JP2010050373A - Semiconductor manufacturing apparatus and manufacturing method of semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce a trimming process cost of a semiconductor chip and to shorten the lead time of manufacturing. <P>SOLUTION: An electrode part and a wiring part on a surface of the semiconductor chip until trimming is photographed, in a duration from a die-bond curing process to a wire bond process of a package assembling process. Then, the electrical properties are measured, and the wiring to be trimmed is decided by referring to production information, and the wiring part at an opening part of a protective film is irradiated by a laser for laser trimming. Accordingly, there is no need to trim the entire wafer, and the cost is reduced. Furthermore, the lead time for product shipment becomes shortened. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a semiconductor manufacturing apparatus and a semiconductor device manufacturing method that perform trimming in a package assembly process.

  In a semiconductor device that requires laser trimming, the voltage, current, frequency, etc. are finely adjusted by trimming a laser trimming fuse or wiring with a laser. Trimming means cutting or connecting a fuse or wiring, and is usually performed in a wafer state. A semiconductor device constituting a semiconductor integrated circuit such as an IC is then assembled into a package in a package assembly process.

  Specifically, if a customer specifies a voltage, current, or frequency for a semiconductor device that has a circuit that can adjust element characteristics by laser trimming, the semiconductor device is laser trimmed in the wafer state to adjust the element characteristics. Then, the wafer is diced and separated into individual semiconductor chips, the separated semiconductor chips are fixed on the lead frame, and the lead frame terminals and the electrode pads of the semiconductor chip are connected by metal wires. Then, a resin mold is assembled and assembled into a package, and finally a final test is performed to check whether the semiconductor device has a characteristic value that meets the customer's required specifications, and the procedure is followed by shipping to the customer.

The laser trimming apparatus can perform trimming control with high accuracy, but is extremely expensive. Therefore, considering only the processing cost of the trimming process, it is possible to perform laser trimming in a wafer state where semiconductor chips are arranged in an orderly manner. It is advantageous to perform laser trimming in a wafer state. As shown in Patent Document 1, it is possible to perform trimming after assembling the package by packaging a part of the package using a material that can transmit laser light, but it is difficult to say that it is general.
JP-A-11-345940

  When laser trimming is performed in a wafer state, it is a production method that is easy to manage by processing only one wafer with the same function product having the same characteristics. However, with the progress of miniaturization of photolithography technology, the number of semiconductor chips collected per wafer has become very large, and even if the actual customer demand is much lower than one wafer, the production of one wafer unit can be reduced. In other words, it was necessary to carry out production, that is, it was necessary to produce a quantity exceeding the actual demand number, or to use an expensive manufacturing apparatus for the production of the part exceeding the actual demand quantity. In addition, even for the production of very few engineering samples based on the producer's circumstances and customer requirements, it is necessary to use a whole expensive wafer. Again, the use of raw materials far exceeding the actual demand and the actual demand Expensive manufacturing equipment is used for production of parts exceeding the above, and although it is necessary, raw materials and production time are wasted.

  In the future, if the diameter size of the semiconductor wafer as the raw material is further increased, the actual demand number may not increase and the portion exceeding the actual demand number may increase further. In that case, the amount exceeding the actual demand number itself is wasted, which increases the manufacturing cost, and for the storage of the staying storage made beyond the actual demand number in anticipation of future orders. In order to temporarily store storage space, waste that is originally unnecessary space is generated, and to maintain the environment such as temperature and humidity in order to prevent degradation of performance and maintain quality In other words, there are problems such as generation of so-called management costs.

  Furthermore, when trimming is performed in the wafer state, at least one entire wafer should be maintained in the processed state, so that all the semiconductor chips that have been trimmed have been trimmed. Until then, it was not possible to move to the next process. In other words, when processing in a wafer state, it is necessary to calculate the entire manufacturing lead time for one wafer.

  Summarizing the above issues, in the trimming process in the wafer state, raw materials and production time are wasted in order to produce more than necessary, management costs are incurred in the storage of manufactured stagnant products, manufacturing There were problems such as a long lead time.

  As a means for solving the above problem, for example, a part having a nonvolatile memory function is added to the inside of the semiconductor chip, and information related to the function and performance of the product is input to the nonvolatile memory unit and stored immediately before the package assembly is completed. There are methods for realizing the functions and performance of a given product. However, adding a portion having a nonvolatile memory function inside the semiconductor chip naturally increases the size of the semiconductor chip and reduces the number of semiconductor chips that can be produced with one wafer, and the memory performance of the nonvolatile memory unit. Because it is necessary to incur quality control costs for guarantees and confirmations, it will also lead to an increase in sales price by pushing up the manufacturing cost by both, and the market competitiveness of the product may decrease, Although it is a selectable means, it is hard to say that it is a rational method.

  As another means for solving the above problem, for example, at least one electrode lead-out wiring from the semiconductor chip is added to add a terminal as the semiconductor device external electrode, and the semiconductor device mounting substrate processor selects the external electrode There is a method of determining the function and performance of the entire semiconductor device mounting substrate by connection or disconnection. However, with such a method, since a new external electrode has to be prepared, there is a disadvantage that the semiconductor chip size is increased and the manufacturing cost of the semiconductor chip is relatively increased. This means that the burden on quality control costs, such as verifying the presence or absence of damage caused by selectively connecting or disconnecting external electrodes to the user, is still a selectable means, but it is a rational method. hard.

  In order to solve the above problems, the electrode part and wiring part on the surface of the semiconductor chip before trimming are photographed between the die bonding cure process and the wire bonding process in the package assembly process, and then the electrical characteristics are measured to produce The wiring to be trimmed is determined with reference to the information, and the laser trimming process is performed in which the wiring portion in the opening of the protective film is irradiated with laser.

  Specifically, the above problem is solved by using the following means.

  A semiconductor manufacturing apparatus for trimming a semiconductor device, comprising: a lead frame having a guide hole; a semiconductor chip fixed on the lead frame; a guide pin inserted into the guide hole to fix the lead frame; Optically photographing a transport part having a transport pin and a guide rail for supporting and guiding the lead frame from below, and a wiring part that is an electrode part and a protective film opening on the surface of the semiconductor chip, An electrical pre-image photographing unit that obtains electrode position information and wiring position information, and an electrical signal is applied to a semiconductor chip fixed on the lead frame based on the electrode position information and an electrical signal is obtained from the semiconductor chip. A pre-measurement unit that inspects the electrical characteristics of semiconductor chips before laser irradiation, and so-called production such as production type, quantity, and production conditions A production control unit that can input information and has a storage means for overall control of the entire production apparatus, the electrode position information and wiring position information from the pre-optical image photographing unit, and the electrical information obtained by the previous measurement unit Based on the characteristics and the production information instructed by the production control unit, a calculation unit for calculating the position coordinates of the wiring to be cut on the surface of the semiconductor chip, and the position coordinate information of the wiring to be cut from the calculation unit are received. A semiconductor manufacturing apparatus comprising: a laser irradiation unit that irradiates a wire in the wiring part of the semiconductor chip with a laser to melt the wiring.

  Further, in the semiconductor chip manufacturing method for adjusting the electrical characteristics of the semiconductor chip using laser trimming, the laser trimming process is after the die bond curing process included in the package assembly process and before the wire bonding process. A method for manufacturing a semiconductor device is provided.

  As described above, according to the present invention, the trimming method in the package assembling process can realize an extremely small lot size as compared with the wafer trimming method, so that it is easy to select a production type and a production quantity. There is no need to make more than the required number, greatly exceeding the demand. Therefore, drastically reducing the production of wasted inventory, minimizing the waste of spending operating time of expensive production lines on the production of wasted inventory, and manufacturing lead time with almost the same production cost Despite significant cost reductions, excess inventory management costs, and the cost of managing sample inventory for promotional purposes and the disadvantages of scheduling for preparing engineering samples It is possible to eliminate the waste of the wafer portion that uses the entire wafer. It is also possible to improve inventory management costs and production lead time for preparing engineering samples that are usually required to be delivered in a very short time.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 1, 2, and 3, the same portions are denoted by the same reference numerals, and redundant description is omitted. FIG. 1 is a schematic configuration diagram of a semiconductor device manufacturing apparatus according to an embodiment of the present invention. FIG. 2 is a schematic view of a semiconductor chip mounted on a lead frame according to an embodiment of the present invention. FIG. 3 is a schematic view of the surface of a semiconductor chip according to an embodiment of the present invention.

  1 mainly includes a production control unit 10, a calculation unit 20, a pre-optical image capturing unit 30, a pre-measurement unit 40, a laser irradiation unit 50, a transport unit 60, a lead frame 70, and a semiconductor chip 1. It is configured. The production control unit 10 includes a production information input unit 11 and a production information storage unit 12, and is a part that supervises so-called production information such as semiconductor product type information, production number information, calculation method, and processing position information. The control unit 20 allows the pre-optical image capturing unit 30, the pre-measurement unit 40, and the laser irradiation unit 50 to perform information communication with each other, thereby performing a series of control from image capturing to laser processing. It has a function of controlling the sequential processing by controlling the transport unit 60 including the guide pins 62 and the like to align and transport the lead frame 70. The pre-optical image photographing unit 30 gives the coordinate offset information of the semiconductor chip 1 fixed on the lead frame 70, and the pre-measurement unit 40 gives the electrical characteristic information of the semiconductor chip 1 to the computing unit 20. Based on this information, the position on the semiconductor chip to be trimmed is output to the laser irradiation unit 50. The laser irradiation unit 50 performs trimming by irradiating the semiconductor chip with laser based on the information received from the calculation unit 20. The above is a rough function and processing flow of each part.

  Usually, a semiconductor device is completed through a pre-process, an inspection process, and a package assembly process. In general, the package assembly process includes a dicing process, a die bond process, a die bond cure process, a wire bond process, a molding process, and the like. The present invention is characterized in that the semiconductor chip trimming process is performed in the package assembly process. It is. In the following, a process flow in which a trimming process is performed after the die bond curing process is completed and then wire bonding is performed will be described.

  The semiconductor wafer is diced through a dicing process to form the semiconductor chip 1 and is fixed on the lead frame 70 with silver paste or the like. FIG. 2 shows a state where a plurality of semiconductor chips 1 are mounted on one lead frame 70. The lead frame 70 is a thin plate made of a highly conductive metal such as copper, and the semiconductor chip 1 is fixed on the semiconductor chip mounting region 74, and a portion that will later become a terminal is processed around the semiconductor chip 1. Further, a lead frame defect marking area 72 is provided on the outer side, guide holes 71 are formed at the corners of the lead frame 4, and a lead frame information marking area 73 is provided on the opposite side of the lead frame. The guide hole 71 is a hole through which the guide pin 62 and the transport pin 63 enter and exit, and is necessary for fixing and transporting the lead frame. It should be noted that the lead frame defect marking region 72 and the lead frame information marking region 73 are not covered with a resin in a later molding process and can be visually confirmed. The lead frame defect marking area 72 is stamped with information for determining whether the semiconductor chip is good or bad, and the lead frame information marking area is stamped with the semiconductor type number, lot number, etc. of the semiconductor chip for identification in a later process. Useful.

  FIG. 1 shows a cross section of the lead frame 70 and the semiconductor chip 1 configured as described above. A plurality of semiconductor chips 1 are fixed on the lead frame 70 on the guide rail 61 constituting the transport unit 60, and when the semiconductor chip 1 comes to a position 2a immediately below the pre-optical image photographing unit 4, the next semiconductor on the right side. The chip 1 is at a position 2 b immediately below the front measurement unit 5, and the semiconductor chip 1 on the right side is at a position 2 c directly below the laser irradiation unit 50. A guide hole 71 is provided at the end of the lead frame, and a conveying pin 63 and a guide pin 62 are provided above and below. When the semiconductor chip 1 on the lead frame is stationary, guide pins 62 are inserted into the guide holes 71. The outer dimension of the guide pin 62 and the inner dimension of the guide hole 71 are substantially the same, and when the guide pin 62 is inserted into the guide hole 71, there is no play. On the other hand, when the semiconductor chip is to be transported, the guide pin 62 is removed from the guide hole 71, and the transport pin 63 is inserted instead to move the lead frame in the right direction in the figure.

  When the semiconductor chip 1 fixed on the lead frame 70 comes to the position 2a immediately below the pre-optical image capturing unit, the pre-optical image capturing unit 30 determines the electrodes of the semiconductor chip 1 based on the semiconductor type information received from the arithmetic unit 20. The electrode position information and the wiring position information are calculated from the video, and these are output to the calculation unit 20. The deviation from the position where the semiconductor chip should be is composed of a translational deviation and a rotational deviation and is expressed by three types of values (x, y, θ), but the electrode position information and the wiring position information are called (xs, ys). The data is converted into a shape and output to the calculation unit 7.

  The electrode part and wiring part to be photographed will be described with reference to FIG. FIG. 3 is a schematic view of the surface of the semiconductor chip. A plurality of electrode portions 3 called electrode pads are provided around the semiconductor chip, and a plurality of wirings 5a, 5b, 5c are not covered with the protective film 6 inside. ... the wiring part 4 with 5m exposed is shown. How much and how the positions of the plurality of electrodes and the plurality of wirings in the wiring part deviate from where they should be and are expressed by the aforementioned (xs, ys). A plurality of pieces of electrode portion position information corresponding to the number of electrode portions arranged above and a plurality of pieces of wiring position information corresponding to the number of wires are transferred to the arithmetic unit 20.

  When shooting is completed, the lead frame 70 moves to the right, and the semiconductor chip 1 comes to a position 2b immediately below the front measurement unit in FIG. A probe needle 41 is provided at the tip of the front measurement unit 40, the front measurement unit 40 performs position correction based on the electrode position information output from the calculation unit 20, and the probe needle 41 is the electrode unit of the semiconductor chip 1. It moves to the position where it can contact 3. When the probe needle 41 descends and contacts the electrode unit 3, a specific test program is selected based on the semiconductor type information obtained from the calculation unit 20, and an electrical signal for measurement is transmitted from the probe needle 41 to the electrode of the semiconductor chip. Applied to the part 3, the electrical characteristics of the semiconductor chip 1 are measured, and the previous measurement result is obtained. The obtained previous measurement result is sent to the calculation unit 20, and the calculation unit 20 calculates the coordinates of the wiring to be cut from the previous measurement result, the wiring position information, and the semiconductor type information, and stores it as trimming processing information. The calculated trimming processing information can be expressed as a set of positional information of a plurality of wirings to be cut among the wirings exposed in the wiring part of the semiconductor chip. For example, if eight wirings are exposed on the semiconductor chip and the target specifications of the semiconductor chip can be achieved by cutting three of the first, fourth, and sixth wirings, trimming information May be a set of three pieces of coordinate information of (xs1, ys1) (xs4, ys4) (xs6, ys6).

  When the measurement at the pre-measurement unit 40 is completed, the semiconductor chip 1 comes to a position 2c immediately below the laser irradiation unit in FIG. A laser light source unit 52 and a laser irradiation control unit 51 are attached to the laser irradiation unit 50. The laser irradiation control unit 51 receives trimming processing information from the calculation unit 20, corrects the position of the laser irradiation unit 50, and performs predetermined processing. This means that the wiring is melted by laser irradiation. The blown wiring reaches an electrically cut state, but the wiring not irradiated with the laser remains as it is without fusing. As in the above example, if the trimming information is a set of three pieces of coordinate information (xs1, ys1) (xs4, ys4) (xs6, ys6), the first and fourth of the eight wirings. The third three wires are irradiated with laser, and those wires are fused, but the remaining five wires are not irradiated with laser, and remain as they are.

  These series of operations, ie, production information determination, pre-optical imaging, pre-measurement, and laser irradiation, are repeatedly performed on multiple semiconductor chips and multiple lead frames on which semiconductor chips are mounted. It continues until the number (for example, 1 lot) to finish. In the lead frame 70 after the trimming process, the lead frame terminals and the semiconductor chip electrode pads are connected by metal wires in the wire bonding process, the semiconductor chip is resin-sealed in the molding process, and the package inspection process. The semiconductor device is completed through the final test.

  There are generally the following two types of structural unit, that is, lot size, related to the production of the production type to which the package assembly process trimming method is applied, depending on the configuration of the lead frame. That is, a so-called short type unified with a fixed length of about 300 mm length and a hoop-like ultra-long type in which the length of the lead frame is extended until it falls within the weight and size that can be transported and handled manually.

  In a production system that uses a short type, it is natural to take an integer multiple of the number of semiconductor chips mounted on the lead frame, and the processing order is always fixed in a fixed direction in any processing equipment. Has been done.

  On the other hand, in a production system that employs a hoop-shaped ultra-long type, after the completion of a certain group of processing steps, it is wound on a hoop take-up reel. In general, the order of the steps is reversed. However, if the pre-optical imaging, pre-measurement, and laser irradiation are maintained continuously, the problem of order reversal will not be hindered. In the hoop-like ultra-long type, the lot size can be selected by adjusting the length, and a smaller quantity than the short type can be selected.

  As described above, in either of the lead frame configurations, the lot size can be drastically reduced as compared with the production type determination method for each wafer described in the problem. As a result, the production number other than the necessary number, that is, the surplus number exceeding the actual demand is the final production number if the production control unit 10 has the production production number set to the quantity that anticipates the production yield after this process. It can be limited to a surplus slightly exceeding the number of semiconductor chips mounted on the lead frame.

  In addition, since it is possible to switch the production type to a unit determined by the number and length of lead frames, the waste of using manufacturing equipment for the production of parts exceeding the planned number of production can be reduced to the limit, and the operating rate of the manufacturing equipment is Even at the same time, it is possible to produce the necessary production varieties with very high equipment usage efficiency, and it is possible to realize the optimum number of production regardless of the quantity.

  In addition, by changing the production type based on the number and length of lead frames, it becomes possible to process various types of production using a single wafer made of the same semiconductor chip. There is no waste.

  Even for the creation of a very small number of engineering samples based on the producer's circumstances and customer requirements, the trimming method of the package assembly process according to this application can be produced in units of lead frames, and the waste that occurs is trimmed in the wafer state. It can be drastically smaller than the case.

  In addition, since the wafer state trimming process according to the present application shifts to the package assembly process trimming method, the manufacturing lead time can be reduced.

  The new processing equipment parts necessary for realizing the package assembly trimming process method according to the present application are the pre-optical image capturing part, the pre-measuring part, and the laser irradiation part, which are replaced with the laser trimming equipment in the wafer trimming process. In the case of wafer trimming, if it is an 8-inch wafer, a stage system that can move within a range of about 200 mm □ was required. However, in the case of package assembly process trimming, the moving range of the laser irradiation unit is a semiconductor. Since it is sufficient if it is about the size of several chips, it is much more compact than the wafer trimming method. This means that the manufacturing apparatus of the present system is cheaper than the conventional system.

  In the above, an example in which semiconductor chips are mounted in one row and three columns on the lead frame has been shown. However, the number of semiconductor chips mounted is not limited to this, and a plurality of rows and columns may be mounted. Absent.

  As described above, the effects of the present invention can be summarized. The package assembly process trimming processing method according to the present application can make the lot size of production varieties extremely small compared to the wafer trimming method, so that it is necessary to produce more than the necessary number. Can dramatically reduce waste, spending an expensive production line on the production of wasteful inventory can be reduced to a very low level, and can substantially reduce the production lead time with almost the same production cost, It is possible to improve inventory management cost and production lead time for preparing engineering samples that are usually required to be delivered in a short period of time.

Schematic configuration of a semiconductor device manufacturing apparatus according to an embodiment of the present invention Schematic diagram of semiconductor chip lead frame mounting according to an embodiment of the present invention. Schematic diagram of the surface of a semiconductor chip according to an embodiment of the present invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Semiconductor chip 2a Position 2b just under optical pre-image photographing part 2b Position just under front measurement part 2c Position just under laser irradiation part 3 Electrode part (electrode pad)
4 Wiring part (area without protective film)
5, 5a, 5b, 5c, 5m Wiring 6 Protective film 10 Production control unit 11 Production information input unit 12 Production information storage unit 20 Calculation unit 30 Pre-optical image photographing unit 40 Pre-measurement unit 41 Probe needle 50 Laser irradiation unit 51 Laser irradiation Control unit 52 Laser light source unit 60 Transport unit 61 Guide rail 62 Guide pin 63 Transport pin 70 Lead frame 71 Guide hole 72 Lead frame defective marking region 73 Lead frame information marking region 74 Semiconductor chip mounting region

Claims (2)

A semiconductor manufacturing apparatus for manufacturing a semiconductor device by trimming a semiconductor chip fixed on a lead frame having a guide hole,
A transport unit having a guide pin inserted into the guide hole and fixing the lead frame; a transport pin for transporting; and a guide rail supporting and guiding the lead frame from below;
A pre-optical image photographing unit that optically photographs the electrode part on the surface of the semiconductor chip and the wiring part that is the opening of the protective film, and obtains electrode position information and wiring position information;
Based on the electrode position information, an electrical signal is applied to the semiconductor chip fixed on the lead frame, and an electrical signal from the semiconductor chip is obtained to inspect the electrical characteristics of the semiconductor chip before laser irradiation. A pre-measurement unit;
A production control unit that has input means and storage means that can input so-called production information such as production type, quantity, and production conditions, and performs overall control of the entire production apparatus;
Cutting on the surface of the semiconductor chip based on the electrode position information and wiring position information from the pre-optical image photographing unit, the electrical characteristics obtained by the pre-measurement unit, and the production information from the production control unit A calculation unit for calculating the position coordinates of the power wiring;
Receiving the position coordinate information of the wiring to be cut from the arithmetic unit, a laser irradiation unit for irradiating the wiring in the wiring unit of the semiconductor chip and fusing the wiring;
A semiconductor manufacturing apparatus comprising: A manufacturing method for manufacturing a semiconductor device by trimming a semiconductor chip fixed on a lead frame having a guide hole,
Transporting the semiconductor chip fixed on the lead frame to a pre-optical image capturing unit;
Optical pre-image imaging step of obtaining electrode position information and wiring position information by optically imaging a wiring part that is an electrode part and a protective film opening on the surface of the semiconductor chip;
Transporting the semiconductor chip fixed on the lead frame to a pre-measurement unit;
An electrical signal is applied to the semiconductor chip fixed on the lead frame based on the electrode position information, and an electrical signal from the semiconductor chip is obtained to inspect the electrical characteristics of the semiconductor chip before laser irradiation. Pre-measurement process;
Cutting on the surface of the semiconductor chip based on the electrode position information and wiring position information obtained in the pre-optical image photographing step, the electrical characteristics obtained in the pre-measurement step, and production information from a production control unit. A calculation step for calculating the position coordinates of the power wiring;
Transporting the semiconductor chip fixed on the lead frame to a laser irradiation unit;
A laser irradiation step of receiving the position coordinate information of the wiring to be cut calculated in the calculation step, and irradiating the wiring in the wiring portion of the semiconductor chip to melt the wiring;
A method for manufacturing a semiconductor device comprising:

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