SUMMERY OF THE UTILITY MODEL
An object of the utility model is to provide a flip-chip LED chip to solve the problem is hindered on the top of flip-chip LED chip in the packaging process.
In order to achieve the above object, the utility model provides a flip-chip LED chip, include:
the LED chip comprises an LED chip body, a first layer of N electrode and a first layer of P electrode;
the two electrode leading-out ends are positioned on the LED chip body and are respectively and electrically connected with the first layer of N electrode and the first layer of P electrode; and the number of the first and second groups,
and the insulating protection layer covers the area of the top surface of the LED chip body except the electrode leading-out end and part of the top surface of the electrode leading-out end.
Optionally, the thickness of the insulating protection layer is 1 μm to 10 μm.
Optionally, the insulating protection layer comprises a polyimide layer.
Optionally, the insulating protective layer includes a silicone layer and/or an epoxy resin layer.
Optionally, a top surface of the electrode lead is lower than a top surface of the insulating protection layer.
Optionally, the LED chip body further includes:
a substrate;
the epitaxial layer comprises a first semiconductor layer, a light emitting layer and a second semiconductor layer which are sequentially arranged on the substrate;
a recess in the epitaxial layer and extending from a top surface of the second semiconductor layer into the first semiconductor layer; and the number of the first and second groups,
and the insulating reflecting layer fills the groove and extends to cover the second semiconductor layer.
Optionally, the first layer of N electrode is located on the first semiconductor layer at the bottom of the groove and electrically connected to the first semiconductor layer; the first layer of P electrode is positioned on the second semiconductor layer and is electrically connected with the second semiconductor layer.
Optionally, the two electrode leading-out ends include a first electrode leading-out end and a second electrode leading-out end, the first electrode leading-out end penetrates through the insulating reflective layer and is electrically connected to the first layer of N electrode, and the second electrode leading-out end penetrates through the insulating reflective layer and is electrically connected to the first layer of P electrode.
Optionally, in a direction perpendicular to the thickness direction, a width of the first layer N electrode is smaller than a width of the groove, and a gap is formed between the first layer N electrode and a sidewall of the groove, and the gap is filled with the insulating reflective layer.
Optionally, the LED chip body further includes:
a current blocking layer on the second semiconductor layer and covering a portion of the second semiconductor layer; and the number of the first and second groups,
the current spreading layer is positioned on the second semiconductor layer and covers a part of the second semiconductor layer and the current blocking layer;
wherein the first layer of P-electrodes is located on the current spreading layer.
The utility model provides a flip-chip LED chip has following beneficial effect:
1) the region of drawing forth the end except that the electrode at the top surface of LED chip body covers one deck insulating protective layer, and when the encapsulation, what the thimble pushed up is insulating protective layer, because insulating protective layer's mechanical properties is good, tensile strength is high, can not be hindered by the thimble top, can effectually slow down the impact force of thimble when solid brilliant, protects flip-chip LED chip's functional layer, improves flip-chip LED chip's reliability and stability.
2) The electrode leading-out end is located insulating protective layer, and insulating protective layer can protect the electrode leading-out end not by external damage, simultaneously, because insulating protective layer covers the top surface of LED chip body can play the guard action to the top surface of LED chip body, prevents that the top surface of LED chip body from being by external damage.
3) When the follow-up encapsulation of flip-chip LED chip, can carry out reflow soldering or eutectic bonding (the temperature is 250 degrees centigrade-330 degrees centigrade), because insulating protective layer includes the polyimide layer, polyimide's heatproof temperature is greater than 330 degrees centigrade, can avoid insulating protective layer to warp because of high temperature in the packaging process to can not influence flip-chip LED chip's performance.
4) The insulating protective layer with the heat-resisting temperature of more than 330 ℃ generally has higher insulativity, the insulation grade can reach more than H grade, the insulating property between the electrode leading-out ends is improved, and the reliability of the flip LED chip is further improved.
5) The insulating protective layer can cover part of the top surface of the electrode, has certain passivation protection effect on the top surface of the electrode, and can prevent the electrode from metal migration.
6) The top surface of the electrode leading-out end is lower than that of the insulating protection layer, when the LED chip is packaged in an inverted mode, the insulating protection layer can prevent solder paste on the electrodes from overflowing, and the phenomenon of short circuit between the electrodes is prevented;
7) after the leading-out terminal electrode is formed, the insulating protective layer is formed, so that the insulating protective layer covers part of the top surface of the leading-out terminal electrode and/or the top surface of the leading-out terminal electrode is lower than the top surface of the insulating protective layer, and the effects of preventing the metal migration phenomenon of the electrode leading-out terminals and/or the short circuit phenomenon of the electrode leading-out terminals are achieved.
8) The insulating protection layer comprises a polyimide layer, and compared with other organic materials, the polyimide layer is easy to pattern, and a required pattern can be formed through photoetching and etching, so that the preparation process is simplified; and polyimide's mobility is strong, can effectively cover the step on the top surface of LED chip body in the preparation process, is favorable to promoting the humidity resistance of chip.
Detailed Description
The following description of the embodiments of the present invention will be described in more detail with reference to the drawings. The advantages and features of the present invention will become more apparent from the following description. It should be noted that the drawings are in simplified form and are not to precise scale, and are provided for convenience and clarity in order to facilitate the description of the embodiments of the present invention.
Example one
Fig. 8a and 8b are schematic structural diagrams of the flip LED chip provided in this embodiment, where fig. 8a is a schematic cross-sectional diagram of the flip LED chip provided in this embodiment along a thickness direction, and fig. 8b is a top view of the flip LED chip provided in this embodiment. As shown in fig. 8a and 8b, the flip-chip LED chip includes an LED chip body, an insulating protection layer 700 and two electrode terminals, wherein the insulating protection layer 700 is located on the LED chip body and completely covers the top surface of the LED chip body, and the two electrode terminals are located on the insulating protection layer 700 and electrically connected to the LED chip body respectively. In this embodiment, the LED chip body has a functional surface 100a, the functional surface 100a may also be referred to as a front surface of the LED chip body, which is a surface of the LED chip body for forming electrode terminals, and the insulating protection layer 700 and the two electrode terminals are both located on the functional surface 100a of the LED chip body. In the die bonding process, the ejector pins can be ejected on the insulating protection layer 700 to eject the flip LED chip, so that the die is conveniently removed, and the insulating protection layer 700 has excellent mechanical properties and high tensile strength, and cannot be damaged by the ejector pins, so that the impact force of the ejector pins can be effectively reduced in the die bonding process, the functional layer of the flip LED chip is protected, and the reliability and the stability of the flip LED chip are improved.
Further, the material of the insulating and protecting layer 700 may be an organic polymer material with a heat-resistant temperature greater than 330 ℃. When the flip LED chip is subsequently packaged, reflow soldering or eutectic soldering (the temperature is 250-330 ℃) can be usually carried out, and because the heat-resisting temperature of the insulating and protecting layer 700 is higher than 330 ℃, the insulating and protecting layer 700 cannot deform due to high temperature in the packaging process, so that the performance of the flip LED chip cannot be influenced. In addition, the insulating protection layer 700 with the heat resistance temperature of over 330 ℃ generally has high insulating property, the insulating grade can reach over H level, the insulating property between the electrode leading-out ends is improved, and the reliability of the flip-chip LED chip is further improved.
In this embodiment, the insulating protection layer 700 is a polyimide layer, which has a heat resistance temperature up to 400 ℃, and has high insulating properties. In addition, compared with other organic materials, the polyimide is easy to pattern, and a required pattern can be formed through photoetching and etching, so that the preparation process is simplified; and polyimide has strong mobility, can effectively cover the steps on the surface of the LED chip body in the preparation process, and is favorable for improving the moisture resistance of the flip LED chip. It should be understood that the material of the insulating and protecting layer 700 is not limited to polyimide, and may be other organic materials with good heat resistance.
It is understood that the insulating and protecting layer 700 may also be a silicone layer and/or an epoxy layer, and the insulating and protecting layer 700 may be a single-layer structure or a combination of multi-layer structures.
In this embodiment, the thickness of the insulating protection layer 700 is 1 μm to 10 μm, for example, 3 μm, 6 μm, 8 μm, or 9 μm.
Further, referring to fig. 8a and 8b, the insulating protection layer 700 completely covers the functional surface 100a of the LED chip body, so as to protect the surface of the LED chip body and prevent the surface of the LED chip body from being damaged by the outside, and both of the electrode terminals are located on the insulating protection layer 700.
Specifically, the two electrode terminals are a first electrode terminal 901 and a second electrode terminal 902, respectively, and the first electrode terminal 901 and the second electrode terminal 902 are arranged in bilateral symmetry with respect to the center of the functional surface 100 a; it should be understood that the first electrode lead 901 and the second electrode lead 902 are not limited to being disposed symmetrically left and right with respect to the center of the functional surface 100a, but may be disposed symmetrically up and down with respect to the center of the functional surface 100a, or the first electrode lead 901 and the second electrode lead 902 may be disposed diagonally; of course, the first electrode lead 901 and the second electrode lead 902 may also be asymmetrically distributed, and this embodiment is not limited. Further, the first electrode terminal 901 and the second electrode terminal 902 need to be separated by a certain distance to realize electrical isolation.
With reference to fig. 8a and 8b, the LED chip body includes a substrate 100, an epitaxial layer 200, a current blocking layer 300, a current spreading layer 400, a first N electrode 501, a first P electrode 502, and an insulating reflective layer 600.
Specifically, in this embodiment, the substrate 100 is a high-transmittance sapphire substrate (Al)2O3) As an alternative embodiment, the substrate 100 may also be a substrate such as silicon (Si), silicon carbide (SiC), gallium nitride (GaN), or zinc oxide (ZnO). Further, the substrate 100 is a Patterned Sapphire Substrates (PSS), such as a micro/nano Patterned sapphire substrate. The upper surface of the substrate 100 is used for forming functional layers of the flip-chip LED chip, a top surface of the stacked functional layers serves as a functional surface 100a of the LED chip body, and the lower surface of the substrate 100 serves as a back surface of the LED chip body.
With reference to fig. 8a, the epitaxial layer 200 is located on the substrate 100, and the epitaxial layer 200 includes a first semiconductor layer 201, a light emitting layer 202, and a second semiconductor layer 203 sequentially disposed from bottom to top. The epitaxial layer 200 has a groove 200a therein, the groove 200a extends from the top surface of the second semiconductor layer 203 into the first semiconductor layer 201 after penetrating the light emitting layer 202, and the groove 200a has a certain interval to form a PN step. The upper step surface of the PN step is the second semiconductor layer 203, the lower step surface is the first semiconductor layer 201, and the upper step surface and the lower step surface are connected to form a PN step side surface.
In this embodiment, the first semiconductor layer 201 in the epitaxial layer 200 is an N-type semiconductor layer and is located above the substrate 100, and the first semiconductor layer 201 is made of N-GaN; the light emitting layer 202 is located above the first semiconductor layer 201, the light emitting layer 202 is a multi-period quantum well layer (MQWS), and the material of the MQWS is any one or combination of AlN, GaN, AlGaN, InGaN, and AlInGaN; the second semiconductor layer 203 is a P-type semiconductor layer and is located above the light emitting layer 202, and the material of the second semiconductor layer 203 is P-GaN.
With reference to fig. 8a, the current blocking layer 300 and the current spreading layer 400 are both located on the second semiconductor layer 203, the current blocking layer 300 covers a portion of the second semiconductor layer 203, and the current blocking layer 300 has a good current guiding effect. The width of the current spreading layer 400 in the direction perpendicular to the thickness direction is greater than the width of the current blocking layer 300, so that the current spreading layer 400 covers not only the second semiconductor layer 203 but also the current blocking layer 300 completely, thereby facilitating lateral spreading of current.
In this embodiment, the current blocking layer 300 and the current spreading layer 400 are transparent film layers, so that the light emitting efficiency and the light emitting intensity are not adversely affected. The material of the current blocking layer 300 may be silicon oxide, silicon nitride, titanium oxide, aluminum oxide, or perovskite type electronic ceramic (ABO3), or the like; the current spreading layer 400 is made of ITO or AZO. In this embodiment, the current blocking layer 300 is a single silicon oxide layer, and the current spreading layer 400 is made of ITO.
With reference to fig. 8a, the first layer of N-electrode 501 and the first layer of P-electrode 502 are respectively formed in the groove 200a and on the current spreading layer 400, and are electrically connected to the first electrode terminal 901 and the second electrode terminal 902. The first layer N electrode 501 is located at the bottom of the groove 200a and electrically connected to the first semiconductor layer 201, in a direction perpendicular to the thickness direction, the width of the first layer N electrode 501 is smaller than the width of the groove 200a, and a gap is formed between the first layer N electrode 501 and the sidewall of the groove 200a, so that electrical insulation between the first layer N electrode 501 and the first layer P electrode 502 is achieved; the first P-electrode layer 502 is disposed on the current spreading layer 400 and electrically connected to the second semiconductor layer 203 through the current spreading layer 400.
Further, the first layer P electrode 502 corresponds to the position of the current blocking layer 300, and the area of the current blocking layer 300 is larger than that of the first layer P electrode 502, the current blocking layer 300 can reduce light loss caused by light absorption/blocking by the first layer P electrode 502, and reduce vertical current transmission and increase lateral transmission.
Further, the insulating reflective layer 600 covers the second semiconductor layer 203 and fills the groove 200 a. That is, the insulating reflective layer 600 covers the entire surface of the chip, and the gap between the first layer N electrode 501 and the sidewall of the groove 200a is also filled with the insulating reflective layer 600, so that the first layer N electrode 501 and the first layer P electrode 502 can be electrically insulated by the insulating reflective layer 600, and further, the first electrode terminal 901 and the second electrode terminal 902 can be electrically insulated; meanwhile, the insulating reflective layer 600 has a light reflecting function and may act as a mirror for reflecting a portion of the light emitted from the light emitting layer 202 toward the insulating reflective layer 600. The material of the insulating reflective layer 600 includes two or more of silicon oxide, amorphous silicon, titanium oxide, aluminum oxide, or silicon nitride, and in this embodiment, the reflective mirror layer 600 is formed by alternately evaporating at least two layers of high and low refractive index films, but not limited thereto.
In this embodiment, the insulating reflective layer 600 can realize electrical insulation between the first N electrode 501 and the first P electrode 502, and can also serve as a reflector, thereby simplifying the chip structure, and since the insulating reflective layer 600 covers the entire surface, the area is large, and the reflective effect is better.
Referring to fig. 8a, the first electrode lead 901 penetrates through the insulating protection layer 700 and the insulating reflective layer 600, and the bottom surface of the first electrode lead 901 contacts the first N-electrode 501 to be electrically connected, so that the first electrode lead 901 can be electrically connected to the first semiconductor layer 201 through the first N-electrode 501. Similarly, the second electrode terminal 902 penetrates through the insulating protective layer 700 and the insulating reflective layer 600, and the bottom surface of the second electrode terminal 902 contacts the first P-electrode 502 to be electrically connected, so that the second electrode terminal 902 is electrically connected to the second semiconductor layer 203 through the first P-electrode 502 and the current spreading layer 400. The first electrode lead 901 and the second electrode lead 902 may be used as an N-type electrode and a P-type electrode of the flip-chip LED chip, respectively.
In this embodiment, the material of the first electrode lead 901 and the second electrode lead 902 may be metal such as titanium (Ti), platinum (Pt), aluminum (Al), nickel (Ni), chromium (Cr), gold (Au), or gold-tin alloy (Au).
In this embodiment, referring to fig. 8a, the first electrode leading-out terminal 901 and the second electrode leading-out terminal 902 are both located on the insulating protection layer 700, so that the insulating protection layer 700 can be formed after the insulating reflection layer 600 is formed, and the insulating reflection layer 600 and the insulating protection layer 700 can be etched synchronously, which is relatively simple to manufacture.
In this embodiment, the insulating reflective layer 600 is a film layer that is not planarized, so that the top surface of the insulating reflective layer 600 has a step, and the insulating protective layer 700 in this embodiment can effectively cover the step on the top surface of the insulating reflective layer 600, thereby improving the moisture resistance of the chip. Further, the first electrode lead 901 and the second electrode lead 902 are formed on the insulating protective layer 700 having a flat surface, and the surfaces of the first electrode lead 901 and the second electrode lead 902 are also flat.
Fig. 1 to fig. 8b are schematic structural diagrams illustrating corresponding steps of a method for manufacturing a flip LED chip provided in this embodiment. Next, a method for manufacturing the flip LED chip will be described in detail with reference to fig. 1 to 8 b.
As shown in fig. 1, a substrate 100 is provided, and an epitaxial layer 200 is formed on the substrate 100, where the epitaxial layer 200 includes a first semiconductor layer 201, a light emitting layer 202, and a second semiconductor layer 203, which are sequentially disposed from bottom to top.
The substrate 100 and the epitaxial layer 200 are formed, for example, by: a pattern is etched on the surface of the substrate 100 using a standard photolithography process, and then the substrate 100 is etched using ICP (inductive plasma coupled etching) to pattern the surface of the substrate 100, for improving the light emitting efficiency. Further, the epitaxial layer 200 may be fabricated on the substrate 100 by any one of epitaxial techniques, such as metal chemical vapor deposition, laser-assisted molecular beam epitaxy, hydride vapor phase epitaxy, evaporation, and the like, and the epitaxial layer 200 may be a polycrystalline structure or a single crystal structure.
As shown in fig. 2, the epitaxial layer 200 is partially etched to form a groove 200a, and the groove 200a penetrates through the second semiconductor layer 203 and the light emitting layer 202 and extends into the first semiconductor layer 201. Specifically, the step of forming the groove 200a includes: through a photoetching process, a luminous region MESA pattern is manufactured, the epitaxial layer 200 is etched by ICP to form the groove 200a, the etching depth needs to exceed the luminous layer 202, the first semiconductor layer 201 is exposed, a platform (MESA) is etched from the side view to form a PN step, the PN step comprises an upper step surface and a lower step surface, the upper step surface is a second semiconductor layer 203, the lower step surface is the first semiconductor layer 201, and the upper step surface and the lower step surface are connected to form the side surface of the PN step.
As shown in fig. 3, a current blocking layer 300 is formed on the second semiconductor layer 203. The step of forming the current blocking layer may be: a current blocking material (not shown in fig. 3) is deposited on the entire surface by a deposition process, a mask is made by using a photoresist, and then a portion of the current blocking material on the second semiconductor layer 203 is remained by removing a portion of the current blocking material and the mask by an etching process and a photoresist removing process, and the remaining current blocking material constitutes the current blocking layer 300.
As shown in fig. 4, a current spreading layer 400 is formed on the second semiconductor layer 203. The step of forming the current spreading layer 400 includes: a current spreading material (not shown in fig. 4) is fully deposited through a deposition process, a mask is made of photoresist, and then a part of the current spreading material and the mask are removed through an etching process and a photoresist removing process, so that a part of the current spreading material on the second semiconductor layer 203 and all the current spreading material on the current blocking layer 300 are retained, and the remaining current spreading material forms the current spreading layer 400.
As shown in fig. 5, a first layer of N-electrode 501 and a first layer of P-electrode 502 are formed on the recess 200a and the current spreading layer 400, respectively. The steps of forming the first layer N electrode 501 and the first layer P electrode 502 may be: forming a patterned photoresist layer on the current spreading layer 400, wherein the patterned photoresist layer defines a pattern for forming a first N electrode 501 and a first P electrode 502, forming a first electrode material by a process such as sputtering, and finally stripping the patterned photoresist and removing the first electrode material on the patterned photoresist, and the remaining first electrode material can form the first N electrode 501 and the first P electrode 502.
As shown in fig. 6, an evaporation reflective layer 600 is deposited on the entire surface of the second semiconductor layer 203, and the insulating reflective layer 600 fills the groove 200a and extends to cover the second semiconductor layer 203. An insulating protective layer 700 is then formed on the insulating reflective layer 600. Since the insulating protection layer 700 is a polyimide layer, the insulating protection layer 700 may be directly formed without performing a planarization process after the insulating reflection layer 600 is formed, and since polyimide has high fluidity, the step on the top surface of the insulating reflection layer 600 may be effectively covered, which simplifies the process and is also advantageous to improve the moisture resistance of the chip.
In this embodiment, the insulating protection layer 700 may be formed by a combination of high-speed spin coating and vapor deposition.
As shown in fig. 7, the insulating protection layer 700 and the insulating reflective layer 600 are etched to form a first opening 801 and a second opening 802, wherein the first opening 801 and the second opening 802 penetrate through the insulating protection layer 700 and the insulating reflective layer 600 and expose the top surfaces of the first N electrode 501 and the first P electrode 502, respectively. Compared with other organic materials, polyimide is easy to pattern, and a required pattern can be formed by photoetching and etching, so that the insulating reflective layer 600 and the insulating protective layer 700 can be synchronously etched in the step, and the manufacturing is relatively simple.
As shown in fig. 8a and 8b, the first opening 801 and the second opening 802 are filled with a conductive material, and the conductive material further extends to cover the top surface of the insulating protection layer 700. Then etching is performed to remove a portion of the conductive material on the top surface of the insulating protection layer 700, the conductive material in the first opening 801 and a portion of the conductive material on the top surface of the insulating protection layer 700 constitute the first electrode terminal 901, and the conductive material in the second opening 802 and the remaining conductive material on the top surface of the insulating protection layer 700 constitute the second electrode terminal 902.
Example two
Fig. 13a and 13b are schematic structural diagrams of the flip LED chip provided in this embodiment, where fig. 13a is a schematic cross-sectional diagram of the flip LED chip provided in this embodiment along a thickness direction, and fig. 13b is a top view of the flip LED chip provided in this embodiment. As shown in fig. 13a and 13b, the difference from the first embodiment is that in this embodiment, the insulating protection layer 700 covers the top surface of the LED chip body in the region outside the electrode terminals and the partial top surfaces of the electrode terminals, that is, the first electrode terminal 901 and the second electrode terminal 902 are actually located at the same layer as the insulating protection layer 700, and the insulating protection layer 700 exposes the partial top surfaces of the first electrode terminal 901 and the second electrode terminal 902.
Specifically, with continued reference to fig. 13a and 13b, the thickness of the first electrode lead 901 and the second electrode lead 902 is less than the thickness of the insulating protection layer 700, such that the top surface of the first electrode lead 901 and the second electrode lead 902 is lower than the top surface of the insulating protection layer 700. In this way, when the LED chip is packaged by flip chip, the insulating protection layer 700 can prevent solder paste on the first electrode terminal 901 and the second electrode terminal 902 from overflowing, and prevent a short circuit phenomenon between the first electrode terminal 901 and the second electrode terminal 902.
With reference to fig. 13a and 13b, in the present embodiment, the insulating protection layer 700 further covers a portion of the top surfaces of the first electrode terminal 901 and the second electrode terminal 902, specifically, covers the edge portions of the top surfaces of the first electrode terminal 901 and the second electrode terminal 902. At this time, the insulating protective layer 700 has a certain passivation protection effect on the top surfaces of the first and second electrode taps 901 and 902, and can prevent the metal migration phenomenon from occurring in the first and second electrode taps 901 and 902.
Fig. 9 to fig. 13b are schematic structural diagrams corresponding to corresponding steps of the method for manufacturing a flip LED chip provided in this embodiment. Referring to fig. 9 to 13b, different from the first embodiment, in the present embodiment, when the flip-chip LED chip is manufactured, a first electrode terminal 901 and a second electrode terminal 902 are formed first, and then the insulating protection layer 700 is formed.
Specifically, referring to fig. 9 to 10, after the insulating reflective layer 600 is formed, the insulating reflective layer 600 is etched to form a first opening 801 and a second opening 802, and the first opening 801 and the second opening 802 penetrate through the insulating reflective layer 600 and expose the first N electrode 501 and the first P electrode 502, respectively.
As shown in fig. 11, a conductive material (not shown in fig. 11) is formed on the insulating reflective layer 600, and the conductive material fills the first opening 801 and the second opening 802 and extends to cover the insulating reflective layer 600. Then, an etching process is used to remove a portion of the conductive material on the insulating reflective layer 600, the conductive material in the first opening 801 and a portion of the conductive material on the top surface of the insulating reflective layer 600 form the first electrode terminal 901, and the conductive material in the second opening 802 and the remaining conductive material on the top surface of the insulating reflective layer 600 form the second electrode terminal 902.
As shown in fig. 12, an insulating protective layer 700 is formed on the insulating reflective layer 600, and the insulating protective layer 700 covers the insulating reflective layer 600, the first electrode tap 901, and the second electrode tap 902. Then, an etching process is used to remove at least a portion of the insulating protection layer 700 on the top surfaces of the first electrode terminal 901 and the second electrode terminal 902, so that at least a portion of the top surfaces of the first electrode terminal 901 and the second electrode terminal 902 is exposed out of the insulating protection layer 700.
It should be understood that, although the flip chip is exemplified as the flip LED chip in the present embodiment, in fact, the flip chip provided in the present embodiment is not limited to the flip LED chip, but may also be any flip chip such as a CPU chip, a GPU chip, or an RF chip, when the flip chip is another chip, the electrode terminals are not limited to two, but may be two, three, four, or five, and the distribution manner of the electrode terminals on the flip chip may also be designed according to the actual situation, and will not be explained one by one here.
To sum up, the utility model provides an among the flip-chip LED chip, the top surface of LED chip body covers the one deck insulating protective layer except that the electrode draws forth the region outside the end, and when the encapsulation, what the thimble pushed up is insulating protective layer, because insulating protective layer's mechanical properties is good, tensile strength is high, can not be hindered by the thimble top, can effectually slow down the impact force of thimble when solid brilliant, protects flip-chip LED chip's functional layer, improves flip-chip LED chip's reliability and stability.
Furthermore, the electrode leading-out terminal is positioned on the insulating protective layer, and the preparation process can be simplified by preparing the electrode leading-out terminal after the insulating protective layer is formed.
Further, since the insulating protection layer covers the top surface of the LED chip body, the top surface of the LED chip body can be protected, and the top surface of the LED chip body is prevented from being damaged by the outside.
Further, when the flip LED chip is subsequently packaged, reflow soldering or eutectic soldering (the temperature is 250-330 ℃) can be usually carried out, and because the heat-resisting temperature of the insulating protective layer is higher than 330 ℃, the insulating protective layer can not deform due to high temperature in the packaging process, so that the performance of the flip LED chip can not be influenced.
Furthermore, the insulating protection layer with the heat-resisting temperature of more than 330 ℃ generally has higher insulativity, the insulation grade can reach more than H level, the insulating property between the electrode leading-out ends is improved, and the reliability of the flip LED chip is further improved.
Furthermore, the electrode leading-out end is positioned in the insulating protection layer, the insulating protection layer can protect the electrode leading-out end from being damaged by the outside, and meanwhile, the insulating protection layer covers the top surface of the LED chip body, so that the top surface of the LED chip body can be protected, and the top surface of the LED chip body is prevented from being damaged by the outside.
Furthermore, the insulating protection layer can cover part of the top surface of the electrode leading-out terminal, and has certain passivation protection effect on the top surface of the electrode leading-out terminal, so that the phenomenon of metal migration of the electrode leading-out terminal can be prevented.
Further, the top surface of the electrode leading-out end is lower than that of the insulating protection layer, when the LED chip is packaged in a flip chip mode, the insulating protection layer can prevent solder paste on the electrode leading-out end from overflowing, and the phenomenon of short circuit between the electrode leading-out ends is prevented.
Furthermore, an insulating protective layer is formed after the insulating reflecting layer is formed, so that synchronous etching operation can be synchronously performed, and the manufacturing is relatively simple.
Further, the insulating protective layer is formed after the electrode leading-out terminal is formed, so that the insulating protective layer can cover part of the top surface of the electrode leading-out terminal and/or the top surface of the electrode leading-out terminal is lower than the top surface of the insulating protective layer, and the effects of preventing the metal migration phenomenon of the electrode leading-out terminal and/or the short circuit phenomenon between the electrode leading-out terminals can be achieved.
Furthermore, the insulating protection layer comprises a polyimide layer, compared with other organic materials, the polyimide layer is easy to pattern, and a required pattern can be formed through photoetching and etching, so that the preparation process is simplified; and polyimide has strong mobility, can effectively cover the steps on the surface of the LED chip body in the preparation process, and is favorable for improving the moisture resistance of the chip.
It should be noted that, in the present specification, the embodiments are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments may be referred to each other. For the system disclosed by the embodiment, the description is relatively simple because the system corresponds to the method disclosed by the embodiment, and the relevant points can be referred to the method part for description.
It should be noted that, although the present invention has been described with reference to the preferred embodiments, the above embodiments are not intended to limit the present invention. It will be apparent to those skilled in the art from this disclosure that many changes and modifications can be made, or equivalents modified, in the embodiments of the invention without departing from the scope of the invention. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention are still within the protection scope of the technical solution of the present invention, unless the content of the technical solution of the present invention is departed from.
It should be further understood that the terms "first," "second," "third," and the like in the description are used for distinguishing between various components, elements, steps, and the like, and are not intended to imply a logical or sequential relationship between various components, elements, steps, or the like, unless otherwise indicated or indicated.
It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to limit the scope of the present invention. It must be noted that, as used herein and in the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. For example, reference to "a step" or "an apparatus" means a reference to one or more steps or apparatuses and may include sub-steps as well as sub-apparatuses. All conjunctions used should be understood in the broadest sense. And, the word "or" should be understood to have the definition of a logical "or" rather than the definition of a logical "exclusive or" unless the context clearly dictates otherwise. Further, implementation of the methods and/or apparatus of embodiments of the present invention may include performing the selected task manually, automatically, or in combination.
The above description is only for the preferred embodiment of the present invention, and does not limit the present invention. Any technical personnel who belongs to the technical field, in the scope that does not deviate from the technical scheme of the utility model, to the technical scheme and the technical content that the utility model discloses expose do the change such as the equivalent replacement of any form or modification, all belong to the content that does not break away from the technical scheme of the utility model, still belong to within the scope of protection of the utility model.