Patent Document

REFERENCE TO RELATED APPLICATION 
       [0001]    This application is a continuation application of U.S. patent application Ser. No. 14/150,439, now pending, the content of which is hereby incorporated by reference in its entirety. 
     
    
     TECHNICAL FIELD 
       [0002]    The present application relates to a method for flipping multiple semiconductor devices in wafer form or in chip form. 
       DESCRIPTION OF BACKGROUND ART 
       [0003]    In order to fit in the process of producing a semiconductor device or adjust by the limitation of the apparatus, the semiconductor device needs to be flipped so as to reverse the top surface and the bottom surface of the semiconductor device. 
         [0004]    Presently the flipping step is carried out manually. As a result, the flipping step requires human effort and is time-consuming, and furthermore, the semiconductor device during the flipping step is prone to damage. 
       SUMMARY OF THE DISCLOSURE 
       [0005]    A method for automatically transferring multiple semiconductor devices from a first substrate to a second substrate comprises steps of providing a first substrate on which the semiconductor device is formed, providing a second substrate directly under the first substrate, automatically moving the first substrate toward the second substrate such that the semiconductor devices are close to the second substrate; connecting the semiconductor devices to the second substrate by exerting force to the second substrate, and taking out the semiconductor devices simultaneously from the first substrate. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]      FIG. 1  is a diagram of the apparatus for flipping a semiconductor device in accordance with the present application; 
           [0007]      FIGS. 2   a  to  2   c  schematically show a semiconductor device fixed on an adhesive substance in accordance with an embodiment of the present application; 
           [0008]      FIG. 3  schematically shows a step of flipping the semiconductor device in accordance with an embodiment of the present application. 
       
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0009]    Exemplary embodiments of the present application will be described in detail with reference to the accompanying drawings hereafter. The following embodiments are given by way of illustration to help those skilled in the art fully understand the spirit of the present application. Hence, it should be noted that the present application is not limited to the embodiments herein and can be realized by various forms. Further, the drawings are not precise scale and components may be exaggerated in view of width, height, length, etc. Herein, the similar or identical reference numerals will denote the similar or identical components throughout the drawings. 
         [0010]      FIG. 1  is a diagram of the apparatus for flipping a semiconductor device in accordance with an embodiment of the present application. The apparatus for flipping a semiconductor device comprises: a platform  1  comprising an upper surface  1   a , a roller system  2  and a carrier  3  on the upper surface  1   a ; a positioning unit  5  comprising an upper surface  5   d  above the platform  1  and comprising a circular opening  5   a ; and an elevating unit  6  connecting the platform  1  and the positioning unit  5 . 
         [0011]    In the present embodiment, the roller system  2  comprises a roller  2   a  and a track  2   b , wherein the roller  2   a  moves along the track  2   b . The roller  2   a  comprises non rigid body or elastic material, such as rubber. More preferably, the roller  2   a  is composed of rubber. The roller  2   a  can roll and exert a downward pressure on an object. The roller  2   a  can roll with a constant speed, variable speed, or a constant acceleration. Besides, the shape of the roller  2   a  can be a cylinder or a barrel-shaped cylinder with two extending cylinder ends. Specifically, the barrel-shaped cylinder is defined as a cylinder having a lager thickness in the middle portion than the other portion. The carrier  3  comprises a heating unit (not shown). The apparatus for flipping a semiconductor device further comprises a fixture  3   a  on the carrier  3 . Besides, an adhesive substance (not shown) is adhered to the fixture  3   a , wherein the stickiness of the adhesive substance changes with the change of temperature. In the present embodiment, the adhesive substance can be a foam sealing agent. 
         [0012]    The positioning unit  5  is above the platform  1  and comprises the circular opening  5   a . Furthermore, a movable heater  4  is fixed on a pillar  7 . The pillar  7  can move along the vertical direction so as to change the position of the movable heater  4  above the positioning unit  5 . The elevating unit  6  is between the platform  1  and the positioning unit  5  and connects the platform  1  and the positioning unit  5 . The elevating unit  6  further comprises a pneumatic cylinder (not shown) for providing driving force. In the present embodiment, the elevating unit  6  comprises 4 adjustable uniaxial cylinders. The elevating unit  6  moves along the vertical direction so as to move the positioning unit  5  toward or away from the platform  1 . 
         [0013]    The apparatus for flipping a semiconductor device in accordance with the present application is capable of flipping a semiconductor device so as to reverse a top surface and a bottom surface of the semiconductor device, wherein the semiconductor device is in wafer form or in chip form, such as light-emitting diode wafer or light-emitting diode chip. In the present embodiment, the semiconductor device comprises multiple light-emitting diode chips  8 . The steps of the operation method of the apparatus for flipping a semiconductor device are described as follows. 
         [0000]    1. The light-emitting diode chips  8  are fixed on an adhesive substance  5   c  attached to an iron ring  5   b  as shown in  FIGS. 2   a  to  2   c . Specifically, referring to  FIG. 2   a , an iron ring  5   b  is provided. Referring to  FIG. 2   b , an adhesive substance  5   c  is applied to associate with the iron ring  5   b . In the present embodiment, the adhesive substance  5   c  can be an adhesive film. Referring to  FIG. 2C , the light-emitting diode chips  8  are fixed to the iron ring  5   b  by directly connecting each bottom surface of the light-emitting diode chips  8  to the adhesive substance  5   c , wherein each top surface of the light-emitting diode chips  8  faces upwardly. In the present embodiment, the stickiness of the adhesive substance  5   c  changes with the change of the temperature, and the change of the stickiness does not contaminate and affect the light-emitting diode chips  8 .
 
2. The iron ring  5   b  is fixed to the positioning unit  5 . Specifically, the iron ring  5   b  attached to the adhesive substance  5   c  is fixed at the circular opening  5   a  and each top surface of the light-emitting diode chips  8  faces downwardly while the positioning unit  5  is at a position where a distance between the upper surface  5   d  of the positioning unit  5  and the upper surface  1   a  of the platform  1  is D, wherein the position is defined as starting position.
 
3. The positioning unit  5  is set to a predetermined position. Specifically, referring to  FIG. 3 , a substrate (not shown) is disposed on the fixture  3   a , wherein the substrate comprises Al 2 O 3 . Besides, an adhesive substance (not shown) such as a foam sealing agent is adhered to the substrate. The heating unit of the carrier  3  is then turned on to heat the adhesive substance so as to enhance the stickiness of the adhesive substance. The relative position and the distance between the circular opening  5   a  and the fixture  3   a  of the carrier  3  are adjusted by moving the elevating unit  6  so as to facilitate the following flipping step. In the present embodiment, the distance d between the iron ring  5   b  and the fixture  3   a  is not more than 0.2 cm.
 
4. The light-emitting diode chips  8  are flipped. Specifically, referring to  FIG. 3 , after the positioning unit  5  being completely set to the predetermined position, the roller  2   a  rolls and exerts a downward pressure while moving along the track  2   d  as shown in  FIG. 1 . In the present embodiment, the roller  2   a  rolls on the surface of the adhesive substance  5   c  attached to the iron ring  5   b  back and forth at least one time. In general, the movement of the rolling and exerting a downward pressure of the roller  2   a  can be carried out by a programmable logic controller (PLC) (not shown). The pillar  7  then moves downwardly to change the position and the distance of the movable heater  4  above the adhesive substance  5   c  attached to the iron ring  5   b . The movable heater  4  is then turned on to heat the adhesive substance  5   c  so as to change the stickiness of the adhesive substance  5   c  with the change of the temperature. As a result, the light-emitting diode chips  8  that were originally adhered to the adhesive substance  5   c  are now transferred to the adhesive substance of the substrate of the fixture  3   a . Finally, the top surface and the bottom surface of each light-emitting diode chip are reversed.
 
5. The positioning unit returns to the starting position.
 
6. The light-emitting diode chips  8  are taken out from the adhesive substance of the substrate of the fixture  3   a.  
 
7. In the present embodiment in accordance with the present application, the semiconductor device comprises multiple light-emitting diode chips  8 , wherein each light-emitting diode chip  8  comprises AlGaInP-based material, AlGaInN-based material or ZnO-based material.
 
         [0014]    The foregoing description of preferred and other embodiments in the present disclosure is not intended to limit or restrict the scope or applicability of the inventive concepts conceived by the Applicant. In exchange for disclosing the inventive concepts contained herein, the Applicant desires all patent rights afforded by the appended claims. Therefore, it is intended that the appended claims include all modifications and alterations to the full extent that they come within the scope of the following claims or the equivalents thereof.

Technology Category: b