JP2003234364A - Apparatus and method for predicting wire deformation - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To predict the deformation of a wire precisely and efficiently. <P>SOLUTION: A first parameter group acquisition section 103 calculates a first parameter group (the viscosity of resin η in the cavity and the product Vn.tf of the traveling velocity of a resin 902 and the duration of collision) from various data provided via a GUI section 101. A deformation prediction/ modification receiving section 104 finds the quantity of deformation when a metal wire 906 having strength specified by a second parameter group receives a force specified by the first parameter group by using the first parameter group and the second parameter group (a loop height hr of a metal wire 906, an actual length L, a diameter L and an elastic coefficient E) which a second parameter group acquisition section has acquired via the GUI section 101. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for predicting a wire deformation amount due to resin injection into a cavity for resin-sealing a connection portion in an electronic circuit device in which at least a connection portion formed by a wire is resin-sealed.

[0002]

2. Description of the Related Art There is an electronic circuit device in which at least a connecting portion by a wire is resin-sealed. This type of electronic circuit device is manufactured as follows. That is, first, an electronic circuit element is mounted on a substrate or a lead frame, and both are electrically connected by a wire. then,
As described above, the module in which the electronic circuit element is connected to the substrate or the lead frame is placed in the cavity, and the thermosetting resin is injected into the cavity and cured by the transfer molding method.

Now, in an electronic circuit device, in order to connect an electronic circuit element to a substrate or a lead frame, a large number of very thin wires are stretched in a dense state. Here, the wire collides with the resin when the resin is injected into the cavity,
It deforms due to that force. If the amount of deformation becomes large, adjacent wires may come into contact with each other, resulting in a defect. Conventionally, by changing design conditions such as wire shape (length, height, diameter) and molding conditions such as cavity shape, resin temperature, resin injection speed, etc. I was looking for it.

[0004]

As described above, conventionally, trial production is repeated to find optimum design conditions and molding conditions. Therefore, much time is required from the completion of the basic design of the electronic circuit device to the start of production.

Incidentally, Japanese Patent Laid-Open No. 11-232250 discloses a technique for predicting the flow state of resin by simulation. However, this technique analyzes the flow of thermosetting resin by the finite element method and determines the forming conditions based on the analysis result, and the wire deformation amount cannot be calculated directly from this technique.

Further, as described above, in the electronic circuit device, since a large number of very thin wires are stretched in a dense state, the flow state of the resin in the vicinity of the wires is described in JP-A-11-232250. If an attempt is made to analyze using technology, the number of meshes will become enormous and it will take a great amount of calculation time. Further, when the wire is deformed, the boundary of the mesh is moved accordingly, so that it is difficult to perform a strict analysis.

The present invention has been made in view of the above circumstances, and in an electronic circuit device in which at least a connection portion by a wire is resin-sealed, resin is injected into a cavity for resin-sealing the connection portion. It is to be able to accurately and efficiently predict the amount of wire deformation.

[0008]

In order to solve the above-mentioned problems, the present invention provides a first parameter group that can specify the force exerted by the resin on the wire during resin injection. The resin viscosity, the resin moving speed at the collision position between the resin and the wire at the time of resin injection, and the collision duration time are acquired.

Here, the resin viscosity is as described in JP-A-11-232.
Similar to the technique disclosed in Japanese Patent Publication No. 250, the calculation may be performed from the resin flow state predicted by simulation. That is, the isothermal viscosity equation serving as a function of time and temperature may be calculated by numerical analysis in combination with the continuous equation, the momentum conservation equation, and the energy conservation equation. At this time, by setting the boundary condition without considering the wire shape and performing the numerical analysis, the amount of calculation by the analysis can be significantly reduced.

Further, the resin moving speed and the collision duration are the cutting area, the volume in the cavity, and the injection obtained by cutting the inside of the cavity by a plane orthogonal to the main flow of the injected resin at the wire deformation measuring position. The volume of the resin filled in the cavity by the time the main resin flow reaches the wire deformation measurement position may be calculated as the product of the two.

Further, according to the present invention, the shape (length, height, diameter, etc.) of the wire and the elastic coefficient, which are a second parameter group capable of specifying the strength of the wire, are acquired. Each of these parameters may be directly input by the user, or may be automatically acquired from various data stored in the storage device.

Then, the wire having the strength specified by the second parameter group acquired as described above is deformed when it receives the force specified by the first parameter group acquired as described above. Calculate the amount.

In the present invention, when the calculated deformation amount exceeds a predetermined reference value, a message indicating that fact may be transmitted to prompt the user to reconsider the design condition and / or the molding condition. .

Further, it is possible to accept a change of an arbitrary parameter from the obtained first and / or second parameter group, and use the first and second parameter group reflecting this change. Then, the deformation amount may be calculated again.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below.

First, an electronic circuit device whose wire deformation amount is predicted by the wire deformation prediction system of this embodiment will be described.

FIG. 1 is a schematic diagram of an electronic circuit device in which the wire deformation amount is predicted by the wire deformation prediction system of this embodiment. FIG. 1A is a plan view and FIG.
FIG. 2 is a sectional view taken along line AA shown in FIG.

As shown in the figure, a substrate 901 is installed on the lead frame 903, and further the substrate 90
A component 904 such as a capacitor and an electronic circuit chip 905 are mounted on the unit 1.

The electronic circuit chip 905 is electrically connected to a pattern (not shown) formed on the substrate 901 by a large number of very thin gold wires 906. Furthermore, the pattern formed on the substrate 901 is electrically connected to a large number of terminal leads 907 by a large number of aluminum wires 908.

Further, as shown in the figure, the electronic circuit device is
Except for a part of the lead frame 903 and the terminal lead 907, the entire module is sealed with a thermosetting resin 902. Here, the resin 902 is
It is injected through the gate 909 into the cavity in which the electronic circuit device before being sealed with the resin 902 is arranged, and thereafter, heat is applied to cure the resin.

FIG. 2 is a diagram (side view) for explaining a state in which the electronic circuit device is resin-sealed. As shown in the figure, the assembled module has a lead frame 903.
The end portion (not shown) and a part (not shown) of the terminal lead 907 are sandwiched between the upper mold 910 and the lower mold 911 and fixed to the mold. The mold is, for example, 1 by a heater (not shown).
It is kept at a temperature of about 80 ° C. And the resin 902 is
It is thrown into the pot 912, pushed by the plunger 913 attached to the transfer molding machine (not shown), and flows into the cavity 915 through the runner 914 and the gate 909 while melting. This allows the cavity 915
The inside is filled with resin 902. At this time, a force is applied to the very thin gold wire 906 by the flow of the resin 902 and the gold wire 906 is deformed.

FIG. 3 is a diagram (plan view) for explaining the deformation of the gold wire 906 caused by the flow of the resin 902. 3A is a diagram showing a state of the gold wire 906 before resin injection, and FIG. 3B is a diagram showing a state of the gold wire 906 after resin injection / curing.

As shown in the figure, the gold wires 906 extend radially from the electronic circuit chip 905, and the ends thereof are the substrate 901.
It is connected to the upper pattern (not shown). Where resin 9
The main flow of No. 02 is the direction in which the resin flows with the gate 909 side as the upstream. The force applied to the gold wire 902 by the collision of the resin 902 is influenced by the angle θ formed between the mainstream direction of the resin 902 and the direction of the gold wire 902. The greatest force is applied to the gold wire 906 having the largest angle θ. Therefore, in FIG.
In the example shown in (b), the gold wire 906 located in the portion A and having an angle θ of about 90 degrees is most deformed.

FIG. 4 is a diagram (plan view) for explaining the amount of deformation of the gold wire 906. Here, the dotted line 971 is the gold wire 906 before deformation, and the solid line 972 is the gold wire 9 after deformation.
06 is shown. As shown, the maximum deformation is gold wire 9
It occurs near the center of 06. In this embodiment, the gold wire 90
The maximum value of the deflection that occurs near the center of the gold wire 906 when both ends of 6 are fixed is defined as the maximum deformation amount δmax that is the target to be predicted.

FIG. 5 is a diagram (side view) for explaining each parameter for specifying the shape of the gold wire 906.
The gold wire 906 is first fixed on the electronic circuit chip 905 at a high temperature by a capillary (not shown) which is a connecting device. Then, it stands up to a certain distance from the fixed position. The height of this vertical portion is defined by the loop height hr. The gold wire 906 is then turned diagonally downward and the other end is thermocompression bonded onto the pattern electrode (not shown) of the substrate 901. At this time, the actual length from the portion of the gold wire 906 that is turned obliquely downward to the connection portion with the substrate 901 is defined as the length L. Also, the gold wire 906
Has a circular cross section, and its diameter is defined by a diameter D.

The maximum deformation amount δmax shown in FIG. 4 varies depending on each parameter shown in FIG. 5 and other parameters. However, usually, the management of wire deformation is often expressed by the deformation rate. In the present embodiment, the bending rate (deformation rate) ζ of the gold wire 906 is defined by the following equation.

[0027] ζ = 100 δmax / L (Equation 1)

Next, as one embodiment of the present invention, the deformation of the gold wire 906 of the electronic circuit device having the above-described configuration is predicted, and the design change of the electronic circuit device or the transfer molding condition is performed according to the prediction result. A wire deformation prediction system that supports the change of the above will be described.

FIG. 6 is a schematic diagram of a wire deformation prediction system which is an embodiment of the present invention.

In the figure, GUI (Graphic User Inter
The face) unit 101 receives various instructions from the user via the display screen and presents information to the user.

The second parameter group acquisition unit 102 uses the GUI
An input of each parameter (second parameter group) for specifying the strength of the gold wire 906 is received from the user via the unit 101. Here, the parameters included in the second parameter group are specifically the actual length L of the gold wire, the loop height hr,
The diameter D and the elastic modulus E.

The first parameter group acquisition unit 103 uses the GUI
When the resin is injected by the user through the portion 101, the resin 902
Accepts input of various data necessary for calculation of each parameter (first parameter group) for specifying the force exerted by the gold wire 906. Then, based on the received various data, the first
Each parameter of the parameter group of is calculated. Also, the first
Flow simulation unit 1 of the parameter group acquisition unit 103
031 calculates a resin viscosity η which is one of the parameters included in the first parameter group by performing a flow simulation based on various data received from the user. Here, the parameters included in the first parameter group are specifically the resin viscosity η and the moving speed of the resin 902 (the gold wire 90
6 orthogonal component) Vn, and resin 902 and gold wire 90
6 is the collision duration tf with 6.

In the deformation prediction / change accepting unit 104, the gold wire 906 having the strength specified by the second parameter group acquired by the second parameter group acquiring unit 102 is the first wire acquired by the first parameter group acquiring unit 103. The amount of deformation when receiving the force of the resin 902 specified by the parameter group is calculated. In addition, when the deformation amount exceeds a predetermined reference value, a message is presented to the user via the GUI unit 101, and the user receives a change in the parameters included in the first and / or second parameter group. . Then, the deformation amount is calculated again using the first and second parameter groups in which this change is reflected.

Now, the wire deformation prediction system having the above-mentioned configuration has, for example, a CPU 201, a memory 202, and an external storage device 203 such as a hard disk device as shown in FIG.
And a reading device 205 for reading data from a portable storage medium 204 such as a CD-ROM or a DVD-ROM,
An input device 206 such as a keyboard or a mouse, and a CRT or L
A computer system having a general configuration, which includes an output device 207 such as a CD, a communication device 208 that communicates via a network such as the Internet, and a bus 209 that connects these devices, or this computer It can be built on a network system provided with a plurality of systems.

A program for realizing the above wire deformation prediction system on such a computer system or network system is stored in the external storage device 20.
3 or from the storage medium 204 via the reading device 205, may be loaded onto the memory 202 and executed by the CPU 201. Alternatively, by loading from the network onto the memory 202 via the communication device 208,
The CPU 201 may be made to execute.

Next, the operation of the wire deformation prediction system having the above configuration will be described.

8 to 11 are diagrams for explaining the operation flow of the wire deformation prediction system to which the embodiment of the present invention is applied.

In the following description, the gold wire 906 is the gold wire 90 stretched over the electronic circuit chip 905.
Of the six, any one gold wire 9 that is the deformation amount prediction target
06 is to be designated.

First, the GUI section 101 accepts the input of various data specified from the design drawing of the electronic circuit device by the user via the display screen (S100). The second parameter group acquisition unit 102 selects the second parameter from the various data.
The parameters (actual length L of gold wire 906, loop height hr, diameter D and elastic coefficient E) of the parameter group are acquired and held (S101).

Further, the GUI section 101 accepts the input of various data specified from the die drawing for resin sealing of the electronic circuit device from the user via the display screen (S10).
2). The first parameter group acquisition unit 103 uses the various data and the various data relating to the design drawing received in S100, the moving speed Vn of the resin 902 (orthogonal component with the gold wire 906), the resin 902 and the gold. The product Vn · tf of the collision duration tf with the line 906 is calculated, and the calculation result is held (S103).

The gold wire 906 is deformed by the gold wire 906 after the resin 902 flowing into the cavity collides with the gold wire 906 until the inside of the cavity is filled with the resin 902 and the flow of the resin 902 stops. Greatly affects the force applied to. In the present embodiment, the value of the product Vn · tf of the moving speed Vn and the collision duration tf is used as the evaluation measure.

Here, an example of a method of calculating the product Vn · tf of the moving speed Vn and the collision duration tf will be described in detail.

The average flow velocity Vm when the resin 902 passes the central position of the gold wire 906 (the position where the maximum deformation amount δmax is considered to occur, see FIG. 4) can be calculated by the following equation.

Vm = Qc / Sa (Equation 2) Here, Qc is the resin flow rate in the cavity. Also,
Sa is obtained by cutting the cross-sectional area of the flow path orthogonal to the mainstream of the resin 902 at the central position of the gold wire 906, that is, by cutting the inside of the cavity at the central position of the gold wire 906 by a plane orthogonal to the mainstream of the resin 902. The area of the cut surface.

The moving speed Vn of the resin 902 (orthogonal component to the gold wire 906) is the above-mentioned average flow velocity Vm and 9 of the resin.
The angle θ between the main flow direction of 02 and the direction in which the gold wire 906 is stretched (see FIG. 3) can be calculated by the following equation.

Vn = Vm sin θ (Equation 3)

On the other hand, the resin filling time tc in the cavity
Can be calculated by the following equation.

Tc = Vc / Qc (Equation 4) where Vc is the volume in the cavity (cavity volume)
Is.

The collision duration tf between the resin 902 and the gold wire 906 is the resin filling time tc, the cavity volume Vc,
The resin 906 filled in the cavity by the time the main stream of the resin 902 reaches the central position of the gold wire 906.
The volume can be calculated by the following equation using the volume (volume filled in the cavity) Va.

[0050] tf = tc (Vc-Va) / Vc (Equation 5)

When the above equation 5 is expressed using the resin flow rate Qc, the collision duration tf is expressed by the following equation.

[0052] tf = (Vc-Va) / Qc (Equation 6)

On the other hand, by substituting equation 2 into equation 3 above, the following equation is obtained.

Vn = Qc sin θ / Sa (Equation 7)

Therefore, the product Vntf of the moving speed Vn and the collision duration tf can be obtained by the following equation.

[0056] Vn · tf = sin θ (Vc−Va) / Sa (Equation 8)

The cavity volume Vc used in the above equation 8 is one of various data specified from the die drawing. Further, the angle θ, the filling volume Va in the cavity, and the cross-sectional area Sa that are formed are the shape inside the cavity and the arrangement inside the cavity of the electronic circuit device (before resin sealing) specified by various data of the mold drawings, and the design. By the arrangement of the gold wire 906 in the electronic circuit device specified from various data of the drawing,
You can ask. That is, each element on the right side used in the above equation 8 can be obtained using the product drawing and the die drawing.

Therefore, in this embodiment, the GUI unit 101
Accepts the input of the angle θ made by the user, the cavity volume Vc, the cavity filling volume Va, and the cross-sectional area Sa via the display screen, and the first parameter group acquisition unit 103 substitutes these data into the above equation 8. By doing so, the moving speed of the resin 902 (a component orthogonal to the gold wire 906) Vn,
Product Vn of collision duration tf between resin 902 and gold wire 906
-Calculating tf.

Further, the GUI section 101 accepts input of various data regarding molding conditions and various data regarding resin 902 from the user via the display screen (S10).
4, S106).

Now, the flow simulation unit 1031 of the first parameter group acquisition unit 103 sets the viscosity parameter and the like included in various data regarding the resin 902 to the isothermal viscosity equation for the thermosetting resin. Further, the thermophysical property values (density ρ of resin 902, specific heat C and thermal conductivity λ) included in various data are held (S105).

In the present embodiment, various data including viscosity parameters are converted into isothermal data for thermosetting resin by using the technique described in Japanese Patent Application Laid-Open No. 2-120642 (Patent No. 2771195) invented by the present inventors. Set to the viscosity formula. Specifically, various data including viscosity parameters are set in the following isothermal viscosity equation for thermosetting resin.

Η = η ₀ ((1 + t / t ₀ ) / (1-t / t ₀ )) ^C (Equation 9) η ₀ = a exp (b / T) (Equation 10) t ₀ = d exp (E / T) (Equation 11) c = f / T-g (Equation 12) where η is viscosity, T is temperature, t is time, η ₀ is initial viscosity, t ₀ is gelation time, and c is Viscosity increase coefficient, and
a, b, d, e, f, g are resin-specific viscosity parameters. Initial viscosity η ₀ , gelling time t ₀ , viscosity increasing coefficient c, and viscosity parameters a, b, d, e, f, g
Is received from the user as various data regarding the resin 902.

The flow simulation unit 1031 adds the initial viscosity η ₀ , the gelation time t ₀ , the viscosity increase coefficient c, and the viscosity parameters a, b, d, e, to the above equations 9 to 12.
By setting f and g, it is possible to obtain a viscosity change curve in an isothermal state peculiar to the resin.

Next, the flow simulation unit 1031
Combines the isothermal viscosity equation for the thermosetting resin obtained as described above with the continuous equation, the momentum conservation equation, and the energy conservation equation. Then, the temperature of the resin 902 on the gold wire 906 is numerically analyzed by using the initial condition and the boundary condition obtained from the data of the product drawing, the mold drawing, and the molding condition received from the user via the GUI unit 101. Changes in physical quantities such as viscosity, pressure, etc. are sequentially determined. Thereby, the flow of the resin 902 in the cavity is simulated (S107).

Here, it is assumed that the mold is a combination of a runner and a gate of circular tubes having an equivalent volume, and the inside of the cavity is a circular tube having an equivalent volume except the volume of the insert.
Examples of a continuous equation, a momentum conservation equation, and an energy conservation equation for simulating the flow of the resin 902 in this case are shown in Equations 13 to 15, respectively.

Q = 2π∫ ₀ ^R V _Z r dr (Formula 13) ∂P / ∂Z = (1 / r) · ∂ (rη (∂V _Z / ∂r)) / ∂r (Formula 14) ρC ( (∂T / ∂t) + V _Z (∂T / ∂Z)) = (1 / r) ・ ∂ (rλ (∂T / ∂r)) / ∂r + η (∂V _Z / ∂r) ² (Equation 15) Here, Q is the resin flow rate, R is the radius of the cavity, V _Z is the flow velocity of the resin in the cavity tube axial direction, r is the cavity radial direction distance, Z is the cavity axial direction distance, and P is Pressure in cavity, ρ is density of resin, C is specific heat of resin, λ
Is the thermal conductivity of the resin, η is the resin viscosity, T is the temperature, and
t is time.

For the above resin flow simulation, the technique described in Japanese Patent Laid-Open No. 11-232250 described in the prior art can be used. However, in this embodiment, the initial condition and the boundary condition which are determined without considering the shape and shape change of the gold wire 906 are used.

By the above resin flow simulation,
The resin viscosity η of the resin 902 at the position of the gold wire 906 can be calculated (S108).

The deformation predicting / change accepting unit 104 receives the first parameter group obtained as described above (the loop height hr of the gold wire 906, the wire elastic coefficient E, obtained in S101,
Wire diameter D and actual length L) and the second parameter group (S1
The maximum deformation amount δmax of the gold wire 906 is obtained using the product Vn · tf of the moving speed Vn of the resin 902 calculated in 03 and the collision duration tf, and the resin viscosity η of the resin 902 calculated in S108. (S109).

Specifically, the first parameter group and the second parameter group
Each parameter of the parameter group is expressed by the following equation (Equation 16, Equation 1)
7), the bending rate (deformation rate) ζ of the gold wire 906 is calculated, and by substituting this and the actual length L of the gold wire 906 into the above equation 1, the maximum deformation amount of the gold wire 906 is calculated. δmax
Is calculated.

[0071] ψ = η (Vn · tf) 0.66 · hr 1.75 / (E · D 4 · L 0.4) ( Equation 16) ζ = 32.72 ((ψ / (1.285 × 10 - 3)) 1.1 / + (ψ / (1.285 × 10 - 3)) 1.1)) ( equation 17) where, [psi is the wire deformation prediction parameter, in this embodiment, the unit is s / mm ^1.99.

Next, the deformation prediction / change accepting unit 104 causes the maximum deformation amount δmax of the gold wire 906 predicted as described above.
Is below an allowable value (range in which contact failure is less likely) (S110). Then, if it is less than or equal to the allowable value, a message to that effect is displayed and the processing is terminated (S111).

Here, the permissible value may be input by the deformation prediction / change receiving unit 104 directly from the user via the GUI unit 101, or by the user via the GUI unit 101 from the electronic circuit chip 905. Pitch intervals of terminals, pitch intervals of pattern terminals of the substrate 901, and
Accept the actual length L of the gold wire 906, and from these data,
The distance between the gold wire 906 and the adjacent gold wire 906 at the center position may be calculated and set to an allowable value.

On the other hand, in S110, if the allowable value is not less than the allowable value, it is determined that contact failure is likely to occur, and a message or the like indicating that it is necessary to change conditions such as design or molding is displayed. Then, the maximum deformation amount δmax of the gold wire 906
A change in the parameter that affects the value is received, the maximum deformation amount δmax of the gold wire 906 is recalculated using the changed parameter, and it is determined again whether the maximum deformation amount δmax is less than or equal to the allowable value.
In the present embodiment, the parameter changes for suppressing the maximum deformation amount Δmax to the allowable value or less are accepted in order from the one that is easy to change.

First, the deformation prediction / change acceptance unit 104 determines whether or not various data regarding the current molding conditions can be changed in order to reduce the resin viscosity η of the resin 902 (S112). For this, for example, an allowable value of various data regarding molding conditions (this is determined by the resin 902 to be used, the specifications of the molding machine, etc.) is received in advance from the user via the GUI unit 101. Then, when the difference between the various data regarding the current molding conditions and the allowable value is less than or equal to a predetermined value, it is determined that the various data regarding the current molding conditions cannot be changed. Or GUI
A user may directly receive the determination result of whether or not various data regarding the molding conditions can be changed via the unit 101.

If it is determined in S112 that the various data regarding the current molding conditions cannot be changed, the process proceeds to S118. On the other hand, if it is determined that the various data regarding the current molding conditions can be changed, the deformation prediction / change accepting unit 104 instructs the GUI unit 101 to acquire the various data regarding the molding conditions again. In response to this, the GUI unit 101 accepts the input of various data regarding the molding condition from the user again (S113).

Next, the flow simulation unit 1031 of the first parameter group acquisition unit 103 changes the data relating to the molding conditions into the data relating to the molding conditions acquired again at S113, and executes the above S107 and S108.
The resin viscosity η of the resin 902 is calculated (S114). Then, the above-mentioned S109 is executed by using this resin viscosity η, and the maximum deformation amount δmax of the gold wire 906 is calculated again (S
115).

Then, the transformation prediction / change acceptance unit 104
The maximum deformation amount δma of the gold wire 906 predicted as described above
If x is less than or equal to the allowable value (S116), a message to that effect is displayed and the processing is terminated (S11).
7) If not, the process returns to S112 to continue the process.

Next, in step S118, the deformation prediction / change acceptance unit 104 can change various data relating to the current mold design (particularly, flow channel specifications) in order to reduce the resin viscosity η of the resin 902. Determine whether or not. This is S
Similar to the determination as to whether or not the data regarding the molding conditions in 112 can be changed, for example, the user allows an allowable value of various data regarding the mold design via the GUI unit 101 (for example, the diameter of the flow path determined from the size of the mold or the like). The maximum value of 1) is received in advance. Then, when the difference between the various data on the current mold design and the allowable value is less than or equal to a predetermined value, it is determined that the various data on the current mold design cannot be changed. Alternatively, the user may directly receive the determination result of whether or not various data regarding the mold design can be changed via the GUI unit 101.

If it is determined in S118 that the various data relating to the current die design cannot be changed, the process proceeds to S124. On the other hand, if it is determined that the various data on the current die design can be changed, the deformation prediction / change accepting unit 104 instructs the GUI unit 101 to reacquire the various data on the die design. . In response to this, the GUI unit 101 accepts the input of various data regarding the mold design from the user again (S119).

Next, the first parameter group acquisition unit 103
The data on the mold design is changed to the data on the mold design acquired again at S119, and the above S103 is executed to calculate the product Vn · tf of the moving speed Vn of the resin 902 and the collision duration tf. . Further, the flow simulation unit 1031 of the first parameter group acquisition unit 103 changes the data on the mold design into the data on the mold design acquired again at S119, and the above S107 and S10.
8 to calculate the resin viscosity η of the resin 902 (S1
20). Then, the resin viscosity η and the resin 90
Using the product Vn · tf of the moving speed Vn of 2 and the collision duration tf, the above S109 is executed, and the maximum deformation amount δmax of the gold wire 906 is calculated again (S121).

Then, the transformation prediction / change reception unit 104
The maximum deformation amount δma of the gold wire 906 predicted as described above
If x is less than or equal to the allowable value (S122), a message to that effect is displayed and the processing is terminated (S12).
3) If not, the process returns to S118 and continues.

Next, in S124, the deformation prediction / change reception unit 104 determines whether or not various data regarding the gold wire 906 can be changed.

This is similar to the determination of whether or not the data relating to the molding conditions can be changed in S112, for example, the GUI unit 1
An allowable value (determined by the wire cost, wiring accuracy, etc.) of the data regarding the gold wire 906 is received in advance from the user via 01. And the current gold wire 90
If the difference between the various data regarding No. 6 and the allowable value is less than or equal to a predetermined value, it is determined that the various data regarding the current gold wire 906 cannot be changed. Or GU
The determination result as to whether or not various data regarding the gold wire 906 can be changed may be directly received from the user via the I section 101.

As is clear from the above equations 16 and 17, reducing the loop height hr of the gold wire 906 and increasing the diameter D is the maximum deformation amount δ of the gold wire 906.
This is effective in reducing max. When the actual length L of the gold wire 906 is increased, the bending rate ζ changes in the direction of decreasing, but the maximum deformation amount δmax changes in the increasing direction. Therefore, it is necessary to determine which is to be prioritized by the distance between adjacent wires.

If it is determined in S124 that the various data regarding the current gold wire 906 cannot be changed, the process proceeds to S130. On the other hand, if it is determined that the various data regarding the current gold wire 906 can be changed, the deformation prediction / change accepting unit 104 instructs the GUI unit 101 to obtain the various data regarding the gold wire 906 again. . In response to this, the GUI unit 101 accepts the input of various data regarding the gold wire 906 from the user again (S).
125).

Next, the second parameter group acquisition unit 102
The above-mentioned S101 is executed, and the parameters of the second parameter group (actual length L of gold wire 906, loop height h
Acquire and hold r, diameter D and elastic modulus E). Further, the first parameter group acquisition unit 103 changes various data regarding the gold wire 906 into various data regarding the gold wire 906 which is input again in S125, executes the above S103, and calculates the moving speed Vn of the resin 902. The product Vn · tf with the collision duration tf is calculated. Furthermore, the flow simulation unit 1031 collects various data regarding the gold wire 906 in S12.
5 is changed to various data regarding the gold wire 906, which has been input again, and the above-described S107 and S108 are executed.
The resin viscosity η of No. 02 is calculated (S126). then,
The actual length L, loop height hr, diameter D and elastic coefficient E of the gold wire 906, the resin viscosity η, and the moving speed V of the resin 902.
Using the product Vn · tf of n and the collision duration tf, the above S109 is executed, and the maximum deformation amount δmax of the gold wire 906 is calculated again (S127).

Then, the transformation prediction / change reception unit 104
The maximum deformation amount δma of the gold wire 906 predicted as described above
If x is less than or equal to the allowable value (S128), a message to that effect is displayed, and the processing is terminated (S12).
9) If not, the process returns to S124 and continues.

Next, in step S130, the deformation prediction / change reception unit 104 determines whether or not various data (particularly the arrangement position) regarding the electronic circuit chip 905 can be changed. This is similar to the determination of whether or not the data regarding the molding conditions in S112 can be changed, for example, in the GUI unit 101.
The user accepts in advance the allowable values of various data relating to the electronic circuit chip 905 (determined by the margin of arrangement of the wiring pattern of the board) through the user. Then, when the difference between the various data regarding the current electronic circuit chip 905 and the allowable value is less than or equal to a predetermined value, it is determined that the various data regarding the current electronic circuit chip 905 cannot be changed. Alternatively, the user may directly receive the determination result of whether or not various data regarding the electronic circuit chip 905 can be changed via the GUI unit 101.

The electronic circuit chip 905 is made of resin 902.
If the collision duration time tf between the resin 902 and the gold wire 906 is reduced by arranging it on the substrate 901 so as to be located on the downstream side of the The maximum deformation amount δmax of the line 906 can be reduced. Further, the resin viscosity η can be lowered by revising the arrangement position of the electronic circuit chip 905.

If it is determined in S130 that various data regarding the current electronic circuit chip 905 cannot be changed, the process proceeds to S136. On the other hand, if it is determined that various data regarding the current electronic circuit chip 905 can be changed, the deformation prediction / change reception unit 104 determines that the G
The UI unit 101 is instructed to acquire various data regarding the electronic circuit chip 905 again. In response to this, GU
The I unit 101 accepts the input of various data regarding the electronic circuit chip 905 from the user again (S131).

Next, the first parameter group acquisition unit 103
The data relating to the electronic circuit chip 905 is changed to the data relating to the electronic circuit chip 905 which has been input again in S131, and the above S103 is executed, and the resin 902
Then, the product Vn · tf of the moving speed Vn and the collision duration tf is calculated. Further, the flow simulation unit 1031 changes various data relating to the electronic circuit chip 905 into various data relating to the electronic circuit chip 905 whose input is accepted again in S131, executes the above S107 and S108, and calculates the resin viscosity η of the resin 902. Is calculated (S132). Then, using the product of the resin viscosity η and the moving speed Vn of the resin 902 and the collision duration tf, Vn · tf, the above S1 is obtained.
09 is executed, and the maximum deformation amount δmax of the gold wire 906 is calculated again (S133).

Then, the transformation prediction / change reception unit 104
The maximum deformation amount δma of the gold wire 906 predicted as described above
If x is less than or equal to the allowable value (S134), a message to that effect is displayed and the processing is terminated (S13).
5) If not, return to S130 to continue the processing.

Finally, in S136, the deformation prediction / change receiving unit 104 determines whether or not various data regarding the resin 902 can be changed. This is S112
Similar to the determination as to whether or not the various data regarding the molding conditions can be changed in step 1, for example, an allowable value of various data regarding the resin 902 from the user via the GUI unit 101 (a characteristic required for sealing the electronic circuit device). It is determined by the value etc.) in advance. Then, when the difference between the various data regarding the current resin 902 and the allowable value is less than or equal to a predetermined value, it is determined that the various data regarding the current resin 902 cannot be changed. Alternatively, the determination result of whether or not various data regarding the resin 902 can be changed may be directly received from the user via the GUI unit 101. Since the resin 902 is closely linked to various qualities of the molded product, it is necessary to select the candidate material after considering the characteristics of various items other than the viscosity.

If it is determined in S136 that the various data relating to the current resin 902 cannot be changed, the GUI unit 101 issues a message prompting a total change such as the fact that a new resin needs to be developed. After outputting, the processing is terminated (S142). On the other hand, when it is determined that the various data regarding the current resin 902 can be changed, the deformation prediction / change accepting unit 104 instructs the GUI unit 101 to obtain the various data regarding the electronic circuit chip 905 again. . In response to this, the GUI unit 1
01 accepts the input of various data regarding the electronic circuit chip 905 from the user again (S137).

Next, the first parameter group acquisition unit 103
The data relating to the resin 902 is changed to the data relating to the resin 902 which has been input again in S137, and the above S105, S107 and S108 are executed, and the resin 902 is executed.
The resin viscosity η of is calculated (S138). Then, using this resin viscosity η, the above-described S109 is executed, and the gold wire 9
The maximum deformation amount δmax of 06 is calculated again (S139).

Then, the transformation prediction / change reception unit 104
The maximum deformation amount δma of the gold wire 906 predicted as described above
If x is less than or equal to the allowable value (S140), a message to that effect is displayed and the processing is terminated (S14).
1) If not so, return to S160 to continue the processing.

The present inventors compared the deformation value of the gold wire 906 of the electronic circuit device shown in FIGS. 1 to 5 with the predicted value by the wire deformation prediction system of this embodiment and the actual measurement value. Various data of the electronic circuit device are as follows.

(1) Various data of gold wire 906 Loop height hr = 0.28 mm Actual loop length L = 1.94 mm Diameter D = 0.03 mm Elastic coefficient E = 65 Gpa (2) Various data of resin 902 Resin 902 (referred to as resin A and resin B) was prepared.

[0100] Various data viscosity of the resin A parameter ^{a = 7.2 × 10 - 10 (} Pa · s) Viscosity parameters b = 10270 (K) viscosity parameter ^{d = 5.57 × 10 - 6 (} s) viscosity parameter e = 6975 (K) Viscosity parameter f = 2092 (K) Viscosity parameter g = 2.8 Thermal conductivity λ = 0.7 (W / (mK)) Specific heat C = 879 (J / (kgK)) Density ρ = 1890 (kg / m ³ )

[0102] Various data viscosity of the resin B parameters ^{a = 1.8 × 10 - 10 (} Pa · s) Viscosity parameters b = 10270 (K) viscosity parameter ^{d = 4.3 × 10 - 6 (} s) viscosity parameter e = 6975 (K) Viscosity parameter f = 2092 (K) Viscosity parameter g = 1.0 Thermal conductivity λ = 1.97 (W / (m · K)) Specific heat C = 963 (J / (kg · K)) Density ρ = 2650 (kg / m ³ )

Various data of mold For simplification of flow simulation of resin 902,
The runner and the gate are represented by a combination of circular tubes having an equivalent volume, and the inside of the cavity is represented as a circular tube having an equivalent volume by excluding the volume of the insert.
Formula 15 can be applied. As a result, the resin viscosity η calculated by the wire deformation prediction system of the present embodiment was resin A = 70 (Pa · s) and resin B = 20 (Pa · s).

Under the above-mentioned conditions, the inventors of the present invention fix each data except the position of the gold wire 906, and the many gold wires 90 stretched on the electronic circuit chip 905.
The predicted value and the actually measured value were compared for a plurality of 6 items. In the actual measurement, the finished product obtained by injecting the resin 902 and curing was taken out from the mold, and a photograph was taken from above the finished product with a soft X-ray to observe the deformed state of the gold wire 906.

FIG. 12 shows the case where resin A is used.
It is a figure for demonstrating comparison of the deformation | transformation predicted value of gold wire 906, and an actual measurement value. Here, the gold wire No on the horizontal axis is shown in FIG.
It indicates the gold wire No. in (a). Actually measured value is gold wire 906
As the angle θ formed by the resin 902 in the mainstream direction increases, the bending rate ζ also tends to increase. The calculated (predicted) value also shows the same tendency, and the absolute value is also very close to the measured value.

On the other hand, FIG. 13 is a diagram for explaining the comparison between the predicted value and the measured value of the deformation of the gold wire 906 when the resin B is used. The measured value shows the same tendency as in FIG. 12, but the absolute value is considerably small. The calculated (predicted) value shows the same tendency, and the absolute value is also very close to the measured value. The reason why the value of the bending rate ζ becomes very small when the resin B is used is that the resin viscosity η of the resin B becomes considerably lower than that of the resin A, as can be seen from the calculation result of the flow simulation.

The embodiment of the present invention has been described above.

According to this embodiment, the resin 9 is injected at the time of resin injection.
02 is a first parameter group that can specify the force applied to the gold wire 906, the resin viscosity η in the cavity, the moving speed of the resin 902 during resin injection (gold wire 9
06) and the collision duration Vn · tf
Is calculated from various data given by the user via the GUI unit 101.

Then, these calculation results and the GUI unit 1
A loop height hr, a loop actual length L, a diameter D and an elastic coefficient E of the gold wire 906, which is a second parameter group that can specify the strength of the gold wire 906 given by the user via 01. By calculation, the deformation amount δ when the gold wire 906 having the strength specified by the second parameter group is subjected to the force specified by the first parameter group.
Seeking max. Thus, according to this embodiment,
The deformation amount δmax of the gold wire 906 can be accurately and efficiently predicted without actually measuring it.

Further, in the present embodiment, in the simulation of the flow of the resin 902, for simplification, the runner and the gate are represented by a combination of circular tubes having an equivalent volume, and
The above equations 13 to 15 can be applied by expressing the mold with the inside of the cavity as a circular tube whose volume is equivalent except for the volume of the insert. In addition, numerical analysis is performed by setting boundary conditions and the like without considering the shape of the gold wire 906. By doing so, the amount of calculation by analysis can be significantly reduced.

Further, in this embodiment, the predicted gold wire 90 is used.
When the deformation amount of 6 exceeds the allowable value, a message indicating that is sent to prompt the user to reconsider the design condition and / or the molding condition. Then, it accepts any parameter change from the first and / or second parameter group, and again uses the first and second parameter groups reflecting this change to change the deformation amount of the gold wire 906 again. It is calculated.

By doing so, it is no longer necessary to find optimum design conditions and molding conditions by repeating the trial manufacture of the electronic circuit device and measuring the deformation amount as in the conventional case. Therefore, the time from the completion of the basic design of the electronic circuit device to the start of production can be significantly reduced. .

The present invention is not limited to the above-mentioned embodiments, and various modifications can be made within the scope of the gist thereof.

For example, in the above embodiment, various data necessary for predicting the deformation amount of the gold wire 906 is received from the user via the GUI unit 101. However, the present invention is not limited to this.

For example, the wire deformation prediction system of this embodiment is connected to a CAD system for designing an electronic circuit device or a mold via a network. And
By receiving the CAD data of the target electronic circuit device or the die from the user via the GUI unit 101, the wire deformation prediction system accesses the CAD system, and the gold wire 906 of the gold wire 906 is accessed from the designated CAD data. Various data necessary for predicting the amount of deformation may be acquired. In this case, it is advisable to add identification information for identifying the deformation amount of the gold wire 906 included in the CAD data to the wire deformation prediction system.

Further, in the above embodiment, the GUI unit 101 is made to have a function as a Web server so that various data necessary for predicting the deformation amount of the gold wire 906 can be received from the Web client terminal. Good.
Then, for the Web client terminal, the gold wire 906
It is also possible to present a message such as the predicted value of the deformation amount and whether the predicted value is less than or equal to the allowable value.

Further, as a matter of course, the electronic circuit device to be measured in the wire deformation prediction system of this embodiment is not limited to those shown in FIGS. The present invention is
In an electronic circuit device in which at least a connection portion formed by a wire is resin-sealed, the present invention can be widely applied to prediction of wire deformation due to resin.

[0117]

As described above, according to the present invention,
The wire deformation can be predicted accurately and efficiently.

[Brief description of drawings]

FIG. 1 is a schematic diagram of an electronic circuit device in which a wire deformation amount is predicted by a wire deformation prediction system according to an embodiment of the present invention.

FIG. 2 is a diagram (side view) for explaining a state in which the electronic circuit device shown in FIG. 1 is resin-sealed.

FIG. 3 is a diagram (plan view) for explaining the deformation of the gold wire 906 caused by the flow of resin 902.

FIG. 4 is a diagram (plan view) for explaining a deformation amount of a gold wire 906.

FIG. 5 is a diagram (side view) for explaining parameters for specifying the shape of a gold wire 906.

FIG. 6 is a schematic diagram of a wire deformation prediction system that is an embodiment of the present invention.

FIG. 7 is a diagram showing a hardware configuration example of a wire deformation prediction system to which an embodiment of the present invention is applied.

FIG. 8 is a diagram for explaining an operation flow of the wire deformation prediction system to which the embodiment of the present invention is applied.

FIG. 9 is a diagram illustrating an operation flow of the wire deformation prediction system to which the embodiment of the present invention is applied.

FIG. 10 is a diagram illustrating an operation flow of the wire deformation prediction system to which the embodiment of the present invention is applied.

FIG. 11 is a diagram illustrating an operation flow of the wire deformation prediction system to which the embodiment of the present invention is applied.

FIG. 12 is a diagram for explaining a comparison between a predicted value of deformation of the gold wire 906 and an actually measured value when a resin A is used.

FIG. 13 is a diagram for explaining a comparison between a predicted value and a measured value of the deformation of the gold wire 906 when resin B is used.

[Explanation of symbols]

101 ... GUI unit, 102 ... Second parameter group acquisition unit,
103 ... First parameter group acquisition unit, 1031 ... Flow simulation unit, 104 ... Deformation prediction / change reception unit, 20
1 ... CPU, 202 ... Memory, 203 ... External storage device,
204 ... Storage medium, 205 ... Reading device, 206 ... Input device ,. 207 ... Output device, 208 ... Communication device, 209 ...
Bus, 901 ... Substrate, 902 ... Resin, 903 ... Lead frame, 904 ... Component, 905 ... Electronic circuit chip, 90
6 ... Gold wire, 907 ... Terminal lead, 908 ... Aluminum wire, 9
09 ... Gate, 910 ... Upper mold, 911 ... Lower mold, 912 ...
Pot, 913 ... Plunger, 914 ... Runner, 915
…cavity

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kazuhiko Kawakami             Hitachinaka City, Ibaraki Prefecture 2520 Takaba             Ceremony Company Hitachi Ltd. Automotive equipment group (72) Inventor Mitsuyasu Masuda             Hitachinaka City, Ibaraki Prefecture 2520 Takaba             Ceremony Company Hitachi Ltd. Automotive equipment group F-term (reference) 5F061 AA01 BA01 CA21 DB01

Claims (10)

[Claims] 1. An electronic circuit device in which at least a connecting portion by a wire is resin-sealed, and a wire deformation predicting device for predicting a deformation amount of the wire due to resin injection into a cavity for resin-sealing the connecting portion. Which is a first parameter group that can specify the force exerted by the resin on the wire during resin injection, the resin viscosity in the cavity, and the collision position between the resin and the wire during resin injection Parameter group acquisition means for acquiring the resin moving speed and the collision duration time, and the wire shape and elastic coefficient which are the second parameter group capable of specifying the strength of the wire. And a second parameter group acquiring means for acquiring the parameter, and an intensity specified by the second parameter group acquired by the second parameter group acquiring means. Wire deformation, comprising: wire deformation amount calculation means for calculating a deformation amount when the ear receives a force specified by the first parameter group acquired by the first parameter group acquisition means. Prediction device. 2. The wire deformation predicting device according to claim 1, wherein the resin is a thermosetting resin, and the first parameter group acquisition means is an isothermal viscosity equation that is a function of time and temperature. , Continuous equation, momentum conservation equation, and energy conservation equation, and the resin viscosity for calculating the resin viscosity in the cavity, which is one of the parameters included in the first parameter group, by numerical analysis. A wire deformation prediction device comprising a calculation means. 3. The wire deformation predicting apparatus according to claim 2, wherein the resin viscosity calculating means performs the numerical analysis without considering the shape of the wire, and A wire deformation prediction device characterized by calculating viscosity. 4. The wire deformation predicting apparatus according to claim 1, wherein the first parameter group acquisition means is orthogonal to the main flow direction of the resin injected into the cavity at a wire deformation measurement position. The cutting area obtained by cutting along a plane, the volume in the cavity, and by the time the main flow of the injected resin reaches the measurement position of wire deformation,
A wire deformation prediction device, characterized in that a product of a resin moving speed and a collision duration is calculated using a volume of resin filled in the cavity. 5. The wire deformation prediction device according to claim 1, 2, 3 or 4, wherein a message is transmitted when the deformation amount calculated by the wire deformation amount calculation means exceeds a predetermined reference value. A wire deformation prediction device further comprising a message sending means for 6. The wire deformation prediction apparatus according to claim 1, further comprising a parameter changing means for accepting a change in the parameters acquired by the first and second parameter group acquiring means. The wire deformation amount calculation means calculates, when the parameter change means receives a parameter change, the wire deformation amount using the first and second parameter groups in which the change is reflected. A wire deformation prediction device characterized by the above. 7. A wire deformation predicting method for predicting a deformation amount of the wire due to resin injection into a cavity for resin-sealing the connection portion, in an electronic circuit device in which at least a connection portion formed by a wire is resin-sealed. Which is a first parameter group that can specify the force exerted by the resin on the wire during resin injection, the resin viscosity in the cavity, and the collision position between the resin and the wire during resin injection The second parameter using the resin moving speed and the collision duration, and the wire shape and elastic coefficient that are the second parameter group that can specify the strength of the wire. A wire having a strength specified by a group calculates a deformation amount when a force specified by the first parameter group is received. Deformation prediction method. 8. The method for predicting wire deformation according to claim 7, wherein the resin is a thermosetting resin, and the isothermal viscosity equation that is a function of time and temperature is a continuous equation, a momentum conservation equation, and A method for predicting wire deformation, characterized in that the resin viscosity in the cavity, which is one of the parameters included in the first parameter group, is calculated by numerical analysis in tandem with the energy conservation formula. 9. The wire deformation prediction method according to claim 8, wherein the resin viscosity in the cavity is calculated by performing the numerical analysis without considering the shape of the wire. Wire deformation prediction method. 10. An electronic circuit device in which at least a connection portion by a wire is resin-sealed, and a program for predicting a deformation amount of the wire due to resin injection into a cavity for resin-sealing the connection portion. The program in the cavity is a first parameter group that can be read and executed by a computer system to specify the force exerted by the resin on the wire during resin injection. The shape of the wire, which is a second parameter group that can specify the viscosity, the resin moving speed at the collision position between the resin and the wire at the time of resin injection, and the collision duration, and the strength of the wire. , And elastic modulus, the wire having the strength specified by the second parameter group is The process of calculating the deformation amount when subjected to a force which is specified by data group, program characterized by causing to the computer system.