad with the electrode portion of the semiconductor element and the second surface of the inner lead tip facing in the same direction. In addition, the surface opposite to the electrode portion side is fixed with an adhesive material, and the electrode portion is electrically connected to the second surface side of the inner lead tip by a wire, which is a BGA type resin seal. Static semiconductor device.