Method of manufacturing a semiconductor device, components used and corresponding semiconductor device

Abstract

Methods of manufacturing semiconductor devices, assemblies for use, and corresponding semiconductor devices are disclosed. A leadframe includes a pattern of electrically conductive structures with one or more sacrificial connection structures bridging between a pair of the electrically conductive structures. The sacrificial connection structure or structures are formed at one of a first surface and a second surface of the leadframe and have a thickness between the first surface and the second surface that is less than a thickness of the leadframe. A fill of electrically insulative material is molded between the electrically conductive structures of the leadframe, with the electrically insulative material being molded between the connection structure and the other of the surfaces of the leadframe. The sacrificial connection structure counteracts deformation and displacement of components during formation and pre-molding of the leadframe.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to Italian application No. 102020000031553, filed on December 18, 2020, the contents of which are incorporated herein by reference to the full extent permitted by law. Technical Field

[0003] This instruction pertains to semiconductor devices.

[0004] For example, one or more embodiments may be applied to semiconductor devices such as integrated circuits (ICs). Background Technology

[0005] Various types of semiconductor devices can benefit from the use of pre-molded lead frames.

[0006] The Quad Plane No-Lead (QFN) package, which has peripheral pads on the bottom of the package to provide electrical connection to a substrate such as a printed circuit board (PCB), is an example of such a device.

[0007] A pre-molded leadframe includes a resin / plastic material surrounding metal leads and pads / soldering plates on which a semiconductor chip or die is attached; a molding compound (e.g., epoxy resin) is then molded onto the chip or die attached to the pre-molded leadframe.

[0008] For example, in the case of a QFN package, photolithography is used to etch metal (e.g., copper) lead frames on the top and bottom to create a desired pattern of one or more pads / solder boards together with leads connected to bars.

[0009] The etched leadframe is then completely filled with plastic resin during the pre-molding step. This may involve using standard molding techniques to fill the gaps in the leadframe.

[0010] After molding, matte and coating processes can be applied to obtain clean top and bottom copper surfaces. The pre-molded resin encapsulates the leadframe components in a stable planar structure.

[0011] During (pre)molding, resin flows through open spaces to penetrate the leadframe thickness. The structure within the leadframe should remain in the desired position to avoid any displacement or deformation during filling.

[0012] For this purpose, components of the leadframe (such as pads) can be supported / secured using connecting rods. These connecting rods can be located, for example, at the corners of the pads to save space and leave usable remaining space for the signal leads.

[0013] For example, if there are two or more pads / solder boards in the leadframe, it is almost impossible to reliably “lock” all pads / solder boards with multiple connections. Undesirable movement of pads or solder boards with (only) two connections has been observed during molding.

[0014] In complex designs with more pads / solder boards, providing adequate connection to the external rod is practically impossible. For example, in circuit layouts that include discrete components, the die pads connected by the rod may not be the desired electrical insulation; for instance, the drain and collector may often be short-circuited.

[0015] Furthermore, the locations used to form additional connecting rods consume valuable area and may render some leads in the lead frame unusable and thus lost.

[0016] In summary, conventional methods for handling undesirable displacement or deformation during pre-molding carry the risk of electrical insulation loss between frame fixtures, and have disadvantages such as: potential reduction in pin count and potential increase in package size; design constraints in multi-die pad cases; and electrically shorted die pads.

[0017] There is a need in this field to provide improved solutions that overcome the shortcomings of the existing technical solutions discussed above. Summary of the Invention

[0018] One or more embodiments may relate to a method.

[0019] One or more embodiments may relate to components used in this method. A pre-molded leadframe including semi-etched temporary connecting rods between pads may be an example of such a component.

[0020] One or more embodiments may relate to corresponding semiconductor devices that can be manufactured using such components.

[0021] One or more embodiments may involve temporary (sacrificial) connections etched halfway along the bottom (or back) side of the leadframe. These connections help keep the leadframe structure together during etching and pre-molding, reducing the risk of deformation and unwanted displacement.

[0022] In one or more embodiments, the die pads are only temporarily short-circuited and can be physically separated during the etching step that removes the connecting rod.

[0023] One or more embodiments effectively reduce deformation and promote stronger leadframe stability during pre-molding, saving space for additional pads.

[0024] One or more embodiments do not negatively impact package size and / or the number of available signal leads; multiple pads / soldering boards can be accommodated without design limitations. Attached Figure Description

[0025] One or more embodiments will now be described by way of example only with reference to the accompanying drawings, wherein:

[0026] Figure 1A and Figure 1B This is a perspective view of the lead frame according to an embodiment of this specification before pre-molding;

[0027] Figure 2A and Figure 2B This is a perspective view of the lead frame after pre-molding according to an embodiment of this specification;

[0028] Figure 3 It is along Figure 2B A magnified copy of the cross-sectional view of line II-II;

[0029] Figure 4 It essentially corresponds to the view showing the results of the etching steps. Figure 3 Cross-sectional view; and

[0030] Figure 5A and Figure 5B This is a perspective view of a semiconductor device to which the embodiments of this specification can be applied.

[0031] It should be understood that, for clarity and ease of understanding, various figures may not be drawn to the same scale. Detailed Implementation

[0032] In the following description, various specific details are shown to provide a thorough understanding of various examples of embodiments according to the description. Embodiments may be obtained without one or more specific details, or by utilizing other methods, components, materials, etc. In other instances, known structures, materials, or operations have not been detailed or described in such a way that various aspects of the embodiments are not obscured.

[0033] References to "embodiment" or "an embodiment" within the framework of this specification are intended to indicate that a particular configuration, structure, or feature described with respect to that embodiment is included in at least one embodiment. Therefore, phrases such as "in an embodiment," "in one embodiment," etc., which may appear at various points in this specification, do not necessarily refer precisely to one and the same embodiment. Furthermore, in one or more embodiments, particular conformations, structures, or features may be combined in any suitable manner.

[0034] The headings / references used herein are provided for convenience only and do not define the scope of protection or the scope of embodiments.

[0035] Furthermore, similar parts or components are represented by similar reference symbols throughout the drawings, and for the sake of brevity, the corresponding descriptions will not be repeated for each drawing.

[0036] The term leadframe (or lead frame) is currently used to refer to the metal frame that provides support for a semiconductor chip or die (see, for example, the USPC Generalized Glossary of Terms by the U.S. Patent and Trademark Office), as well as the electrical leads that couple the semiconductor chip or die to other electrical components or contacts.

[0037] Essentially, a leadframe comprises an array of conductive structures (leads) extending inward from a peripheral location along the direction of the semiconductor chip or die, thereby forming an array of conductive structures from die pads having at least one semiconductor chip or die attached thereto. This can be achieved using a die-attach adhesive (e.g., die-attach film or DAF).

[0038] Electrical coupling between the leads in the leadframe and the semiconductor chip or die can be achieved by wires forming a wire bonding pattern around the chip or die.

[0039] The leadframe and the semiconductor die (now also known as a semiconductor chip) mounted on it are one of the main components of the plastic package of a semiconductor device. It is made of conductive materials (such as metals like copper) and uses various interfacing materials: glue, tape, solder paste, etc., to configure and shape it to support the die attached to it.

[0040] Various types of semiconductor devices can benefit from the use of pre-molded leadframes. A pre-molded leadframe comprises a resin / plastic material surrounding metal leads and a die bonding pad on which a semiconductor chip or die can be attached; a molding compound (e.g., epoxy resin) is then molded onto the chip or die attached to the pre-molded leadframe.

[0041] Figure 1A and Figure 1B This is a perspective view of the "bare" lead frame 10 (before pre-molding). Figure 1A The image shows a view from the top or front (the side on which the semiconductor die is mounted). Figure 1B Views are shown from the bottom or the back.

[0042] like Figure 1A and Figure 1B As shown (by way of example only), leadframe 10 may include lead array 12 and at least one die pad 14 on which one (or more) semiconductor chip ICs (shown in dashed outline) may be mounted.

[0043] As illustrated by way of example in this document, lead frame 10 (for semiconductor devices such as electronic fuses – eFuse, or simply E-fuse) may include additional pads or pads 14', 14" that are configured to couple to (power) connections, such as so-called ribbons for semiconductor chip ICs (shown in dashed lines).

[0044] Those skilled in the art will readily understand that the description provided herein regarding die pad 14 also applies to pads or boards, such as 14' and / or 14".

[0045] The conventional technique used to produce leadframes (such as 10) is photolithography. A raw (e.g., copper) sheet in the form of a panel or roll is topped / bottomed with a resist that is developed through masking and etching. The exposed metal is etched away, and the resist is eventually removed. With this technique, leads 12 and pads / soldering plates 14, 14', and 14" can be formed simultaneously.

[0046] For example, as shown in the diagram, the semiconductor die of an integrated circuit (IC) is attached to a pad such as 14, and gold, silver, or copper wires (not visible in the diagram for simplicity) are provided during wire bonding to connect the die to the wires / pads. After wire bonding, the packaging / soldering step completes the packaging process.

[0047] In those types of semiconductor devices that use pre-molded lead frames, Figure 1A and Figure 1B The "bare" leadframe undergoes a pre-molding process, resulting in leadframe 10 becoming a pre-molded leadframe.

[0048] exist Figure 2A and Figure 2B This pre-molded lead frame can be seen in the image, wherein: Figure 2A The pre-molded lead frame 10 is shown as viewed from the top or front. Figure 2B The pre-molded leadframe 10 is shown as viewed from the bottom or rear. The pre-molded leadframe 10 is “fully filled” with a resin / plastic material 16 (e.g., epoxy resin), allowing it to penetrate into the space around the metal leads 12 and the pads or solder plates 14, 14', 14” (and cure therein).

[0049] Subsequently, a molding compound is molded onto the (pre-molded) leadframe 10, onto which the chip or die 14 is attached. For simplicity, such a molding compound (e.g., epoxy resin, different from or the same as the pre-molded resin 16) is... Figure 2A It is not visible in the middle, but in Figure 5A and Figure 5B The number 18 is indicated by a dashed line, as described below.

[0050] Generally speaking, the pre-molded leadframe technology discussed above is a conventional technology in the field, which makes it unnecessary to provide a more detailed description here.

[0051] During the manufacturing process of the pre-molded lead frame (and) Figure 1A and Figure 1B In comparison, see Figure 2A and Figure 2B The etched lead frame is completely filled with resin (e.g., 16), which penetrates into the empty spaces through the thickness of the bare lead frame, such as... Figure 1A and Figure 1B As shown.

[0052] As previously stated, the various structures (leads 12, pads or solder plates 14, 14', 14"), including die pads 14, should ideally maintain their positions to avoid displacement or deformation during lead frame formation and during pre-molded resin filling.

[0053] In one or more embodiments, a temporary (sacrificial) connection may be provided, such as Figure 1A , Figure 1B and Figure 2B The example is illustrated at point 100. As shown in the figure, these connectors can be provided, for example, between a solder plate or pad and another solder plate or pad, and between a solder plate or pad and a lead. At least in principle, lead-to-lead connections can also be considered.

[0054] In one or more embodiments, in order to produce Figure 1A and Figure 1B During the etching process of the “bare” lead frame 10, the connector 100 can be provided as a half-etched formation on the bottom or back of the lead frame.

[0055] As in Figure 3 As can be seen in the cross-sectional view, the connector 100 has two conductive portions partially etched in the lead frame 10 (in... Figure 3 In the case shown, the die pad 14 and the adjacent solder plate 14”) extend in a bridge manner, without extending to the entire depth or height of the lead frame 10.

[0056] That is, such as Figure 3 As shown (where the lead frame is shown from the bottom side upwards, i.e., viewed from its bottom side or back), a certain amount of pre-molded resin 16 remains on the top or front side of the connector 100 (basically a rod) and the lead frame. Figure 3 Between (the middle and the bottom).

[0057] In accordance with current language in the art, this document uses the term "semi-etched" to refer to a connector 100 that does not extend to the full depth or height (measured between opposing surfaces of the lead frame 10), but this does not mean that the connector 100 must have a thickness / height equal to or close to 50% of the thickness / height of the lead frame 10. Figure 1A and Figure 1B As shown, the leadframe is partially etched from (i.e., on) the top / front and bottom / rear sides. A resin / plastic material 16 filling the space around the metal leads 12 and pads or solder plates 14, 14', 14" respectively fills the partially etched openings extending from the top / front side and the partially etched openings extending from the bottom / rear side, and after curing will have a front surface coplanar with the top / front side of the leadframe and a rear surface coplanar with the bottom / rear side of the leadframe. See also Figure 2A and Figure 2B .

[0058] Depending on the application / process, the thickness / height of connector 100 can be selected to facilitate subsequent removal of connector 100 (e.g., Figure 3 The dashed line at SE is shown schematically.

[0059] like Figure 4 As shown, the removal (e.g., etching) of connector 100 results in the formation of a groove at the location where connector 100 is provided.

[0060] The removal of connector 100 may involve, for example, a (further) etching step of lead frame 10.

[0061] Such (selective) etching - as Figure 3 The SE shown in the figure can also be applied to the lead frame 10 for other purposes where there is no particular interest in the features of the embodiments discussed herein.

[0062] As discussed, connector 100 helps to keep the lead frame structure stronger and more robust during the formation of lead frame 10 (e.g., by etching) and during pre-molding, reducing the risk of unwanted deformation and displacement of the component.

[0063] By comparison Figure 3 and Figure 4 It is understandable that the removal of connector 100 re-establishes the adjacent conductive portions of the lead frame (such as...). Figure 3 and Figure 4 Electrical isolation between die pads 14 and solder plate 14” (shown in the figure), these conductive parts were previously connected by connector 100 (mechanical and electrical).

[0064] Figure 5A and Figure 5BThis is a perspective view of a semiconductor device 20 (electronic fuse – simply e-fuse), which includes a pre-molded lead frame 10 processed as described above. Specifically, Figure 5A The device 20 is shown as viewed from the top or front side. Figure 5B The device 20 is shown as viewed from the bottom or rear side.

[0065] As illustrated by example, leadframe 10 may include other pads or pads 14', 14'" configured to receive (power) connections, such as so-called clips or strips R coupled to a semiconductor chip IC (shown in dashed outline).

[0066] exist Figure 5A With the center surface facing upwards, molding compound 18 is molded onto a (pre-molded) lead frame 10, which has a chip IC and electrical contacts (bands) R disposed thereon on its top or front surface. The contour of molding compound 18 (e.g., epoxy resin, different from or the same as pre-molded resin 16) is... Figure 5A and Figure 5B The middle part is indicated by a dashed line.

[0067] Of course, referring to the electronic fuse as the semiconductor device 20 applicable to the embodiment is merely an example and not an interpretation in a limiting sense of the embodiment.

[0068] Figure 5B The bottom or rear-facing representation of the center lead frame 10 shows a possible "residue" 100' of the removal of the connector 100 retained in the final device 20.

[0069] exist Figure 5B The image illustrates residue 100' of two connectors between pads / solder plates 14 and 14'. It is also understood that such residue can exist anywhere (“semi-etched”) the connector 100 was originally present and subsequently removed.

[0070] These residues 100' may include recesses or grooves in the bottom or back surface of the lead frame 12 (and device 20), located at the sites where the connectors 100 were initially provided and subsequently removed (e.g., "etched away") to provide electrical insulation between the conductive structures of the lead frame 10, for example... Figure 3 and Figure 4 14 and 14' in the middle.

[0071] Note that in some embodiments, the residue 100' may include recesses or grooves, which are subsequently filled at least partially by other materials such as electroplating.

[0072] In any case, the residues 100' still exist, and their presence can be detected in the final complete device as "proof" of the provision and subsequent removal of the connector 100, i.e., as evidence of the connector removal.

[0073] like Figure 4 As shown, the residue 100' may include mutually protruding portions of the conductive structure of the lead frame 10, such as 14 and 14', which were originally used as end abutments of the bridge structure of the connector 100.

[0074] Therefore, one or more embodiments effectively reduce unwanted deformation and displacement of the leadframe during leadframe formation (e.g., by etching) and pre-molding, while saving space for additional pads / soldering plates and signal leads, without particular limitations in design, facilitating the manufacture of smaller packages.

[0075] In summary, one or more embodiments may relate to a method of manufacturing a semiconductor device (e.g., 20), wherein the method includes: arranging at least one semiconductor chip (e.g., IC) onto at least one semiconductor chip mounting region (e.g., chip mounting pad 14) in a first (e.g., top or front) surface of a leadframe (e.g., 10), the leadframe including a pattern of conductive structures (e.g., leads 12 and pads / soldering plates 14, 14', 14") and having a second (e.g., bottom or back) surface opposite the first surface and a leadframe thickness between the first and second surfaces (i.e., measured in a direction perpendicular to the total plane of the leadframe).

[0076] The methods illustrated herein may include: forming (providing) at least one (sacrificial) connection structure (e.g., 100), in a pattern of said conductive structures, in a pair of conductive structures (e.g., see...). Figure 3 A bridge-like extension is formed between 14 and 14' in the at least one connection structure, wherein the at least one connection structure is formed at one of the first and second surfaces of the lead frame (e.g., between the first and second surfaces), and has a thickness less than the thickness of the lead frame between the first and second surfaces. Then, a filler of electrically insulating material (e.g., 16) is molded between the conductive structures in the pattern of the conductive structure, wherein the insulating material from the filler is molded (and thus penetrates) between the at least one connection structure and the other surface connection structure of the first and second surfaces (e.g., the second surface) of the lead frame. Then, the connection is eliminated (see, for example, see...). Figure 3 The SE in the pattern of the conductive structure refers to the at least one (sacrificial) connection structure between the pair of conductive structures.

[0077] The methods illustrated herein may include forming at least one connection structure on a second (e.g., bottom or back) surface of the lead frame.

[0078] The methods illustrated herein may include forming or providing (e.g., by etching) at least one connection structure together with the conductive structure pattern in the lead frame.

[0079] The methods illustrated herein may include patterning the at least one connection structure and the conductive structure by etching a metallic material.

[0080] The methods illustrated herein may include forming (providing) at least one connection structure with a thickness approximately half the thickness of the lead frame between a first surface and a second surface.

[0081] As used in this article, the term “approximate” refers to technical features produced within the technical tolerances of the method used to manufacture it.

[0082] The leader frame (e.g., 10) illustrated herein is helpful to be provided as a component for the methods illustrated herein.

[0083] like Figure 1A and Figure 1B As shown, such a component can be provided as a "bare" (e.g., metal-only) leadframe having a first surface including at least one semiconductor chip mounting region (e.g., 14) and a second surface opposite the first surface, the leadframe having a leadframe thickness located between the first and second surfaces. The leadframe includes: a pattern of conductive structures (e.g., 12, 14, 14', 14"); and at least one connection structure (e.g., 100) bridging between a pair of conductive structures (e.g., 14, 14') in the pattern of conductive structures, wherein the at least one connection structure is located at one of the first and second surfaces of the leadframe (e.g., at both the first and second surfaces) and has a thickness less than the leadframe thickness between the first and second surfaces.

[0084] Advantageously, at least one connection structure may be located on the second surface of the lead frame (10).

[0085] Advantageously, at least one connection structure may have a thickness of approximately half the thickness of the lead frame between the first and second surfaces of the lead frame.

[0086] Here, the term "approximate" also refers to technical features produced within the technical tolerances of the manufacturing method.

[0087] like Figure 2A and Figure 2BAs illustrated, the components discussed herein can also be provided as “pre-molded” (e.g., metal plus pre-molded resin) lead frames, including fillers (e.g., 16) of electrically insulating material molded between conductive structures in the pattern of the conductive structures, wherein the electrically insulating material from the filler is molded between the first surface and the other surface (e.g., bottom or back surface) of the at least one connection structure and the lead frame (10).

[0088] Semiconductor devices as illustrated herein (see, for example, see...) Figure 5A and Figure 5B 20) may include: at least one semiconductor chip (e.g., IC) disposed on at least one semiconductor chip mounting region (e.g., 14) in a first (e.g., top or front) surface of a lead frame, the lead frame including a pattern of conductive structures and having a second surface opposite the first surface and a lead frame thickness between the first and second surfaces. The device also includes a filler (e.g., 16) of an electrically insulating material molded between the conductive structures in the pattern of the conductive structures. At least one groove (e.g., 100') is provided at one of the first and second surfaces of the lead frame (e.g., bottom or back surface), the at least one groove being a pair of conductive structures (e.g., see...) in the pattern of the conductive structures. Figure 4 The at least one groove (created by eliminating, for example, the connector of 100) extends in a bridge manner between the first and second surfaces, wherein the depth between the first and second surfaces is less than the thickness of the lead frame, and the pair of conductive structures in the pattern of the conductive structure are electrically insulated from each other at the groove.

[0089] In a semiconductor device as illustrated herein, at least one recess (e.g., 100') may be located on the second surface of the lead frame.

[0090] Without prejudice to the fundamental principles, details and embodiments may be changed, even significantly, relative to the description by way of example only, without departing from the scope of the embodiments.

[0091] The claims are an integral part of the technical disclosure provided herein in conjunction with the embodiments.

[0092] The scope of protection is determined by the appended claims.

Claims

1. A method comprising: A sheet is processed to form a lead frame, the sheet including a first surface, a second surface opposite to the first surface, and a lead frame thickness located between the first surface and the second surface, the lead frame including a semiconductor chip mounting area, a pattern of conductive structures, and at least one connection structure, the at least one connection structure extending in a bridge manner between a pair of conductive structures in the pattern of conductive structures; The at least one connection structure is located on one of the first surface and the second surface, and has a structural thickness less than the lead frame thickness; A filler of electrically insulating material is molded between conductive structures in the pattern of the conductive structure to form a pre-molded lead frame, wherein the electrically insulating material from the filler is present between the at least one connection structure and another of the first and second surfaces of the lead frame; as well as Eliminate at least one connection structure between the pair of conductive structures in the pattern of the conductive structure.

2. The method of claim 1, wherein processing the sheet comprises: Performing a first half-etch from the first surface of the sheet and a second half-etch from the second surface of the sheet to form the lead frame, wherein molding includes: filling the openings provided by the first half-etch and the second half-etch with the electrical insulating material, and curing the electrical insulating material filling the openings to form the pre-molded lead frame having a first surface coplanar with the first surface of the treated sheet and a second surface coplanar with the second surface of the treated sheet.

3. The method according to claim 1, further comprising: The semiconductor chip is mounted onto the semiconductor chip mounting area.

4. The method of claim 1, wherein the semiconductor chip mounting region is located on the first surface, and the at least one connection structure is located on the second surface.

5. The method according to claim 1, wherein the at least one connection structure is formed together with the pattern of the conductive structure in the lead frame.

6. The method of claim 1, wherein the processing comprises: The metal material of the sheet is etched to form patterns of the at least one connection structure and the conductive structure.

7. The method according to claim 1, wherein the thickness of the at least one connection structure is half the thickness of the lead frame.

8. A lead frame having a first surface and a second surface opposite to the first surface, and a lead frame thickness located between the first surface and the second surface, the lead frame comprising: The semiconductor chip mounting area is located on the first surface; Patterns of conductive structures; At least one connecting structure extends in a bridge manner between a pair of conductive structures in the pattern of the conductive structure; The at least one connection structure is located on one of the first and second surfaces of the lead frame, and has a structural thickness less than the thickness of the lead frame; as well as An electrically insulating filler is molded between conductive structures in a pattern of the conductive structure to form a pre-molded lead frame. The electrically insulating material from the filler is molded between the at least one connection structure and another surface of the first and second surfaces of the lead frame. The filler has a first surface coplanar with the first surface of the lead frame and a second surface coplanar with the second surface of the lead frame.

9. The lead frame according to claim 8, wherein the at least one connection structure is located on the second surface of the lead frame.

10. The lead frame according to claim 8, wherein the thickness of the at least one connecting structure is half the thickness of the lead frame.

11. The lead frame of claim 8, wherein the semiconductor chip mounting region, the pattern of the conductive structure, and the at least one connection structure are defined by a first half-etched opening extending from the first surface and a second half-etched opening extending from the second surface.

12. A semiconductor device, comprising: A lead frame has a first surface, a second surface opposite to the first surface, and a lead frame thickness located between the first surface and the second surface, and includes: a semiconductor chip mounting area located on the first surface; and a pattern of conductive structures; A first filler of electrical insulating material is molded between conductive structures in the pattern of the conductive structure to form a pre-molded lead frame; A semiconductor chip is mounted to the semiconductor chip mounting area; and At least one groove is located on one of the first and second surfaces of the lead frame, the at least one groove extending in a bridge manner between a pair of conductive structures in the pattern of the conductive structure; The at least one groove has a depth less than the lead frame thickness between the first surface and the second surface, and the pair of conductive structures in the pattern of the conductive structure are electrically insulated from each other at the groove.

13. The semiconductor device of claim 12, further comprising a second filler of electrically insulating material, the second filler of electrically insulating material being molded over the semiconductor chip and molded onto the first surface of the lead frame and the first filler.

14. The semiconductor device of claim 12, further comprising mutually protruding portions of the conductive structures at the recess, the mutually protruding portions forming end-to-end connections of at least one connection structure which would extend in a bridging manner between the pair of conductive structures in the pattern of the conductive structures.

15. The semiconductor device of claim 14, wherein the mutually protruding portions are located at one of the first and second surfaces of the lead frame and have a partial thickness less than the thickness of the lead frame.

16. The semiconductor device of claim 12, wherein the at least one recess is located on the second surface of the lead frame.

17. The semiconductor device of claim 12, wherein the first filler has a first surface coplanar with the first surface of the lead frame and a second surface coplanar with the second surface of the lead frame.

18. The semiconductor device of claim 12, wherein the pattern of the semiconductor chip mounting region and the conductive structure is defined by a first half-etched opening extending from the first surface and a second half-etched opening extending from the second surface, the first half-etched opening and the second half-etched opening being filled with the first filler.

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