JP5053004B2 - Semiconductor chip mounting apparatus and method - Google Patents

Description

  The present invention relates to a semiconductor chip mounting apparatus for bonding a semiconductor chip to a heated substrate, and a mounting method thereof.

  In general, a semiconductor chip is bonded to a base material such as a circuit board as follows. As shown in FIG. 8A, a single semiconductor wafer 100 is adhered to a wafer sheet 102 via a film-like bonding material 101. The semiconductor wafer 100 and the bonding material 101 are cut into a lattice shape by a dicer (diamond wheel) 200 and divided into individual semiconductor chips 103.

  Next, as shown in FIG. 8B, the wafer sheet 102 is radially expanded by an expanding device (not shown) to increase the interval between the semiconductor chips 103. Then, as shown in FIG. 8C, one semiconductor chip 103 is pushed up from below the wafer sheet 102 by the pushing member 300, and the edge of the bonding material 101 is peeled off from the wafer sheet 102. The semiconductor chip 103 in the pushed up state is attracted and picked up by the collet 400 together with the bonding material 101.

  After the semiconductor chip 103 is picked up, as shown in FIG. 8D, the semiconductor chip 103 is transported onto the base material 600 heated in advance by the heater 500, and the semiconductor chip 103 is pressed against the base material 600 by the collet 400. . The bonding material 101 is softened by the heat of the heated base material 600, and the semiconductor chip 103 is bonded to the base material 600. In this way, the process of picking up semiconductor chips one by one with a collet and bonding them onto the substrate is repeated.

  However, when the bonding process of the semiconductor chip is repeated as described above, the heat of the base material is transmitted to the collet through the semiconductor chip, and the collet is gradually heated. When the collet is heated above a certain temperature (for example, 40 ° C.), when the semiconductor chip is picked up by the collet, the heat of the collet is conducted to the bonding material on the back of the semiconductor chip, and the semiconductor chip becomes a wafer sheet. Stick on. Due to the bonding of the bonding material, there is a problem that the semiconductor chip cannot be stably picked up from the wafer sheet.

In order to solve the above problem, for example, a semiconductor chip mounting apparatus disclosed in Patent Document 1 has been proposed. This mounting apparatus includes a cooling blow nozzle capable of injecting a cooling fluid. And it cools by injecting a cooling fluid to a collet from a cooling blow nozzle, and it suppresses that a collet heats at the time of bonding.
JP 2006-120657 A

  In order to suppress the heating of the collet at the time of bonding, it is also effective to reduce the heat conducted from the base material to the collet, in addition to actively cooling the collet as in Patent Document 1 described above. For example, if the contact time between the collet and the semiconductor chip during bonding can be shortened, the amount of heat of the base material conducted to the collet through the semiconductor chip can be reduced.

  However, in order to securely bond the semiconductor chip, it is necessary to press the semiconductor chip for a predetermined time (about 1 to 2 seconds). In the configuration of the mounting apparatus disclosed in Patent Document 1, the collet and the semiconductor chip in the bonding process It was not possible to shorten the contact time.

  In view of the above problems, the present invention provides a semiconductor chip mounting apparatus and method that can shorten the contact time between a collet and a semiconductor chip in a bonding process.

According to a first aspect of the present invention, there is provided a semiconductor chip mounting apparatus including a collet that sucks and picks up a semiconductor chip on a suction surface on which a suction port is formed and bonds the semiconductor chip to a heated substrate. When bonding to the base material, a fluid is blown out from the suction port to form a pressurized fluid layer between the adsorption surface and the semiconductor chip, and the collet is formed while the pressurized fluid layer is formed. Is configured to be completely non-contact with the semiconductor chip .

  When bonding, the fluid blown out from the collet suction port flows between the suction surface of the collet and the semiconductor chip, thereby forming a pressurized fluid layer. With this pressurized fluid layer, the semiconductor chip is pressed and bonded to the substrate. Further, since the collet and the semiconductor chip are brought into a non-contact state by interposing the pressurized fluid layer, the heat of the base material is not conducted to the collet through the semiconductor chip during this period. Further, the collet is cooled by the fluid blown from the suction port.

  According to a second aspect of the present invention, in the semiconductor chip mounting apparatus according to the first aspect, an ejection port for blowing out the fluid is formed on the suction surface independently of the suction port.

  At the time of bonding, fluid is ejected from the ejection port to form a pressurized fluid layer between the collet adsorption surface and the semiconductor chip. As in the case of the first aspect, the semiconductor chip is pressed against and bonded to the substrate by the pressurized fluid layer. Further, since the collet and the semiconductor chip are brought into a non-contact state by interposing the pressurized fluid layer, the heat of the base material is not conducted to the collet through the semiconductor chip during this period. Further, the collet is cooled by the fluid blown out from the injection port.

  According to a third aspect of the present invention, in the semiconductor chip mounting apparatus according to the second aspect, a plurality of the injection ports are formed on the suction surface, and the injection ports are arranged symmetrically with respect to the center of the suction surface. It is set.

  Since each injection port is arranged symmetrically with respect to the center of the suction surface, the pressing force by the pressurized fluid layer acts uniformly on the semiconductor chip. Thereby, the bonding precision to the base material of a semiconductor chip improves.

  According to a fourth aspect of the present invention, in the semiconductor chip mounting apparatus according to any one of the first to third aspects, the fluid is a cooling medium.

  It is possible to enhance the cooling effect of the collet by blowing out the cooling medium from the suction port or the injection port of the collet.

According to a fifth aspect of the present invention, in the semiconductor chip mounting method, the semiconductor chip is picked up and picked up by the suction surface on which the suction port of the collet is formed, and the semiconductor chip is bonded to a heated substrate with the collet. When bonding the semiconductor chip to the base material, a step of pressing the semiconductor chip against the base material with the collet, and a fluid is blown out from the suction port so that a pressurized fluid layer is formed between the suction surface and the semiconductor chip. And forming the pressurized fluid layer completely in contact with the semiconductor chip, and pressing the semiconductor chip against the substrate by the pressurized fluid layer. And completing the bonding.

  Since the collet and the semiconductor chip are brought into a non-contact state by interposing the pressurized fluid layer, the heat of the base material is not conducted to the collet through the semiconductor chip during this period. Further, the collet is cooled by the fluid blown from the suction port.

  According to a sixth aspect of the present invention, in the semiconductor chip mounting method according to the fifth aspect, after the semiconductor chip is bonded to the base material, the suction port is used until the next semiconductor chip is picked up by the collet. This is a method for blowing out the fluid.

  After the bonding, the collet is cooled by the fluid blown out before the next chip is picked up. In other words, the collet is reliably cooled by ensuring a long fluid blowing time.

The invention of claim 7 is a method for mounting a semiconductor chip, wherein the semiconductor chip is adsorbed and picked up on a suction surface on which a suction port of a collet is formed, and the semiconductor chip is bonded to a heated substrate with the collet. When bonding the semiconductor chip to the base material, the step of bringing the semiconductor chip adsorbed by the collet close to the base material, and blowing out a fluid from the suction port to drop the semiconductor chip onto the base material Forming a pressurized fluid layer between the adsorption surface and the semiconductor chip, and making the collet completely non-contact with the semiconductor chip while forming the pressurized fluid layer ; And the step of pressing the semiconductor chip against the base material by the pressurized fluid layer to complete the bonding.

  In this bonding process, the collet does not come into contact with the base material via the semiconductor chip. Therefore, the heat of the base material is not conducted to the collet through the semiconductor chip.

  According to the present invention, during bonding, the semiconductor chip is pressed against the substrate by the air pressure (pressurized fluid layer) blown from the collet, so that the contact time between the collet and the semiconductor chip can be shortened. Thereby, the heat transmitted from the base material to the collet through the semiconductor chip at the time of bonding can be reduced, and the heating of the collet can be suppressed. Then, in the subsequent pick-up process, sticking of the bonding material due to heat transfer from the collet to the bonding material on the back surface of the semiconductor chip can be prevented.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
1 and 2 are schematic configuration diagrams showing an embodiment of a semiconductor chip mounting apparatus according to the present invention. As shown in FIGS. 1 and 2, the mounting apparatus of the present invention includes a collet 1 having a suction port 70 for picking up a semiconductor chip, a collet holder 2 that holds the collet 1, a vacuum generator 3, and a fluid. A supply device 4, a switching valve 5 that selectively connects the vacuum generator 3 and the fluid supply device 4 to the suction port 70 of the collet 1, and a control unit 6 that controls the switching valve 5 are provided.

  In addition, the mounting apparatus of the present invention includes a horizontal movement mechanism that horizontally moves the collet 1 and the collet holder 2 between a pickup position for picking up a semiconductor chip and a bonding position for bonding the semiconductor chip to a substrate, The collet 1 and the collet holder 2 are provided with a lifting mechanism that lifts and lowers the pickup position and the bonding position (not shown).

  The collet 1 and the collet holder 2 are continuously formed with air holes 7. The lower end of the vent hole 7 is open to the suction surface 1 a of the collet 1, and the opening is the suction port 70.

  FIG. 3 is a view showing the suction surface 1 a of the collet 1. As shown in FIG. 3, in this embodiment, five suction ports 70 are opened on the suction surface 1a. Specifically, suction ports 70 are respectively formed at the center and four corners of the suction surface 1a formed in a quadrilateral shape, and these suction ports 70 are symmetrical with respect to the center of the suction surface 1a. The shape of the suction surface 1a of the collet 1 and the number, size, or position of the suction ports 70 are not limited to the embodiment shown in FIG.

  The vacuum generator 3 and the fluid supply device 4 are each composed of, for example, a vacuum pump and an air compressor. The switching valve 5 is a three-port type electromagnetic switching valve 5. The two ports of the switching valve 5 are connected to the vacuum generation device 3 and the fluid supply device 4 via pipe lines 8 and 9, respectively, and the remaining one port of the switching valve 5 is connected to the vent hole 7. Connected to the common conduit 10. By switching the switching valve 5 with the control unit 6, the flow paths 8 and 9 connected to the vacuum generator 3 and the fluid supply apparatus 4 are configured to selectively communicate with the common pipe 10. .

  That is, when the switching valve 5 is in the state shown in FIG. 1, the vacuum generator 3 and the common conduit 10 are in communication, and air is sucked from the suction port 70 of the collet 1. When the switching valve 5 is in the state shown in FIG. 2, the fluid supply device 4 and the common conduit 10 communicate with each other, and air is blown out from the suction port 70.

  Moreover, as shown in FIG. 4, you may form in the suction surface 1a of the collet 1 the injection port 70a for blowing off air independently from the suction port 70b for sucking air. For example, the collet 1 and the collet holder 2 are each independently provided with an injection vent hole 7a and a suction vent hole 7b, and the fluid supply device 4 is connected to the injection vent hole 7a in communication with the suction vent hole 7a. The vacuum generator 3 is connected in communication with the vent hole 7b. A plurality of these injection ports 70a and suction ports 70b may be provided.

Hereinafter, a semiconductor chip mounting method using the mounting apparatus will be described with reference to FIGS.
5A shows a semiconductor wafer cutting process, FIG. 5B shows an expanding process, and FIG. 5C shows a semiconductor chip pick-up process. 6A and 6B show a semiconductor chip bonding process.

  First, as shown in FIG. 5 (A), a semiconductor wafer 13 disposed on a wafer sheet 11 via a film-like bonding material 12 is cut together with the bonding material 12 by a dicer 14 to obtain a large number of semiconductors. Divide into chips 15. Next, as shown in FIG. 5B, the wafer sheet 11 is radially expanded by an expanding device (not shown) to increase the interval between the semiconductor chips 15.

  As shown in FIG. 5C, one of a large number of semiconductor chips 15 is pushed up by a pushing member 16. The collet 1 is moved above the pushed-up semiconductor chip 15 (pickup position), and the collet 1 is moved closer to the semiconductor chip 15. At this time, the switching valve 5 is in the state shown in FIG. 1, and the semiconductor chip 15 is adsorbed to the collet 1 by the air sucked from the suction port 70 of the collet 1. Then, the semiconductor chip 15 is picked up while being sucked by the collet 1 and transported to the bonding position.

Next, the bonding process which is a characteristic part of the present invention will be described.
As shown in FIG. 6A, the semiconductor chip 15 picked up at the pick-up position is arranged above the base material 17 (bonding position) heated by the heater 18. Then, the collet 1 is lowered and the semiconductor chip 15 is pressed against the base material 17 for a predetermined time.

  Thereafter, the switching valve 5 is switched to the state shown in FIG. 2, and air is blown out from the suction port 70 for a predetermined time as shown in FIG. 6 (B). A uniform pressurized fluid layer is formed between the suction surface 1 a of the collet 1 and the semiconductor chip 15 by the blown-out air. That is, at this time, the collet 1 is slightly lifted upward by the pressurized fluid layer, and the collet 1 and the semiconductor chip 15 are in a non-contact state. On the other hand, the semiconductor chip 15 is pressed against the base material 17 by the air pressure (pressurized fluid layer) blown out from the suction port 70. Further, since these suction ports 70 are symmetrical to each other with respect to the center of the suction surface 1a, uniform air pressure acts on the semiconductor chip 15.

  By the pressing by the collet 1 and the subsequent pressing by the pressurized fluid layer, the heat of the base material 17 is transmitted to the bonding material 12 on the back surface of the semiconductor chip 15 to be softened, and the semiconductor chip 15 is bonded to the base material 17. Then, after finishing the bonding process, the collet 1 is moved to the pickup position of the next semiconductor chip 15, and the switching valve 5 is switched to the suckable state shown in FIG. Thereafter, similarly, the pickup process and the bonding process are repeated.

  In the present invention, the semiconductor chip 15 can be pressed against the substrate 17 by air pressure (pressurized fluid layer) blown from the collet 1 during bonding. In other words, the semiconductor chip 15 can be bonded while the collet 1 and the semiconductor chip 15 are not in contact with each other for a predetermined time. Therefore, in the bonding process, the contact time between the collet 1 and the semiconductor chip 15 can be shortened. Thereby, the heat transmitted from the base material 17 to the collet 1 through the semiconductor chip 15 can be reduced, and the heating of the collet 1 can be suppressed.

  Further, the air blown out from the suction port 70 flows along the suction surface 1a of the collet 1, whereby the suction surface 1a of the collet 1 is cooled. In this embodiment, the fluid supplied from the fluid supply device 4 is air. However, an inert gas such as nitrogen is supplied so that the semiconductor chip or the like is not oxidized during bonding, or the cooling effect of the collet 1 is increased. A cooling medium may be supplied for further improvement.

  And by suppressing the heating of the collet 1 in the said bonding process, the heat conduction from the collet 1 to the joining material 12 in a subsequent pick-up process can be suppressed. Thereby, it becomes possible to prevent the bonding material from sticking to the wafer sheet during pickup.

Further, another bonding process of the present invention will be described with reference to FIGS. The pickup process is the same as that described with reference to FIG.
As shown in FIG. 7A, the semiconductor chip 15 picked up at the pick-up position is brought close to the base material 17 heated by the heater 18. At this time, the semiconductor chip 15 is held in a state slightly separated from the base material 17 while being adsorbed to the collet 1.

  Then, the switching valve 5 is switched to the state shown in FIG. 2, and air is blown out from the suction port 70 for a predetermined time as shown in FIG. 7B. As a result, the semiconductor chip 15 adsorbed and held on the collet 1 falls onto the base material 17, and the pressurized fluid layer formed uniformly between the collet 1 (adsorption surface 1 a thereof) and the semiconductor chip 15. Thus, the semiconductor chip 15 is pressed against the base material 17.

  By the pressing by the pressurized fluid layer, the heat of the base material 17 is transmitted to the bonding material 12 on the back surface of the semiconductor chip 15 to be softened, and the semiconductor chip 15 is bonded to the base material 17.

  According to the bonding method shown in FIG. 7, the collet 1 can bond the semiconductor chip 15 without contacting the substrate 17 at all (via the semiconductor chip 15). Therefore, the heat of the base material 17 is not conducted to the collet 1 through the semiconductor chip 15 and the heating of the collet 1 is prevented. In the case of this embodiment, when the semiconductor chip 15 is dropped from the collet 1 onto the base material 17, a positioning mechanism is provided for placing the semiconductor chip 15 at a predetermined position on the base material 17 with high accuracy. May be.

  Further, after the bonding process and before the next semiconductor chip 15 is picked up, air may be blown out from the suction port 70 to ensure a sufficient cooling time for the collet 1.

  As mentioned above, although one Embodiment of this invention was described, this invention is not limited to the above-mentioned embodiment, Of course, a various change can be added in the range which does not deviate from the summary of this invention.

It is a schematic block diagram which shows one Embodiment of the mounting device of the semiconductor chip which concerns on this invention. It is a schematic block diagram which shows the state which switched the switching valve from the state shown in FIG. It is a principal part enlarged view which shows the adsorption surface of a collet. It is a schematic block diagram which shows other embodiment of this invention. It is a figure explaining the mounting method of the semiconductor chip of this invention, (A) is a figure which shows the cutting process of a semiconductor wafer, (B) is a figure which shows an expanding process, (C) is a figure which shows a pick-up process. It is a figure explaining the mounting method of the semiconductor chip of this invention, (A) (B) is a figure which shows a bonding process. It is a figure explaining the other mounting method of the semiconductor chip of this invention, (A) (B) is a figure which shows a bonding process. It is a figure explaining the mounting method of the conventional semiconductor chip, (A) is a figure which shows the cutting process of a semiconductor wafer, (B) is a figure which shows an expanding process, (C) is a figure which shows a pick-up process, (D) is a figure It is a figure which shows a bonding process.

Explanation of symbols

1 Collet 1a Adsorption surface 15 Semiconductor chip 17 Base material 70 Suction port 70a Ejection port 70b Suction port

Claims (7)

In a semiconductor chip mounting apparatus comprising a collet that sucks and picks up a semiconductor chip on a suction surface where a suction port is formed, and bonds the semiconductor chip to a heated substrate.
When bonding the semiconductor chip to the substrate, fluid is blown out from the suction port to form a pressurized fluid layer between the suction surface and the semiconductor chip, thereby forming the pressurized fluid layer. In the meantime , the semiconductor chip mounting apparatus is configured such that the collet is completely non-contact with the semiconductor chip.   2. The semiconductor chip mounting apparatus according to claim 1, wherein an ejection port for ejecting the fluid is formed on the suction surface independently of the suction port.   3. The semiconductor chip mounting apparatus according to claim 2, wherein a plurality of the ejection ports are formed on the suction surface, and the ejection ports are arranged symmetrically with respect to the center of the suction surface.   The semiconductor chip mounting apparatus according to claim 1, wherein the fluid is a cooling medium. In the semiconductor chip mounting method of adsorbing and picking up the semiconductor chip on the suction surface on which the suction port of the collet is formed, and bonding the semiconductor chip to a heated substrate with the collet,
A step of pressing the semiconductor chip against the substrate with the collet when bonding the semiconductor chip to the substrate;
A fluid is blown out from the suction port to form a pressurized fluid layer between the suction surface and the semiconductor chip. While the pressurized fluid layer is formed , the collet is completely attached to the semiconductor chip. A non-contacting process;
And a step of pressing the semiconductor chip against the substrate by the pressurized fluid layer to complete the bonding.   The semiconductor chip mounting according to claim 5, wherein the fluid is blown out from the suction port after the semiconductor chip is bonded to the base material and before the next semiconductor chip is picked up by the collet. Method. In the semiconductor chip mounting method of adsorbing and picking up the semiconductor chip on the suction surface on which the suction port of the collet is formed, and bonding the semiconductor chip to a heated substrate with the collet,
A step of bringing the semiconductor chip adsorbed by the collet closer to the base material when bonding the semiconductor chip to the base material;
A fluid is blown out from the suction port to drop the semiconductor chip onto the substrate, and a pressurized fluid layer is formed between the adsorption surface and the semiconductor chip, and the pressurized fluid layer is formed. While making the collet completely non-contact with the semiconductor chip ,
And a step of pressing the semiconductor chip against the substrate by the pressurized fluid layer to complete the bonding.

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