JP5248232B2 - Lead frame and manufacturing method thereof - Google Patents

Description

The present invention relates to a MAP (Molded Array Package) type lead frame, and more particularly to a lead frame capable of improving the productivity of a lead frame and the reliability of a semiconductor device and a method for manufacturing the same .

  10A and 10B show a MAP type lead frame according to the prior art, where FIG. 10A is a plan view, FIG. 10B is a sectional view taken along line DD in FIG. 10A, and FIG. It is. First, the semiconductor lead mounting part 11, the lead 12, the tie bar 13, and the support bar 14 are stamped or etched from a thin plate material such as a copper alloy to form the matrix lead frame 10. Thereafter, in order to prevent the lead 12 from falling out of the resin, the step 12a is formed in the lead 12 by half-etching to provide a step, thereby improving the adhesion with the resin. About the said technique, it describes in patent documents 1-3.

  By the way, when the step 12a is manufactured by half etching, the productivity is low and the manufacturing cost is high. Therefore, it is desired to form a step by stamping instead of half etching.

  In FIG. 10B, the stepped portion 12a is processed by half punching (or coining) using a cutter consisting of a punch 22 and a die (not shown).

Japanese Patent No. 3839321 JP 2007-294715 A Japanese Patent No. 360637

However, half punching processes the stepped portion 12a of the adjacent lead 12 across the tie bar 13 with different punches, so that each punch 22 becomes thin, the strength is not increased, and it is damaged during processing. There was a problem. Further, the processing stress applied at the time of half punching is not released, and deformation such as warping or twisting occurs in the lead frame 10 as shown in FIG. 10 (c). It flowed and adhered to the back surface (the side exposed from the package), causing a connection failure when placed on the mounting board.

  The present invention has been made in view of such circumstances, and is intended to improve the productivity and reduce the manufacturing cost of a MAP type lead frame, prevent deformation such as distortion and twist, and use this lead frame. It is an object to improve the reliability of a semiconductor device.

In order to solve the above-described problem, a lead frame according to a first configuration of the present invention includes a unit frame including a semiconductor chip mounting portion and a support bar that supports the semiconductor chip mounting portion in a matrix shape via a tie bar. A lead frame formed by a plurality of sets, wherein the tie bar is half-punched or coined, and a slit is provided in the half-punched region or coining region of the tie bar.
According to the first aspect of the invention, half punching or coining into a tie bar can be processed in a shorter time than when processing by half etching, and productivity is high and manufacturing cost can be suppressed. In addition, by providing slits, it is possible to prevent lead frame warping and twisting because it prevents residual stress in the lead frame due to half-cutting or coining, and the resin does not wrap around the back surface of the lead frame. The connected semiconductor device and the mounting board can be reliably connected.

A lead frame according to a second configuration of the present invention is characterized in that a part of a group of leads adjacent to each other with the tie bar interposed therebetween is integrally half-punched or coined including the tie bar.
Thereby, the level | step difference to a lead can be processed in a short time, productivity is high, and manufacturing cost can be suppressed. In addition, since the adjacent lead group can be processed with one wide punch, the punch strength is increased and breakage can be prevented.

In the lead frame according to the third configuration of the present invention, the slit has a length at least equal to or longer than the lead group.
Thereby, the stress of half blanking or coining can be relieved effectively.

In the lead frame according to the fourth configuration of the present invention, the slit is formed beyond the half-blanked region or coining region.
As a result, it is possible to effectively relieve the stress of half punching or coining, and the degree of freedom of the slit shape can be increased.

The lead frame according to the fifth configuration of the present invention is characterized in that a widened portion is formed at an end of the slit.
Thereby, the stress by half punching or coining in both the vertical and parallel directions can be relieved.

In the lead frame according to the sixth configuration of the present invention, the support bar is also half-cut or coined.
Thus, also about the support bar which supports the semiconductor chip mounting part of a unit frame, adhesiveness with resin can be improved by performing half extraction or coining similarly to a lead, and giving a level | step difference.

The lead frame according to the seventh configuration of the present invention is characterized in that a hole is formed in an outer peripheral region of the unit frame on an extension line of the half-cut or coined support bar.
Thereby, the stress when the support bar is half cut or coined can be relieved.

According to an eighth aspect of the present invention, there is provided a lead frame manufacturing method in which a plurality of unit frames each including a semiconductor chip mounting portion and a support bar that supports the semiconductor chip mounting portion are assembled in a matrix through a tie bar. In the method of manufacturing the lead frame formed as described above, the method includes a half-cutting or coining process for half-cutting or coining the tie bar, and a slit-forming process for forming a slit in the half-cutting area or coining area of the tie bar. It is characterized by.
Thereby, half punching or coining to a tie bar can be processed in a shorter time than half etching, and productivity is high and manufacturing cost can be suppressed. Furthermore, by providing slits, the lead frame can be prevented from warping or twisting because it prevents residual stress in the lead frame due to half-cutting or coining. Can be stopped.

In the lead frame manufacturing method according to the ninth configuration of the present invention, a half punching process or a coining process step in which a part of a group of adjacent leads sandwiching the tie bar is half punched or coined including the tie bar. It is characterized by having.
According to the ninth aspect of the invention, the step to the lead can be processed in a shorter time than when manufactured by half etching, and the productivity is high and the manufacturing cost can be suppressed. In addition, since the adjacent lead group can be processed with one wide punch, the punch strength is increased and breakage can be prevented.

The lead frame manufacturing method according to the tenth configuration of the present invention is characterized in that the slit formed in the slit forming step is formed to have a length at least equal to or longer than the lead group.
Thereby, the stress of half blanking or coining can be relieved effectively.

The lead frame manufacturing method according to the eleventh configuration of the present invention is characterized in that the slit is formed beyond the half-blanked region or coining region.
As a result, it is possible to effectively relieve the stress of half punching or coining, and the degree of freedom of the shape of the slit can be increased.

The lead frame manufacturing method according to the twelfth configuration of the present invention is characterized in that a widened portion is formed at an end of the slit.
Thereby, the stress by half punching or coining in both the vertical and parallel directions can be relieved.

The lead frame manufacturing method according to the thirteenth configuration of the present invention is characterized in that the support bar also includes a half punching process or a coining process for performing half punching or coining.
Thus, also about the support bar which supports the semiconductor chip mounting part of a unit frame, adhesiveness with resin can be improved by performing a half cut or coining like a lead, and giving a level | step difference.

In the lead frame manufacturing method according to the fourteenth aspect of the present invention, a hole is formed in advance in the outer peripheral area of the unit frame on the extension line of the half-punched or coined support bar prior to the half-punching or coining. And a hole forming step.
Thereby, the stress when the support bar is half cut or coined can be relieved.

A semiconductor device according to a fifteenth configuration of the present invention is a lead frame in which a plurality of unit frames each including a semiconductor chip mounting portion and a support bar that supports the semiconductor chip mounting portion are assembled in a matrix through a tie bar. After the semiconductor chip is mounted on the semiconductor chip mounting portion of each unit frame and the entire lead frame is resin-sealed to form a resin sealing body, the resin sealing is performed along the tie bar. Each semiconductor device manufactured by cutting a body, wherein the tie bar is half punched or coined, and has a lead frame provided with a slit in the half punched region or coining region of the tie bar Features.
As a result, warping and twisting of the lead frame can be prevented, and a semiconductor device in which the resin is sealed in a normal form can be obtained without causing the resin to wrap around the back surface of the lead frame.

A semiconductor device according to a sixteenth configuration of the present invention is characterized in that a part of a group of leads adjacent to each other with the tie bar interposed therebetween has a lead frame that is integrally half-punched or coined including the tie bar.
Thereby, the level | step difference to a lead can be processed in a short time, productivity is high, and manufacturing cost can be suppressed. In addition, since the adjacent lead group can be processed with one wide punch, the punch strength is increased and breakage can be prevented.

A semiconductor device according to a seventeenth configuration of the present invention is characterized in that the slit has a lead frame formed with a length at least equal to or longer than the lead group.
Thereby, the stress of half blanking or coining can be relieved effectively.

The semiconductor device according to an eighteenth aspect of the present invention is characterized in that the slit has a lead frame formed beyond the half-blanked region or coining region.
As a result, it is possible to effectively relieve the stress of half punching or coining, and the degree of freedom of the slit shape can be increased.

A semiconductor device according to a nineteenth configuration of the present invention has a lead frame in which a widened portion is formed at an end of the slit.
Thereby, the stress by half punching or coining in both the vertical and parallel directions can be relieved.

A semiconductor device according to a twentieth aspect of the present invention is characterized in that the support bar also has a lead frame that is half cut or coined.
Thus, also about the support bar which supports the semiconductor chip mounting part of the center of a unit frame, adhesiveness with resin can be improved by giving a level | step difference by half punching or coining like a lead.

A semiconductor device according to a twenty-first configuration of the present invention has a lead frame in which a hole is formed in an outer peripheral region of the unit frame on an extension line of the half-punched or coined support bar. .
Thus, by providing a hole on the extended line of the support bar, it is possible to relieve stress when the support bar is half cut or coined.

According to a twenty-second aspect of the present invention, there is provided a method for manufacturing a semiconductor device, wherein a plurality of unit frames each including a semiconductor chip mounting portion and a support bar supporting the semiconductor chip mounting portion are gathered in a matrix through a tie bar. A lead frame is formed, a semiconductor chip is mounted on the semiconductor chip mounting portion of each unit frame, the entire lead frame is resin-sealed to form a resin sealing body, and then the resin is formed along the tie bar. A method of manufacturing each semiconductor device manufactured by cutting a sealing body, wherein the tie bar is half-cut or coined, and the tie bar is half-punched or coined. A lead frame having a slit forming step of providing a slit is used.
As a result, warping and twisting of the lead frame can be prevented, and a semiconductor device in which the resin is sealed in a normal form can be obtained without causing the resin to wrap around the back surface of the lead frame.

In a method of manufacturing a semiconductor device according to a twenty-third configuration of the present invention, a half punching process or a coining process step in which a part of a group of adjacent leads sandwiching the tie bar is integrally half punched or coined including the tie bar. It is characterized by using a lead frame having
Thereby, the level | step difference to a lead can be processed in a short time, productivity is high, and manufacturing cost can be suppressed. In addition, since the adjacent lead group can be processed with one wide punch, the punch strength is increased and breakage can be prevented.

The method for manufacturing a semiconductor device according to a twenty-fourth configuration of the present invention is characterized in that the slit formed by the slit formation uses a lead frame formed at least as long as the lead group.
Thereby, the stress of half blanking or coining can be relieved effectively.

The method for manufacturing a semiconductor device according to a twenty-fifth aspect of the present invention is characterized in that the slit formed in the slit forming step uses a lead frame formed beyond the half-blanked region or coining region.
As a result, it is possible to effectively relieve the stress of half punching or coining, and the degree of freedom of the slit shape can be increased.

A manufacturing method of a semiconductor device according to a twenty-sixth configuration of the present invention is characterized by using a lead frame in which a widened portion is formed at an end of the slit.
Thereby, the stress by half punching or coining in both the vertical and parallel directions can be relieved.

In a method of manufacturing a semiconductor device according to a twenty-seventh aspect of the present invention, the support bar also uses a lead frame having a half punching or coining process for half punching or coining.
Thus, also about the support bar which supports the semiconductor chip mounting part of the center of a unit frame, adhesiveness with resin can be improved by giving a level | step difference by half punching or coining like a lead.

In the method for manufacturing a semiconductor device according to the twenty-eighth configuration of the present invention, a hole is formed in advance in the outer peripheral region of the unit frame on the extension line of the half-punched or coined support bar prior to the half-punching or coining. A lead frame having a hole forming step is used.
Thus, by providing a hole on the extended line of the support bar, it is possible to relieve stress when the support bar is half cut or coined.

According to the present invention, when the step portion of the lead of the lead frame used in the MAP type semiconductor device is formed by half blanking or coining, the slits release the surplus due to half blanking or coining, so that the stress can be relieved. It can be processed in a shorter time than the case of manufacturing by half etching, and the productivity is high, and the manufacturing cost can be reduced.
Further, when the lead frame forming step is performed by stamping, a series of steps from the lead frame forming step to the step of forming a step on the lead is not stopped, and the productivity can be further increased.
Furthermore, since the formed slits prevent residual stress due to half-cutting or coining, the lead frame can be prevented from warping and twisting, and the sealing resin flows and adheres to the back side of the lead frame (the side exposed from the package). Therefore, it is possible to manufacture a semiconductor device that is resin-sealed in a normal form.

Hereinafter, a lead frame and a manufacturing method thereof according to the present invention will be described with reference to the drawings.
1 to 3 show a first embodiment of the present invention. FIG. 1A is a plan view showing a lead frame forming process of the present embodiment, and FIG. 1B is a slit forming process. FIG. 2 is an enlarged cross-sectional view of a tool that performs half punching, and FIG. 3 is an enlarged cross-sectional view of a tool that performs coining.

  In the first embodiment, first, as shown in FIG. 1A, a pad 11, lead 12, and tie bar 13 are made from a thin plate material having a high conductivity such as a copper alloy (for example, a plate thickness of about 0.2 mm). Then, the lead frame 10 is integrally formed by stamping or etching the support bar 14 (lead frame forming step).

  Next, as shown in FIG. 1B, the slits 15 are formed along the formation direction of the lead group of the lead frame in which a plurality of unit frames are arranged in a matrix. The width a of the slit 15 is about 0.2 mm which is the same as the thickness of the lead frame 10, and the length b is formed to be equal to the lead group width A of the lead frame 10. (Slit forming process)

  Next, a step portion (shaded portion) 17 is formed by half-cutting using a press (step processing step). In the present embodiment, the length b of the slit 15 is set to be equal to the lead group width A and less than the region of the stepped portion 17, but the length b of the slit 15 is at least equal to the lead width A. By making it equal to or greater than the above, it is possible to relieve the stress of the lead part 12 half-cut or coining, and it is possible to obtain the lead frame 10 without deformation such as warping or twisting. If the length b of the slit 15 is shorter than the lead group width A, it is difficult to relax the stress, which is not preferable.

In the half-punching, the first area 18-1 is first put in a half-pumped state in the order of the material feeding direction. Next, half cutting is performed for the second area 18-2, and then half cutting is performed for the third area 18-3.
Half punches for the first area 18-1, the second area 18-2, and the third area 18-3 are arranged in a lead frame processing line, and the lead frame is a unit for these half punches. The lead frame is continuously half-punched by moving in the transport direction by the length of the frame.
As shown in FIG. 1B, a part of the lead group adjacent to each other with the tie bar 13 in between is partially half-punched including the tie bar 13, so that a half-punching punch can be widely formed. In this case, breakage of the punch can be prevented.

For half-punching, as shown in FIG. 2, while holding the lead frame material 20 with the stripper 21, it is not completely punched by the punch 22 and the die 23, and the stroke is preferably halfway, preferably half the thickness of the lead frame. Control.
The lead thickness after half-punching is preferably 0.1 mm or more. If it is smaller than 0.1 mm, there is a possibility that the lead is lost when the semiconductor device is cut individually.

  In this half punching, the lead frame material 20 is pushed down by the punch 22 while the thickness of the lead frame material 20 is maintained, so that the stress is relatively smaller than that of coining.

  Further, in the present embodiment, the step portion of the lead can be formed not only by half punching but also by coining. Coining is a process of thinning the lead frame material 20 by performing coining with the punch 24 as shown in FIG. By performing this coining, as shown in FIG. 3B, the coining portion 20a can be made thin while maintaining the thickness of the entire lead frame. However, since the stress applied to the coining portion 20a remains inside, deformation and twist are likely to occur. For this reason, it is desirable to suppress the thickness reduction due to coining to about 0.05 mm with respect to 0.1 mm (half the plate thickness) of half-cut.

  FIG. 4 is a plan view showing a second embodiment of the present invention.

  In the first embodiment, the length b of the slit 15 is formed to be equal to the lead group width A of the lead frame 10, but in the second embodiment, as shown in FIG. The length b was made longer than the lead group width A and further beyond the stepped portion 17 region. In this case, it is preferable that the slits 15 are not connected to each other, for example, a dimension that ensures a distance between B and B 'of at least 0.1 mm or more. In the present embodiment, the length of the slit is formed so as to exceed the region of the stepped portion 17, so that more stress due to half punching or coining can be relieved and warped as compared with the first embodiment. As a result, a lead frame free from deformation such as twisting and twisting can be obtained, and the reliability of the package can be improved.

  In the second embodiment, the half-punching or coining process after the formation of the slit 15 is the same as that in the first embodiment, and the description thereof is omitted.

FIG. 5 is a plan view showing a third embodiment of the present invention.
In the third embodiment, the shape of the slit 15 in the second embodiment is formed in an E shape as indicated by 15 'in FIG. Here, the length of the slit 15 ′ is set to be longer than the lead group width A and beyond the region of the stepped portion 17.

  The E-shaped slit 15 ′ can relieve stress in both the vertical and parallel directions by having widened portions w at both ends. Further, the strength of the slit forming punch is increased and it is difficult to break.

  In the present embodiment, the shape of the widened portion w is rectangular, but may be other shapes such as a circle.

FIG. 6 shows a semiconductor device P manufactured using the lead frame 10 manufactured according to the first, second, and third embodiments. That is, a semiconductor chip is mounted on each of the semiconductor chip mounting portions 11 of the lead frame 10, and the entire lead frame 10 is resin-sealed to form a resin sealing body, and then the resin sealing is performed along the tie bars 13. Each semiconductor device can be manufactured by cutting the body.
6A is a perspective view of the semiconductor device P viewed from the top surface, and FIG. 6B is a perspective view of the semiconductor device P viewed from the bottom surface.

  7A and 7B show a fourth embodiment of the present invention, in which FIG. 7A is a plan view and FIG. 7B is a cross-sectional view taken along the line CC in FIG.

  In the fourth embodiment, in addition to the second embodiment, the support bar 14 is also half cut or coined.

  In this embodiment, first, a lead frame 10 'is formed by the same processing steps as those of the second embodiment.

  Thereafter, as shown in FIG. 7, a hole 19 is formed in the outer peripheral region of the lead frame on the extension line of the support bar 14. The hole 19 has a rhombus in the illustrated example, but may have other shapes such as a triangle, a circle, and an ellipse.

  Then, the support bar 14 is half-cut or coined. By forming the hole 19 in advance, the stress generated by the step processing step of the support bar 14 can be relaxed, and as a result, deformation and twisting of the support bar 14 can be prevented.

  In this embodiment, after the slit forming step and the lead group step processing step, the lead frame outer peripheral region hole forming step and the support bar 14 step processing step are performed, but the processing order is not limited to this. .

FIG. 8 shows a fifth embodiment of the present invention, where (a) is a plan view and (b) is a side view.
In the fifth embodiment, the pad 31 of the lead frame 30 is continuously provided in one direction by the support bar 32. Then, the slits 33 are formed so as to be orthogonal to the direction in which the support bars 32 are arranged. In the figure, 36 is a tie bar.

The width c of the slit 33 is 0.2 mm which is the same as the thickness of the lead frame 30, and the length d is formed to be equal to the width of both ends of the support bar 32 of the lead frame 30.
Next, the stepped portion (shaded portion) 35 is formed in a half-punched state using a press. In the present embodiment, the length d of the slit 33 is set to be equal to the width of both ends of the support bar and less than the region of the stepped portion 35.
Thus, by forming the length d of the slit 33 to be equal to the width of both ends of the support bar 32, it is possible to relieve the half-cutting or coining stress of the support bar 32 to be processed later. If the length d of the slit 33 is shorter than the width of both ends of the support bar 32, it is difficult to relax the stress, which is not preferable.

FIG. 9 shows a sixth embodiment of the present invention, where (a) is a plan view and (b) is a side view.
In the fifth embodiment (FIG. 8), the length d of the slit 33 is formed equal to the width of both ends of the support bar 32 by half punching or coining of the lead frame 30, but in this embodiment, the length of the slit 33 is The length d is longer than the widths of both ends of the support bar 32 and further, the length d exceeds the region of the stepped portion 35. As a result, many stresses due to half punching or coining can be relieved, and a lead frame 30 free from deformation such as warping or twisting can be obtained, and the reliability of the package can be improved.

  A semiconductor device is manufactured using the lead frame 10 ′ or 30 manufactured according to the fourth, fifth, and sixth embodiments. That is, a semiconductor chip is mounted on each of the semiconductor chip mounting portions 11 or 31 of the lead frame 10 ′ or 30, and the entire region of the lead frame 10 ′ or 30 is resin-sealed to form a resin sealing body. Each semiconductor device (not shown) can be manufactured by cutting the resin sealing body along the line.

(A) is the lead frame formation process of the 1st Embodiment of this invention, (b) is a top view which shows a slit formation process and a level | step difference processing process. It is an expanded sectional view of the tool which performs half punching. It is an expanded sectional view of the tool which performs coining. It is a top view which shows the 2nd Embodiment of this invention. It is a top view which shows the 3rd Embodiment of this invention. BRIEF DESCRIPTION OF THE DRAWINGS The shape of the semiconductor device manufactured using the lead frame manufactured by one of the 1st-3rd embodiment of this invention is shown, (a) is the perspective view seen from the upper surface, (b) is It is the perspective view seen from the bottom face. The 4th Embodiment of this invention is shown, (a) is a top view, (b) is CC sectional drawing in (a). The 5th Embodiment of this invention is shown, (a) is a top view, (b) is a side view. The 6th Embodiment of this invention is shown, (a) is a top view, (b) is a side view. The conventional example which forms the level | step-difference part in the lead | read | reed of a lead frame and manufactures a resin-encapsulated semiconductor device is shown, (a) is a top view, (b) is DD sectional drawing in (a), c) is a DD cross-sectional view during deformation.

Explanation of symbols

10, 10 'lead frame 11 pad (semiconductor chip mounting part)
12 Lead 12a Stepped portion 13 Tie bar 14 Support bar 15, 15 'Slit 16 Half blank line 17 Stepped portion 18-1 First area 18-2 Second area 18-3 Third area 19 Hole 20 Lead frame material 20a Coining portion 21 Stripper 22 Punch 23 Die 30 Lead frame 31 Pad (Semiconductor chip mounting part)
32 Support bar 33 Slit 34 Half-punch line 35 Stepped part 36 Tie bar

Claims (6)

A lead frame formed by collecting a plurality of unit frames including a semiconductor chip mounting portion and a support bar supporting the semiconductor chip mounting portion in a matrix through a tie bar,
Characterized in that a part of the lead group adjacent to sandwich the tie bar and the tie bars are-out integrally semi disconnect and its half blanking region, a slit is provided beyond the half vent region And lead frame. The lead frame of claim 1, characterized in that the support bars are also-out semi-disconnect. Wherein the extension of the support bar which is-out semi disconnect, to the unit frame periphery region, a lead frame according to claim 2, wherein a hole portion is formed. In a manufacturing method of a lead frame formed by assembling a plurality of unit frames including a semiconductor chip mounting portion and a support bar supporting the semiconductor chip mounting portion in a matrix through a tie bar,
A slit forming step of forming a slit in the portion of the tie bar between the plurality of unit frames along the formation direction of the lead group of the lead frame;
After the slit formation, it has a half-punch process step of integrally half-punching a tie bar formed with the slit and a part of the adjacent lead group across the tie bar,
A method of manufacturing a lead frame , wherein a length of a slit formed in the slit forming step is formed so as to exceed a half punched region to be half punched in the half punching step .
The half in blanking step, the support bar method for fabricating a lead frame according to claim 4, wherein the performing-out semi-disconnect. Wherein the extension of the support bar which is-out half-disconnect, according to claim 5 characterized by having a hole forming step of forming a pre-hole prior to the half die cutting machining process to the unit frame periphery region Lead frame manufacturing method.

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