TWI447972B - LED chip and LED chip and chip manufacturing methods - Google Patents

Description

LED chip and LED chip and chip manufacturing method

The invention belongs to the technical field of LEDs, and particularly relates to a package structure for heat conduction in an LED chip and a wafer structure for realizing a low heat resistance chip.

Heat dissipation has become a key issue in the development of high-power LEDs. LED heat dissipation can be divided into two major processes: internal heat transfer heat transfer process and external air convection heat transfer process. The thermal conduction heat transfer resistance of the currently disclosed LED chip accounts for a very large proportion of the entire heat transfer resistance. Among the current products, the lowest thermal resistance is also 6 ° C / W, if coupled with insulation on the aluminum substrate The layer thermal resistance should be as small as 10 °C/W.

The heat transfer process in the LED chip is not complicated, but the knowledge of heat transfer and mature heat transfer technology, as well as other basic knowledge related to heat transfer, are not fully understood by the LED industry, thus causing current LED heat dissipation technology and Products are complicated and in their infancy. In addition, the currently disclosed LED chip package structure is developed along the previous small power LED chip and the traditional electronic chip packaging idea, not only the internal heat transfer heat transfer resistance is as high as the above mentioned number, but also the package efficiency is low, and the packaging equipment is expensive. The packaging cost is high, and it is difficult to realize the integrated packaging of the optical module.

The object of the invention is to solve the problem of the LED chip package structure, and propose a new structure, which not only effectively reduces the internal heat conduction thermal resistance problem, but also helps to improve the packaging efficiency and reduce the packaging cost, and is particularly useful for realizing the integrated module of the optical module.

The LED chip of the present invention mainly comprises one or more wafers, a positioning piece and a heat diffusion member. A wafer insert is formed in the positioning sheet to enable the wafer to be embedded in the insert. The wafer and the positioning piece are attached to one side of the heat diffusion member, and the surface is referred to as the A surface of the heat diffusion member. The positioning piece is made of an insulating material, and the positioning piece is provided with a circuit and a lead pad. The electrode pad on the front side of the wafer (the side on which the light is emitted) or the electrode pad on the side wall and the corresponding lead pad on the positioning piece are connected by wire bonding, solder bonding, and conductive bonding. . A solder or adhesive connection is used between the wafer and the A surface of the thermal diffusion member, and the thermal diffusion member is made of a copper material or an aluminum material, or a copper-aluminum composite material.

The greatest innovation of the present invention is the use of a wafer locating sheet on which the circuit and lead pads are placed, and the wafer is embedded in the wafer insert on the locating member. The thickness of the locating tab is designed to be uniform with the thickness of the wafer so that the wafer is on the front side. The method of conducting the connection between the electrode pad and the lead pad on the positioning piece can be performed not only by the wire bonding method (such as the gold ball bonding method) which is currently used, but also by the solder bonding method and the conductive bonding method. Specific measures Shi: the electrode pad on the wafer is placed against the edge, and the corresponding lead pad on the positioning piece is abutted, and the solder (solder paste) or the conductive paste can be placed on the two pads by a printing method, and then heated and melted. Or curing to achieve two-pad conduction. The multiple chips can be put together, one time missing, and the other is heated and welded (or cured), which is high in production efficiency and low in cost, and saves expensive gold ball welding equipment and gold wire. The positioning piece adopts an insulating sheet (film) material, and the die insert is processed by a punching process, and the efficiency is high and the precision is high, and the current printed circuit process can be used to lay the circuit and the lead pad.

For a chip of a flip-chip structure, and a chip whose wafer substrate is a conductor (such as a chip of a tantalum carbide substrate), an electrode pad may be disposed on a sidewall of the wafer (a sidewall of the substrate), which may be soldered or electrically conductive. The glue bonding method connects the electrode pads on the wafer to the lead pads on the positioning tab.

A circuit is arranged on the positioning piece, and the external chip pin of the chip or the external power supply line is connected to the lead pad through the circuit on the positioning piece. The advantage of adopting such a structure is that it is convenient to install a plurality of wafers on one heat diffusion member to form a high-power optical module chip, and the series or parallel connection between the LED chips is realized by connecting the circuits on the positioning sheet. The auxiliary electronic components (such as anti-static components) required for the LED chip can also be placed on the positioning piece, and even a structure similar to the LED chip embedded in the positioning piece can be used, and the auxiliary electronic component (or even the chip of the auxiliary electronic component) can be embedded in the positioning. sheet Among them, the same welding or conductive adhesive bonding method can be used. The structure in which the wafer is embedded in the positioning piece facilitates wafer positioning and alignment, facilitates mass production, and improves efficiency. It is also described in the subsequent embodiments.

Although the heat diffusion member of the present invention is similar to the heat transfer process of the heat sink of the present product, the present invention clearly emphasizes its most important role for the first time, one for thermal diffusion, and thus is called a heat diffusion member, which is common in the LED industry today. The concept of thermal diffusion and its importance are not known. Due to the high thermal conductivity and low price of copper and aluminum, it is preferred to make a thermal diffusion member from a copper material or an aluminum material or a copper-aluminum composite material. LED chip packages must also consider electrical insulation issues, and insulation and thermal conduction are contradictory, especially for high voltage insulation.

The area of the LED chip is small. Taking a wafer of 1×1 mm size as an example, even if the power consumption is ^1.2 W, the heat flux density is as high as 10 ⁶ W/m ² , which is very high. It is very important to reduce the heat flux density. In today's products to solve the problem of electrical insulation, ceramic sheets are commonly used as heat sinks. For cost reasons, Al ₂ O ₃ ceramics are generally used, and the thermal conductivity of Al ₂ O ₃ ceramics is 20 W/m. Around K, the LED wafer is directly placed on the ceramic sheet. If the thickness of the ceramic sheet is 0.2 mm, the thermal conduction temperature difference on the ceramic sheet is 10 °C. In the present invention, the wafer is directly disposed on a heat diffusion member (A surface) made of a copper or aluminum or copper-aluminum composite material, which reduces the heat conduction process between the wafer and the heat diffusion sheet due to the thermal conductivity of copper or aluminum. The high and high heat flux density passes through the heat diffusion member, and the heat flux density is lowered. The insulating layer for solving the problem of electrical insulation (mainly high voltage insulation) can be disposed on the side where the heat diffusion member and the heat sink are in contact with heat transfer (referred to as heat). B side of the diffuser). If the heat flux density is reduced by a factor of five, and a 0.2 mm thick Al ₂ O ₃ ceramic sheet is also used as the insulating layer, the thermal conduction temperature difference on the insulating layer can be lowered to 2 ° C.

As a heat diffusion member, the heat diffusion member should not only use a material with high thermal conductivity, but also have a large enough area and thickness. If the wafer is 1×1 mm, 1 W, the thickness of the heat diffusion member should be 1.0 mm or more, and the area should be greater than 5 mm ² . Its purpose and function is to effectively diffuse heat in the heat diffusion member and reduce the heat flow density.

Preferably, the wafer is directly soldered to the thermal diffusion member because the heat transfer density at the junction of the wafer and the thermal diffusion member is the highest, and the thermal conductivity of the bonding surface material (solder or adhesive) is as high as possible, and the thermal conductivity of the metallic material is high, such as The thermal conductivity of tin is 60W/m. K, much higher than the thermal adhesive (such as silver glue) several times.

In the LED chip of the present invention shown in FIG. 1, the wafer 3 is embedded in the wafer insert in the positioning piece 6, and the wafer 3 and the positioning piece 6 are attached together on the A side of the heat diffusion member 7; the front surface of the wafer and the surface of the positioning piece are provided with a die-bonding protective layer 5; the electrode pad 2 on the wafer is in close contact with the lead pad 1 on the positioning piece, and the conductive connection between the two pads is performed by an ultrasonic ball process, and the wires 4 (gold wire or aluminum wire) are both ends Stand up from the surface of the pad. Since the wire diameter is thin and the strength is low, the die-bonding protective layer 5 on the front side of the wafer should be set by a dispensing process. As shown in the figure, the thickness of the die-bonding protective layer 5 is not uniform.

In the LED chip of the present invention shown in FIG. 2, the wires 4 are flatly attached to the two pads and soldered by a pressure welding process. Since the wires are lying flat and the strength is relatively high, the solid crystal protective layer 5 can be set by a casting process. The thickness of the die bond layer is uniform, as shown in the figure.

In the LED chip of the present invention shown in FIG. 3, the distance between the electrode pad 2 on the wafer 3 and the lead pad 1 on the positioning piece 6 is closer, and the conduction connection between the electrodes 3 can be directly soldered and turned on by solder (such as tin). Or conductive bonding with conductive adhesive. The conductive crystal protective layer 5 can be provided by an adhesive film (or patch) method and a printing (slip printing) method without wires and by solder (or conductive paste).

In the LED chip of the present invention shown in FIG. 4, one electrode pad 2 on the wafer is disposed on the sidewall of the wafer 3, and the other electrode pad 2 is disposed on the front surface of the wafer 3. A wafer in which the substrate is an electrical conductor such as a tantalum carbide substrate is suitable for such a design.

Also shown in Fig. 4, a low-voltage insulating layer 9 is provided on the A side of the heat diffusion member 7, since the wafer 3 is directly attached (welded or bonded) to the low-voltage insulating layer 9, the heat flux density is very high, and the heat conduction of the low-voltage insulating layer 9 The thermal resistance must be low, but the thermal conductivity of the insulating material is low, so the thickness of the insulating layer should be thin, so that the dielectric strength withstand voltage is low, so it is called a low-voltage insulating layer.

Ceramic insulating film formed by vapor deposition, such as diamond, SiC, AlN, BN, BeO, Al ₂ O ₃ and other ceramic films, compact, good insulation, high thermal conductivity, especially diamond, SiC, AlN, BN and BeO are highly thermally conductive ceramics, and can be used not only for the low-voltage insulating layer on the surface of the heat diffusion sheet A in the present invention, but also for the ceramic insulating film on the wafer to be described later. The vapor deposition method includes physical vapor deposition (PVD) and chemical vapor deposition (VCD), both of which can be used to manufacture the low-voltage insulating layer in the present invention.

The low-voltage insulating layer 9 may also be an anodized process, an aluminum oxide film grown directly from the metal aluminum on the surface of the heat diffusion member, but the thickness of the aluminum oxide film is not more than 50 μm. Since the aluminum oxide film formed by anodization has pores, although it can be sealed (for example, rouge), the thermal conductivity of the film is not high, so the thickness of the film should not be too thick and should not be larger than 50 μm. If the heat spreader is made of copper, then a copper-aluminum composite should be used.

In the LED chip of the present invention shown in Fig. 5, both electrode pads 2 on the wafer are disposed on the sidewalls of the wafer 3. Such a design is suitable for wafer flip-chip (also referred to as flip chip) structure, which will be described in more detail later. The die-bonding protective layer 5 can be provided by a printing (e.g., missing) method, and a fluorescent material can be added to the material of the die-bonding protective layer.

Also shown in Fig. 5 is an insulating film 10 which is provided on the back surface of the positioning piece and the wafer, along the caulking between the wafer 3 and the positioning piece 6, as shown in Fig. 6, the middle of the back side of the wafer is left untouched. Insulating film The area covered by 10, which has at least half of the area of the wafer, which is used for thermal conduction. By providing the insulating film 10 by spraying or printing (such as a missing printing), the insulating varnish can be infiltrated into the caulking between the wafer 3 and the positioning piece 6, thereby improving the insulation reliability. Such a design is more important for a structure in which a wafer substrate (such as sapphire) is used as a high-voltage insulating layer in a front-mounted structure.

The high heat flux density of the wafer, after the heat diffusion member is reduced, the heat flux density is lowered, and the insulating layer capable of withstanding high voltage is provided on the heat-dissipating surface of the heat-diffusing member, that is, the surface B, which is called the heat-diffusing member. As shown in FIG. 5, the high-voltage insulating layer is provided with a high-voltage insulating layer 11 on the surface B of the heat diffusion member 7.

In the present invention, the high voltage insulating layer is defined as an insulating layer that withstands a DC breakdown voltage of 500 V or more.

The high-voltage insulating layer may also be an aluminide film grown directly from the metal aluminum on the surface of the heat diffusion member by anodization. If the dielectric strength is required to be high, for example, to withstand a voltage of 2000 V, the aluminum oxide film should be 0.2 mm thick, and the difficulty of anodizing is increased, and the thermal resistance of the aluminum oxide film is too large due to the existence of voids. It can choose to use alumina ceramic sheets sintered into porcelain, which has high density, high thermal conductivity and mature manufacturing process. It is widely used in electronic components and the cost is not high. The alumina ceramic sheet and the heat diffusion member may be joined by a soldering method or a thermal conductive adhesive bonding method. When the soldering method is used, the aluminum oxide ceramic sheet needs to be surface metallized.

FIG. 7 shows an LED lighting module using the LED chip of the present invention, which is called an LED wick. The LED chip is provided with a plurality of wafers, and is fixed on the heat conducting core 12 of the LED wick by screws 13, and the heat conducting core 12 is adopted. The cone structure, the heat generated by the chip is transferred to the heat conducting core 12 through the contact heat transfer between the heat diffusing member 7 and the heat conducting core 12, and is transferred to the heat sink by the heat transfer between the conical surface of the heat conducting core and the heat sink. Then scatter. A low-voltage insulating layer 9 is disposed on the A surface of the heat diffusion member 7, and the high-voltage insulating layer 11 is disposed on the heat conductive core 12.

In FIG. 7, a lens 14 is disposed in front of each of the wafers 3, and a phosphor 15 is embedded in the lens 14. The plurality of lenses on the LED chip can be designed as a whole component, and the whole body is adhered after the phosphor is embedded. In the front of the wafer, the lens 15 can again become a die-bonding protective layer of the wafer 3.

In the LED wick shown in Fig. 8, the heat diffusion member is integrated with the heat conductive core 12 and is a cone. If the electrical isolation insulation is required to be high, such a design is suitable for the wafer to be a formal type, and the wafer substrate is an insulator (such as a sapphire substrate). The die-bonding protective layer 5 may be provided by a missing printing method, and a fluorescent material may be added to the die-bonding protective layer 5. Also shown is a concentrating wick cover 16.

The LED chip shown in FIGS. 1 to 6, and the LED chip in FIG. 7, the heat diffusion member 7 is a plate structure. In order to bear the heat diffusion effect, the area of the heat diffusion member should be large enough, and the area of the heat diffusion member 7 should be greater than five times the sum of the area of all the LED chips on the heat diffusion member; The thickness of the diffuser should also be sufficiently thick, usually not less than 0.5 mm. If the power consumption of the 1X1 mm wafer is 1.0 W, the thickness of the heat spreader should be greater than 1.0 mm.

9 , 10 and 11 illustrate a manufacturing process of an LED chip according to the present invention, the process comprising: a wafer embedding process in which a wafer is embedded in a positioning piece, a pad conducting connection process between an electrode pad on the wafer and a lead pad on the positioning piece; And providing a process of bonding a protective layer, a soldering or bonding process between the wafer and the heat diffusion member. FIG. 9 shows a wafer embedding process in which the wafer 3 is embedded in the positioning piece 6, and a pad conduction connection process between the electrode pad and the lead pad is completed. The figure shows solder soldering or conductive adhesive bonding. In this process, a flat lining should be used to attach the wafer 3 and the positioning piece 6 to the lining. It is preferable to lay a film on the lining surface. With a little glue on the top, when the wafer is embedded in the positioning piece, it can be stuck, not easy to fall off. The glue should be selected to be temperature-resistant. When welding, it is subject to high temperature, and the glue volatilizes itself, so that the subsequent process is simple, and the film is easily removed. The board is an auxiliary tool in the production process.

Fig. 10 shows a step of providing a solid crystal protective layer, which may be carried out by a dispensing method, a spraying method, a casting method, a printing method (such as a stencil method), or a patch (film) method. The process of setting the die bond layer can also be performed before the pad conduction connection process. There is a die-bonding protective layer 5 in front of the wafer 3. The wafer 3 is fixed on the positioning piece 6, and does not fall off. The wafer is protected by a protective layer, and water and air are not easily accessible from the surface. Wafer, which is the name of the solid crystal protective layer, this technical feature is distinct from the solid crystal process in the current LED chip production. The wafer is fixed, and the wafer and the positioning piece can be removed from the liner to perform the next process. If the insulating film 10 is required, the process can be performed. The subsequent steps include a step of attaching the wafer to the heat diffusion member by soldering or bonding, as shown in FIG.

A plurality of positioning pieces can be arranged on a large positioning sheet, and a plurality of wafers can be embedded on each positioning piece, and the heat diffusion parts are also the same, so that solder or conductive glue can be set at the same time (for example, by using a missing printing method). The whole heat is welded or cured, and the solid crystal protective layer is integrally disposed. The large positioning piece is attached to the heat diffusion member together with the wafer, and then slit, so that the production efficiency is improved.

The power-on detection process may be performed after the pad-on connection process and before the die-bonding layer process is performed, so that the problematic solder or conductive paste bond can be repaired or the problematic wafer can be replaced. This can effectively improve the yield of LED chips with multiple wafers, which is not available in the manufacture of existing LED chips.

In the LED chip of the present invention shown in FIG. 12, the substrate 21 is an insulator. Similar to the conventional LED chip of the sapphire substrate, the outer layer of the LED working layer 18 is provided with a transparent electrode 17, and the transparent electrode 17 is provided with an electrode pad 2. (the electrode pad 2 on the left side in the figure), the electrode pad is referred to as an outer electrode pad, and the outer surface of the transparent electrode 17 is provided with Protective layer 19. The main feature of the LED chip of the present invention which is different from the current product is that the sidewall of the LED working layer 18 adjacent to the outer electrode pad (the electrode pad 2 on the left side in the figure) is covered with an insulating layer 20 which extends to the lining. The bottom 21 has the function and purpose of preventing the solder or the conductive paste from contacting the other semiconductor layer in the LED working layer 18 when the solder bonding or the conductive adhesive is used to connect the electrode pads and the lead pads, thereby causing a short circuit. problem. The outer electrode pad may be a p-side electrode pad or an n-side electrode pad (using a lift-off technique to change the substrate). The vapor phase film formation method (deposition method) may be employed, and the insulating layer 20 may be simultaneously formed when the protective film 19 is formed, or the insulating layer 20 may be provided by a lithographic printing technique.

In the LED chip of the present invention shown in Fig. 13, a wafer as shown in Fig. 12 is employed, and a large-area heat-conductive pad 22 is provided on the substrate 21. The wafer is attached to the heat diffusion member 7 by soldering, and the heat on the wafer is transferred to the heat diffusion member 7. As shown in the figure, the solder pad conductive connection or the conductive adhesive bonding conduction connection is used between the electrode pad 2 and the lead pad 1. With the insulating layer 20, the solder or conductive paste on the left side does not contact the working layer 18 of the LED. Another semiconductor layer (the inner layer in the figure) has a short circuit phenomenon.

In the LED chip of the present invention shown in FIG. 14, both electrode pads 2 are on the front side of the wafer, and the insulating layer 20 on the side wall of the LED working layer 18 beside the outer electrode pad extends not only to the substrate 21. And also extended to the sidewall of the substrate 21 because of the wafer The substrate 21 is an electrical conductor such as a tantalum carbide substrate. It can also be seen that the back surface of the wafer (below the substrate) is provided with a ceramic insulating film 23 formed by a vapor deposition method.

The LED chip of the present invention shown in Fig. 15 has a wafer similar to that shown in Fig. 14, the substrate is an electric conductor, and the insulating layer 20 beside the left electrode pad (outer electrode pad) extends to the side wall of the substrate 21, so that It can ensure that the solder or conductive paste 8 on the left side is not easy to contact the conductive substrate, and a short circuit occurs. The difference is that another electrode pad 2 (right side in the figure) on the wafer is disposed on the sidewall of the wafer, and a large-area heat-conductive pad 22 is disposed on the back surface of the wafer, and the wafer is attached to the heat diffusion member 7 by soldering.

The LED chip of the present invention shown in FIG. 16 is flip-chip type (also referred to as flip chip type), and the substrate 21 is a front side (light-emitting surface) of the wafer, and one side electrode pad on the wafer is disposed on the sidewall of the wafer (substrate). The solder connection or the conductive adhesive bonding method is used to achieve a conductive connection with the lead pads on the positioning piece 6. The other side electrode pad on the wafer is on the back side of the wafer, and is used as the heat transfer pad 22, and the heat diffusion member 7 is used as a wire. A high voltage insulating layer 11 is provided on the B surface of the heat diffusion member 7.

The LED chip of the present invention as shown in FIG. 17 is also flip-chip type, and the electrode pads 2 on both sides of the wafer are disposed on the sidewall of the wafer (substrate), wherein the LED working layer beside the one electrode pad The sidewall is provided with an insulating layer 20, which is disposed on the back side of the wafer. The ceramic insulating film 23 is formed by vapor deposition, and a large-area heat-conductive pad 22 is provided outside the film. The insulating layer 20 can also be simultaneously formed by the vapor deposition method together with the ceramic insulating film 23.

In the LED chip of the present invention shown in Fig. 18, the electrode pads 2 on both sides are on the front side of the wafer and are disposed at the corners of the wafer. The wafer is rectangular, which prevents the orientation error of the wafer when the positioning element is embedded. In the LED wafer of the present invention shown in Fig. 19, the electrode pads 2 on both sides are disposed on the side walls of the wafer, also on the corners, and the four corners of the wafer are processed into a quarter circle notch. The advantage that the electrode pads are disposed on the corners of the wafer is that the electrode pads occupy a small effective light-emitting area of the wafer.

In the LED chip of the present invention shown in FIG. 20, three wafers are placed on one of the wafer inserts on the positioning piece 6. This design can be used for the production of a white LED chip with three primary colors, a white LED chip with a red light complementary color, and the like. Application in LED display screens and backlighting of liquid crystal display screens.

(1)‧‧‧ Lead pad

(2) ‧‧‧electrode pads

(3) ‧‧‧ wafer

(4) ‧‧‧ wires

(5) ‧‧‧Crystal protective layer

(6) ‧‧‧ Positioning film

(7) ‧ ‧ heat spreaders

(8)‧‧‧Solder or conductive adhesive

(9) ‧‧‧Low-voltage insulation

(10)‧‧‧Insulation film

(11)‧‧‧High voltage insulation

(12)‧‧‧Conductor core

(13)‧‧‧ screws

(14) ‧ ‧ lens

(15)‧‧‧Silver

(16)‧‧‧War cover

(17) ‧‧‧Transparent electrode

(18) ‧‧‧LED working layer (n-type semiconductor layer + luminescent layer + p-type semiconductor layer)

(19) ‧ ‧ protective film

(20)‧‧‧Insulation

(21) ‧‧‧Substrate

(22)‧‧‧ Thermal pad

(23)‧‧‧Ceramic insulating film

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic cross-sectional view showing the characteristics of an LED chip of the present invention. The wire is welded by an ultrasonic gold wire method, and a solid crystal protective layer is provided by a dispensing method.

2 is a schematic cross-sectional view showing the characteristics of the LED chip of the present invention. The wire is welded by a pressure welding method, and the solid crystal protective layer is provided by a casting method.

3 is a schematic cross-sectional view of a LED chip of the present invention, using soldering The material soldering or the conductive adhesive bonding method realizes the connection between the electrode pads on the wafer and the lead pads on the positioning piece, and the solid crystal protective layer can be disposed by the filming method.

4 is a schematic cross-sectional view showing a characteristic of an LED chip of the present invention. The electrode pad on the wafer is connected to the lead pad on the positioning piece by soldering or conductive bonding, and one electrode pad on the wafer is disposed on the wafer. On the side wall, the A surface of the heat diffusion member is provided with a low voltage insulating layer.

5 is a schematic cross-sectional view of the LED chip of the present invention, both side electrode pads on the wafer are disposed on the sidewall of the wafer, and the B surface of the heat diffusion member is provided with a high voltage insulating layer, the A surface of the thermal diffusion member and the positioning piece and An insulating film is disposed between the partial areas of the wafer.

Fig. 6 is a schematic view showing the back surface of the positioning piece and the wafer in the LED chip of the present invention. The insulating film is provided along the caulking of the wafer and the positioning piece, but there is no insulating film in the middle of the wafer.

7 is a schematic cross-sectional view showing an LED wick (or optical module) using the LED chip of the present invention, and the heat conducting core adopts a cone structure.

Fig. 8 is a schematic cross-sectional view showing the LED wick using the LED chip of the present invention. The heat diffusion member is integrated with the heat conductive core, and a concentrating wick cover is used.

9, 10 and 11 are schematic views showing a manufacturing process of the LED chip of the present invention.

Figure 12 is a schematic cross-sectional view showing the LED wafer of the present invention. The substrate is an insulator, and both electrode pads on the wafer are on the front side of the wafer.

Figure 13 is a schematic cross-sectional view showing the characteristics of the LED chip of the present invention, the substrate being an insulator and a formal structure.

Figure 14 is a schematic cross-sectional view showing the LED wafer of the present invention. The substrate is an electrical conductor, and both electrode pads on the wafer are on the front side of the wafer.

Figure 15 is a schematic cross-sectional view showing the characteristics of the LED chip of the present invention. The substrate is an electrical conductor, a formal structure in which one side electrode pad is disposed on the sidewall of the wafer.

Figure 16 is a schematic cross-sectional view showing the characteristics of the LED chip of the present invention, the substrate being an insulator, a flip-chip structure in which one side electrode pad is disposed on the sidewall of the wafer.

Figure 17 is a schematic cross-sectional view showing the characteristics of the LED chip of the present invention. The substrate is an insulator, a flip-chip structure, and both side electrode pads on the wafer are disposed on the sidewall of the wafer.

Figure 18 is a schematic illustration of the LED wafer of the present invention with the electrode pads on the front side of the wafer and disposed at four corners.

Figure 19 is a schematic illustration of the LED wafer of the present invention with electrode pads on the sidewalls of the wafer and disposed at four corners.

Figure 20 is a schematic illustration of the LED chip of the present invention showing a plurality of wafers embedded in a wafer insert.

(1)‧‧‧ Lead pad

(2) ‧‧‧electrode pads

(5) ‧‧‧Crystal protective layer

(6) ‧‧‧ Positioning film

(7) ‧ ‧ heat spreaders

(8)‧‧‧Solder or conductive adhesive

(18) ‧‧‧LED working layer

(20)‧‧‧Insulation

(22) ‧‧‧thermal welding

(23)‧‧‧Ceramic insulating film

Claims (11)

An LED chip comprising one or more wafers, a positioning piece and a heat diffusion member, wherein the positioning piece is provided with a wafer insert, the wafer is embedded in the wafer insert, and the position of the wafer on the positioning piece is embedded by the wafer. Fixed, the wafer and the positioning piece are attached to the A surface of the thermal diffusion member; the positioning piece is made of an insulating material and is provided with a lead pad; the electrode pad on the front surface of the wafer or the side wall and the corresponding wire bonding on the positioning piece The conductive connection between the discs is a wire bonding connection, a solder bonding connection, and a conductive adhesive bonding connection; a solder or adhesive connection is used between the wafer and the A surface of the heat diffusion member; the thermal diffusion member is made of a copper material or aluminum. Material, or copper-aluminum composite. The LED chip according to claim 1, wherein the front surface of the wafer and the outer surface of some or all of the positioning sheets are provided with a die-bonding protective layer. The LED chip according to claim 1 is characterized in that: on the back surface of the positioning piece and the wafer, an insulating film is disposed along the caulking of the wafer and the positioning piece, and at least half of the area of the back surface of the wafer is not allowed to be The insulating film is covered. The LED chip according to claim 1, wherein the heat diffusion member has a plate structure, and the area of the heat diffusion member is greater than five times the sum of the areas of all the LED chips on the heat diffusion member. The LED chip according to the fourth aspect of the invention is characterized in that the B surface of the heat diffusion member is provided with a high voltage insulating layer which is subjected to a DC breakdown voltage of more than 500V. The LED chip according to claim 5, characterized in that the heat is The high-voltage insulating layer on the B-plane of the diffuser is an alumina film grown directly from the metal aluminum on the surface of the heat spreader by anodization or an alumina ceramic sheet sintered into a porcelain. The LED chip according to claim 4, wherein the surface of the thermal diffusion member is provided with a ceramic insulating film formed by a vapor deposition method or anodized directly from the surface of the thermal diffusion member. The aluminum oxide film has a thickness of not more than 50 μm. An LED chip comprising a substrate, an LED working layer and an electrode pad, both of which are on the front side of the wafer, characterized in that an insulating layer is covered on a sidewall of the LED working layer near the outer electrode pad, the insulating layer The layers are located at the outermost side of the wafer sidewall and extend to the substrate. An LED chip comprising a substrate, an LED working layer, and an electrode pad, wherein an electrode pad is disposed on a sidewall of the wafer, the electrode pad is located at a corner of the wafer, and the corner is processed into four points One of the round gaps. The LED wafer according to claim 8 or 9, wherein a ceramic insulating film formed by a vapor deposition method is provided on the back surface of the wafer. An LED chip manufacturing method, the LED chip comprises one or more wafers, a positioning piece and a heat diffusion member, the positioning piece is made of an insulating material, and is provided with a lead pad, the positioning piece is provided with a wafer insert, and the chip is embedded in the chip In the positioning piece, a front surface of the wafer is provided with a solid crystal protective layer, the wafer and the positioning piece are attached to the thermal diffusion member, and the thermal diffusion member is made of a copper material or an aluminum material or a copper-aluminum composite material, and the LED chip manufacturing step The method includes: a wafer embedding step in which the wafer is embedded in the positioning piece, a pad guiding between the electrode pad on the wafer and the lead pad on the positioning piece a step of bonding, a step of providing a solid crystal protective layer, a soldering or bonding step between the wafer and the heat diffusion member, wherein the step of bonding the pad and the step of providing a solid crystal protective layer are provided on the wafer and the heat diffusion member Before the soldering or bonding step, the wafer is embedded in the positioning sheet step; the pad conducting connection step uses a wire bonding method, a solder bonding method, and a conductive bonding method.