KR100844347B1 - Reflow curing system and method for semi-conductor package - Google Patents

Abstract

A reflow curing system for A semiconductor package and a reflow curing method thereof are provided to obtain high quality by curing uniformly semiconductor packages stacked within a magazine. A transfer pallet(5) is loaded in an upper loading unit(10) while a plurality of packages are stacked in a container(3). A reflow chamber(20) is formed to cure a molding part of a stacked package while the transfer pallet is transferred to one side within a hot wind space. A first lifting plate(30) is formed to move the transfer pallet discharged from the reflow chamber in a vertical direction. A cooling unit(40) is positioned at a lower part of the loading unit in order to supply cold wind to the stacked package. A second lifting plate(50) is formed to move the transfer pallet in the vertical direction. A lower unloading unit(60) is installed between the cooling unit and the upper loading unit in order to draw the container from the transfer pallet.

Description

REFLOW CURING SYSTEM AND METHOD FOR SEMI-CONDUCTOR PACKAGE}

1 is a perspective view schematically showing the external structure of the curing apparatus of the present invention.

2 is a container loading state of the magazine in which the packages are stacked

Figure 3 is a side view showing the internal structure of the curing apparatus of the present invention.

Figure 4 is a front view showing the internal structure of the curing apparatus of the present invention.

5 is a transfer path diagram in the curing process of a semiconductor package.

Figure 6 is a flow chart of the curing process of the present invention.

Figure 7 is a schematic diagram of the temperature setting in the reflow chamber of the curing apparatus of the present invention.

Figure 8 is a graph of the temperature change of the total driving time in the present invention.

<Explanation of symbols for the main parts of the drawings>

1: package 2: magazine

3: container 3a: through-hole

4: handle 5: pallet

10: upper loading part 11: feed roller

13: input roller 14: output roller

20: reflow chamber 21: inlet door

22: exit door 23: blowing fan

24: heater 25: guide duct

26: hot air jet nozzle 27: hot air space

28: transfer chain 29: chain drive motor

30: lifting platform 31: lifting screw

32: guide rod 33: feed roller

40: cooling part 41: cooling fan

42: feed roller 50: 2nd platform

51: lifting cylinder 52: guide rod

53: feed roller 60: lower unloading part

61: guide rail 62: handle

63: feed roller

The present invention relates to a semiconductor package curing apparatus and a curing method using the same, and more particularly, to an apparatus and method for allowing mass production and high quality curing in the process of curing a semiconductor package in which a molding process is completed. will be.

In general, a semiconductor package assembly process includes a wafer sawing process for separating a wafer on which an integrated circuit is formed into respective semiconductor chips, and a die attach for mounting each semiconductor chip to a lead frame using predetermined bonding means. The die attach process, the wire bonding process of connecting the electrode pad of the semiconductor chip and the lead of the lead frame with fine metal wires, and the sealing of the semiconductor chip-mounted part with a molding resin to protect it from the external environment The molding process includes a molding process and a test process for verifying the reliability of the semiconductor package in which the molding process is completed, and additionally, various processes are additionally performed.

In particular, a curing process is performed after the molding process in the semiconductor package manufacturing process. The hardening process is a process for protecting internal semiconductor chips and fine metal wires from external chemical and mechanical stress by applying heat to a semiconductor package in which a molding process is completed for a certain time to stabilize molding resin properties.

Typically, after the molding process is completed, a lead frame strip is loaded into a storage container such as a magazine or a carrier, and then the storage container is placed in a semiconductor package curing apparatus and formed on the lead frame strip. The semi-finished semiconductor package is cured.

On the other hand, the conventional semiconductor package curing apparatus is a device having a curing oven capable of generating and maintaining heat at a predetermined temperature, and usually a plurality of storage containers are put into the curing oven at once to cure. Of course, the front door of the semiconductor package curing apparatus is provided so that the storage container can be entered.

However, in the case of such a conventional curing device, since the hardening operation is performed in a state in which each package is loaded in a magazine unit, there is a problem in that production yield is limited and production efficiency is lowered.

In addition, the inter-process movement of the package constitutes a planar movement path, which inevitably increases the workplace area occupied by the facility, thereby increasing the space charge and the worker's movement.

The present invention has been proposed to improve the above problems in the prior art, and the object of the present invention is to maximize the package yield by allowing the curing process to be made in large quantities by continuous operation in a state where a plurality of packages are loaded in a container unit. have.

In addition, another object of the present invention is to improve the space utilization while minimizing the worker's work line by providing a device facility that the curing movement path of the package can be made in the horizontal and vertical direction.

The object of the present invention is that in the process of transporting the loading unit and the transport pallet introduced from the loading unit is seated together with the transport pallet in a state where a plurality of molding packages are stacked in the container is transferred to one side in the hot air space inside A reflow chamber in which the molded part of the loaded package is hardened, a first platform for moving up and down in a vertical direction, and a transport platform discharged from the reflow chamber, and a lower part of the loading part A cooling unit for supplying cold air to the package loaded in one side of the conveying pallet conveyed by the lifting platform, a second lifting platform for vertically moving the conveying pallet via the cooling unit upward, the cooling unit and the loading unit It is installed at the intermediate height between the vessels of the container from the transportation pallet which is raised by the second platform. It is a structure including a an unloading provided to enable it is possible to achieve through the semiconductor package curing device, characterized by yirum.

Hereinafter, specific embodiments of the present invention will be described in detail with reference to the accompanying drawings.

First, looking at the overall device configuration for the operation of the curing equipment according to the present embodiment, the upper loading portion 10 for the initial transfer of the pallet (5) for the transfer of the package 1 is configured on the front of the device, the transfer The reflow chamber 20 is installed to cure the package 1 formed at a high temperature atmosphere. The package loading pallet 5 discharged to the outlet side of the reflow chamber 20 is disposed at one side of the upper loading part 10. The first platform 30 is configured to drive the empty pallet 5 up and down to the upper loading part 10 after the lowering or the package 1 is carried out in the vertical direction to move toward the cooling part 40 of the apparatus. On the opposite side to the first platform 30, a second platform 50 for raising the package loading pallet 5 via the cooling unit 40 is configured, the upper loading unit 10 and the cooling unit 40 Between the height of the second platform 50 A lower unloading unit (60) for projecting toward the front of the raised package loading pallet 5 through consisted.

As shown in FIG. 2, a plurality of packages 1 to be cured are mounted in a stacked form at a predetermined height in the magazine 2, and these magazines 2 are provided with a plurality of through holes 3a. Formed to be stored in the container 3 is formed is to be provided on the pallet (5). Reference numeral 4 denotes a handle.

In addition, the upper loading unit 10 is provided with a transport roller 11 for transporting the pallet 5 to one side at regular intervals along the guide rail 12, and on one side, the transported pallet 5 includes a reflow chamber ( 20) The input roller 13 for moving to an entrance side is comprised so that lifting by a lower up-down cylinder (not shown) is possible.

On the other hand, the reflow chamber 20 is configured to open and close the inlet door 21 on one side, the outlet door 22 is configured on the other side, the inside is entered through the inlet side by the input roller 13 The conveying chain 28 for conveying the pallet 5 to the exit side is configured on both sides of the lower side, and a plurality of hot air spray nozzles 26 are installed on the side wall along the moving path of the package loading pallet 5 and hot air. A blowing fan 23 for forcibly blowing air along the guide duct 25 toward the injection nozzle 26 is provided at the upper part of the chamber, and the heater 24 is mounted on the guide flow path of the blower air, It is configured to exchange heat with high temperature hot air during the movement. An opening / closing cylinder (not shown) for opening and closing operations of the inlet door 21 and the outlet door 22 is configured. Reference numeral 29 denotes a chain drive motor for driving the transfer chain 28.

In addition, the output roller 14, which is driven up and down by an up-down cylinder (not shown), is transported to the upper surface of the first platform 30 to assist withdrawal of the pallet 5 discharged from the outlet side of the reflow chamber 20. It was configured with a roller 33. In addition, one side of the first lifting platform 30 is provided with a lifting screw 31 penetrating in a vertical direction in the vertical direction, the lifting screw 31 receives power from the upper drive motor (not shown). The guide rods 32 are provided on both sides of the elevating screws 31 to support the stable elevating operation of the elevating platforms 30 and 50.

The second elevating platform 50 is configured such that the elevating drive is performed from the lower floor to the second floor by the elevating cylinder 51, and the guide rod 52 for supporting the elevating drive is installed in the vertical direction. Reference numeral 53 denotes a feed roller configured in the second platform 50.

In addition, while the cooling unit 40 at the bottom of the apparatus is provided with a plurality of cooling fans 41 for blowing cold air to the package 1 formed of high temperature curing, the transfer rollers 42 are configured at regular intervals. have.

In addition, the lower unloading part 60 is provided with guide rails 61 on both sides so as to be able to move horizontally back and forth, and a handle 62 is provided on the front side, and a transfer roller 63 for conveying the pallet 5. ) Is mounted at regular intervals.

Each of the transfer rollers 11, 42, and 63 of the above configuration is provided with a conventional motor roller (or power roller) forming a structure of an internal stator and an external rotor so that self rotation is performed by an electric action force without transmitting power from the outside. This is preferred.

In addition, the input roller 13 and the output roller 14 are configured in a symmetrical form at the same position in the reflow chamber 20. Rotational driving is performed, but the lower driving unit is judged to be a conventional technology, and thus detailed description of components will be omitted.

On the other hand, looking at the apparatus of the present invention, since the upper loading portion 10, the lower unloading portion 60 and the cooling portion 40 forms a vertical arrangement structure by varying the height at the same position, the pallet 5 It can be seen that the structure that can maximize the space utilization for the movement path.

The effects of the operation of the curing apparatus system of the present invention constituting such a device configuration will be described with reference to FIGS. 5 to 8.

First, in a state in which the magazine 2 loaded with the package 1 in a stacked form is mounted on the container 3, the worker places the container 3 together with the pallet 5 on the upper loading part 10. The roller 11 is gradually transferred to one side and moved to the inlet door 21 side of the reflow chamber 20. (ST 1)

At this time, when the pallet 5 detection signal is transmitted to the control unit by a sensor (not shown) mounted on the inlet door 21 side, the control unit applies a driving signal to the opening / closing cylinder to raise the inlet door 21 while the inlet is raised. At the same time, as the input roller 13 is simultaneously driven up and raised in a protruding form by an up-down cylinder operation, the pallet 5 is converted into a right direction at right angles to enter the reflow chamber 20.

In this way, the package loading pallet 5 that enters the inlet of one side of the reflow chamber 20 is hardened at a high temperature in the process of being transferred to the outlet of the other side via the hot air space 27.

That is, the transport path in the reflow chamber 20 can be divided into four sections according to the temperature change, of which the temperature of the package 1 for moving the hot air space 27 gradually increases in the initial stage of entry. The preheating process (ST 2-1) is performed, and when the temperature reaches a certain temperature, the activation process (ST 2-2) is performed to keep the temperature constant, and then the heating process further increases the curing temperature (ST 2-). After 3), the reflow process (ST 2-4) of maintaining the temperature again is sequentially performed.

FIG. 7 illustrates an example of a change in temperature of each package transfer section in the reflow chamber 20 as an experimental example. As illustrated, in the initial preheating process (ST 2-1), the internal temperature is increased to about 90 to 110 ° C. FIG. Raise the activation process (ST 2-2) to activate the molded part of the package (1), and then in the heating process (ST 2-3) to increase the temperature in the chamber to 130 ~ 150 ℃ again reflow process (ST In 2-4), it was confirmed that the molding part was completely cured.

As such, the reason why the activation process (ST 2-2) and the reflow process (ST 2-4) for maintaining the curing temperature of the package 1 to be maintained for a predetermined time is performed in the second stage is the magazine (2). The package (1) located in any one of the plurality of packages (1) inserted in the stack to ensure that the uniform and excellent curing quality is always shown, and the curing quality is improved through a separate activation process It becomes possible.

On the other hand, when the package 1, which has undergone high temperature curing in the reflow chamber 20, reaches the end of the chamber, the exit door 22 is opened and opened, and at the same time, the outside of the chamber is driven by the upward / outward driving of the output roller 14. The first platform 30 is lowered by the rotation of the elevating screw 31 received power from the drive motor (not shown), and then cooled down to form a state seated on the upper surface of the first platform 30. It is located on one side of the same height as the portion 40. (ST 3)

In addition, the pallet 5 which is lowered together with the first platform 30 is supplied and passed to the cooling unit 40 by the transport roller 33 of the platform and the transport roller 42 of the cooling unit 40. In this process, cooling of the package 1 is performed by forced blowing of a plurality of cooling fans 41 provided. (ST 4)

Then, when the pallet (5) passes through the cooling unit 40 and is located in the second platform 50, the second platform 50 is elevated by driving the lifting cylinder 51 to lower the unloading unit 60 After being positioned at the same height as (ST 5), a discharge waiting state is achieved by driving the transport rollers 53 of the lift table and the transport rollers 63 of the lower unloading unit 60.

In this state, when the operator pulls the handle 62 formed on the front side of the unloading part 60 to the front side, the lower unloading part 60 is protruded toward the front side along the guide rail 61, and thus the pallet (5) After the operator lifts the container 3 seated on the handle 4 using the handle 4 to move to the next work process, the unloading part 60 in which only the empty pallet 5 remains is pushed back to its original position. (ST 6)

At this time, the first lifting platform 30 is in the state of being raised at the same height as the lower unloading unit 60, in this state, the lower unloading unit 60 in the continuous feed roller 63 to drive the The empty pallet 5 is moved to one side to form a state seated on the first platform 30, and then the first platform 30 is raised to the uppermost height by the lifting screw 31 driving the pallet (5) is to return to the original position by moving horizontally to the upper loading portion 10 which is the initial working position to achieve a standby state for seating the container 3 to be the next work. (ST 7)

Therefore, the curing of the plurality of packages 1 carried by the pallet 5 in the process of the circulation process of the pallet (5) is made efficiently, and the continuous operation can be made, so that mass production of the product It can be seen that it can be achieved.

The present invention as described above, the curing of the molded semiconductor package is a whole package provided therein with a continuous transfer operation after a plurality of packages are stacked in a container again stacked in a magazine unit in a group unit Exhibits a uniform curing state as a whole, thereby producing a large amount of continuous production of high quality products.

In particular, while the setting temperature in the reflow chamber can be stably maintained within the setting range, the curing quality of the package can be maximized by allowing the curing to be carried out in two steps by varying the temperature.

In addition, the transport path of the package is not only horizontal but also vertical, making it possible to make full use of the entire space of the facility, thereby minimizing the area occupied by the facility, thereby reducing worker traffic. It shows the advantage to improve.

In addition, the empty pallet after the unloading of the package is lifted up again through the platform to be returned to the initial loading position, so that the continuous repetitive work can be performed.

Claims (5)

An upper loading part 10 in which a plurality of packages 1 formed with molding are stacked together with the transfer pallet 5 in a state in which the plurality of packages 1 are stacked in the container 3; The reflow chamber 20 which hardens the molding part of the package 1 loaded in a process in which the transfer pallet 5 introduced from the upper loading part 10 is transferred to one side in the hot air space 27 therein. ; A first lift table 30 which moves the transport pallet 5 discharged from the reflow chamber 20 in a vertical direction; Located in the lower portion of the upper loading portion 10, the cooling unit 40 for supplying cold air to the package (1) loaded in one side transfer process of the transport pallet (5) conveyed by the first platform 30 ; A second lifting platform 50 for vertically moving the transfer pallet 5 via the cooling unit 40 upward; It is provided at the intermediate height between the cooling unit 40 and the upper loading portion 10, the lower portion provided to enable the carrying out of the container (3) from the transport pallet (5) raised by the second platform 50 Unloading unit (60); semiconductor package curing apparatus characterized in that it comprises a configuration comprising. The method according to claim 1, The reflow chamber 20 may include a blower fan 23 installed at an upper portion for forced flow of air, and a heater configured to heat the air flowing to the guide duct 25 by the blower fan 23. 24, and a plurality of hot air spray nozzles installed at different heights in order to spray the hot air heated by the heater 24 in a horizontal direction with respect to the package 1 provided in the container 3 to be transported in the chamber. A semiconductor package curing apparatus, characterized in that (26) is configured. The method according to claim 1, The upper loading unit 10 is provided with a transfer roller 11 for transferring the pallet 5 to one side at regular intervals, one side for moving the conveyed pallet (5) to the inlet side of the reflow chamber 20 The semiconductor package curing apparatus, characterized in that the input roller (13) is configured. The method according to claim 1, The container (3) is a plurality of through-holes (3a) is formed, the semiconductor package curing apparatus, characterized in that equipped with a magazine (2) in which a plurality of packages (1) are stacked stacked. Package loading step of seating the transport pallet provided with a plurality of packages on the upper loading unit; (ST 1) In the curing of the package molding part by passing the loaded package into a high temperature chamber, a preheating process (ST 2-1) for supplying hot air to the package entered into the chamber and gradually warming it, Activation process to maintain for a certain time (ST 2-2), heating process to further increase the maintained temperature to high again (ST 2-3), and reflow process to maintain the set temperature to a high temperature for a certain time (ST 2) the curing step to proceed to (ST 2-4) A lowering driving step in which the cured package is moved downward in a vertical direction from one side of the apparatus by a lifting platform; (ST 3) Cooling step for horizontally moving the lowered package to the other side, via the cooling unit of the low temperature during the movement; (S 4) An upward driving step of raising the cooled package; (ST 5) An unloading step of horizontally moving the unpacked package to a height of the unloading part to facilitate carrying out; When the unloading step (ST 6) is completed, the empty pallet (5) is a pallet return step of being returned to the upper loading portion by the platform; (ST 7) comprising the step of hardening the semiconductor package.

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