GB2501571A

GB2501571A - LED circuit board

Info

Publication number: GB2501571A
Application number: GB1223413.4A
Authority: GB
Inventors: Yu-Tien Wang
Original assignee: Individual
Current assignee: Individual
Priority date: 2012-04-23
Filing date: 2012-12-27
Publication date: 2013-10-30
Also published as: FR2989828A3; GB201223413D0; KR20130006304U; TW201344976A; AU2013100167A4

Abstract

A method for manufacturing an LED circuit board with bowl like reflective cups12 includes the steps of combing a glass fiber layer 20 and a copper foil layer 25 to form a combining layer and attaching it to an upper surface of a copper substrate 10; drilling a plurality of penetrating holes 11 through the combining layer and the copper substrate; etching the copper foil; drilling the combining layer to form a plurality of cups; sandblasting; electroplating gold 30 to the copper foil layer of the combining layer for increasing electric conduction and heat dissipation; printing an insulating ink mask layer (or a paint) 40 on the upper surface of the gold layer; electroplating a plurality of metal joints 50 on the ink layer portions as electric joints; and removing parts of the insulating ink layer so as to expose the gold layer and baking the structure.

Description

METHOD FOR MANUFACTURING LED CIRCUIT BOARD WITH

BOWL LIKE CUPS THEREIN AND THE DEVICE MANUFACTURED

FROM THE SAME

FIELD OF THE INVENTION

The present invention related to LED heat dissipation module, and in particular to a method for manufacturing LED circuit board with bowl like cups therein and a device manufactured from the same.

BACKGROUND OF THE INVENTION

Since the crisis of energy, power saving has become an important problem concurrent by modern people. LED lamps are effective in power saving and thus they are used to replace the conventional lamps. This is because the LED lamps have the advantages over the conventional lamps, including the advantages of low power consumption, long lifetime, tolerant in use, etc. Because of widely uss of LED lamp, demand for high power LED lamps is increased gradually, especially in street lamps, Generally, street lamps need high power. However, the higher the power of LED lamps, the more the heat being dissipated. Current technology cannot effectively resolve this power. As a result, the lifetime of the high power LED lamps is sufficient long to match current requirement. This problem is especially important with the increment of the number of LED dice in the LED lamp.

Therefore, there is an eager demand for a novel technology which can improve above mentioned problem.

SUMMARY OF THE INVENTION

Accordingly, the object of the present invention is to provide a method for manufacturing LED circuit board with bowl like cups therein, wherein CNC drilling is used to form holes in the copper substrate. A special knife with a flat bottom is used to form the cambered cups 12 in the copper substrate.

Then LED dice are placed in the cups. Then wire bonding technology is used to bond wire between the LED die and the metal joints. Then epoxy serves to seal the periphery of the LED die. The present invention has the advantages of being tolerable for transient maximum currents operating through a long time period; better heat dissipation effect, uniform illumination; high safety; etc. A gold layer is used to cover the copper foil so as to increase heat dissipation efficiency. Therefore, the present invention has solved the problem of heat dissipation of high power LED lamp.

To achieve above object, the present invention provides a method for manufacturing LED circuit board with bowl like cups therein includes the steps of: getting a copper substrate; combing a glass fiber layer and a copper foil layer to an upper surface of the copper substrate; drilling a plurality of penetrating holes on the combining layer; etching the for forming conductive circuit; drilling the first combining layer to form a plurality of cups; sandblasting; electroplating gold to the upper surface of the copper foil layer of the first combining layer for increasing electric conduction and heat dissipation; printing an ink layer (or a paint) on the upper surface of the second combining layer as a third combining layer; electroplating a plurality of metal joints on the radiated ink portions as electric joints; remove parts of the insulating ink layer which is not radiated so as to expose the gold layer thereunder and baking the structure. The device manufactured from the method is also included.

BRIEF DESCRIPTION OF TIlE DRAWINGS:

Fig. I shows the process of the present invention.

Fig. 2 is a perspective view of the present invention.

Fig. 3 is front view of the present invention.

Fig. 4 is another process of the present invention.

Fig. 5 is a schematic view showing the small substrate and the LED dice according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

In order that those skilled in the art can further understand the present invention, a description will be provided in the following in details, Flowever, these descriptions and the appended drawings are only used to cause those skilled in the art to understand the objects, features, and characteristics of the present invention, but not to be used to confine the scope and spirit of the present invention defined in the appended claims.

With reference to Fig. 1, the LED circuit board of the present invention is made according to the following steps of: (1) Getting a copper substrate; (2) Combing a glass fiber layer and a copper foil layer to an upper surface of the copper substrate to form as a first combining layer; the copper foil layer being glued to the glass fiber layer; the glass fiber layer being as an insulating layer and being gluing to the copper substrate; (3) Drilling a plurality of penetrating holes on the combining layer; (4) Coating a layer of dry film to an upper surface of the first combining layer; (5) Performing etching process, i.e., developing the second combining layer to remove some parts of dry film and then etching the copper foil not covered by the dry film (6) Removing other dry film in previous step and the copper foil not etched is used as conductive circuit and for dissipating heat from LEDs; (7) Drilling the first combining layer by CNC so as to form a plurality of cups on the upper surface of the first combining layer for installing LET) dice; wherein the cups do not penetrate through the first combining layer; (8) Sandblasting the upper surface of the first combining layer for coarsening and flattening the surface of the first combining layer; (9) Electroplating gold to the upper surface of the copper foil layer of the first combining layer for increasing electric conduction and heat dissipation and also beneficial for the succeeding bonding operation; the structure combining the first combining layer and the gold is as a second combining layer; (10) Cleaning dirt or acid material on a surface of the first combining layer; (ii) Printing an ink layer (or a paint which is insulated) on the upper surface of the second combining layer; this structure is now as a third combining layer; (12) Locating a negative (as an optical mask) above the ink layer; (13) Using an exposure machine to emit ultraviolet ray to pass through the transparent portions of the negative; and then the ultraviolet ray passing through the negative will radiate portions of the ink layer under the transparent portions so that the radiated ink portions are completely attached to the copper foil; (14) Removing the negative; (15) Electroplating a plurality of metal joints on the radiated ink portions as electric joints or for succeeding bonding operation; (16) Passing the insulating ink layer through developer and potassium carbonate is sprayed upon the insulating ink layer to remove part of the insulating ink layer which is not radiated by ultraviolet ray to expose the gold layer thereunder.

(17) Backing the third combining layer; (18) Dividing the third combing layer into a plurality of small substrate; However, in the present invention, before electroplating gold to the upper surface of the copper foil, nickel can be plated upon the upper surface of the copper foil and then the gold is electroplated on the nickel.

With reference to Figs. 2 and 3, the structure of the present invention will be described herein.

A copper substrate 10; A glass fiber layer 20 and copper foil layer 25 is installed on the copper substrate 10 so as to form as a first combining layer 15. The copper foil layer is glued to the glass fiber layer; and the glass fiber layer being as an insulating layer and is glued to the copper substrate. A plurality of penetrating holes 11 are formed on the first combining layer 1 5 by CNC drilling. A plurality of non-penetrating cups 12 are formed on the first combining layer 15 by CNC drilling for installing LED dice 60 therein. The copper foil layer 25 is etched to leave only some parts of the copper foil as conductive wires in the circuit board.

A gold plating layer 30 is formed on the copper foil layer 25 for increasing heat conductivity and heat dissipation and the gold plating layer 30 is beneficial to succeeding bonding work. The combination of the first combining layer and the gold plating layer 30 is used as a second combining layer.

An insulating ink layer 40 is plated on the upper surface of the second combining layer so as to form as a third combining layer. Some parts of the insulating ink layer 40 is etched to expose internal gold plating layer 30.

Some parts of the insulating ink layer 40 are plated with metal as metal joints.

In manufacturing process, a negative (of a photo) is placed upon the insulating ink layer 40. Then overall structure is moved to be under an exposure unit for radiating with ultraviolet rays. The ultraviolet ray will pass through some transparent areas in the negative to the insulating ink layer under the negative so that the parts of the insulating ink layer 40 radiated by ultraviolet rays are completely attached to the gold plating layer 30.

Then the insulating ink layer 40 passes through developer (not shown) and potassium carbonate is sprayed upon the insulating ink layer 40 to remove part of the insulating ink layer 40 which is not radiated by ultraviolet ray to expose the gold plating layer 30 thereunder.

A plurality of gold joints 50 are plated on the insulating ink layer 40 which are used as joints or used for bonding.

After the dividing operation, a second stage operation is performed. In that, the small substrate is combined with LED dice. Referring to Fig. 5, it illustrates the combination process of the small substrate with LED die. The process includes the following steps: (1) Preparing LED die 60; (2) Adding silver glue to a cup of the small substrate by a dispensing robot dispenser; (3) Fixing the LED die in position by a die bonding machine; (4) Baking the small substrate; (5) Bonding wires to the metal joints so that the joints are conductive; (6) Performing electric current impact testing; (7) Filling epoxy to a periphery of the LED die; (7) Baking the small substrate through eight hours under a temperature about 120 degree C. With reference to Fig. 5, by above mentioned process, the LED dice 60 are placed in the cups of the small substrate. The positive and negative electrodes of the LED dice 60 are wire-bonding to the metal joints 50.

Epoxy 70 is used to seal the periphery of the LED die.

In the present invention, CNC drilling is used to form holes in the copper substrate. A special knife with a flat bottom is used to form the cambered cups 12 in the copper substrate. Then Led dice 60 are placed in the cups 12.

Then wire bonding technology is used to bond wire between the LED die 60 and the metal joints 50. Then epoxy serves to seal the periphery of the LED die. The present invention has the advantages of being tolerable for transient maximum currents within a long time period; better heat dissipation effect, uniform illununation; high safety; etc. A gold layer is used to cover the copper foil so as to increase heat dissipation efficiency. Therefore, the present invention has solved the problem of heat dissipation of high power LED lamp.

The present invention is thus described, it will be obvious that the same may be varied in many ways. Such variations are not to he regarded as a departure from the spirit and scope of the present invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.

Claims

WHAT IS CLAIMED IS: 1. A method for manufacturing LED circuit board with bowl like cups therein, comprising: getting a copper substrate; combing a glass fiber layer and a copper foil layer to an upper surface of the copper substrate to form as a first combining layer; the copper foil layr being glued to the glass fiber layer; the glass fiber layer being as an insulating layer and being gluing to the copper substrate; drilling a plurality of penetrating holes on the combining layer; etching some parts of copper foil; and the copper foil not etched being used as conductive circuit and for dissipating heat from LEDs; drilling the first combining layer by CNC so as to form a plurality of cups on the upper surface of the first combining layer for installing LED dice; the cups do not penetrate through the first combining layer; sandblasting the upper surface of the first combining layer for coarsening and flattening the upper surface of the first combining layer; plating gold to the upper surface of the copper foil layer of the first combining layer for increasing electric conduction and heat dissipation; the structure combining the first combining layer and the gold being as a second combining layer; cleaning dirt or acid material on a surface of the first combining layer; printing an ink layer (or a paint) on the upper surface of the second combining layer as a third combining layer; radiating some part of ink portions so that these parts of ink portions being attached to the copper foil; plating a plurality of metal joints on the radiated ink portions as electric joints; remove parts of the insulating ink layer which is not radiated to expose the gold layer thereunder, and backing the third combining layer.
2. The method for manufacturing LED circuit board with bowl like cups therein as claimed in claim 1, wherein a knife with a flat bottom is used to form the cambered cups.
3. The method for manufacturing LED circuit board with bowl like cups therein as claimed in claim 1, wherein the step of etching some parts of copper foil, ii eluding the steps of: coating a layer of dry film to an upper surface of the first combining layer; performing etching process, i.e., developing the second combining layer to remove a part of dry film and then etching the copper foil not covered by the dry film; and removing other dry film in previous step and the copper foil not etched being used as conductive circuit and for dissipating heat from LEDs.
4. The method for manufacturing LED circuit board with bowl like cups therein as claimed in claim 3, wherein the step of radiating some parts of ink portions comprising the steps of: locating a negative (as an optical mask) above the ink layer; and using an exposure machine to emit ultraviolet ray to pass through the transparent portions of the negative; and then the ultraviolet ray passing through the negative will radiate portions of the ink layer under the transparent portions so that the radiated ink portions are completely attached to the copper foil;
5. The method for manufacturing LED circuit board with bowl like cups therein as claimed in claim 4, wherein the step of electroplating a plurality of metal joints comprising the steps of: removing the negative; plating a plurality of metal joints on the radiated ink portions as electric joints or for succeeding bonding operation.
6. The method for manufacturing LED circuit board with bowl like cups therein as claimed in claim 5, wherein the step of removing parts of the insulating ink layer comprising the steps of: passing the insulating ink layer through developer and potassium carbonate is sprayed upon the insulating ink layer to remove part of the insulating ink layer which is not radiated by ultraviolet ray to expose the gold layer thereunder.
7. The method for manufacturing LED circuit board with howl like cups therein as claimed in claim 1, wherein dividing the third combing layer into a plurality of small substrate.
8. The method for manufacturing LED circuit board with bowl like cups therein as claimed in claim 1, wherein before electroplating gold to the upper surface of the copper foil, rnckel is plated upon the upper surface of the copper foil and then the gold is electroplated on the nickel.
9. The method for manufacturing LED circuit board with bowl like cups as claimed in claim 7, wherein after dividing the third combing layer into a plurality of small substrate; further comprising the step of preparing LED die; adding silver glue to a cup of the small substrate by a dispensing robot dispenser; fixing the LED die in the cup by a die bonding machine; baking the small substrate; bonding wires to the metal joints so that the joints are conductive; performing current impact testing; filling epoxy to a periphery of the LED die; and baking the small substrate through eight hours under a temperature about degree C.
10. An LED circuit board with bowl like cups therein, comprising: a copper substrate; a glass fiber layer and a copper foil layer installed on the copper substrate so as to form as a first combining layer; the copper foil layer being glued to the glass fiber layer; and the glass fiber layer being as an insulating layer and being glued to the copper substrate; a plurality of penetrating holes being formed on the first combining layer; a plurality of non-penetrating cups being formed on the first combining layer for installing LED dice therein; the copper foil layer being etched to leave only some parts of the copper foil as conductive wires in the circuit board; a gold plating layer being formed on the copper foil layer for increasing heat conductivity and heat dissipation; and the combination of the first combining layer and the gold plating layer being a second combining layer; an insulating ink layer being plated on the upper surface of the second combining layer so as to form as a third combining layer; some parts of the insulating ink layer being etched to expose internal gold plating layer; and some parts of the insulating ink layer being plated with metal as metal joints; and a plurality of gold joints on the insulating ink layer which are ased as joints or used for bonding work.
11. The LED circuit board with bowl like cups therein as claimed in claim 10, wherein a nickel layer is plated upon the upper surface of the copper foil and is under the gold layer.
12. The LED circuit board with bowl like cups therein as claimed in claim 10, wherein in manufacturing process, a negative (of a photo) is placed upon the insulating ink layer; then overall structure is moved to be under an exposure unit for radiating with ultraviolet rays; the ultraviolet ray will pass through some transparent areas in the negative to the insulating ink layer under the negative so that the parts of the insulating ink layer radiated by ultraviolet rays are completely attached to the gold plating layer; then the insulating ink layer passes through developer and potassium carbonate is sprayed upon the insulating ink layer to remove part of the insulating ink layer which is not radiated by ultraviolet ray to expose the gold plating layer thereunder.
13. A method of manufacturing an LED circuit board substantially as hereinbefore described with reference to the accompanying drawings.
14. An LED circuit board manufactured by the method claimed in Claim 13.