Semiconductor device and method for manufacturing the same

Abstract

To provide a semiconductor device with improved secondary mounting reliability.SOLUTION: A semiconductor device includes: a lead frame that includes a bed part and a first lead part; an organic material that extends between the bed part and the first lead part; a first semiconductor element that is located above the bed part; a sealing resin that is located above the organic material and the first semiconductor element; and a first bonding wire that connects an electrode of the first semiconductor element to the first lead part. The first bonding wire is disposed within the sealing resin. The first lead part includes a lead upper side, a lead bottom side opposite to the lead upper side, an inner side surface, and an outer side surface opposite to the inner side surface. The first bonding wire is bonded to the lead upper side, and the first lead part includes a stepped shape on the outer side surface of the lead frame.SELECTED DRAWING: Figure 2-1

Description

[Technical field]

[0001] The present invention relates to a semiconductor device and a method for manufacturing the semiconductor device. [Background technology]

[0002] In recent years, in order to accommodate the miniaturization of electronic devices, the semiconductor components mounted on electronic devices have become increasingly dense. As a result, semiconductor components are becoming smaller and thinner. For this reason, a package including a resin-encapsulated semiconductor device that can achieve further thinning at low cost has been developed. It is required.

[0003] There are many types of semiconductor packages depending on their shape, material and corresponding mounting method. Semiconductor packages can be broadly divided into those that connect the leads of the package to a printed wiring board, etc. The lead insertion type is inserted into a through hole in the PCB and soldered, while the lead insertion type is directly attached to the surface of the PCB. There are surface mount types that are mounted by soldering. Among them, the surface mount type QFN (Quad Flat Non-leaded package) is a resin-sealed A type of semiconductor device that has exposed leads on the bottom instead of the side of the body is attracting attention. It has been done.

[0004] Figure 6 shows the structure of a typical conventional QFN. The semiconductor device 1 has a bed portion (semiconductor element mounting portion) 2b and its tip extending around the bed portion. The lead frame 2 has a plurality of lead portions 2a and is placed on the bed portion 2b. The semiconductor element 6 is connected to the electrodes 4 of the semiconductor element 6 and the respective lead portions 2a by bonding. The wire 3, the semiconductor element mounting side of the lead frame 2, the semiconductor element 6, and the bonding wire and a sealing resin 5 that seals the core 3. This semiconductor device 1 is sealed with resin using a backing to prevent resin leakage during the molding process. The back tape is removed after the resin sealing process.

[0005] However, the use of a back tape causes the following problems. Since the resin surface is flush with the lead frame, the solder 11 is The connection is only on the surface of the lead portion 2a and the bed portion 2b, improving the secondary mounting reliability. It's difficult. If the back tape 12 does not adhere well, mold resin burrs 5a may occur as shown in FIG. 7B. Also, if the adhesion is too good, adhesive residue 12a of the back tape 12 will be left when peeled off. This can also be a factor in reducing reliability. The lead frame 2 is made of metal, so even if the surface of the base material is roughened or otherwise improved, The adhesion between the mold resin, which is an organic material, is poor. When the product was evaluated under these environmental conditions, damage due to repeated stress, thermal damage due to high temperatures, After a certain period of time, due to chemical damage caused by humidity, internal peeling occurs as shown in Figure 7C. 13 occurred.

[0006] In the patent document 1, in the manufacturing process of QFN, a gold layer is applied to the exposed surface of the lead before the resin sealing. After the resin sealing, the metal plating is chemically removed to remove the The present invention describes a method for manufacturing a semiconductor device that simultaneously removes resin burrs generated on the exposed surface of the semiconductor device. It is being done.

[0007] In addition, in Patent Document 2, as shown in FIG. 8, a semiconductor device is mounted on a bed portion 22 of a lead frame 21. The electrodes of the semiconductor element 24 are connected to the lead portions 23 of the lead frame. A bonding wire 25 for electrically connecting the semiconductor element 24 and the bonding wire 25 The sealing resin 26 that seals the lead portion 23 and one side of the opening of the lead frame 21 The resin 27 is filled to a thickness smaller than the thickness of the lead frame 21 by a predetermined thickness d. The semiconductor device 20 is shown having the following structure. The lead portion 23 and the bed portion 22 are protruded at a uniform height, so that the semiconductor device 20 can be mounted on the semiconductor device 20. This improves reliability when installed. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] JP 2001-156233 A [Patent Document 2] JP 2002-93982 A Summary of the Invention [Problem to be solved by the invention]

[0009] In the present invention, when the resin is encapsulated, unlike the conventional method, the opposite side of the lead frame on which the semiconductor element is mounted is By not using the method of providing back tape on the side, secondary mounting reliability is improved. It is an object of the present invention to provide a semiconductor device having improved characteristics. [Means for solving the problem]

[0010] That is, the present invention is as described below. (1) a lead frame consisting of a lead portion and a bed portion; an organic material layer that covers at least the space of the lead frame from the semiconductor element mounting surface side; an opening provided in an organic material layer in a lead portion to be connected to a bonding wire; A semiconductor element mounted on the bed portion; a bonding wire for electrically connecting the lead portion of the opening and an electrode of the semiconductor element; , a sealing resin for sealing the organic material layer, the bonding wires, and the semiconductor element; A semiconductor device having the above structure. (2) The organic material layer is also formed on the bed portion at the semiconductor element mounting position, and the semiconductor element is The semiconductor device according to (1) above is mounted on the organic material layer at the semiconductor mounting position. (3) The organic material layer has an opening at the position where the semiconductor element is mounted on the bed portion, and the semiconductor element is mounted on the opening. The semiconductor element mounting position of the semiconductor element mounting device according to the above item (1) is mounted on the bed portion at the opening of the semiconductor element mounting position. Semiconductor device. (4) A semiconductor device having a plurality of semiconductor elements mounted on an organic material layer formed on a bed portion. A conductive element and a semiconductor element mounted on the bed portion in an opening formed in the organic material layer. The semiconductor device according to (1) above, (5) At least a part of the periphery of the bed portion and / or the periphery of the lead portion has a step. The semiconductor device according to any one of the above (1) to (4). (6) Applying an organic material layer to the semiconductor element mounting surface of a lead frame having a bed portion and a lead portion. forming a An opening A is formed in the organic material layer formed at the connection part with the bonding wire of the lead part. and forming an opening B in the organic material layer at a position where a semiconductor element is mounted on the bed portion; An opening A in the organic material layer formed at the connection portion of the lead portion with the bonding wire forming a plating film on the fixing a semiconductor element to the bed portion at the opening of the bed portion with an adhesive; The electrodes of the semiconductor element and the plating film of the lead portion are electrically connected by bonding wires. and connecting the A step of sealing the semiconductor element, the bonding wires and the organic material layer with a sealing resin. and, A method for manufacturing a semiconductor device comprising the steps of: (7) forming an opening in an organic material layer formed at a connection portion between the lead portion and the bonding wire; forming an opening B in the organic material layer at the position where the semiconductor element is mounted on the bed portion; The method for producing a semiconductor device according to (6) above, further comprising the steps of: (8) Applying an organic material layer to the semiconductor element mounting surface of a lead frame having a bed portion and a lead portion. forming a An opening A is formed in the organic material layer formed at the connection part with the bonding wire of the lead part. and forming an opening B at at least one of the plurality of semiconductor element mounting positions of the bed portion; forming a plating film in the opening A; At the semiconductor element mounting position having an organic material layer, the semiconductor element is fixed on the organic material layer with adhesive. At the semiconductor element mounting position having the opening B, the semiconductor element is fixed on the bed portion by adhesive. determining the The electrodes of the semiconductor element and the plating film of the lead portion are electrically connected by bonding wires. and connecting the A step of sealing the semiconductor element, the bonding wires and the organic material layer with a sealing resin. and, A method for manufacturing a semiconductor device comprising the steps of: (9) forming an opening in an organic material layer formed at a connection portion between the lead portion and a bonding wire; forming a portion A; and forming an opening B in at least one of the semiconductor element mounting positions of the bed portion. The method for manufacturing a semiconductor device according to (8) above, further comprising the steps of: Effect of the Invention

[0011] By using the semiconductor device of the present invention, the secondary mounting reliability of the semiconductor device is improved. can be done. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a diagram showing a semiconductor device according to a first embodiment of the present invention. [Figure 2-1] FIG. 2-1 is a diagram showing a semiconductor device according to a second embodiment of the present invention. [Figure 2-2] FIG. 2-2 is a diagram showing the structure of a lead frame in the semiconductor device shown in FIG. 2-1. [Figure 3-1] FIG. 3-1 is a diagram showing a semiconductor device according to a third embodiment of the present invention. [Figure 3-2] FIG. 3-2 is a diagram showing the lead frame and the organic material layer in the semiconductor device shown in FIG. 3-1. [Figure 4] FIG. 4 is a diagram showing a semiconductor device according to a fourth embodiment of the present invention. [Diagram 5] 5A to 5E are diagrams illustrating a method for manufacturing a semiconductor device according to an embodiment of the present invention. In each diagram, (a) is a plan view, and (b) is a cross-sectional view. FIG. 5A is a diagram showing a lead frame. FIG. 5B is a diagram showing a state in which an organic material layer has been formed on the surface of the lead frame. FIG. 5C is a diagram showing a state in which an opening for a wire connection portion has been formed in the organic material layer on the lead portion of the lead frame. FIG. 5D is a diagram showing a state in which a plating film has been formed in the opening for the wire connection portion. FIG. 5E is a diagram showing a state in which a semiconductor element has been mounted on the organic material layer on the semiconductor element mounting portion of the lead frame. [Figure 6] FIG. 6 is a cross-sectional view of a conventional semiconductor device. [Figure 7] Figures 7A to 7C are cross-sectional views of a conventional semiconductor device. Figure 7A is a diagram showing solder attached to a lead frame. Figure 7B is a diagram showing a state in which the back tape is being peeled off from the semiconductor device. Figure 7C is a diagram showing a state in which internal peeling of the sealing resin has occurred within the semiconductor device. [Figure 8]FIG. 8 is a cross-sectional view of a conventional semiconductor device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. It is possible for a person to easily modify or alter the present invention within the scope of the claims to create other embodiments. These changes and modifications are intended to be included within the scope of the claims, and the following description is The following are merely examples of embodiments of the present invention, and are not intended to limit the scope of the claims. It is not something that can be achieved.

[0014] (First embodiment) The semiconductor device of this embodiment is shown in FIG. The semiconductor device 1 shown in FIG. 1 includes a lead frame 2a and a bed 2b. 2, and an organic material layer 1 covering the semiconductor element mounting surface side of the lead frame 2 and having an opening 9. 0, and a semiconductor mounted on the semiconductor element mounting portion 2b via an organic material layer 10 and an adhesive layer 7. The element 6, the plating film 8 formed on the lead portion 2a of the opening 9, and the electrode of the semiconductor element 6 4 and the plating film 8 are electrically connected to the bonding wire 3, and the semiconductor element 6 is sealed in a resin. and a sealing resin 5 for sealing.

[0015] In the semiconductor device of this embodiment, the organic material layer 10 covers the space of the lead frame 2. Therefore, when the resin is sealed, the molding resin does not get around the terminal surface of the lead frame 2. Therefore, in addition to the bottom surface of the lead portion 2a, the side surface 2c of the lead portion 2 can also be used as a mounting surface. can. As a result, fillets are formed in all directions on both the lead portion 2a and the bed portion 2b. , the secondary mounting reliability is improved.

[0016] In addition, in the semiconductor device of this embodiment, a back tape is used to prevent resin leakage when the resin is sealed. Since the organic material layer 10 is used as a component of the semiconductor device instead of the mold tape, Therefore, there is no need to peel off the back tape, and no adhesive residue is left behind. We can expect a positive effect. The material of the organic material layer 10 is preferably one that is durable against the injection pressure of the mold. Dry film and LαZ, a high Tg material made by Sumitomo Bakelite Co., Ltd., are used. can.

[0017] In the semiconductor device of this embodiment, an opening is provided in a part of the organic material layer 10 formed on the lead portion 2a. The surface of the lead portion 2a at the opening 9 is plated. The exposed metal area of ​​the lead frame 2 on the device mounting surface side can be minimized. This is expected to increase adhesion between the organic material layer 10 and the sealing resin 5, and to suppress peeling during various reliability evaluations. The following effects can be expected.

[0018] A method for manufacturing the semiconductor device of the first embodiment will be described with reference to FIGS. 5A to 5E. The semiconductor device is a lead frame formed by connecting a plurality of unit lead frames using tie bars. A large number of semiconductor devices are manufactured at once using a frame, and finally, they are divided into individual semiconductor devices. It is produced by converting The unit lead frame 2 has a bed portion 2b formed in the center and a bedding portion around the bed portion. The lead frame is made up of a lead portion and a lead portion formed at an interval. It is sometimes called a "lead frame." The left-hand side of each figure (a) shows the lead frame and semi-finished product in the manufacturing process of a semiconductor device. The right side (b) shows a unit lead frame and a unit semiconductor device. FIG. 2 is a cross-sectional view of a semi-finished product of the device.

[0019] <Lead frame preparation process (see Figure 5A)> A plurality of unit lead frames 2 each having a bed portion 2b and a lead portion 2a surrounding the bed portion 2b are connected together. A sheet-like lead frame having a patterned surface is prepared. The lead frame is made of a thin metal plate made of a good conductor such as an iron-based alloy or a copper-based alloy, which is etched. The lead frame is then processed to form a plurality of unit lead frames. In the following, the side of the lead frame on which the semiconductor element is mounted is referred to as the front side, The side opposite is called the back side.

[0020] <Organic material layer forming process (see FIG. 5B)> An organic material layer 10 is formed on the front surface of the lead frame 2 . The organic material layer 10 is formed on the front surface of the lead frame 2. The space between the lead portion 2a and the bed portion 2b in the semiconductor device 2 is covered with an organic material layer 10. This state occurs.

[0021] <Bonding Wire Connection Portion Opening Forming Process (see FIG. 5C)> An opening 9 is formed in an organic material layer 10 formed on a bonding wire connection portion of the lead portion 2a. This hole drilling process can be performed using a CO2 laser or a YAG laser.

[0022] <Plating process (see FIG. 5D)> A plating film 8 made of a conductive metal is formed on the opening 9 of the lead portion 2a by electrolytic plating. This plating film 8 improves the electrical connection between the lead portion 2a and the bonding wire. The thickness of plating film 8 is preferably 1.0 μm to 10.0 μm.

[0023] <Semiconductor element mounting process (see Fig. 5E)> A semiconductor element 6 is fixed onto the bed portion 2b of the lead frame 2 via an adhesive layer 7. As the adhesive 7, an adhesive such as silver paste or an adhesive tape can be used.

[0024] The subsequent processes (wire bonding, resin sealing, and singulation) are the same as the conventional method. The process can be carried out in the same manner, but the subsequent steps are shown below.

[0025] <Wire bonding process> A connecting member is provided between the electrode pad 4 of the semiconductor element 6 and the plating film 8 of the corresponding lead portion 2a. The connection is made by a bonding wire 3 .

[0026] <Resin sealing process> The semiconductor element 6 is sealed with a sealing resin 5 . In the resin sealing process, an organic material layer 10 is formed on the front surface of the lead frame 2. Therefore, the side surfaces of the lead portion 2a and the bed portion 2b are not covered with the sealing resin. Therefore, the side surfaces of the lead portion 2a and the bed portion 2b can also be used as mounting surfaces. Since fillets are formed in all directions on both the lead portion 2a and the bed portion 2b of the frame, the secondary Mounting reliability is improved. In addition, since no back tape is used for resin sealing, no resin burrs are generated and no back No adhesive residue from the back tape is left behind when the tape is peeled off, improving secondary mounting reliability. Sexuality improves.

[0027] <Semiconductor element individualization process> A plurality of semiconductor devices formed in each of a plurality of unit frames on a lead frame are separated into individual semiconductor devices. Singulate into body apparatus.

[0028] Second Embodiment The semiconductor device of this embodiment is shown in FIG. The semiconductor device of this embodiment is the semiconductor device of embodiment 1, except that the surrounding area of ​​the lead portion 2 and The thickness of the peripheral portion of the bed portion 2b is made thinner to provide a step portion s. FIG. 2-2 shows the shape of the lead frame 2 of the semiconductor device of the second embodiment. The peripheral portion of the lead portion 2a and the peripheral portion of the bed portion 2b are etched to a predetermined thickness d. This step portion s is formed by removing the organic material layer 10 and the lead frame 2 from the adhesive layer 10. The adhesion can be improved. The step s may be provided in a part of the periphery of the lead portion 2a and the bed portion 2b.

[0029] (Third embodiment) The semiconductor device of this embodiment is shown in FIG. The semiconductor device of this embodiment is the same as the semiconductor device of the first embodiment except that, as shown in FIG. An opening 14 is also provided in the semiconductor element mounting region of the organic material layer 10 formed on the pad portion 2b. The conductive element 6 is adhered and fixed to the bed portion 2b via an adhesive layer 7. In this way, by directly fixing the semiconductor element 6 to the bed portion 2b, the operation of the semiconductor element This makes it possible to efficiently release heat generated by the operation to the outside. The opening 9 and the opening 14 may be formed at the same time. The step of forming 14 may be separate.

[0030] When the openings 9 and 14 are formed simultaneously, in the step of forming the plating film 8, In this case, a method of forming the plating film 8 by covering the opening 14 with a plating mask can be adopted. Cut. When the process of forming the opening 9 and the process of forming the opening 14 are provided separately, first, A method of forming the opening 14 after forming the opening 9 and forming the plating film 8 is adopted. can be done. Since it is preferable to perform the opening step in one go, it is preferable to adopt the former method.

[0031] (Fourth embodiment) The semiconductor device of this embodiment is shown in FIG. The bed portion 2b may be equipped with a plurality of semiconductor elements. Parts may be mounted. In this embodiment, an example is shown in which two semiconductor elements (6a, 6b) are mounted on the bed portion 2b. The semiconductor device of this embodiment is the semiconductor device of embodiment 1, except that a plurality of It is equipped with a semiconductor element 6a and a semiconductor element 6b. In the example shown in FIG. 4, a semiconductor element 6a is mounted on a bed portion 2b via an organic material layer 10. This shows an example in which a semiconductor element 6b is mounted on a bed portion 2b without an organic material layer 10. do. The semiconductor elements 6a and 6b may be mounted on the bed portion 2b via an organic material layer 10. The conductive elements 6a and 6b may be mounted on the bed portion 2b without the organic material layer 10 therebetween. By adopting such a structure, it is possible to provide a multi-functional semiconductor device. By opening the organic material layer 10 according to the characteristics of the element, it is possible to obtain a semiconductor device that matches the characteristics of the element. The package structure becomes feasible. [Explanation of symbols]

[0032] 1 Semiconductor device 2 Lead Frame 2a Lead part 2b Bed section (semiconductor element mounting section) 2c Lead frame side 3 Bonding Wire 4 electrodes 5 Sealing resin 6, 6a, 6b Semiconductor elements 7 Adhesive layer 8 Plating film 9 Openings 10 Organic material layer 11 Solder 12 Back Tape 12a Glue residue 13 Internal peeling 14 Openings 20 Semiconductor Devices 21 Lead frame 22 Bed section 23 Lead section 24 Semiconductor elements 25 Bonding Wire 26 Sealing resin 27 Resin d Thickness s Step

Claims

1. a lead frame including a bed portion and a first lead portion; an organic material extending between the bed portion and the first lead portion; A first semiconductor element above the upper side of the bed portion; a sealing resin above the organic material and the first semiconductor element; a first bonding wire connecting an electrode of the first semiconductor element and the first lead portion; the first bonding wire is in the sealing resin; the first lead portion includes a lead top side, a lead bottom side opposite the lead top side, an inner side surface, and an outer side surface opposite the inner side surface; the first bonding wire is coupled to an upper side of the lead; The first lead portion includes a step shape on the outer side surface of the lead frame.

2. The semiconductor device of claim 1 , wherein the outer side surface of the first lead portion is free of the organic material.

3. The semiconductor device according to claim 1 , wherein the outer side surface of the first lead portion is flush with the sealing resin.

4. The semiconductor device according to claim 1 , wherein a portion of said first lead portion is outside said sealing resin.

5. 2. The semiconductor device of claim 1, wherein a portion of said organic material is in said bed portion of said lead frame.

6. 2. The semiconductor device according to claim 1, wherein the first bonding wire is connected to the first lead portion through an opening in the organic material.

7. A plurality of semiconductor elements including the first semiconductor element; a plurality of bonding wires including the first bonding wire; a plurality of leads including the first lead portion; the plurality of semiconductor elements are located above the bed portion, 2. The semiconductor device according to claim 1, wherein each of said plurality of bonding wires is connected to an electrode of one of said plurality of semiconductor elements and one of said plurality of leads.

8. a lead frame including a bed portion and a first lead portion; an organic material extending between the bed portion and the first lead portion; A first semiconductor element above the upper side of the bed portion; a sealing resin above the organic material and the first semiconductor element; a first bonding wire connecting an electrode of the first semiconductor element and the first lead portion; the first bonding wire is in the sealing resin; the first lead portion includes a lead top side, a lead bottom side opposite the lead top side, an inner side surface, and an outer side surface opposite the inner side surface; the first bonding wire is coupled to an upper side of the lead; The length of the top side of the lead is different from the length of the bottom side of the lead, The outer side surface of the first lead portion is flush with the sealing resin.

9. The semiconductor device according to claim 8 , wherein the inner side surface is covered with the organic material.

10. 9. The semiconductor device according to claim 8, wherein a portion of said first lead portion is outside said sealing resin.

11. 9. The semiconductor device according to claim 8, wherein a portion of said organic material is between said lead frame and said sealing resin.

12. The semiconductor device according to claim 8 , wherein said first lead portion includes a stepped shape.

13. 9. The semiconductor device of claim 8, wherein a portion of said organic material is in said bed portion of said lead frame.

14. 9. The semiconductor device according to claim 8, wherein said first bonding wire is connected to said first lead portion through an opening in said organic material.

15. A plurality of semiconductor elements including the first semiconductor element; a plurality of bonding wires including the first bonding wire; a plurality of leads including the first lead portion; the plurality of semiconductor elements are located above the bed portion, 9. The semiconductor device according to claim 8, wherein each of said plurality of bonding wires is connected to one electrode of said plurality of semiconductor elements and one of said plurality of leads.

16. providing a lead frame including a bed portion and a first lead portion; providing an organic material extending between the bed portion and the first lead portion; A first semiconductor element is provided above an upper side of the bed portion; providing a first bonding wire that connects an electrode of the first semiconductor element and the first lead portion; A method for manufacturing a semiconductor device, comprising the steps of: supplying a sealing resin above the organic material and the first semiconductor element, the first lead portion includes a lead top side, a lead bottom side opposite the lead top side, an inner side surface, and an outer side surface opposite the inner side surface; The length of the top side of the lead is different from the length of the bottom side of the lead, the first bonding wire is coupled to an upper side of the lead and is within the sealing resin; The first lead portion includes a stepped shape.

17. The method of claim 16 , wherein the exterior side of the first lead portion is free of the organic material.

18. The method of claim 16 , wherein the outer side of the first lead is flush with the encapsulation compound.

19. The method of claim 16 , wherein a portion of the first lead portion is outside the encapsulation resin.

20. The method of claim 16 , wherein a portion of the organic material is in the bed portion of the leadframe.

21. 17. The method of claim 16, wherein the first bond wire connects to the first lead through an opening in the organic material.

22. A plurality of semiconductor elements including the first semiconductor element; a plurality of bonding wires including the first bonding wire; providing a plurality of leads including the first lead portion; the plurality of semiconductor elements are located above the bed portion, 17. The method according to claim 16, wherein each of the plurality of bonding wires is connected to an electrode of one of the plurality of semiconductor elements and one of the plurality of leads.

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