CN210073768U

CN210073768U - Precise metal support structure

Info

Publication number: CN210073768U
Application number: CN201921253230.3U
Authority: CN
Inventors: 李国华
Original assignee: Hongjie Industry Co Ltd
Current assignee: Hongjie Industry Co Ltd
Priority date: 2019-08-05
Filing date: 2019-08-05
Publication date: 2020-02-14
Anticipated expiration: 2029-08-05

Abstract

The utility model relates to an accurate metal support structure, it can regard as emitting diode support or wafer lead frame, mainly includes: the lead frame comprises an insulation sheet, a metal foil and an insulation layer, wherein at least one opening is formed on the insulation sheet, the first surface of the metal foil and the insulation sheet are bonded and fixed through an adhesive layer, the metal foil positioned at the opening forms a first joint, in addition, the second surface of the metal foil forms at least one lead and at least one second joint formed on partial leads in an etching mode, the insulation layer is formed on the second surface of the metal foil, and the second joint on the at least one lead exposes the insulation layer, so that the traditional stamping mode is replaced by the etching of the insulation sheet and the metal foil to form the lead frame or the LED metal support. Besides, the occurrence of errors in subsequent processing of the lead frame or the LED metal bracket can be reduced, and the cost for developing a precise mold of the lead frame or the LED metal bracket can be saved.

Description

Precise metal support structure

Technical Field

The utility model relates to a supporting structure indicates an accurate metal support structure especially.

Background

In the conventional semiconductor chip package, the chip is first fixed at a predetermined position of the lead frame, and then gold wire bonding is performed to electrically connect the chip IO and the inner lead circuit. After the gold wires are bonded, resin is used for forming a packaging body on the chip and the lead frame, the packaging body packages the chip and the inner pin circuit of the lead frame inside, and only the outer pin circuit is exposed outside. After the barrier bars (Dam bar) and Tie bars (Tie bar) are cut, the packaged semiconductor device is preliminarily formed. Then, the finished product can be delivered from the factory after the processes of electroplating, shearing, forming, detecting and the like.

Similarly, the package of the led die has a similar process. The conventional side-type LED package structure mainly includes a rubber base and an LED metal frame. The LED metal support is made of a copper strip through stamping, the LED metal support is subjected to electroplating treatment, and the silver material is electroplated on the surface of the LED metal support to form an electroplated layer. And then placing the electroplated LED metal support on a male mold and a female mold, and forming the rubber base on the LED metal support by utilizing hot pressing or injection molding. The rubber base is provided with a hollow functional area for exposing the LED metal support, and the hollow functional area can be used for die bonding and routing. And injecting colloid into the hollow functional area after routing, thereby completing the packaging process of the lateral light-emitting diode.

Both the lead frame and the LED metal bracket generally need to be punched through a die, and the related punching die has high technical threshold and high cost; if the etching technique is used, there is a high possibility of under-etching or over-etching during the etching process, resulting in poor yield after packaging. In addition, problems such as pin deviation, tape overflow, peeling, missing cutting of the cut pin, and plating deviation are easily generated in the electroplating and subsequent processes.

For the above process problems of the conventional lead frame and LED metal frame, the packaging industry needs an innovative precise metal frame structure and its manufacturing method.

SUMMERY OF THE UTILITY MODEL

The utility model solves the technical problem that: the insulating sheet and the metal foil are etched to replace the traditional stamping method to form the lead frame or the LED metal bracket. Besides, the occurrence of errors in subsequent processing of the lead frame or the LED metal bracket can be reduced, and the cost for developing a precise mold of the lead frame or the LED metal bracket can be saved.

The technical means adopted by the utility model are as follows.

To achieve the above object, the present invention provides an accurate metal support structure. The precise metal support structure can be used as a light-emitting diode support or a wafer lead frame, and an insulating sheet, wherein at least one opening is formed on the insulating sheet; a metal foil, the first surface of the metal foil and the insulation sheet are pressed and adhered by an adhesive layer, the metal foil positioned at the opening forms a first joint, wherein the second surface of the metal foil forms at least one lead and at least one second joint formed on part of the lead in an etching way; and an insulating layer formed on the second surface of the metal foil, wherein the second contact on the at least one conductive line is exposed from the insulating layer.

According to an embodiment of the present invention, the insulating sheet is a PI film or a metal-free substrate.

According to an embodiment of the present invention, the metal-foil-free substrate (at least one side of which is attached with an adhesive layer) is an FR-4 substrate or an FR-5 substrate.

According to an embodiment of the present invention, the thickness of the insulation sheet is between 3 μm and 1 mm.

According to an embodiment of the present invention, the adhesive layer is a silicone adhesive, an Acrylic adhesive or an Epoxy adhesive.

According to an embodiment of the present invention, the opening on the insulation sheet is formed by punching, mechanical drilling or laser drilling.

According to an embodiment of the invention, wherein the maximum thickness of the metal foil is not more than 140 μm.

According to an embodiment of the present invention, the insulating layer exposes the second contact by photolithography process.

According to an embodiment of the present invention, the insulating layer is Solder resist (Solder Mask), silicone, Acrylic glue, or Epoxy glue.

The utility model discloses produced technological effect as follows: besides, the occurrence of errors in subsequent processing of the lead frame or the LED metal bracket can be reduced, and the cost for developing a precise mold of the lead frame or the LED metal bracket can be saved.

Drawings

Fig. 1 is a perspective view of a preferred embodiment of the present invention.

FIG. 2 is a cross-sectional view of a first structure of FIG. 1, taken along line A-A.

Fig. 3 is a schematic cross-sectional view of a second manufacturing structure according to a preferred embodiment of the present invention.

Fig. 4 is a schematic cross-sectional view of a third manufacturing structure according to a preferred embodiment of the present invention.

Fig. 5 is a schematic cross-sectional view of a fourth manufacturing structure according to a preferred embodiment of the present invention.

Fig. 6 is a schematic cross-sectional view of a fifth manufacturing structure according to a preferred embodiment of the present invention.

Fig. 7 is a schematic top view of the etched copper foil structure of the present invention.

Fig. 8 is a schematic top view of another copper foil etched structure according to the present invention.

FIG. 9 is a schematic top view of another fifth exemplary fabrication structure of the present invention.

Description of the figure numbers:

precision metal support structure … … 1

Insulating sheet … … … … … … … 10

Opening … … … … … … … … 100

Adhesive layer … … … … … … … 102

Metal foil … … … … … … … 12

First surface … … … … … … 120

Second surface … … … … … … 122

First contact … … … … … … 124

Lead … … … … … … … … 126

Second contact … … … … … … 128

Insulating layer … … … … … … … 14.

Detailed Description

Please refer to fig. 1 and fig. 2, which are a schematic perspective view of a preferred embodiment of the present invention and a schematic sectional view of a first manufacturing structure of the partial sectional line a-a structure of fig. 1. Fig. 3, fig. 4, fig. 5 and fig. 6 are also shown, which are a schematic cross-sectional view of a second manufacturing structure, a schematic cross-sectional view of a third manufacturing structure, a schematic cross-sectional view of a fourth manufacturing structure and a schematic cross-sectional view of a fifth manufacturing structure according to a preferred embodiment of the present invention. The utility model relates to a precise metal support structure, which can be used as a light emitting diode support or a wafer lead frame, the precise metal support structure 1 mainly comprises an insulation sheet 10, a metal foil 12 and an insulation layer 14, wherein at least one opening 100 is formed on the insulation sheet 10, the metal foil 12 is defined with a first surface 120 and a second surface 122, the metal foil 12 is pressed and adhered and fixed by the first surface 120 and the insulation sheet 10 through an adhesion layer 102, the metal foil 12 forms a first joint 124 through a copper plating way corresponding to the opening 100, meanwhile, the second surface 122 also forms a copper thickness due to the copper plating relation, at least one wire 126 and at least one second joint 128 formed on part of the wire 126 are formed on the second surface 122 of the metal foil 12 in an etching way, and the insulation layer 14 (Solder resist, Solder Mask, silica gel, Acrylic resin glue or Epoxy resin glue)) is formed on the second surface 122 of the metal foil 12, the second contact 128 of the at least one conductive line 126 is exposed from the insulating layer 14.

The specific manufacturing method of the precise metal bracket structure 1 is as follows, firstly providing the insulating sheet 10 and the metal foil 12, wherein the insulating sheet 10 has two types: a PI film (polyimide) or a metal foil-free substrate (which may be an FR-4 substrate or an FR-5 substrate). In the present embodiment, the insulating sheet 10 is a PI film, and the thickness of the PI film or the metal-free substrate is between 3 μm and 1 mm. The metal Foil 12 is made of a Copper Foil material, which is a common material for manufacturing flexible printed circuits, and can be generally classified into Rolled aluminum Foil (mechanical Copper Foil) and electrolytic Copper Foil (electrolytic Copper Foil), the former has better mechanical properties and is suitable for devices with flexibility requirements, but it should be noted that the Copper Foil itself is used as a transmission body of electrical signals, so the Copper Foil needs to be a complete and unprocessed piece. The thickness of the copper foil has various specifications, and in practice, the thickness of the copper foil should be not more than 140 μm in consideration of workability. That is, the thickness remaining after etching the copper foil does not exceed 140 μm at the end.

Since a piece of PI film can be used to fabricate many precise metal supporting structures 1, the openings 11 can be classified into different precise metal supporting structures 1, if the precise metal supporting structure 1 is larger, a piece of PI film can also be used to fabricate only one precise metal supporting structure 1, and the openings 100 thereon can be used to form different first contacts 124. For convenience of explanation, the following description will be made with reference to a partial structure along the line A-A in FIG. 1. It should be noted that the opening 100 on the insulation sheet 10 is formed by punching, machine drilling or laser drilling.

During manufacturing, a plurality of openings 100 are formed on the insulating sheet 10(PI film), the positions of the openings 100 correspond to the positions of the metal foil 12 (copper foil) to be laminated, and they are the positions of the first contacts 124 to be formed, the first surface 120 of the metal foil 12 and the insulating sheet 10 are pressed, adhered and fixed through the adhesive layer 102 (which may be silica gel, Acrylic adhesive or Epoxy adhesive), and the PI film and the copper foil are adhered at high temperature and high pressure in the pressing and adhering process (refer to fig. 2). The metal foil 12 under each opening 100 is then copper plated to form a plurality of first contacts 124 at the openings 100, and the second surface 122 of the metal foil 12 is copper plated to increase the copper thickness. The first contact 124 may slightly protrude from the surface of the insulating sheet 10 or be lower than the surface of the insulating sheet 10 after the copper plating is completed, and the copper plating may be performed by electroless copper plating (thickened copper) or electrolytic copper plating (refer to fig. 3). Next, the second surface 122 of the insulating sheet 10 is etched to form a plurality of conductive lines 126 and second joints 128 (refer to fig. 4) on the conductive lines 126. The second surface 122 of the metal foil 12 is then filled with an insulating layer 14 (Solder resist, Solder Mask) (refer to fig. 5). Finally, the insulating layer 14 (Solder resist, Solder Mask, silicone, Acrylic or Epoxy) is subjected to a photolithography process (see fig. 5) to expose the second contacts 128 (different from the Solder resist) (see fig. 6).

It should be noted that, since the method of the present embodiment can be applied to form a single precise metal frame structure 1 or simultaneously form a plurality of precise metal frame structures 1, the precise metal frame structure 1 manufactured by cutting can be selectively performed to obtain independent unit bodies. For leadframe applications, each singulated unit is a separate leadframe to which a die may be attached.

Fig. 7 and 8 are a schematic top view of a copper foil etched structure and another schematic top view of a copper foil etched structure according to the present invention. The first contact 124 and the second contact 128 are formed in different ways, except for the location where they are formed. Note that, at this time, the insulating sheet 10 is partially thinned as a conductive structure, and is partially cut through even for forming different wires 126. Please refer to fig. 7 and 8 for an aspect of the etched insulation sheet 10. In the embodiment of fig. 7, the insulating sheet 10 is an integral body, and a plurality of first contacts 124 are formed on the first surface 120 and a plurality of second contacts 128 are formed on the second surface 122 (which cannot be seen directly, and are shown by dashed lines). In addition, the insulating sheet 10 also includes a plurality of holes 104 formed by etching process, and a single conductive line 126 is defined by the plurality of holes 104. This structure is suitable for use as a light emitting diode holder.

In the embodiment of fig. 8, the appearance of the insulating sheet 10 is etched into a plurality of conductive lines 126, and a portion of the conductive lines 126 have first contacts 124 on the first surface 120 or second contacts 128 on the second surface 122. This structure is suitable for use as a lead frame for a chip. Since the insulation sheet 10 is fixed by the PI film, the pin offset problem of the lead frame internal lead when the chip IO is combined is virtually reduced. In addition, compared with the conventional lead frame formed by stamping, the insulating sheet 10 formed by the method can be replaced, thereby saving the development cost of a precise die.

Fig. 9 is a schematic top view of another fifth manufacturing structure according to the present invention. Unlike the insulating layer 14 (Solder resist Mask) of fig. 6, in which the second contact 128 is exposed by photolithography, the insulating layer 14 is made of silicon, for example, in order to expose the second contact 128, the second contact 128 is polished to be coplanar with the insulating layer 14, and the insulating layer 14 is also thinned during polishing.

Claims

1. A precision metal support structure, which is used as a light emitting diode support or a chip lead frame, comprises:

an insulating sheet having at least one opening formed therein;

a metal foil, the first surface of the metal foil and the insulation sheet are pressed and adhered by an adhesive layer, the metal foil positioned at the opening forms a first joint, wherein the second surface of the metal foil forms at least one lead and at least one second joint formed on part of the lead in an etching way; and

an insulating layer formed on the second surface of the metal foil, wherein the second contact on the at least one conductive line is exposed from the insulating layer.

2. The precise metal standoff structure of claim 1 wherein the insulating sheet is a PI film or a metal-foil-free substrate.

3. The precise metal bracket structure of claim 2, wherein the metal-foil-free substrate with at least one adhesive layer is an FR-4 substrate or an FR-5 substrate.

4. The precise metal standoff structure of claim 1 wherein the insulating sheet has a thickness of between 3 μm and 1 mm.

5. The precision metal standoff structure of claim 1 wherein said adhesion layer is a silicone, Acrylic or Epoxy glue.

6. The precise metal support structure of claim 1, wherein the opening in the insulating sheet is formed by stamping, mechanical drilling, or laser drilling.

7. The precision metal standoff structure of claim 1 wherein the metal foil has a maximum thickness of no greater than 140 μm.

8. The precision metal standoff structure of claim 1 wherein said insulating layer exposes said second contact by a photolithographic process.

9. The precision metal standoff structure of claim 1 wherein the insulating layer is a solder resist, a silicone gel, an Acrylic gel, or an Epoxy gel.